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6.2. SR 01-13-2003Item 6.2. Howard R, Green Company January 8, 2003 File: 818980J-0030 Honorable Mayor and City Council City of Elk River 13065 Orono Parkway Elk River, MN 55330 RE: 2003 PAVEMENT REHABILITATION IMPROVEMENTS FEASIBILITY STUDY Dear Council Members: Attached is the feasibility study for the 2003 Pavement Rehabilitation Improvements. As you are aware, this project consists of Fourth Street from Main Street to Trunk Highway 10; Rush Avenue, Quinn Avenue and Oxford Avenue from Fourth Street to Fifth Street; Norfolk Avenue from Fourth Street to Main Street; and Morton Avenue from Main Street to Trunk Highway 10. The total estimated project cost is $1,897,300. This includes total street reconstruction, minor storm sewer improvements, major watermain improvements, and sidewalk improvements. The project will be funded by assessments to the benefiting properties in the amount of $5,000 per unit, Elk River Municipal Utilities funding for the watermain improvements, and an estimated $993,300 funded by the City. It is recommended that the City utilize the City Street Reserve for their portion of the project cost. Attached for your consideration are two resolutions. The first resolution orders the feasibility report. In looking back at the past actions of the City Council, staff realized that the City Council only directed work to begin on this feasibility study and never officially adopted a resolution ordering it. The second resolution receives the feasibility report and orders the public headng to be held on February 24. We would recommend adoption of both resolutions. If you have any questions, I will be in attendance at your January 13, 2003 City Council meeting. Sincerely, Howard R. Green Company Terry J. Maurer, P.E. TJM:sw Enclosures Ltr-OlO803-Council 1326 Energy Park Drive · St. Paul, MN 55108 · 651/644-4389 fax 651/644-9446 toll free 888/368-4389 RESOLUTION 03 - A RESOLUTION FOR THE CITY OF ELK RIVER A RESOLUTION FOR THE CITY OF ELK RIVER ORDERING A PRELIMNARY FEASIBILITY REPORT IN THE MATTER OF THE PAVEMENT REHABILIATION IMPROVEMENT OF 2003 WHEREAS WHEREAS the City has determined that it should consider improving certain property by reconstructing the existing streets; and Council must first secure a preliminary feasibility study in order to consider making the improvement; NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Elk River, Minnesota: This matter shall be referred to Howard R. Green Company, who is requested to provide to the City Council a report advising, in a preliminary way, whether the proposed improvement is feasible and whether the improvement should thus be made as proposed or in connection with some other improvement and the estimated cost of the improvement as recommended. Passed and adopted this 13 day of January, 2003. ATTEST: Stephanie A. Klinzing, Mayor Sandra A. Peine, City Clerk O:\PROJ\818980J\0030\Res-010803-A7.doc RESOLUTION 03 - A RESOLUTION FOR THE CITY OF ELK RIVER A RESOLUTION RECEIVING THE FEASIBILITY REPORT AND ORDERING A PUBLIC HEARING ON THE IMPROVEMENT IN THE MATTER OF THE PAVEMENT REHABILITATION IMPROVEMENT OF 2003 WHEREAS the Feasibility Report ordered by the Council has been prepared with reference to the 2003 Pavement Rehabilitation improvement and was received by the City on January 13, 2003; and WHEREAS the Feasibility Report recommends that the proposed improvement is feasible; NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Elk River, Minnesota: The City Council will consider the 2003 Pavement Rehabilitation improvement as described in the Feasibility Report and the assessment of the property abutting this proposed improvement for all or a portion of the cost of the improvement pursuant to Minnesota Statutes, Section 429, at an estimated total cost for the improvement of $1,803,000. A public hearing shall be held before the City Council on the proposed improvement on the 24th day of February, 2003, at 6:30 o'clock p.m. at the Elk River City Hall Council Chambers. The City Clerk shall provide two published notices (one week apart) in the official newspaper with at least three days between the last publication date and the hearing, and mailed notice ten days prior to the hearing as required by law. Passed and adopted this 13th day of January, 2003. Stephanie A. Klinzing, Mayor ATTEST: Sandra A. Peine, City Clerk O:\PROJ\818980J\0030\Res-010603-A8.doc Proj. No. 818980J FEASIBILITY STUDY FOR 2003 PAVEMENT REHABILITATION IMPROVEMENTS ELK RIVER, MINNESOTA January 2003 CERTIFICATION PAGE I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly licensed Professional Engineer under the laws of the State of Minnesota. Terry J. Mauref,,P.E. Lic. No. 15316 Date Prepared/Dy": Paul Wallick, P.E. Lic. No. 40151 Date Howard R. Green Company 1326 Energy Park Drive St. Paul, MN 55108 Phone: 651-644-4389 Fax: 651-644-9446 Toll-Free: 1-888-368-4389 II. IV. V. VI. vii. viii. IX, X. Xll. INDEX Page INTRODUCTION .......................................................................................................... 1 PROJECT SCOPE ....................................................................................................... 1 NECESSITY AND COST-EFFECTIVENESS ............................................................... 1 EXISTING CONDITIONS ............................................................................................. 2 PROPOSED IMPROVEMENTS ................................................................................... 3 CITY/MUNICIPAL UTILITIES COORDINATION ........................................................... 5 RIGHT-OF-WAY, EASEMENTS AND PERMITS .......................................................... 5 INFORMATIONAL HEARING ....................................................................................... 5 ESTIMATED PROJECT COSTS .................................................................................. 6 FINANCING AND ASSESSMENTS ............................................................................. 6 PROJECT SCHEDULE ................................................................................................ 7 CONCLUSION ............................................................................................................. 7 EXHIBITS Exhibit 1 - Exhibit 2 - Exhibit 3 - Exhibit 4 - Exhibit 5 - Exhibit 6 - Exhibit 7 - Exhibit 8 - Study Area Map Zoning Map Existing Sanitary Sewer Existing Watermain Existing/Proposed Storm Sewer Proposed Street Sections Proposed Watermain Improvements Assessable Units APPENDICES Appendix A - Geotechnical Report Appendix B - Photos of Existing Parking Appendix C - City/Municipal Utilities Meeting Minutes Appendix D - Informational Meeting Minutes I. INTRODUCTION In October 2002, Elk River City Council adopted the Pavement Rehabilitation Report prepared by Howard R. Green Company. The Report outlined the standards and project area for the reconstruction of the streets within the Old Core City. It was determined that Fourth Street from Main Street to Trunk Highway (TH) 10 and additional side streets should be included in the first proposed project scheduled for construction in 2003. The area to be included in the first project is shown in Exhibit '1. After adoption of the Pavement Rehabilitation Report, the Elk River City Council directed Howard R. Green Company to prepare a Feasibility Study for the 2003 Pavement Rehabilitation Improvements. The proposed 2003 Pavement Rehabilitation Improvements includes the reconstruction of roads, sidewalks, storm drainage improvements, and watermain improvements. The major components of the proposed project include the reconstruction of the following streets: Street From To Fourth Street Main Street TH 10 Rush Avenue Fourth Street Fifth Street Quinn Avenue Fourth Street Fifth Street Oxford Avenue Fourth Street Fifth Street Norfolk Avenue Fourth Street Main Street Morton Avenue TH 10 Main Street II. PROJECT SCOPE The purpose of this study is to analyze the reconstruction of the proposed streets included in the 2003 Pavement Rehabilitation Improvements. In addition, existing sanitary sewer, watermain, and storm sewer systems will be evaluated and necessary improvements proposed. The study will discuss the existing conditions, proposed improvements, estimated construction costs, and overhead costs which include city administration, engineering, fiscal, and legal expenses. The Pavement Rehabilitation Report prepared by Howard R. Green and adopted by the City Council in October 2002 will be used as a guideline to discuss financing methods for the proposed improvements. III. NECESSITY AND COST-EFFECTIVENESS The improvements proposed in this study are necessary for a number of reasons. The reconstruction of the streets is a cost-effective means of continuing the City's proactive street efforts and ensuring an adequate means of transportation for the residents. In addition to rehabilitating street pavement, a total street reconstruction will allow for correction of existing drainage problems through the construction of concrete curb and gutter, modifying street grades, and the installation of a storm sewer collection system as needed. Watermain improvements are necessary due to under sized mains, which result in inadequate water flow. The proposed improvements will provide a project large enough to ensure a competitive bidding environment. Therefore, the proposed improvements will be cost-effective. Based on the information contained within this report, the proposed improvements are necessary, cost-effective, and feasible from an engineering standpoint. IV. EXISTING CONDITIONS Street The streets proposed to be reconstructed are as follows: Street Length (feet) Existing Width Curb and (feet) Gutter Sidewalk Fourth Street 2,350 42 Yes Both Sides Rush Avenue 400 38 Yes Both Sides Quinn Avenue 400 28 No One Side Oxford Avenue 400 33 No No Norfolk Avenue 550 28 No One Side Morton Avenue 650 32 Yes No Soil borings indicated between 2-inches and 5-inches of existing bituminous throughout the study area. Approximately 100 feet west of the intersection of Fourth Street and Quinn Avenue there is an area of approximately 140 square feet that has 6.5-inches of concrete under the bituminous. The geotechnical report is provided as Appendix A. The majority of the property within the study area is zoned Single Family Residential (Rlc). A small area is zoned Highway Commercial (C3) and Multiple Family Residential (R4). No zoning changes are proposed. A zoning map of the study area is provided as Exhibit 2. Sanitary Sewer 8-inch sanitary sewer is located on all the streets in the study area with the exception of Oxford Avenue where there is currently no sanitary sewer. The majority of the existing sanitary sewer is made of concrete, with a few segments constructed of vitrified clay pipe. The existing sanitary sewer is shown on Exhibit 3. Watermain 4-inch ductile iron pipe watermain is located on all the streets in the study area with the exception of Quinn Avenue, Oxford Avenue, and Norfolk Avenue where there is currently no watermain. The existing watermain is shown on Exhibit 4. Storm Sewer A 12-inch storm sewer system and catch basins are located at the south end of Rush Avenue. Runoff from Fourth Street approximately 400 feet east of Rush Avenue flows to these catch basins. In addition, the Rush Avenue runoff from approximately Fifth Street south flows to these catch basins. 2 A 12-inch storm sewer system and catch basins are located at the intersection of Proctor Avenue and Fourth Street. Runoff from Fourth Street approximately 425 feet west of Proctor flows to these catch basins. Catch basins are located on the south side of Fourth Street approximately 200 feet west of the intersection of Fourth Street and Morton Avenue. Runoff from the intersection of Fourth Street and Morton Avenue to the east and from the intersection of Fourth Street and Proctor Avenue to the west flows to these catch basins. A 12-inch storm sewer system and catch basins are located approximately 150 feet north of the intersection of Morton Avenue and Main Street. Runoff from the intersection of Morton Avenue and Fourth Street and from the intersection of Morton Avenue and Main Street flows to these catch basins. The existing storm sewer is shown as Exhibit 5. Existing Private Utilities Private utilities that have facilities in or near the project area will be notified of the project and requested to incorporate repairs and replacements with the project as needed at their cost. Private utilities include Charter Communications, Elk River Municipal Utilities, Minnegasco, Northstar Access, Sherburne Telephone Systems, and Qwest. V. PROPOSED IMPROVEMENTS The proposed improvements for the 2003 Pavement Rehabilitation Improvements include street, storm sewer, sanitary sewer, and watermain construction. A detailed description of each proposed improvement is provided below. Street The proposed typical section for the majority of the streets will be in accordance with the section adopted as part of the Pavement Rehabilitation Report. The proposed street section, shown on Exhibit 6, consists of a 32-foot wide street with concrete curb and gutter. This typical section will require widening or narrowing of the existing roadways within the project area. Fourth Street will be reconstructed as an exception to the adopted typical section. Due to the location of three churches adjacent to Fourth Street, on-street parking currently occurs on a regular basis and will need to be provided for in the future. According to State Aid guidelines the proposed street section to allow for on street parking on Fourth Street should consists of a 38-foot wide street section with B618 concrete curb and gutter. This section will allow for parking on both sides of the street. Photos showing the existing parking needed are provided as Appendix El. The proposed pavement section for all the streets consists of 6 inches Class 5 aggregate base, 2 inches of bituminous base course, and 1.5 inches of bituminous wear course. The proposed street section has been verified by a geotechnical investigation. The proposed street sections are shown as Exhibit 6. The proposed improvements also include a 6-foot wide sidewalk located on both sides of the majority of the streets within the project area. Existing sidewalk will be removed and reconstructed to City Standards. Areas where sidewalk will not be constructed include streets where sidewalk construction is not feasible due to extreme grades or where it is desired to protect trees. For example, on Norfolk Avenue it will not be feasible to construct a sidewalk on the west side of the street because of the grade difference between the roadway and adjacent Hanke Pit at the intersection of Norfolk Avenue and Main Street. Other locations where sidewalk may not be feasible will be determined during design. It is proposed that Elk River Municipal Utilities will install street lighting after the project. Storm Sewer A review of the drainage patterns and pavement conditions reveals that some locations do not currently drain runoff away effectively. Replacement and addition of curb and gutter, slight grade revisions, and storm sewer extensions are needed to facilitate drainage. The existing storm sewer system will be extended and inlets installed at appropriate locations to provide adequate drainage for the area. Storm sewer is shown as Exhibit 5. Sanitary Sewer The sanitary sewer within the project area was televised to determine the extent that repairs or replacement would be necessary. A review of the Closed Circuit Televised Sewer Inspection Report determined that although regular maintenance would be required to remove roots in certain areas no structural damage had occurred to the pipe. The report was discussed with Mr. Gary Leirmoe, Chief Operator, and it was determined that no improvements or repairs to the sanitary sewer system are necessary. Watermain Watermain improvements were discussed with Mr. Bryan Adams, General Manager of Elk River Municipal Utilities (ERMU). The following items were a result of the discussions and will be incorporated during design: Some existing services may be lead or other non-copper material. ERMU policy states that non-copper services must be replaced with copper. These services will be identified and replaced as part of the improvements project. The existing 4-inch watermain on Fourth Street should be replaced with a larger size main. The exact size will be determined during design through modeling. It is anticipated that a 12-inch main will be required. The existing 4-inch watermain should be replaced with 8-inch watermain throughout the remainder of the study area. · Where no watermain exists on Quinn Avenue, Oxford Avenue, and Norfolk Avenue, install 8-inch watermain. 4 · All existing hydrants will be replaced and possible additional hydrants added. The location of new hydrants will be discussed with Fire Chief Bruce West. The proposed watermain improvements are shown as Exhibit 7. VI. CITY/MUNICIPAL UTILITIES COORDINATION On December 5, 2002, Pat Klaers, City Administrator; Lori Johnson, City Finance Director; Bryan Adams, Municipal Utilities General Manager; and Terry Maurer, City Engineer met to discuss coordination issues involved in the 2003 Pavement Rehabilitation Improvements. A copy of the meeting minutes is provided in Appendix C. It was agreed at the meeting that the Municipal Utilities would fund all of the construction costs associated with their water improvements. The construction costs would include a pro rato share of the mobilization bid item based on construction costs, and a pro rato share of the signing during construction based on length of construction. In addition, the Municipal Utilities agreed to pay a percentage of construction cost for plan and specification preparation. This percentage is proposed to be 10 percent. Finally, the Municipal Utilities agreed to pay directly for services during construction, including construction staking, construction observation, contract administration and record drawing preparation. VII. RIGHT-OF-WAY, EASEMENTS, AND PERMITS Right-of Way and Easements No right-of-way will need to be acquired for the street improvements. Temporary construction easements may be 'required throughout the project area to accommodate driveway repair, water service replacement, and/or finished grading. Verbal permission will be secured from private property owners during the construction process should work need to be completed on private property, outside of obtained rights-of-way. Permi~ Several permits will be required prior to construction of the proposed improvements. Required permits include, but are not limited to, the following: · Minnesota Department of Transportation · Minnesota Department of Health · Minnesota Pollution Control Agency Work in the Right-of-Way Watermain Grading VIII. INFORMATIONAL HEARING An informational hearing was held on November 6, 2002 with residents and the City Engineer. The project was discussed and residents were encouraged to voice their concerns and to ask questions. Issues of concern raised were possible tree removals 5 and sidewalks. The residents were assured that every effort would be made to minimize tree removals. A walk through will be scheduled with the residents prior to construction. Appendix C describes the informational hearing in more detail including minutes, mailing list, signup sheet, and handout material. IX. ESTIMATED PROJECT COST The estimated construction costs and associated overhead costs for the proposed improvements are Summarized in Table 1. Based on past experiences on similar complex-type projects in the City, the overhead costs have been estimated at 35% of the total construction cost. The overhead costs include city administration, engineering design, construction staking and inspection, and fiscal and legal costs. Table 1 Project Cost Estimate Street/Drainage Watermain Total Construction Cost Administration, Engineering, Fiscal, & Legal Contingency (5%) Total Project Cost $985,000 ~3701000 $1,355,000 $474,300 $ 68,000 $1,897,300 X. FINANCING AND ASSESSMENTS The improvements discussed in this report are proposed to be financed through a number of different methods. Benefiting properties would be assessed on a per unit basis for street, curb and gutter, sidewalks, and storm sewer. A residential lot that could not be further subdivided would be assessed as one unit. Lots that can be subdivided would be assessed as multiple units as appropriate. The Hanke School, library, and churches would be assessed as multiple units determined by the lot area and front footage. The number of assessable units is 92, as shown on Exhibit 8. In accordance with the adopted Pavement Rehabilitation Report, the proposed assessment is $5,000.00 per unit. The total assessment amount would then be $460,000. The Elk River Municipal Utilities would be responsible for funding all water improvements, including construction cost plus associated overhead. Based on discussions between the City and Municipal Utilities regarding these costs, the estimated total project funding from the Elk River Municipal Utilities is $444,000. Based on the estimated total project cost of $1,897,300, total assessments of $460,000 and Elk River Municipal Utilities contribution of $444,000, the remaining project cost to 6 be funding by the City is $993,300. It is recommended that the City Street Reserve Fund be used for financing this portion of the project. Xl. PROJECT SCHEDULE Feasibility to City Council Public Hearing Plans and Specifications Ordered Prepare Plans and Specifications Walk Through with Residents Plans and Specifications Approved by City Council Advertise for Bid Assessment Hearing Bid Awarded Begin Construction Construction Substantially Complete First Assessment Payment with Real Estate Taxes Place Final Bituminous Lift Final Project with Contractor January 13, 2003 February 24, 2003 February 24, 2003 30 -60 days Spring 2003 Spring 2003 30 days April 2003 May 2003 Spring 2003 Fall 2003 May 2004 Summer 2004 Summer 2004 Xll. CONCLUSION The total estimated project cost for street, storm sewer, and watermain including overhead costs is $'1,897,300. The project is necessary and cost-effective. As previously stated, this cost will be financed through a combination of assessments to benefiting properties, Elk River Municipal Utilities funds, and City Street Reserve funds. Based on the information gathered and the analysis presented, the proposed improvements discussed in this study are feasible from an engineering standpoint. 7 EXHIBITS oTOWER LION'S ri PARK HAN ELEM. ;CHOOL ~ STREET IMPROVEMENTS 400 , I DESIGNED BY: DRA1M~I BY: RK~M · I APPROVI~D BY:. JO~ NUMBER 818980J ' I CAD DATE: December 05, 2002 8:54:23 o.m. ~ CAD FILE: 818980J~DwqX, C"~858980J-EXl.DWG (RMONJ~ . 1326 ENERGY PARK DRIVE: ST. PAUL. MINNESOTA 5510a ~ (651) 644-4389 Howard R. Green Company CONSULTING ENGINEERS 2003 PAV~EI~ RE~,-~A'I~ D C2 5TH STREET I1 4TH STREET Two Family Residential December 05. 2002 9:00:58 o.m. 818980J~Dwg~C~818980J -EX 2.DWG (RMONJEA) Two F~rna~y ReeidentiaJ ~ Townhouse/Multiple Fan~ly nemdent~ ~ Multiple F~iy Re~identieJ ~ Planned Unit Developement Fi~ Bueine~m Park ~ I-flghwsy Commercial ~ Con~mercial Medium Induslrial sor4d Ws~te Fac:~T~y Antenna Towe~' Mineral Excavation 0 300 ST. PAUL. MINNESOTA .55108 (651) 644-4389 Howard R. Green Company CONSULTING ENGINEERS ZONING MAP 2003 PAVEEMENT REHABILITATION IMPROVElVlENTS December 05, 2002 9:02:41 o.m. 818980J\Ow9~C~818980J -EX3.DWG (RMONJEA) 0 160 EX. SAN TARY SEWER , ST. PAUL, MINNESOTA 55108 (651) 644-4589 Howard R. Green Company CONSULTING ENGINEERS EXISTING SANFI'ARY SEWER 2003 PAVEMENT REHABILITATION IMPROVEMENTS CZ> December 30. 2002 9:4-1:13 a.m. 818980J~Dwg~C~818980J -£X4.DWG (RMONJ~'A) 0 160 EX. WATERMAIN ST. PAUL, MINNESOTA :55108I (651) 644-4589 I Howard R ~een Company CONSULTING ENGINEERS EXISTING WA'[ERMAIN 2003 PAVEMENT REHABILITATION IMPROVEMENTS 5TH STREET 4TH STREET 2 December 05, 20D2 9:18:31 o.m. 818gs0J~Dwg~C~818980J -EX5.DWG (RMONJEA) 0 160 PROPOSED EX. STORM STORM SEWER SEWER 15 ST. PAUL. MINNESOTA 55108 81'-EETNO. (651) 644-4389 PROPOSED STORM SEWER IVlPROVEMENTS Howard R Green Company 2oo3 PAVEMENT REHABILITATION IMPROVEMENTS 5 CONSULTING ENGINEERS ROW 6' SIDEWALK ~ I 17' 16' 16' 1' ONCIDENTAL) ~- SOD I I 2" 2550 TYPE LV5 NONWEARING COURSE MIXTURE 6" CLASS 5 AGGREGATE BASE APPROVED SUBGRADE 0.67 2, 2'~L ROW LIGHT ~- 6' SIDEWALK B618 CONCRETE CURB & GUTTER TYPICAL STREET SECTION ROW 14' 19' 19' 6' SIDEWALK 0N~IDENTAL> '-- SO0 1.5" 2350 TYPE MV5 WEARING COURSTEAcMKIX~(~ARET 2" 2350 TYPE LV5 NONWEARING COURSE MIXTURE -- 6" CLASS 5 AGGREGATE BASE APPROVED SUBGRADE 0.67 2,2'~ ROW 14' LIGHT )~POLE _~1'--~ _~, SIDEWALK RANULAR BEDDING SOD (INCIDENTAL) k__ B618 CONCRETE CURB & GUTTER TYPICAL STREET SECTION ON 4TH STREET TYPICAL STREET SECTION 2003 STREET IMPROVEMENTS DESIGNED BY: DRAWN BY: RKM APPROVE:D BY: JO~ NUMBER 818980J CAD DATE: December 05, 2002 9:20:07 o.m. CAD FILE: 8i8980J'~Dwq~C"~8189BOJ-EX6.DWG (RMONJI 1526 ENERGY PARK DRIVE ST, PAUL, MINNESOTA 55108 (651) 644-4589 Howard R. Green Company CONSULTING ENGINEERS 2003 PA~=MENT REf'IABI.~A'IIC~I T '3AY (] ~IOJXO '3AY ~l()IOOHd '3AY NNIn© 'EIAV HSn~! T Z w w O_ W u_i1 1 <1 1 D2 rr 2 2 1 ,i (~111 3 1 r-~_ DENOTES ASSESSABLE NITS 92 December 30, 2002 11:~8:O§ a.m. 818980J~Dwg~C~818980J-EXS.DWG (RMONJEA) 0 160 ~ I Ld n~l 1 11 4TH STREET 8 'OTAL) 111 2 12/ DQ 4 1 1 1 2 1 HARDEES 1 1 1 1 1 1326 ENERGY PARK DRIVE ST. PAUL, MINNESOTA 5.5108 (651) 644-4389 I-bward R. Green Company CONSULTING ENGINEERS ASSESSABLE UNITS 2003 PAVEMENT REHABILITATION IIdPROVEbENTS APPENDIX A -~T-~ 0 o N S U LTANT._~ STS Consultants, Ltd. 10900 73rd Avenue North, Suite 150 Maple Grove, Minnesota 55369-5547 voice 763-315-6300 fax 763 -315 -1836 web www.stsconsultants.com December 9, 2002 City of Elk River cio Mr. Paul Wallick Howard R. Green Company 1326 Energy Park Drive St. Paul, MN 55108 Re: Subsurface Exploration for the 2003 Street Improvements at Fourth Street Between Rush Avenue and Morton Avenue in Elk River, Minnesota; STS Project 98934 Dear Mr. Wallick: We have performed a subsurface exploration and geotechnical engineering analysis for this road reconstruction project in Elk River. This work was performed based on the scope of services defined in our proposal dated October 17, 2002. This work was authorized by Mr. Paul Wallick on October 22, 2002, acting on behalf of the City of Elk River. Project Description You propose to reconstruct Rush, Quinn, Oxford, Norfolk, and Morton Avenues, and the section of Fourth Street between Rush and Morton Avenues. New watermain will be installed in these streets at approximately 7-1/2 foot depth, followed by installation of new pavements. Little or no grade changes are anticipated. Project Scope and Purpose The purposes of this exploration are to perform a subsurface exploration and testing program consisting of seven soil borings to 10 foot depths, and to record the thicknesses of pavement and base course penetrated by the borings. We were to describe the soil and groundwater conditions encountered in our exploration, present recommendations for soil compaction, and provide an estimated stabilometer R-value for pavement thickness design. Procedure Howard R. Green Company selected the number of borings and the boring locations. A Howard R. Green survey crew staked the borings in the field. We drilled the borings on November 14, 2002 with a truck-mounted Diedrich D-50 drill rig operated by a two person crew. We followed conventional drilling and soil sampling procedures. The soil samples recovered were examined in our laboratory by an engineer, who prepared soil boring logs. 100-LH.8 City of Elk River STS Project 98934 December 9, 2002 Page 2 Exploration Results Soil Conditions - Our borings penetrated from 2 inches to 4 inches of bituminous concrete pavements. At boring 2, near the southwest intersection of Quinn Avenue and 4th Street, the pavement was underlain by a 6-1/2 inch thick concrete slab. We subsequently delineated the extent of this slab, and found it to be 6 feet wide by 22 feet long, with the long axis being along 4th Street. At boring 6, we found 2 inches of bituminous pavement over 3 inches of aggregate base course, over 3 inches of old bituminous pavement. We did not find a well defined base course layer below the pavement. It appears that some or most of the pavements were placed directly over the native sand or over sand fill. Below the pavement, we penetrated possible fill to depths of 1.5 to 10 feet at borings 3, 4, 5, and 7. The fill consists of a mixture of fine to medium sand and silty sand with variable gravel content. The major native underlying soil type at this site is fine to medium sand. This extends to the 10 foot termination depths of the borings. Standard penetration N-values in the sand range from 4 to 21, representative of a loose to medium dense condition. Groundwater Conditions - We did not encounter free groundwater or saturated soils in our exploration. The groundwater level at this site is more than 10 feet below pavement surface, and should not affect the proposed construction. Analysis and Recommendations The utility line trenches should be bedded in and backfllted with on-site sand or silty sand. This should be placed in 8 to 10 inch loose lifts and compacted to at least 98% of the maximum Standard Proctor dry density, ASTM D-698, up to a level of 3 feet below pavement surface. The uppermost 3 feet of the trench backfill should be compacted to at least 100% of the Standard Proctor dry density. A compacted fine to medium sand or silty fine to medium sand would have an estimated stabilometer R-value of 45. We recommend that this value be used for the pavement thickness design. Construction Considerations - We do not anticipate unusual soil or groundwater conditions for this project. The soil is basically a fine to medium sand with silt and gravel traces. General Qualifications - This report has been prepared to aid in the design of the road reconstruction projects in Elk River. The scope is limited to the specific road projects and locations described herein, and our description of the project represents our understanding of the significant aspects relevant to soil s and foundations. In the event that there are changes in the design or locations of the roadways, the opinions and recommendations contained in this report shall not be considered valid unless STS reviews these changes and modifies or verifies the recommendations of this report in writing. Standard of Care The recommendations and opinions contained in this report are based on our professional judgment. The soil testing and geotechnical engineering services performed for this project have been conducted in a manner consistent with that level of skill and care ordinarily exercised by other members of the profession currently practicing in this area under similar budgetary and time constraints. No other warranty, express or implied, is made. City of Elk River STS Project 98934 December 9, 2002 Page 3 We trust that this provides the information you require. Sincerely, STS CONSULTA~, k.~ M~ss, P.E. Senior Project Engineer MM/dn Encs. C6934001.doc If we can be of further service, please call us. Reviewed by: James H. Overtoom, P.E. Principal Engineer/Vice President I HEREBY CERTIFY THAT I AM A PROFESSIONAL ENGINEER REGISTERED UNDER THE LAWS OF THE STATE OF MINNESOTA, AND THAT THIS REPORT WAS PREPARED BY ME OR U~R MY DIRECT SUPERVISION. S i g n e d ~/~J~'~J/~ ~ ~ Registration No. 8435 M~'~r~ IV~ndeSslI P.E. Date ~)~C, ,-~~ APPENDIX 2. 3. 4. 5. 7. 8. 9. 10. Boring Location Diagram Boring Logs STS General Boring Log Notes STS Soil Classification System STS Field and Laboratory Procedures Subsurface Exploration Procedures Sampling Procedures Laboratory Index Test Procedures STS Standard Boring Log Procedures ASTM Specification D-1586 STS Subgrade Protection Guideline STS Subgrade Stabilization Guideline STS Earthwork Guideline #2 £ £ BORING #2 CONCRETE UNDERLA~ENT ~ B A = 12' TO ~ST B = 1' TO NORTH ^ ~ c c = lO' TO EAST D D = 5' TO SOU TH~ DETAIL LEGEND ~ 8B ~ BOFIIN~ LOOATION ~#7 0 1 O0 200 SCALE IN FEET STS Consultants Ltd. Consulting Engineers SIS PROJECT NO. 98934 STS PROJECT FILE 0634001 .DWG SC~.E AS SHOWN FIGURE NO. 1 _1 OWNER LOG OF BORING NUMBER 1 City of Elk River Rush Avenue ~ PROJECT NAME ARCHITECT-ENGINEER ST$ Consultants Ltd. 2003 Street Improvements Howard R. Green Company SITE LOCATION ~ UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota '-~ TONS/FT.2 I 2 3 4 5 ~' PLASTIC WATER LIQUID LIMIT % CONTENT % LIMIT % ~. ~ zO ~ DESCRIPTION OF MATERIAL ~: SURFACE ELEVATION ~ ~ ~) PENETRATION BLOWS/FT. ~ 10 20 30 40 50 ~ Fine to medium sand - brown - damp - medium dense to loose - (SP) 1 SS 2.5 PA I 2 SS I I 5.0 PA 3 SS 7.8 Fine to coarse sand, trace fine gravel - brown - damp - loose - (SP-SM) 4 10.0 10.0 End of boring at 10.0 ff. Boring backfilled with cuttings. The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual. WL BORING STARTED STS OFFICE Dry 11/14/02 Minneapolis Area - 06 WL BORING COMPLETED ENTERED BY SHEET NO OF 11/14/02 DN I 1 WL RIG/FOREMAN APP'D BY STS JOB NO. Diedrich D-50/TM MM 98934 lJ OWNER LOG OF BORING NUMBER 2 City of Elk River Fourth Street PROJECT NAME ! ARCHITECT-ENGINEER STS Consultants Ltd. 2003 Street Improvements Howard R. Green Company SITE LOCATION ~_ UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota '~' TONS/ET? 1 2 3 4 5 ~ ~ PLASTIC WATER LIQUID LIMIT % CONTENT % LIMIT % ~ ~ DESCRIPTION OF MATERIAL X- - · -z5 u5 ~ ~ ~, ~,~ ~ ~o 2o 30 40 50 :~ ~ ~ o t- ~ STANDARD ~ ~< ~< ~ ~ SURFACE ELEVATION ~ u ~) PENETRATION BLOWS/ET. 10 20 30 40 50 3" bituminous pavement PA 6.5" concrete slab 9.8 Fine to medium sand, traces fine gravel below 7 ft. depth - brown - damp - loose to medium dense - (SP) ~ SS 2.5 PA ¢o 2 SS 5.0 PA t 3 SS ~ 7.5 PA 4 SS 10.0 10.0 End of boring at 10.0 ft. Boring backfilled with cuttings. The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual. WL BORING STARTED STS OFFICE Dry 11/14102 Minneapolis Area - 06 WL BORING COMPLETED ENTERED BY SHEET NO, OF WL RIG/FOREMAN APP'D BY STS JOB NO, Diedrich D-50/TM MM 98934 1 OWNER LOG OF BORING NUMBER 3 City of Elk River Quinn Avenue PROJECT NAME ARCHITECT-ENGINEER STS Consultants Ltd. 2003 Street Improvements Howard R. Green Company SITE LOCATION ~ UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota ~'"' TONS/FT? 1 2 3 4 5 u_ ~) PLASTIC WATER LIQUID ~' z LIMIT % CONTENT % LIMIT % ~ ~ DESCRIPTION OF MATERIAL STANDARD ~- SURFACE ELEVATION ~ ~ (~) PENETRATION BLOWS/FT. -J 10 20 30 40 50 PA D.3 3" bituminous pavement Possible FILL: Mixed fine to medium sand, and silty sand, traces gravel - dark brown - damp to moist - loose to medium ~10 dense - (SP-SM) 1 SS i 2,5 PA 2 SS I 5.0 PA :7 3 SS 7,~ pA 15 4 SS 10.0 10.0 End of boring at 10.0 ft. Boring backfitled with cuttings. The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual. WL BORING STARTED STS OFFICE Dry 11/14102 Minneapolis Area - 06 WL BORING COMPLETED ENTERED BY SHEET NO. OF 11/14/02 DN I 1 WL RIG/FOREMAN APP'D BY STS JOB NO. Diedrich D-50/TM MM 98934 ..1 OWNER LOG OF BORING NUMBER 4 City of Elk River Oxford Avenue PROJECT NAME ARCHITECT-ENGiNEER STS Consultants Ltd. 2003 Street Improvements Howard R. Green Company SITE LOCATION ~ UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota ~" TONS/FT? 1 2 3 4 5 ~' uJ PLASTIC WATER LIQUID ~- ~ w ~ LIMIT % CONTENT % LIMIT % ~ ~ ~- _ ~ DESCRIPTION OF MATERIAL ~ ~ ~ o ~ ~ STANDARD SURFACE ELEVATION ~ ~ ~ PENETRATION BLOWSIFT. 10 20 30 40 50 PA I I I~ ~ 2,, bituminous pavement .... Base course FILL: Silty fine to medium sand - dark brown - 1.5 Fine to medium sand, trace gravel - brown - damp - loose - (SP) ~0.0 ~0.o End of bodn~ at 10.0 ~. ~odn~ backfilled with cuttings. The stratification lines represeat the approximate bounda~ lines between so~l types: in situ, the transition may bo ~radual. WL BORING STARTED STS OFFICE D~ 11/14/02 Minneapolis Area - 06 WL BORING COMPLETED ENTERED BY SHEET NO. OF 11114102 DN 1 1 WL RIG/FOREMAN APP'O BY STS JOB NO. Diedrich D-SO/TM MM 98934 !F_~ ~_]I OWNER LOG OF BORING NUMBER City of Elk River Fourth Street PROJECT NAME ARCHITECT-ENGINEER STSConsul~ar~s Ltd. 2003 Street Improvements Howard R. Green Company SITE LOCATION ~ UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota 'J TONS/FT.z 1 2 3 4 5 ~' LU PLASTIC WATER LIQUID ~' ~ I.u ~ LIMIT % CONTENT % LIMIT % - ~: ~ ~ DESCRIPTION OF MATERIAL ~ ~ ~ ~ .... ° ~ .~ ~ ~o ?- STAND^RD ~] ~ ~ m~ ~: SURFACE ELEVATION ~ ~ ® PENETRATION BLOWS/FT, 0.2 ~2" bituminous pavement -~ ~0 20 30 40 50 I Possible FILL: Fine to medium sand trace gravel - dark brown ~ 1 SS I I I 12.o PA ] I t Possible FILL: Silty fine to medium sand, little gravel ~ brown - 2.5 ] I I damp to moist - medium dense - (SM) 3 SS .5 Fine to medium sand, little graYel - brown - damp - medium dense - (SP) 7.5 pA 4 SS 10.0 10.0 End of boring at 10.0 ff. Boring backfilled with cuttings. The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual. WL BORING STARTED STS OFFICE Dry 11114/02 Minneapolis Area - 06 WE BORING COMPLETED ENTERED BY SHEET NO OF 11/14102 DN 1 1 WL RIG/FOREMAN APP'D BY STS JOB NO Diedrich D-50/TM MM 98934 ] OWNER LOG OF BORING NUMBER City of Elk River Norfolk Avenue ~ PROJECT NAME ARCHITECT-ENGINEER sMconsu~nts ua. 2003 Street Improvements Howard R. Green Company SITE LOCATION 4"%-UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota '-J TONSIFT? 1 2 3 4 5 ~ ~, P~XST~C WATER ~ <~ LIMIT % CONTENT % LIMIT % ~ o_ ~~ DESCRIPTION OF MATERIAL ~ ..... · .... ~ ~ ~ ~ ~ ~ ~. 10 20 30 40 50 ~ ~: ~; g I- -- STANDARD ~] ~ ~< ~< ~ SURFACE ELEVATION ~ ~ ~) PENETRATION BLOWS/FT. 10 2o 30 40 50 2" bituminous pavement AS 3" aggregate base course 0,7 -..3" old bituminous pavement Fine to medium sand, trace gravel - dark brown to brown - damp - loose to medium dense - (SP) I SS 2.5 PA 2 SS I I 5.0 PA I 3 SS 7.5 PA 10 4 SS 10.0 10.0 End of boring at 10.0 ft. Boring backfilled with cuttings. The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual. WL BORING STARTED STS OFFICE Dry 11/14/02 Minneapolis Area - 06 WL BORING COMPLETED ENTERED BY SHEET NO. OF 11/14/02 DN I 1 WL RIG/FOREMAN APP'D BY STS JOB NO Diedrich D-50/TM MM 98934 .._] OWNER LOG OF BORING NUMBER 7 City of Elk River Morton Avenue PROJECT NAME ARCHITECT-ENGINEER STS Consultants Ltd. 2003 Street Improvements Howard R, Green Company SITE LOCATION ~ UNCONFINED COMPRESSIVE STRENGTH Elk River, Minnesota "-~ TONS/FT? I 2 3 4 5 u- PLASTIC WATER LIQUID LIMIT % CONTENT % LIMIT % ~ ~'_ ~ua. ~- DESCRIPTION OF MATERIAL ~-- -- · >- . 10 20 30 40 50 0 uJ ~ ~0 STANDARD PA 0.3 3-1/4" bituminous pavement Base Course FILL: Fine to medium sand, little to some gravel, trace silt - dark brown - damp - medium dense - (SP) 1 SS / 1.8 / Fine to medium sand, trace silt and gravel - dark brown - damp 2.5 PAJ, J, - I°°se ' (SP) 2 SS 7,5 J PA 4 SS 10.0 10.0 End of boring at 10.0 ft. Boring backfilled with cuttings. The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual. WL BORING STARTED STS OFFICE Dry 11/14/02 Minneapolis Area - 06 WL BORING COMPLETED ENTERED BY SHEET NO. OF 11 / 14/02 D N 1 1 WL RIG/FOREMAN APP'D BY STS JOB NO Diedrich D-50/TM MM 98934 STS General Boring Log Notes DRILLING & SAMPLING SYMBOLS: SS: ST: AS: WS: OS: BS: CS: Split Spoon- I 3/8" I.D., 2" O.D. Unless otherwise noted Shelby Tube-2" O.D., Unless otherwise noted Auger Sample Wash Sample Osterberg Sampler - 3" Shelby Tube Bulk Sample from Exposed Material Continuous Sample Tube PA: HS: RB: FT: DB: VS: PM: HA: Power Auger- 4 1/4" unless otherwise noted Hollow Stem Auger Tri-Cone Rotary Bit Fish Tail Bit Diamond Coring Bit Vane Shear Pressuremeter Test, In-Situ Hand Auger Standard Penetration Test N-value: Total blows for last foot of penetration of a 2 inch O.D. split spoon sampler driven by a 140 pound hammer falling 30 inches, except where otherwise noted. WATER LEVEL MEASUREMENT SYMBOLS: WL: Water Level WCl: Wet Cave In WS: While Sampling DCl: Dry Cave In WD: While Drilling BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal Water levels indicated on the boring logs are the levels measured in the boreholes at the time indicated. In relatively pervious soils (e.g. sands and gravels), the indicated groundwater levels are considered reliable. In relatively impervious soils (e.g. silts and clays), the indicated groundwater levels may not be reliable. For boreholes or wells in Iow permeability soils, relatively long periods of time are usually required for the groundwater to obtain an equilibrium position. Generally, a more accurate determination of water levels can be made from monitoring wells or piezometers sensing aquifers of interest with readings over a period of weeks to months. GRADATION DESCRIPTION & TERMINOLOGY: Coarse grained or granular soils have more than 50% of their dry weight retained on a #200 sieve; they are generally described as: boulders, cobbles, gravel or sand. Fine grained soils have less than 50% of their dry weights retained on a No. 200 sieve; they are generally described as: clays, silty clays, or clayey silts if they are cohesive and silts if they are non-cohesive. Granular soils are also described on the basis of their relative in- place density and fine grained soils are described on the basis of their strength, consistency and plasticity. Major Description Of Component Components Also Percent of Dry of Sample Size Ran.qe Present in Sample Wei.qht Boulders Over 12 in. (200 mm) Trace 1-9 Cobbles 12 inches to 3 inches Little 10-19 (200 mm to 75 mm) Gravel 3 inches to #4 sieve Some 20-34 (75 mm to 4.76 mm) Sand #4 to #200 sieve And 35-50 (4.76 mm to 0.074 mm) Silt Passing #200 sieve (0.074 mm to 0.002 mm) Clay Passing #200 sieve Smaller than 0.002 mm CONSISTENCY OF COHESIVE SOILS RELATIVE DENSITY OF GRANULAR SOILS: Unconfined Compressive SPT N-Value Relative Strength, Qu (tsf) Consistency (blows/ft) Density 0.25 Very Soft 0-3 Very Loose 0.25-0.49 Soft 4-9 Loose 0.50-0.99 Medium (Firm) 10-29 Medium Dense 1.00-1.99 Stiff 30-49 Dense 2.00-3.99 Very Stiff 50-80 Very Dense 4.00-8.00 Hard >80 Extremely >8.00 Very Hard Dense STS Soil Classification System UNIFIED SOIL CLASSIFICATION SYSTEM Major Divisions Group Symbols Typical Names Laboratory Classification Criteria ~ ~ ~' Well graded gravels, gravel- -~ ~ ce GW : C, ¥,~r~4;Cc=~bet~e~la~3 ~= sand mi~ures, little or no fines ~ = . · Poorly graded gravels, gravel- E E ~ ~ ~ GP m ~ Not meeting all gradation requirements for G~ - ~ sand mixtures, little or no fines ~ ~ ~ Atterberg limits below · O~ ~ Silty gravels, gravel-sand-clay ~ ~ ~ GM N '5 "A" line or P.I. less than Above "A" line with ~ ~ ~ ~ & mixtures · E 4 P.I. baleen 4 and 7 ~ ~ ~ are borderline cases z ~ ~ ~ ~ GC Clayey gravels, gravel-sand-~ ~ ~ ~ Atte~erg limits above requiring use of dual ~ ~ ~ ~ · "A" line wi~ P.I. symbols ~ O ~ clay mixtures ~ ~ greater than 7 ~ ~ Well graded sands, gravelly e.~' '~ ~ ~ sands, little or no fines ~ ~ '-~ ~ ~ Poorly graded sands, gravelly ~ ~ ~: ~ ~ i -- ~ ~ ~ SP ~ ~ ~ ~ ~ : Not meeting all gradation requirements for SW ~ ~ '~ ~ sands, traces or no fines ~ ~ = ~ - ~ Atterberg limits below Limits plotting in ~ d ~ Silty sands, sand and silt ~ ~o~ z ~ ~ SM 8 ~ [~ "A" line or P.I. less that hatched zone with ~ ~ E mixtures ~ ~ ~ 8 [ ~ ~ ~m ~ 4 P.I. between4and7 ~ ~~ [ ~ ~ ~ ~ ~ are borderline cases c ~ .D ~ ~ ~ ~ o c w requiring use of dual - - '~ ' ~ Atte~erg limits above e ~ ~ SC Clayey sands, sand and clay '~ ~ ~ ~ ~ symbols ~ o o "A" line with P.I. ~ o ~ ~ mixtures ~ ~ ~ ~ E greater than 7 Inorganic silts, rock flour, silty or Liquid Limit Plastici~ Cha~ ML clayey fine sands or clayey silts 60 with slight plasticity / '~ ~ Inorganic clays of Iow to mediu~ 50 -- ~ ~ ~ CL plasticity, gravelly clays, sandy ~ ~ ~ days, ~ilty dayg, lean ~la~ ~ ~ Or~ani~ silt~ and or~ani~ silty 'g OL ~ ~ days o~ ~ pla~tidty ~ ~H diatoma~ou~ ~ne gilty goilg, - .-'- ~ ~ Inor~ani8 ola~g o~ffi~ff pla~tidt~, 4 I OL-~L ~ ~ ~ ~, 0 ~ 20 30 40 ~0 ~0 ~0 80 ~0 ~00 ~ : '~ Or~anio ola~g, gilt~ or ~ilt and ~ ~ .~ OH ~ ~ day mixtum~ ~[ medium to ~i~ff For dagsi~oation o[ fin~-~rained goil~ and ~ne fraction o[ ~oar~e- ~ plastidt~ ~rained soilg. ~ ~ '~ Pt Peat an~ otffer ffi~ffly or~ani~ A~rber~ Limitg plottin~ in ffatoffe~ area are ~orderline ~ ~ goils ~la~gi~oation~ requidn~ uge of dual gym~olg. ,/ .' / OH orUH CL _ CL-ML STS Subsurface Exploration Procedures Hand Auger Drillin_q {HA) In this procedure, a split-barrel sampler or Shelby tube is driven into the soil by repeated blows of a sledge hammer or a guided drop hammer. After the sampler is driven to the desired sample depth, a soil sample is retrieved. The hole is then advanced by manually turning and withdrawing a hand auger until the next sampling depth increment is reached. This hand auger drilling between sampling intervals helps to clean and enlarge the bore hole in preparation for obtaining the next sample. Casing is not utilized to maintain an open bore hole. Power Auger Drilling (PA) In this type of drilling procedure, solid-stem, continuous flight helical augers are used to advance the bore holes. Normally 4 1/4-inch diameter augers are utilized. They are turned and hydraulically advanced and withdrawn by an engine powered drill rig mounted on a skid, truck or all-terrain vehicle. In auger drilling, casing and drilling mud are not utilized to maintain open bore hole. Hollow Stem Auqer Drilling (HS) In this drilling procedure, continuous flight augers having open stems are used to advance the bore holes. Typically, the hollow stem auger has a 6 to 8-inch outside diameter and a 2 1/4 to 4 1/4-inch inside diameter. The open stem allows the sampling tool to be used without removing the augers from the bore hole. Hollow stem augers thus provide support to the sides of the bore hole during the sampling operations. Drilling fluid is normally not used with this method. Rotary Bit Drillinq (RB) In employing rotary drilling methods, various cutting bit types and bit diameters are rotated and pushed hydraulically to advance the bore holes. In this process, near surface casing and/or drilling fluids are used to maintain open bore holes. The drilling fluid typically consists of a soil-water mix, a bentonite-soil slurry or a colloidal gel-soil slurry that is circulated down through the drill rod and bit and up the bore hole annulus with drill cuttings. Diamond Core Drillinq (DB) Diamond core drilling is used to sample hard, cemented formations such as rock. In this procedure, a double tube (or triple tube) core barrel with diamond teeth cuts an annular space around a cylindrical column of the material being sampled. The sample is retrieved by a catcher just above the bit. Samples recovered by this procedure are placed in sturdy containers in sequential order from top to bottom. STS Sampling Procedures Auger Sampling (AS) In this procedure, soil samples are collected from cuttings off of the auger flights as they are removed from the ground. The samples are typically retained in sealed jars or plastic bags, then shipped to a laboratory for further examination and testing. Such samples provide a general indication of subsurface conditions; however, they do not provide undisturbed samples, nor do they provide samples from discrete depths. Split-barrel Sampling (SS) - (ASTM Standard D-1586) In the split-barrel sampling procedure, a 1.375-inch I.D., 2-inch O.D., split barrel sampler is driven into the soil a distance of 18 inches by means of a 140 pound hammer falling 30 inches. The value of the Standard Penetration Resistance, N, is obtained by counting the number of blows of the hammer over the final 12 inches of driving. This value provides a qualitative indication of the in-place relative density of cohesionless soils and consistency of cohesive soils. The indication is qualitative only, because many factors such as soil composition, gravel and cobble content, type of hammer, sample depth and groundwater seepage pressure can significantly affect the Standard Penetration Resistance N Value. Results in similar soils obtained by drill crews using different rigs, drilling procedures, and hammer-rod-spoon assemblies may not correlate directly. A representative portion of the recovered sample is placed in a sample jar, labeled and then shipped to a laboratory for further analysis and testing. Shelby Tube Sampling Procedure (ST) - (ASTM Standard D-1587) In the Shelby tube sampling procedure, a thin-walled steel seamless tube with a beveled cutting edge is pushed hydraulically into the soil and then pulled to obtain a relatively undisturbed sample. This procedure is typically used to sample firm to hard cohesive soils. Two-inch diameter tubes are generally utilized. Three-inch diameter tubes are occasionally utilized to sample softer soils where minimally disturbed samples are desired. The tubes are sealed, labeled, and then shipped to a laboratory for extrusion, further analysis and testing. Bulk Sample (BS) Bulk samples are typically obtained by hand tool digging into soil or rock deposits that are exposed at the ground surface or within an excavation (walls or bottom). Bulk samples are typically retained in sealed jars or plastic bags. Continuous Sample Tube (CS) This type of sampling device consists of 5-ft. sections of thin-wall tubes or split-barrel pipes which are capable of retrieving continuous columns of soil in 5-ft. maximum increments. Because of a continuous slot in the sampling tubes, the sampler allows field determination of stratification boundaries and containerization of soil samples from any sampling depth within the 5-ft. interval. This sampler is used inside a hollow-stem auger and is advanced slightly ahead of the auger head as the auger is turned into the soil. Split-barrel samples are typically opened in the field. Recovered soil is logged and representative samples retained in sealed jars. Tube samples are sealed, labeled and shipped to a laboratory for extrusion and testing. STS Laboratory Index Test Procedures Water Content (Wc) (ASTM 22t 6) The water content of a soil is the ratio of the weight of water in a given soil mass to the weight of the dry soil. Generally, the soil is dried in a conventional or microwave oven. Water content is commonly expressed as a percentage. Hand Penetrometer (Qp) In the hand penetrometer test, the unconfined compressive strength of a soil is estimated, to a maximum value of 4.5 tons per square foot (tsf), by measuring the resistance of a representative portion of a cohesive soil sample to penetration by a 1/4-inch diameter, spring-calibrated cylinder. Results from penetrating into a stone or obviously disturbed portions of the sample are generally disregarded. Hand penetrometer testing has been carefully correlated with unconfined compressive strength tests, and when performed correctly provides a useful and a relatively simple testing procedure in which soil strength can be quickly and reliably estimated. Unconfined Compression Test (Qu) (ASTM D 2166) In the unconfined compression strength test, a undisturbed cylinder of cohesive soil 2 to 3 inches in diameter with a height of 4 to 6 inches is loaded axially until failure or until a 20% stain has been reached, whichever occurs first. It provides an indication of the samples undrained shear strength. Atterberg Limits (ASTM D 318) Atterberg Limits tests provide a measure of a cohesive soils plasticity. The liquid limit is the water content at which a 1/2-inch wide groove that is cut into a shallow cup of remolded soil closes with 25 10mm drops of the cup. The plastic limit is the water content below which the soil no longer behaves as a plastic material based on behavior of rolled soil ribbons. The Plasticity Index is the difference between the liquid and plastic limits. Grain Size Analysis (ASTM D 422) Grain size analyses are performed to determine the distribution of particles by weight for a soil sample. The distribution of particles larger than 0.075 mm (retained on a No. 200 sieve) is determined by sifting a dried and broken soil sample through a series of generally smaller sieves, then weighing the retained portions. If specified, the distribution of particles smaller than 0.075 mm is also determined using a hydrometer to determine particle dispersion and settlement within water. Classification of Samples In conjunction with the sample testing program, retained soil samples are examined in our laboratory and are classified on the basis of their texture and plasticity in accordance with the United Soil Classification System (USCS). The soil descriptions on the boring logs are in conformance with this system and the estimated group symbols according to this system are included in parentheses following the soil descriptions on the boring logs. A separate sheet entitled "STS Soil Classification System" provides a brief explanation of this system of soil classification and is also included in the Appendix. STS Standard Boring Log Procedures ~"~ In the process of obtaining and testing samples and preparing this report, common procedures are followed regarding field logs, laboratory data sheets and samples. Field logs are prepared during performance of the drilling and sampling operations and are intended to document field test data, subsurface observations, sampling depths and exploration procedures. Samples obtained in the field are generally subjected to additional testing and reclassification in the laboratory by more experienced soil technicians, engineers or geologists. The engineer preparing the report reviews the field boring logs and laboratory sample descriptions, classifications and test data. The engineer then uses judgment and experience in interpreting this data and compiling it into the final boring logs. As a result, differences between the field and final boring logs may exist described in the text of the report, as appropriate. The descriptive terms and symbols used on the logs are described on the attached sheet, entitled: "General Boring Log Notes". We follow a common practice of the geotechnical engineering profession by generally not including field logs and laboratory data sheets in our engineering reports. We do this because the field logs do not represent the engineer's final opinions on appropriateness of field descriptions of conditions encountered in the exploration and testing work. On the other hand, we are aware that certain contractors and subcontractors submitting bids or proposals on work might have an interest in studying these documents before submitting a bid or proposal. For this reason, the field logs are retained in our office for review after authorization by our client. We welcome interpretation questions and an opportunity to explain how the information was obtained and why any boring log changes were made in the preparation of our final logs and report. Samples taken in the field, some of which are later subjected to laboratory tests, are retained in our laboratory for sixty days and then are eventually disposed unless special disposition is requested by our client. Samples retained over a long period of time, even in sealed jars, are subject to moisture loss which changes the density and strength of cohesive soil-generally increasing soil strength from that which was originally encountered in the field. Since these samples are then no longer representative of the moisture, density and strength conditions initially encountered, potential observers of these samples should recognize this factor if considering sample re-examination weeks or months after samples were retained. STS Sampling Procedures AMERICAN SOCIETY FOR TESTING AND MAT~RLa_T~ St~__r~dard Method for PENETRATION TEST AND SPLIT-BARREL SAMPV.r~G OF SOILS This standard is issued under the fixed desertion D 1 §86; the number imm~llsJ~ly following the designation indicates the year of adoption or, in the case of revision, the year of the last rev/sion. A number in parentheses indicates the year of last reapproval. A superscript epsllon (~) indicates an editorial change since the last revision or reapproval. This method has been approved for use by agencies of the Department.of Defense and for listing in the DOD Index of Specifications and 1. Scoge 1.1 This method describes the proce- dure, generally known as the Standard Penetration Test (SPT), for driving a split-barrel sampler to obtain a repre- sentative soQ sample and a measure of the resistance of the soil to penetration of the sampler. 1.2 This standard may involve haz- ardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult and establish ap- propriate safety and health practices and determine the applicability of reg- ulatory limitations prior to use. For a specific precautionary statement, see §.4.1. 1.3 The values stated in inch-pound units are to be regarded as the stan- dard. 2. Appi/cable Documents 2.1 ABTM Standard~: D2487 Test Method for Classification of SolM for Engineering Purposes2 D2488 Practice for Description and Identification of Soils (Visual- Manual Procedure)2 D4220 Practice for Preserving and Transporting Soft Samples2 8. DescriDttons of Terms 8Decific tO 3.1 anvil---that portion of the drive- weight assembly which the hammer strikes and through which the ham- mer energy passes into the drill rods. 3.2 cathead--the rotating drum or windlass in the rope-cathead llft sys- tem around which the operator w-raps a rope to lift and drop the hammer by successively tightening and loosening the rope turns around the drum. 3.3 drill rods--rods used to transmit downward force and torque to the drLll bit while drilling a borehole. 3.4 drive-weight assembly--a device consisting of the hammer, hammer faU guide, the anvil, and any hammer drop system. 3.8 hammer--that portion of the drive-weight assembly consisting of the 140 ~ 2 lb (63.5 ± I kg) impact weight which' is successively lifted and dropped to provide the energy that ac- complishes the sampling and penetra- tion. 3.6 h~mrner drop system--that po~ tion of the drive-weight assembly by which the operator accomplishes the lifting and dropping of the h~mroer to produce the blow. 3.7 hammer fall guide--that part of the drive-weight assembly used to guide the fall of the b~mmer. 3.8 N-value--the blowcount repre- sentation of the penetration resistance of the soil. The N-value, reported in blows per foot, equals the sum of the number of blows required to drive the sampler over the depth interval of 6 to 18 in. (150 to 450 mm) 3.9 &N--the number of blows ob- tained from each of the 6-in. (1§0-mm) intervals of sampler penetration (see 7.3). 3.10 number of rope turns--the total contact ~%~e between the rope and the cathead at the beg~n.tng of the opera- tor's rope slackening to drop the ha~n- ruer, divided by 360° (see Fig. 1). 3.1 1 sampling rods~rods that con- nect the drive-weight assembly to the sampler. Drill rods are often used for this purpose. 3.12 SPT---abbreviation for Standard Penetration Test, a term by which en- gineers commonly refer to this method. 4.1 This method provides & soft sam- ple for identification purposes and for laboratory tests appropriate for soil obtained from a sampler that may pro- duce large shear strain disturbance in the sample. 4.2 This method is used extensively in a great variety of geoteohnioal ploration projects. Many local correla. tions and widely published correla- tions which relate SPT blowcount, N-value, and the engineering behavioz of earthworks and foundation are available. IThis method is under the jur~dlctlon of Committee D-IS on 5off and Hock and is the responsibility of ~uboommltt~ D 18.02 on Sampl lng and Helat~l Field Testing for Soft Investiga tlons. 0urrent edition &pproved Sept. 11, 1984 Published November 1984. Ol, lg~-~,ll~' publish~ as DI586--~ST. Last previous edition (1974). 2A~n~al Book of ASTM/~t~ndards, V01 04.05. 6.1 Drilling Rqulpment---Any dril- ling equipment that provides at the time of sampling a suitably clean open hole before insertion of the sampler and ensures that the penetration test ls performed on undisturbed soft shall be aceeptabls. The following pieces of equipment have proven to be suitable for advancing a borehole in some sub- su~fa~e conditions. 5.1.1 Drag, Chopping, and Fishtail Bits, less tb_~n 6.§ in. (162 mm) and gr~tter th~n 2.2 111. (56 mm) in diamet- er m~y be used In co~unotion with open-hole rotary drilling or casing- advanoemen~ drilling me,hods. To avoid disturbance of ~he underlying soil, ~t~m ~c~ge bl~ are not ~r- mit~d; o~ side dMchar~g bits a~e 5.1.2 Roller,one Bits, less th~ 6.5 ~. (162 mm) ~d ~ea~r than (56 mm) ~ di~e~r may be used co,unction with open-hole rotary dr~g or casing-advancement ~ill- lng methods ff the drill~g fluid dis- c~ge M deflec~d. 5.1.3 Hollow-Stem Continuous Fl~ht Augers, ~th or without a cen- ~r bit ~semb~, may be used the ~. ~e ~ide ~e~r of the hoHow-s~m a~ers sh~l be less than 6.5 ~. (162 mm) and ~ea~r th~ 2.2 ~. (56 mm). 5.1.4 Solid, Continuous Flight, Bucket ~d ~d A~ers, less ~ 6.5 ~. (162 mm) ~d ~ea~r th~ (56 mm) ~ d~me~r ~ ~ ~ ff ~e soft on ~e side of ~e ~r~ does not cave onto the sampler or sampling r~ d~ s~p~. 8.2 Sampling Hods--Flush-Joint s~el ~ r~ sh~ ~ used ~ ~ect the spllt-ba~el sampler to the ~lve- weight assembly. The sampl~g rod s~ ~ve a st~ness (moment of ~er- tis) equal ~ or ~eater than that of parallel wall 'A' rod (a steel rod w~ch has ~. (41.2 mm) ~d of 1R ~. (28.5 ~m). NOTE l--Recent research and oomp&rative testtng lndlc~e8 the type rod used. with stiffness l~n~ng from 'A' size rod to 'N' size rod, will usually have a negligible effect on the N-values to depth~ of &t lea~t 100 ft (30 m). §.3 Split-Barrel Sampler--The sam- pler shall be constructed with the menslons indicated in Fig. 2. The driv- ing shoe sb;~ll be of hardened steel and shall be replaced or repaired when it A$1'M ue$1gnauon: u lo~ becomes dented or distorted. The use of liners to produce a constant inside diarrleter of 1% in. (35 mm) iS permit- ted, but shall be noted on the penetra- tion record if used. The use of a sample retainer basket is permitted, and should also be noted on the penetra- tion record if used. NOTE 2--Both theory &nd available test d~Lta 8~gest that N-values may increase between 10 to ~;0% when liners a~e used. §.4 Drive-Weight A~sembly: 5.4.1 Hammer and Anvil--The ham- mer shall weigh 140 ± 2 lb (63.5 ± 1. kg) and shall be a solid rigid metallic mass. The h~mmer shall strike the an- vil and make steel on steel contact when it is dropped. A'hammer fall. guide permitting a free fall shall be used. Hammers used with the cathead and rope method shall have an unim- peded overlfft capacity of at least 4 in. (100 mm). For safety reasons, the use of a h;cmmer assembly with an inter- nal anvil is encouraged. NOTE 3---It iS suggested that the h~mraer fall guide be permanently marked to enable the opera- tor or h-~spector to Judge the hammer ch'op height. 5.4.2 Hammer Drop System--Rope- cathead, trip, semi-automatic, or auto- matic hammer drop systems may be used, providing the lifting apparatus will not cause penetration of the sampler while re-engaging and lifting the hammer. 5.5 Accessory Equipment--Acces- sories such as labels, sample contain- ers, data sheets, and groundwater lev- el measuring devlces shall be provlded in accordance wlth the requirements of the project and other ASTM start- 6. Dl~lltn_'l[ Procedure 6.1 The boring shall be advanced in- crementally to permit intermittent or continuous sampling.' Test intervals and locations are normally stipulated by the project engineer or geologist. Typically, the intervals selected are 5 ft (1.5 m) or less in homogeneous strata with test and sampling locations at every change of strata. 6.2 Any drilling procedure that pro- rides a suitably clean and stable hole before Inse~tlon of the sampler and as- sures that the penetration test is per- formed on essentially undisturbed soft sh~ll be acceptable. Each of the follow- lng procedures have proven to be ac- ceptable for some subsurface condi- tions. The subsurface conditions anti- clpated should be considered when se- lecting the drilling method to be used. 6.2.1 Open-hole rotary drilling method. 6.2.2 Continuous flight hollow-stem auger method. 6.2.3 Wash boring method. 6.2.4 Continuous flight solid auger method. 6.3 Several-drilling methods produce unacceptable borings. The process of Jetting through an open tube sampler and then sampling when the desired depth is reached shall not be permit- ted. The continuous flight solid auger method, shall not be used for advanc- ing the boring below a water table or below the upper confining bed of a confined non-cohesive stratum that is under artesian pressure. Casing may not be advanced below the sampling elevation prior to sampling. Advancing a boring with bottom discharge bits is not permissible. It is not permissibl'e to advance the boring for subsequent insertion of the sampler solely by means of previous sampling with the SPT sampler. 6.4 The drilling fluid level within the boring or hollow-stem augers shall be maintained at or above the in sltu groundwater level at all times during drilling, removal of drill rods, and sampling. 7. Sampling and Testing Procedure 7.1 After the boring has been ad- vanced to the desired sampling eleva- tion and excessive cuttings have been removed, prepare for the test with the following sequence of operations. 7.1.1 Attach the spllt-bar~el sampler to the sampling rods and lower into borehole. Do not allow the sampler to drop onto the soil to be sampled. 7.1.2 Posltlon the hammer above and attach the anvil to the top of the sampling rods. This may be done be- fore the sampling rods and sampler are lowered into the borehole. 7.1.3 Rest the dead weight of the sampler, rods, anvil, and drive weight on the bottom of the bering and apply a seating blow. If excessive cuttings are encountered at the bottom of the boring, remove the sampler and sam- pllng ~ds from the bering and remove the cuttings. 7.1.4 Mark the drill rods in three successive 6-in. (0.1 §-m) increments so ghat the advance of the sampler un- der the impact of the hammer can be easily observed for each 6-in. (0.15-m) increment. 7.2 Drive the sampler with blows from the 140-lb (63.5-kg) hammer and count the number of blows applied in each 6-in. (0.15-m) increment until one of the following occurs: 7.2.1 A total of 50 blows have been applied during any one of the three 6-in. (O.15-m) increments described in 7.1.4. 7.2.2 A total of 100 blows have been applied. 7.2.3 There is no observed advance of the sampler during the application of 10 successive blows of the hammer. 7.2.4 The sampler is advanced the complete 18 in. (0.45 m) without the limiting blow counts occurring as de- scribed in 7.2.1, 7.2.2, or 7.2.3. 7.3 Record the number of blows re- quired to effect each 6 in. (O.15m) of penetration or fraction thereof. The first 6 in. is considered to be a seating drive. The sum of the number of blows required for the second and third 6 in. of penetration is termed the 'standard penetration resistance", or the 'N-value". If the sampler is driven less than 18 in. (0.45 m), as permitted in 7.2.1, 7.2.2, or 7.2.3, the number of blows per each complete 6-in. (O. 15-m) increment and per each partial incre- ment shall be recorded on the boring log. For partial increments, the depth of penetration shaft be reported to the nearest 1 in. (25 mm), in addition to the number of blows. If the sampler advances below the bottom of the bor- Ing under the static weight of the drill rods or the weight of the drill rods plus the static weight of the hammer, this information should be noted on the boring log. 7.4 The raising and dropping of the 140-lb (63.5-kg) hammer shall be ac- complished using either of the follow- hug two methods: 7.4.1 By using a trip, automatic, or semi-automatic hammer drop system which lifts the 140-lb (63.5-kg) ham- mer and allows it to drop 30 ± 1.0 in. (0.76 m ± 25 mm) unimpeded. 7.4.2 By using a cathead to pull a rope attached to the hammer. When the cathead and rope method is used the system and operation shall con- form to the following: 7.4.2.1 The cathead shall be essen- tially free of r~dst, oil, or grease and have a dt~meter in the range of 6 to 10 in. (150 to 280 mm). ASTM Designation: D 1586 7.4.2.2 The cathead should be operated at a minimum speed of rota- tion of 100 BPM, or the approximate speed of rotation shall be reported on the boring log. 7.4.2.3 No more than 2~ rope turns on the cathead may be used during the performance of the penetration test, as shown in Fig. 1. NOTE 4--The operator should generally use either 1 ~ of 2~ rope turns, depending upon whether or not the rope comes off the top turns) or the bottom (mZ turns) of the cathead. It ~s generally known and accepted that 2~ or more rope turns considerably impedes the fall of the hammer and should not be used to perform the test. The cathead rope should be mahntained hu a relatively dry, clean, and unfrayed condition. 7.4.2.4 For each hammer blow, a 30-in. (0.76-m) lift and drop shall be employed by the operator. The opera- tion of pulling and throwing the rope shall be performed rhythmically with- out holding the rope at the top of th'e~ stroke. 7.5 Bring the sampler to the surface and open. Record the percent recovery or length of sample recovered. De- scribe the soft samples recovered as to composition, color, stratification, and condition, then place one or more rep- resentative portions of the sample into sealable moisture-proof containers (jars) without ramming or distorting any apparent stratification. Seal each container to prevent evaporation of soil moisture. Affix labels to the con- tainers bearing job designation, bor- ing number, sample depth, and the blow count per 6-in. (0.15-m~ incre- ment. Protect the samples against ex- treme temperature changes: If there is a soil change within the sampler, make a Jar for each stratum and note its location in the sampler barrel. 8. R~port 8.1 Drilling information shall be recorded in the field and shall include the following: 8.1.1 Name and location of job, 8.1.2 Names of crew, 8.1.3 Type and make of drilling machine, 8.1.4 Weather conditions, 8.1.5 Date and time of start and finish of boring, 8.1.6 Boring number and location (station and coordinates, if available and applicable), 8.1.7 Surface elevation, ff available, 8.1.8 Method of advancing and cleaning the boring, 8.1.9 Method of keeping boring open, 8.1.10 Depth of water surface and drilling depth at the time of a noted loss of drilling fluid, and time and date when reading or notation was made, 8.1.11 Location of strata changes, 8.1.12 Size of casing, depth of cased portion of boring, 8.1.13 Equipment and method of driving sampler, 8.1.14 Type of sampler and length and inside diameter of barrel (note use of liners), 8.1.15 Size, type, and section length of the sampling rods, and 8..1 .]~6 Remarks. 8.2 Data obtained for each sample shall~be .recorded in. the field and shall include the following: 8.2.1 Sample depth and, if utilized, the sample number, 8.2.2 Description of soft, 8.2.3 Strata changes within sample, 8.2.4 Sampler penetration and re- covery lengths, and 8.2.5 Number of blows per 6-in. (0.15-m) or partial increment. 9. Precision and Bias 9.1 Variations in N-values of 100% or more have been observed when us- Lug different standard penetration test apparatus and drillers for adjacent borings in the same soil formation. Cu~ent opinion, based on field experi- ence; indicates that when using the same apparatus and driller, N-values in the same soil can be reproduced with a coefficient of variation of about 10%. 9.2 The use of faulty equipment, such as an extremely massive or dam- aged anvil, a rusty cathead, a low speed cathead, an old, oily rope, or massive or poorly lubricated rope sheaves can significantly contribute to differences in N-values obtained be- tween operator-drill rig systems. 9.3 The variability in N-values pro- duced by different drill rigs and opera- tors may be reduced by measuring that part of the hammer energy deliv- ered into the drill rods from the sam- pler and adjusting N on the basis of comparative energies. A method for energy measurement and N-value ad- Justment is currently under develop- ment. (&) oountol~oakwi~e rot~.tlon &pprox~mt~ly l~, turns Ro, pe Operator here Cathead Section A-A (b) elookwlAe ~ot~tlon &pproxlm~tely 2~ turns ODerato~ Sectio~ B-8 FZG. 1 D~finition~ of the Number of Rop~ Turz~ and the An_~14 for (a) Cou~t~z~lockwi~e ~t~on and (b) Clockw~e Rotation of the Oathead OPEN SHOE Hi, AD ROLLPIN ~ B ~ dia~ter) 1.0 to 2.0 in. (25 to 60 mm) 18.0 to ~0.0 I~ (0.487 to 0.7Et2 m) 1.575 ~ 0.006 i~ (154.9~ · 0.1~ ~) 1.~ ~ 0.06 - 0.~ m. (~.1 ~ 1.3 - 0.0 ~) 0.10 ~ 0.02 ~. (2.64 ~ 0.26 ~) 2.~ · 0.05 - 0.~ m. (~.8 ~ 1.~ - 0.0 ~) 18.0' ~ ~.~ ~e 1~ ~. (~8 ~) ~e d~ms~r sp~t ~l ~ ~ ~ ~ a 18-g~e w~ ~c~ess split ~e~. ~e ~n~ end of ~e ~eM~ ~i~y for Te~ ~d M~ ~es no ~sition ~ ~e v~ty of ~.~nt ~ ~se~ ~ ~ion ~ ~. U~ of ~ ~ ~ e~ress~ ~vM~ ~t de~tion of ~e v~ty ~ ~ ~ ~nt r~, ~d ~e ~k of ~ement of ~ ~ ~ ~ ~ ~ion ~t ~ ~e ~ ~8 ~s~ ~ ~mmt~ ~ m~ ~ ~ew~ eve~ five y~ ~ p~ o~ ~. Y~ ~ ~ ~ eider for ~lon of ~ ~ or for ~ ~ ~d s~d ~ ~s~ ~ ~ H~q~. ~ve ~ ~iv~ a f~ h~ y~ eh~d ~e y~ ~ews ~o~ ~ ~e ~ ~ on ~, 1916 ~ ~., P~elp~, ~. 1910~. ~8/89~ STS Subgrade Protection Guideline Care should be exercised to minimize disturbance and degradation of subgrade soils for foundations, slabs-on-grade, pavements and areas to be filled. Water should not be allowed to pond on the surface of exposed subgrade soils, as this could cause a softening of the subgrade, particularly when subjected to construction traffic. Disturbed or softened subgrade soils should be removed to a suitable undisturbed subgrade prior to fill or concrete placement. Wet subgrade conditions may result from precipitation, runoff and groundwater seepage through excavation walls and bottom. Precipitation risk can be minimized by scheduling construction for drier seasons. The subgrade should be sloped to drainage ditches and sumps to minimize water accumulations. Runoff from adjacent areas should be eliminated by use of berms and ditches to channel water away. Groundwater seepage may be minimized by use of dewatering systems such as wells and/or groundwater isolation systems such as cutoff walls or trenches. Dewatering wells and/or groundwater isolation systems are recommended where upward seepage is likely to cause the subgrade to loosen and become "quick" or where lateral seepage may erode the face soil or cause "piping" of fines from the soil matrix as exhibited by muddy or silt laden water. If moisture or disturbance sensitive subgrade soils and wet conditions are expected and construction of faci',ities bearing on the subgrade will not promptly protect the subgrade soils, then consideration should be given to protecting the subgrade by promptly placing appropriate combinations of a geotextile, a gravel base course and a lean concrete mud mat over the prepared and approved subgrade. Geotextiles should be considered for use to separate the subgrade and gravel where subgrade soils are at risk of migrating into the gravel base course. A suitably designed gravel base course should help surcharge the subgrade and act as a drainage layer for removing water accumulations. A lean concrete or flowable fill mud mat with a thickness of several inches or more may be placed directly on the subgrade if upward seepage does not exist. If base drainage is needed, a lean concrete or flowable fill mud mat may be placed over a gravel base course. A mud mat will help to isolate water, provide surcharge against loosening and will provide a stable surface which is resistant to disturbance from construction traffic. Sump and pump systems or dewatering wells should be used to remove any accumulating water or water pressure in the gravel base course. In any areas where unsuitable conditions develop despite protection measures, subgrade stabilization should be performed as described in a separate sheet entitled "STS Subgrade Stabilization Guideline". STS Subgrade Stabilization Guideline Subgrade stabilization may be required if zones of unsuitable soil are encountered upon excavating to the subgrade level or if subgrade degradation occurs from construction traffic, moisture accumulations, freeze-thaw cycles or other causes. Care should always be used to minimize disturbance and degradation of subgrade soils below foundations, slabs-on-grade, pavements and fill areas. Water should not be allowed to pond on the surface of exposed subgrade soils, as this could cause a softening of the subgrade, particularly when subjected to construction traffic. Detrimental groundwater seepage should not be allowed to soften or loosen the subgrade. Unsuitable subgrade soils that are encountered or subgrade soils that become disturbed or softened after exposure should be improved prior to concrete or new material placement. The unsuitable soils should either be properly compacted in place (if feasible based on material type, moisture content and thickness), or over- excavations should extend through the unsuitable soils to remove them to an underlying competent soil stratum. If improvement by over-excavating is performed, footing walls can be extended deeper and supported at the level where suitable soil is encountered. Alternatively, the over- excavations can be backfilled to the design level using either a suitable compacted structural fill material or a flowable cementitious fill. If the over-excavations are backfilled using structural soil fill, the over-excavations should extend a minimum of 1 foot horizontally from each edge of the footing for each foot of fill required below the footing base. The structural soil fill should be placed, compacted and tested in accordance with a separate document entitled STS Earthwork Guideline. Generally, a well-graded granular material is more suitable for stabilization work than cohesive soils. If an open-graded granular material is planned as the backfill and the new subgrade or surrounding soils contain zones of cohesionless fine sands or silts which may migrate into the open-graded backfill, then an appropriately designed geotextile should be utilized to separate the stabilization material from the subgrade and surrounding trench soils. Failure to provide such separation may cause lost ground from surrounding soils and detrimental settlements. Horizontal over-excavation is unnecessary if footing walls are extended to the lower suitable subgrade level or if flowable fill is used to backfill the over-excavated area. FIowable fill should have a sufficient Portland cement and/or fly ash content to achieve 28 day unconfined compressive strengths in the range of 50 to 200 pounds per square inch (psi). STS Earthwork Guideline ~"~ Fill or backfill required on the project should consist of a non-frozen, non-organic granular material, aggregate or natural soil that is free of debris and particles larger than 25 percent of the loose lift thickness. The natural water content of cohesive fill soil at the time of compaction should generally be within -2 to +3 percent of the optimum water content as determined by the Standard Proctor test (ASTM D-698). Difficulty in obtaining the desired degree of compaction is expected for soil that is too dry or too wet. The water content should be adjusted by sprinkling if too dry or by scarifying and aerating if too wet. Blending with an additive such as fly ash or drier soil may also help produce an acceptable water content. Fill or backfill which is relatively uniform should be used on the project. Non-uniform materials or mixing two or more materials will reduce the degree of certainty in the test results and will tend to cause variable compressibility of the fill. Fill or backfill should be placed on a firm, checked subgrade in horizontal lifts with a loose thickness not greater than 12 inches for granular material and 9 inches for cohesive soil. It should then be compacted with equipment that is suited to the soil type and compaction requirements. Normally, vibratory roller or plate compactors are better suited for granular soils, while a sheepsfoot or other "kneading" type of compactors are more effective in cohesive soils. Lighter, hand-propelled compactors should generally be utilized to compact backfill within 5 feet of structures unless the structure is designed to resist expected lateral pressures from use of heavier compactors. When using lighter, hand-propelled compactors, a maximum loose lift thickness of 8 inches should be used for granular material and 6 inches for cohesive soil. Unless stated otherwise in the report text, fill or backfill that supports foundations, floor slabs that are loaded in excess of 400 psf, and roadway pavement that is subjected to concentrated automobile or truck traffic should be compacted to a dry density of 95% or more of the maximum dry density determined by Standard Proctor tests (ASTM D-698) on representative samples of the fill material. Fill or backfill that supports lightly loaded floor slabs, sidewalks or pavement that is subjected to dispersed automobile traffic should be compacted to a dry density of 90% or more of the maximum dry density determined by Standard Proctor tests on representative samples of the fill material. Compaction tests may be considered satisfactory if the average of five consecutive tests on similarly compacted material exceeds the required compaction and no individual test is more than 2% below the required percentage of compaction. Proper compaction is generally difficult to achieve near the edge of a slope or embankment fill due to lack of confinement. For this reason, we recommend that the compacted fill or backfill zone extend horizontally beyond the edge of foundations a minimum of I foot at the subgrade level and then with depth at a minimum slope of 1 horizontal to I vertical. Fill material acceptability, subgrade preparation and testing for suitability, fill placement and fill compaction should be monitored continuously or at least regularly by a qualified soils technician whom reports to the geotechnical engineer for the project. Compaction density for structural fill should be tested at a minimum frequency of once per 5000 ft2 of fill area or once per 200 yd3 of compacted material placed unless stated otherwise in our report. In non-structural fill areas, testing frequencies may be reduced in half. APPENDIX B APPENDIX C MEETING MINUTES DECEMBER 5, 2002 ATTENDEES: Bryan Adams, Elk River Municipal Utilities Pat Klaers, City Administrator Lori Johnson, City Finance Director Terry Maurer, City Engineer RE: WATERMAIN IMPROVMENTS AND COSTS 2003 PAVEMENT REHABILITATION PROGRAM We reviewed the limits of the Pavement Rehabilitation Project and the water improvements anticipated with that project. Essentially, the Elk River Municipal Utilities planned to construct new water lines or larger water lines on all of the streets within the 2003 Pavement Rehabilitation Program. Bryan discussed the issue of non-copper water services, which the Elk River Municipal Utilities anticipates running into on the project. The ERMU's policy regarding non-copper services is that they must be replaced by the homeowner when any work is done on the water service. The issue we discussed was whether or not the City/ERMU undertaking this project constituted work on the service and would require replacement all the way to the house. No clear consensus was reached on this issue. However, it was a clear consensus that the services that are non-copper would be replaced in the street right-of-way to the curb stop on each property where they are encountered. Terry asked Bryan if he could have Dave Berg locate as many curb stops as possible on the project site. Terry explained that he thought is would add to a better bid if we were able to locate curb stops and show them on the plan so that the contractor will have some idea of the working conditions he will find when trying to replace non-copper services. Bryan/Dave Berg to notify Terry when the curb stops are located, and Terry will coordinate a survey crew to pick up that information. Terry indicated if necessary, the survey crew could provide Dave Berg a number of wooden lathes that he could use to locate the curb stops, and then our survey crew could remove the lathe after the location was picked up in the field. Bryan started a discussion on whether or not the utilities commission would want to assess the replacement of the water service from the new watermain to the curb stop. Typically, the water services are considered property of the homeowner and are paid for by the homeowner. Terry indicated that the feasibility has not been finalized yet and adding that to the text of the feasibility study would be a possibility so that the assessments would be legal relative to Minnesota Statute 429. Terry did note that they were not discussed as an accessible item at the informational hearing. There was a general discussion about how to best implement the assessment of the water service lines. The water service lines could clearly be discussed in the improvement hearing; the issue was whether or not to assess everyone for the replacement of their water service at the assessment hearing for the street, or wait until later to determine exactly who got a new service, and have supplemental assessment hearing for water services only. Lori indicated it would be a relatively simple thing to refund the water service assessment for anybody who O:\PROJ\818980J\0030~vlin utes-120502.doc was assessed for a water service but did not actually get a water service replaced. Since Bryan anticipates that most of the services will be non-copper, the general consensus was that it would be better to lump the assessment of the water services in with the street and do a rebate after. Terry indicated to Bryan that there will be a cost associated with the actual assessment of the water services. Terry suggested to Bryan that the services be assessed on a unit cost, rather than trying to determine the actual cost of each service to each individual property. Bryan is going to consider this and discuss it with his Utilities Commission next week and will provide information back to Terry, Pat, and Lori after his Utility Commission meeting. There was a discussion relative to how to determine final costs for the water improvements. Terry went through a discussion with Bryan on identifiable water units, which would be bid in the project, such as temporary water service, water service replacement, water service connection, sodding when outside of the sidewalk area is disturbed due to service installation, and rerouting if necessary of any sanitary sewer services, depending on how their contractor pursues his work. We discussed the sanitary sewer replacement, and Terry indicated they will only be paid if they were in direct conflict with the watermainmif they were removed for the contractor's convenience, he would be liable to pay for the reinstallation to them. Terry talked about the overhead costs for engineering being substantially higher than on typical projects that the City and ERMU have done jointly. The reason for it is the amount of time that will be necessary to spend on service relocations and replacements, together with dealing with homeowners relative to water service. Terry had suggested a percentage of construction costs larger than used in the past to compensate for the increased engineering cost. Bryan suggested that the percentage of engineering be set to cover the plan and specification preparation, bidding and construction administration issues, and that staking and construction inspection be billed directly to Bryan at ERMU and that he would pay those bills himself. That proposal was acceptable to everybody. Terry will suggest a percentage for feasibility plan and specification preparation, construction administration, and 429 process to be used for the ERMU portion of the project. Terry also indicated that there should be some percentage of construction costs that ERMU should pay for the incidentals that a contractor puts into his bid, such as bonding costs, mobilization costs, traffic control costs, etc. It was agreed that Terry would do some further investigations and suggest a percentage to be used for this that could be reviewed and agreed upon. Terry suggested that all of the information be assembled relative to what the utilities want to do, how they want to treat the services, what will be paid for during the construction, and that this information be included in the final feasibility study. Terry then suggested that the City Council could approve the feasibility along with the Utilities Commission, so that there would be no confusion when talking to residents about what the Utilities Commission position on the service replacements and/or assessments of them was or on what the City and ERMU has agreed to relative to reimbursement for construction and overhead costs. O:~PROJ\818980J\0030~Vlin utes-120502.doc ADDENDIX D Informational Meeting Minutes 2003 Pavement Rehabilitation Project November 6, 2002 - 6:00 P.M. Terry Maurer, City Engineer, welcomed those present to the neighborhood meeting regarding the proposed 2003 Pavement Rehabilitation Project. The project includes the reconstruction of six roads as shown on the attached exhibit. (See sign in sheet for those in attendance.) Terry explained how the City has been planning and budgeting for the reconstruction of streets within the old core City for the last couple of years. The City Council took another step forward in the process when they approved a Pavement Rehabilitation Report in October 2002, which set the foundation and standards for all of the projects that would follow. The adopted report calls for planning and design ora project in the even years and construction in the odd years. The typical road section that the City Council has approved includes concrete curb and gutter, sidewalk on both sides of the road where feasible, and addition of street lights. The existing sidewalk within the project area will be replaced with six-foot wide concrete sidewalk. During the feasibility study for the 2003 project it will be determined which areas will have sidewalk added. The sidewalk will not be installed if construction would require the removal of large, mature trees or excessive grading as would be necessary next to the valley on the west side of Norfolk Avenue. Terry then reviewed the estimated project costs. The streets to be reconstructed within the old core City were combined into projects that would result in approximately $1,000,000 in construction and overhead costs. This construction amount includes the street improvements and the addition of storm sewer to correct drainage issues. Any repairs or improvements to the watermain and sanitary sewer will be paid through separate funds. Assessments for the street improvements were determined within the adopted Rehabilitation Report and are currently set at $5,000. The assessments will fund approximately one-third of the project, with the remaining amount being funded by the City. Assessments are based on a per unit basis, with a single-family residential lot that cannot be further subdivided as one unit. Within the proposed project area are businesses and churches that will be assessed more than one unit. A sample assessment schedule was included in the handout. Terry noted that the current repayment period is seven years. On past projects, the City Council has extended the term to ten years for anyone who so desired. After the assessment hearing next year, residents would have 30 days to prepay the assessment in full or a portion. After that date the City will pass the information on to.the County who will act as the collection agency. The assessments will be included with the real estate taxes. Property owners are responsible for their sanitary sewer and watermain service from the main in the street. It was noted that if a property owner wishes to have repairs made to their services in conjunction with the project that they could notify the City and it would be added into the project. Any expenses for the repair woUld be billed to the property owner. Terry also discussed the proposed schedule, noting that the City Council has authorized the preparation of the feasibility report. He also discussed what to expect during construction. A period of questions and answers followed: Question: A resident recently had to replace their individual water service and was charged for repair of the roadway. Will they be assessed again for the roadway improvements? Answer: The timing of the repair is unfortunate but the resident will be assessed for the roadway improvements associated with the project. Question: What is a unit considered for the assessments? Answer: A single-family residence is one unit. A typical residential lot size will be used as a cookie cutter over the church, school, etc to determine how many units will be assessed for those properties. Question: Who is responsible for replacing the water service and individual curb stop? Answer: The individual homeowner is responsible. Question: A resident is located at the corner of 5tn and Rush. How will assessments be handled for corner lots? Answer: A comer lot will be assessed one unit. The property will be assessed when the roadway is improved on either side and will not be assessed for future street improvements. Question: Residents questioned if5th Street could be reconstructed at this time as well. Answer: The project size was determined based on a $1,000,000 project that the City felt they could reasonably fund. At this time there is no plan to reconstruct 5t~ Street as part of this project. Question: How was the first project area chosen and what can be done to speed up the timeframe for reconstruction of a different area? Answer: If a neighborhood petitioned for improvements, the City Council could decide to reconstruct that area as part of subsequent projects in an earlier time frame. Question: A resident asked for clarification on the prepayment period and when notice would be provided Answer: A thirty day period is allowed by law after the assessment hearing to prepay assessments. Formal notice will be provided for the hearing and will include individualized notices with property specific information. Question: A resident asked for clarification on how the assessments were being determined Answer: Each residential lot will be assessed one unit unless according to zoning requirements the lot could be further subdivided. Question: Has the initial survey been completed? Answer: The survey has been completed but soil boring will be taken in the next couple of weeks. Question: The manager of Dairy Queen asked if water could be available at all time. Answer: It is anticipated that if new watermain is installed that the main will be in place and tested prior to service hook ups. Water would not be available during the switch from the old to new main. Question: will everyone get new watermain and sanitary sewer? Answer: No, it will only be replaced or repaired on an as needed basis. Question: Is it possible to hire the Contractor to replace a residential driveway in its entirety? Answer: We can not guarantee that the Contractor will be interested. The project is awarded to the lowest responsible bidder and so it cannot be predetermined. Once the contract is awarded the question will be posed to the Contractor and if interest is shown a contact will be included in a construction newsletter. Question: Will sidewalk be added everywhere? Answer: Sidewalk will only be added where feasible and where it can be installed with little disruption to existing trees and other landscaping. Question: How far from the proposed curb line will the sidewalk be installed? Answer: The back of the sidewalk (the edge closest to the residence) will be installed one foot in from the right-of-way. This allows for an adequate boulevard width for snow storage. This is of course the typical scenario and sidewalk has been installed directly behind the curb for ease of construction. Question: Will Norfolk be widened as part of the construction? Answer: In order to adhere to the typical section adopted by Council it is planned to widen Norfolk slightly. Question: A fence was added at the property on the corner of Rush and 5th. Will it need to be removed if sidewalk is added? Answer: The fence should have been installed within the property limits. The new sidewalk would be constructed within City right-of-way and should not impact the fence unless grade changes are necessary. Question: Will boulevard trees be added? Answer: Boulevard trees are not planned as part of the construction. The City does have a budget for installing trees and it is possible that they could be added at a later date. Question: Will curb and gutter be installed on the reconstructed streets? Answer: Yes, according to the typical section. Question: Is it possible that the project may not continue as planned? Answer: The City Council will need to hold a public hearing and assessment hearing. At any of these times they can decide not to proceed with the project. Question: Will the assessment rate be different from the $5,0007 Answer: It is not anticipated that the amount will change at this time. At this time there were no further questions. Terry stated this information would be provided to the City Council in the form of the feasibility study. Terry also thanked those present for taking the time to discuss this project with staff. The meeting was adjourned. Znformational Meeting City PRO3'ECT NAME: OWNER: bATE OF MEETING: 2003 Street and Utility Zmprovements City of Elk River 6:00 p.m., November 6th, 2002 Name (Print) Mailing Address/Zip Phone No. signin.doc