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Home My WebLink About20082274.tiff • Ill • GEOTECHNICAL ENGINEERING REPORT PROPOSED STRUCTURE ANDERSEN PROPERTIES-WCR 39%AND 64 GREELEY, COLORADO NORTHERN COLORADO GEOTECH PROJECT NO. 101-04 JULY 13, 2004 • Prepared for: Pickett Engineering 808 8th Street Greeley, Colorado 80631 Attn: Mr. Michael Hein 1%0\16_ Northern Colorado Geotech 2956 29th Street, Unit 21 Greeley, Colorado 80631 Phone: (970) 506-9244 Fax: (970) 506-9242 • 2008-2274 • S • Northern Colorado Geotech July 13, 2004 2956 29th Street, Unit 21 Greeley, Colorado 80631 Phone: (970)506-9244 Fax: (970)506-9242 Pickett Engineering 808 8th Street Greeley, Colorado 80631 Attn: Mr. Michael Hein Re: Geotechnical Engineering Report Andersen Properties Northern Colorado Geotech Project No. 101-04 Northern Colorado Geotech has completed a geotechnical engineering exploration for the proposed structure to be located on the strip of land located near Weld County Road 39% and 64, north of Greeley, Colorado. This study was performed in general accordance with our proposal number P04023g dated May 19, 2004. The subsurface soils at the site consisted of sandy lean clay and silty sand with gravel. The results • of our field exploration and laboratory testing indicate that the soils have low expansive potential and low load bearing capabilities. Based on the anticipated construction and the results of our engineering exploration, it is our opinion that the proposed structure may be supported on a spread footing foundation system. Slab on grade may be utilized for the interior floor system. If you have any questions concerning this report or any of our consulting services, please do not hesitate to contact us. Sincerely, NORTHERN COLORADO GEOTECH Prepared by: Lam" f �' Doug Leafgr .G. President _,.- Reviewed by: — Gary G. Weeks, P.E. Vice President • Copies to: Addressee (3) • TABLE OF CONTENTS Page No. Letter of Transmittal SCOPE 1 SITE CONDITIONS 1 PROPOSED CONSTRUCTION 1 SITE EXPLORATION 2 Laboratory Testing 2 SUBSURFACE CONDITIONS 3 Soil Conditions 3 Groundwater Conditions 3 Field Test Results 3 Laboratory Test Results 3 • DESIGN RECOMMENDATIONS 3 Foundation Design 3 Footing Foundations 4 Surface Drainage 4 Floor Slab Design and Construction 5 General Earthwork 6 Site Preparation 6 Fill Materials and Placement 6 GENERAL COMMENTS 7 ATTACHMENTS Boring Location Plan Logs of Borings Laboratory Test Results • GEOTECHNICAL ENGINEERING REPORT PROPOSED STRUCTURE ANDERSEN PROPERTIES-WCR 39Y�AND 64 GREELEY, COLORADO NORTHERN COLORADO GEOTECH PROJECT NO. 101-04 JULY 13, 2004 SCOPE This report contains the results of our geotechnical engineering exploration for the proposed structure to be located near Weld County Roads 39% and 64, north of Greeley, Colorado. This report includes descriptions of, and geotechnical engineering recommendations relative to: • subsurface soil and bedrock conditions • groundwater conditions • foundation design and construction• • drainage • floor slab design and construction • earthwork The recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, and experience with similar soil conditions, structures and our understanding of the proposed project. SITE CONDITIONS The site is located at the south end of an agricultural field. Surface drainage is poor to fair to the east and/or southeast. The property is bordered to the south by railroad tracks. Agricultural fields are located to the north, west and east. An existing residence is located further to the east near Weld County Road 41. PROPOSED CONSTRUCTION As we understand it, the project will likely consist of building a 60 foot by 40 foot slab on grade structure near the western property boundary and determining the soil profile for a railroad spur on the property. • • Pickett Engineering Andersen Properties Northern Colorado Geotech Project No. 101-04 SITE EXPLORATION A total of three test borings were drilled on June 7, 2004. The borings were drilled to approximate depths of 15 feet at the locations shown on the Site Plan, Figure 1. All borings were advanced with a truck-mounted drilling rig, utilizing 4-inch diameter solid stem augers. The borings were located in the field by pacing from property lines and/or existing site features. Relative surface elevations at the boring locations were obtained by interpolation from a topographic map provided by King Surveyors. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used to determine each. Lithologic logs of each boring were recorded by an engineering geologist during the drilling operations. At selected intervals, samples of the subsurface materials were taken by driving split- spoon and/or ring samplers. Standard penetration measurements were recorded while driving a split-spoon and/or ring sampler into the subsurface materials. The standard penetration test is a useful index in estimating the density of the materials encountered. Groundwater conditions were evaluated in each boring at the time of subsurface exploration, and one day after the drilling. Laboratory Testing The samples retrieved during the subsurface exploration were returned to our laboratory for observation by the project manager. The soils were classified in general accordance with the Unified Soil Classification System. At that time, the field descriptions were confirmed or modified and an applicable laboratory testing program was formulated. Boring logs were prepared and are attached with this report. Laboratory tests were conducted on selected samples and are presented on the boring logs and attached laboratory test sheets. The test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. Selected samples were tested for the following engineering properties: • Water Content • Atterberg Limits • Dry Density • Percent Fines • Consolidation • Expansion • Compressive Strength • Resistivity • pH • 2 • Pickett Engineering Andersen Properties Northern Colorado Geotech Project No. 101-04 SUBSURFACE CONDITIONS Soil Conditions Soils at the site generally consisted of sandy lean clay to depths of approximately 6% to 15 feet. The clay soils are underlain by silty sand with gravel in Test Borings 2 and 3. Summary boring logs are attached with this report. Groundwater Conditions Groundwater was not observed in any test boring at the time of field exploration, nor when checked one day after the drilling. These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times, or at other locations. Groundwater conditions can be expected to fluctuate with varying seasonal and weather conditions, and other factors. Field Test Results Field test results indicate that the clay soils vary from medium to stiff in consistency. The sand soils vary from loose to medium dense in relative density. Laboratory Test Results Laboratory test results indicate that the soils have low expansive potential and low load bearing capabilities. DESIGN RECOMMENDATIONS Foundation Design Based on the results of our subsurface exploration and the results of the laboratory testing, it is our opinion that a spread footing foundation system may be used for support of the proposed structure. The footings should be placed on undisturbed soils and/or engineered fill material. Design and construction recommendations for foundation systems and other earth connected phases of the project are outlined below. . 3 • • Pickett Engineering Andersen Properties Northern Colorado Geotech Project No. 101-04 Footing Foundations Based on the results of our subsurface exploration and laboratory testing, it is our opinion that a spread footing foundation system bearing upon undisturbed soil and/or engineered fill may be used for support of the proposed structure. The footings may be designed for a maximum bearing pressure of 1,500 psf. The design bearing pressure applies to dead loads plus design live load conditions. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. Exterior footings should be placed a minimum of 30 inches below finished grade for frost protection and to provide confinement for the bearing soils. Finished grade is the lowest adjacent grade for perimeter footings. Footings should be proportioned to reduce differential foundation movement. Proportioning on the basis of equal total movement is recommended; however, proportioning to relative constant dead- load pressure will also reduce differential movement between adjacent footings. Total movement resulting from the assumed structural loads is estimated to be on the order of 3/4 inch or less. Differential movement should be on the order of 1/2 to 3/4 of the estimated total movement. • Additional foundation movements could occur if water from any source infiltrates the foundation soils; therefore, proper drainage should be provided in the final design and during construction. Foundations and masonry walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities in masonry walls is recommended. Foundation excavations should be observed by Northern Colorado Geotech. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations may be required. Surface Drainage Positive drainage should be provided during construction and maintained throughout the life of the proposed project. Infiltration of water into utility or foundation excavations must be prevented during construction. Planters and other surface features which could retain water in areas adjacent to the building or pavements should be sealed or eliminated. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately 5 percent for at least 10 feet from perimeter walls. Backfill • 4 • Pickett Engineering Andersen Properties Northern Colorado Geotech Project No. 101-04 against footings, exterior walls, and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration. Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when the ground surface beneath such features is not protected by exterior slabs or paving. Sprinkler systems should not be installed within 5 feet of foundation walls. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated. Floor Slab Design and Construction Some differential movement of slab-on-grade floor systems is possible should the subgrade soils become elevated in moisture content. To reduce potential slab movements, the subgrade soils should be prepared as outlined in the earthwork section of this report. Additional floor slab design and construction recommendations are as follows: • Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. • • Control joints should be provided in slabs to control the location and extent of cracking. • Interior trench backfill placed beneath slabs should be compacted in accordance with recommended specifications outlined below. • In areas subjected to normal loading, a minimum 4-inch layer of sand, clean-graded gravel or aggregate base course should be placed beneath interior slabs. • Floor slabs should not be constructed on frozen subgrade. Exterior slabs-on-grade, exterior architectural features, and utilities founded on, or in backfill may experience some movement due to the volume change of the backfill. Potential movement could be reduced by: • minimizing moisture increases in the backfill • controlling moisture-density during placement of backfill • using designs which allow vertical movement between the exterior features and adjoining structural elements • 5 • Pickett Engineering Andersen Properties Northern Colorado Geotech Project No. 101-04 • placing effective control joints on relatively close centers General Earthwork All earthwork on the project should be observed and evaluated by Northern Colorado Geotech. The evaluation of earthwork should include observation and, testing of engineered fill, subgrade preparation, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project. Site Preparation Strip and remove existing vegetation, debris, and other deleterious materials from proposed building and pavement areas. All exposed surfaces should be free of mounds and depressions which could prevent uniform compaction. Stripped materials consisting of vegetation and organic materials should be wasted from the site, or used to revegetate landscaped areas or exposed slopes after completion of grading operations. • If unexpected fills or underground facilities are encountered, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. The individual contractor(s) is responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local, and federal regulations, including current OSHA excavation and trench safety standards. Fill Materials and Placement All exposed areas which will receive fill should be scarified to a minimum depth of eight inches, conditioned to near optimum moisture content, and compacted. The placement of soils on the site should be observed by Northern Colorado Geotech. The fill should be assessed for suitability of use in the proposed fill and tested for placement including compaction percentage and moisture content. • 6 • Pickett Engineering • Andersen Properties Northern Colorado Geotech Project No. 101-04 Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Recommended compaction criteria for engineered fill materials are as follows: Clean on-site soils or approved imported materials may be used as fill material. Imported soils (if required) should conform to the following: Percent fines by weight Gradation (ASTM C136) 6" 100 3" 70-100 No. 4 Sieve 50-100 No. 200 Sieve 60 (max) • Liquid Limit 30 (max) • Plasticity Index 15 (max) • Minimum Percent Material ASTM D698) Scarified subgrade soils 95 On-site and imported fill soils: Beneath foundations 95 Beneath slabs 95 On-site or imported clay soils should be compacted within a moisture content range of 2 percent below, to 2 percent above optimum. Granular soils should be compacted within a moisture range of 3 percent below to 3 percent above optimum unless modified by the project geotechnical engineer. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon data obtained from borings performed to obtain representative subsurface conditions at the site. Variations in the soil • 7 • Pickett Engineering Andersen Properties Northern Colorado Geotech Project No. 101-04 between borings will occur. Northern Colorado Geotech should be present during construction to observe the excavation and construction procedures and confirm or modify our recommendations. The scope of services for this project does not include either specifically or by implication any environmental assessment of the site. This report has been prepared in accordance with generally accepted geotechnical engineering practices in this area at this time. No warranties, either express or implied, are intended or made. • • • 8 i • ! RAILROAD AlMal IIIIIIo.l'' RAILROAD SWITCH �� . RAILROAD SWITCH RAILROAD _ ELECTRIC TRANSFORMER ELECTRIC TRANSFORMER 411 ONo.3 ''— � D �� FENCE �� •_ GAS WELL EQUIPMENT BORING LOCATION PLAN ��-�- ANDERSEN PROPERTY WCRe4 AND 33 1/2 15'VER GREELEY,COLORADO FOR MICHAEL HEIN 4®,CMP DUKE ENERGY WRIT LE�CBOXDGE Northern P'as°N°' 1D1-04 TOP ELEV.4690.9 GAS MARKER ON POST �O�Of2dO sok v=200' Geotech DS: 7-7-04, 28502BIh 8tre54311111 UnR27 a v, �BOB31 Ri°dMr DML alwnx (870 5065244 _ Fer {870;5065242 Rua,. 'I . • II LOG OF BORING No. 1 Sheet 1 of 1 • CLIENT ARCHITECT/ENGINEER Pickett Engineering SITE Weld County Roads 391/2 and 64 PROJECT ' Greeley, Colorado Andersen Properties SAMPLES TESTS o(7 m ur Be a w z X 10 O _ F N Z> W l0 ZW I-ZLL U .-W o! j0 W Z L.0 �Oz a x 3J WW W KW N C os oi=cW) CC CI_ �? a o¢ �U ¢� Ogg Approx. Surface Elev.: 4706.0 ft. a o m z z ?? 2 o a x� a o_a 6"TOPSOIL l':i. 4 1 SS 18 17 0.5 4705.5 -1 SANDY LEAN CLAY Brown to tan, moist, edium to stiff • — s 2 RS 12 21 104 2,500 3,600 ohm-cm 5— • /�f - . 10 3 SS 12 19 10- 1-1 8 4 SS 12 25 15.0 4691.0%/y// t5 �V1 BOTTOM OF BORING • WATER LEVEL OBSERVATIONS Northern AVGoradoSTARTED 6l1/04 FINISHED 6/7/04 wL None wDeotech DRILL co. Drilling Eng DRILL RIG CME-55 a WL None A.B. 2956 29th Street,Unit 21 LOGGED BY DEC APPROVED DML O. Greeley,Colorado 80631 When Checked 1 Day A.B. Phone: 970-506-9244 NCG PROJECT NO. t 01-D4 S Fax: 970-506-9242 LOG OF BORING No. 2 Sheet 1 of 1 • CLIENT ARCHITECT/ENGINEER Pickett Engineering SITE Weld County Roads 39%and 64 PROJECT Greeley,Colorado Andersen Properties SAMPLES TESTS 0 r7 N K BR - n W z -- _ = cb ) id m ≥O H W WW - OZ KW O F CI w O 2> > 0- ' O >U ¢0 5N¢ Approx.Surface Elev.: 4696.0 ft. o0 m z z ?? in D. =I- 5 a. 6"TOPSOIL :*.i 7 1 SS 18 15 ' 0.5 4695.5:.%: j j BANDY LEAN CLAY I Brown to tan, moist, medium to stiff j — 8 2 RS 12 13 115 5,000 33/16/67 , 5- • 7.0 4689.0///// - SILTY SAND WITH GRAVEL • Tan, moist, medium dense ,+ 19 3 SS 12 5 1 10- 22 4 SS 12 2 15.0 4681.0 15 lA BOTTOM OF BORING • WATER LEVEL OBSERVATIONS Northern�olorado STARTED 6/7/04 FINISHED 6/7/04 WL None W.D. Geotech DRILL CO. Drilling Eng DRILL RIG C I ME-55 a WL None A.B. 2956 29th Street,Unit 21 LOGGED BY DBC APPROVED DML o Greeley,Colorado 80631 o• When Checked 1 Day A.B. Phone: 970-506-9244 970-506-9242 NCG PROJECT NO. 101-04 Fax: • lit LOG OF BORING No. 3 Sheet 1 of 1 CLIENT ARCHITECT/ENGINEER • Pickett Engineering SITE Weld County Roads 391/2 and 64 PROJECT Greeley, Colorado Andersen Properties SAMPLES TESTS 0 in 0 in— cc ae n iii w z iu o LL :7,- O0 w ?0 D w aw rl0z a = � CO W Ew y a 02 a~uJ CC W OJ� D a ore 0— KU ¢K CaygE Approx. Surface Elev.: 4695.0 ft. o a m z z ?z 2 o a =i- o.a 0.5 6"TOPSOIL 4694.5:a Via, I 8 1 SS 18 20 SANDY LEAN CLAY � � Brown to tan, moist, medium to stiff — 7 2 RS 12 21 110 2,000 pH 7.2 s- 11) 6.5 4688.5� _ SILTY SAND WITH GRAVEL Tan, moist,loose to medium dense — —( 6 3 SS 12 14 10- 1 IV1 14 4 SS 12 3 - 15.0 4680.0 15 BOTTOM OFBORING • WATER LEVEL OBSERVATIONS AC..orthern STARTED 617/04 FINISHED 6/7/04 Colorado WL None W.D. Geotech DRILL CO. Drilling Eng DRILL RIG CME-55 u• WL None A.B. 2956 29th Street,Unit 21 LOGGED BY DBC APPROVED DML 4 Greeley,Colorado 80631 • When Checked 1 Day A.B. Phone: 970-506-9244 NCG PROJECT NO. 101-04 — Fax: 970-506-9242 0 Ill 3 1 — I — , • H I -2 —. i -1 1 e 1 z 1 c co Li • 3 1 4 - • 51 l i 10 0.1 1 STRESS,ksf Specimen Identification Classification 1 Yd MC% • 1 3.0 Sandy Lean Clay 104 20 - • _ CONSOLIDATION TEST Northern 2956 29th Street,unit 21 Client: Pickett Engineering Number: 101-04 Colorado Greeley,Colorado 60631 Phone: 970506-9244 Project: Andersen Properties r Geotech Fax: 970-506-9242 Location: Weld County Roads 39%and 64 - Hello