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Home My WebLink AboutNITTMAN SUBDIVISION - FDP200008 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTJune 10, 2019 Cassy Moorhead (cassandre.moorhead@gmail.com) 1000 Scenic Drive Fort Collins, Colorado 80526 Re: Geotechnical Subsurface Exploration 1000 Scenic Drive Larimer County, Colorado EEC Project No. 19-01-060 Ms. Moorhead: Earth Engineering Company, Inc. (EEC) personnel have completed the geotechnical subsurface exploration you requested for the proposed single-family residence to be constructed on a parcel located at 1000 Scenic Drive southwest of Fort Collins in Larimer County, Colorado. Results of our subsurface exploration are provided in this report. We understand the proposed single-family residence will be a one or two-story wood frame structure with a full, walk-out basement. We expect foundation loads for the proposed structure would be light with continuous wall loads less than 2.5 kips per lineal foot and individual column loads less than 30 kips. Small grade changes are expected to develop final site grades for the structure. The residence is expected to utilize an individual sewage disposal system (ISDS). The purpose of this report is to describe the subsurface conditions encountered in the test borings and test pits completed within the identified building envelope and provide geotechnical recommendations for design and construction of foundations and support of floor slabs and exterior flatwork. The referenced parcel is located at 1000 Scenic Drive southwest of Fort Collins in Larimer County, Colorado. The referenced building site had slight to moderate slopes toward the south and north with an existing residence located to the east of the proposed building envelope. The site was vegetated at the time of our field work. To develop information on existing subsurface conditions in the area of the proposed residence, two soil borings were extended to depths of approximately 20 to 35 feet below present site grades within the approximate building envelope. Two (2) excavated test pits to a depth of approximately 8 feet below present site grades were advanced in the identified area of the ISDS to develop percolation and Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 2 soil profile information. The locations of the test borings were established by pacing and estimating angles from site property corners and identifiable site features. The locations of the borings should be considered accurate only to the degree implied by the methods used to make the field measurements. The borings were performed using a truck-mounted, CME-55 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers and samples of the subsurface materials were obtained using split- barrel and California barrel sampling procedures in general accordance with ASTM Specification D- 1586. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification and testing. EEC field personnel were on-site during drilling to evaluate the subsurface conditions encountered and direct the drilling activities. Field boring logs were prepared based on observation of disturbed samples and auger cuttings. Based on results of the field borings and laboratory testing, subsurface conditions in the proposed residence location can be generalized as follows. Brown to brown/grey and rust sandy lean clay soils were encountered at the near surface at the boring locations. The sandy lean clay soils were very in consistency and exhibited a low potential for swelling with variation in moisture content at current moisture/density conditions. The moderately plastic sandy lean clay soils contained sand and gravel lenses and were underlain by grey/tan and rust sandstone/claystone bedrock at a depth of approximately 6 and 3 feet below present site grades at borings B-1 and B-2, respectively. The sandstone/claystone bedrock encountered in the borings was moderately in consistency and exhibited a low potential for swelling with variation in moisture content at current moisture/density conditions. The sandstone/claystone bedrock contained cemented sandstone lenses and extended to the bottom of borings at a depth of approximately 20 and 35 feet below present site grades. Observations were made at the time of drilling and 3 days after drilling of the borings to determine the presence and depth to hydrostatic groundwater. At the time of drilling, no free water was observed in the borings completed on this property. Three days after drilling, free water was observed at a depth of approximately 18 feet below present site grades at borings B-1 and B-2. Longer-term observations in holes which are cased and sealed from the influence of surface water would be required to more accurately evaluate groundwater levels and possible fluctuations in those groundwater levels over time. Fluctuations in groundwater levels can occur over time based on hydrologic conditions and Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 3 other conditions not apparent at the time of this report. Zones of perched and/or trapped water may also be encountered in more permeable zones within the subgrade soils at times throughout the year. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil types; in-situ, the transition of materials may be gradual and indistinct. Bedrock classification was based on visual and tactual observations of disturbed samples and auger cuttings; coring and/or petrographic analysis may reveal other rock types. In addition, the soil boring provides an indication of subsurface conditions at the test location; however, subsurface conditions may vary in relatively short distances away from the boring. Potential variations in subsurface conditions can best be evaluated by close observation and testing of the subgrade materials during construction. If significant variations from the conditions anticipated from the test boring appear evident at that time, it may be necessary to re-evaluate the recommendations provided in this report. ANALYSIS AND RECOMMENDATIONS General The near surface site soils observed are comprised of sandy lean clay soils underlain by sandstone/claystone bedrock at a depth of approximately 3 to 7 feet below present site grades. To reduce the potential for differential movement in the foundation and floor slabs subsequent to construction, we recommend all foundation footings extend through the sandy lean clay soils and be constructed to bear directly on the low swell potential sandstone/claystone bedrock. Based on the observed depth to bedrock at the borings, we estimate the depth of the at-grade (i.e. garage) footing foundation bearing levels would be approximately 3 to 7 feet below present site grades resulting in ‘tall’ at-grade (i.e. garage) foundation walls. The near surface site bedrock encountered at the borings generally exhibited a low potential for swelling with variation in moisture content; however, some degree of swelling was observed. Foundation elements supported directly on moderately to highly expansive materials would be expected to experience some post-construction heaving. Presented below are our recommendations for construction of the residence using conventional footing foundations supported directly on the low-swelling site bedrock. It should be noted that construction in areas with expansive soils and bedrock carries with it inherent risks regardless of the foundation type chosen. Those risks include post-construction movement of foundations, floor slabs, exterior flatwork and other site improvements. Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 4 Footing Foundations Based on the materials observed in the test borings, it is our opinion the proposed lightly loaded single-family residential structure could be supported on conventional footing foundations bearing in the moderately hard to hard sandstone/claystone bedrock. We recommend all foundation footings extend through the sandy lean clay soils and be constructed to bear directly on the sandstone/claystone bedrock. For design of footing foundations supported on the low swell potential sandstone/claystone bedrock, we recommend using a net allowable total load soil bearing pressure not to exceed 3,000 psf with a minimum dead load pressure of 1,000 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load includes full dead and live loads. Exterior foundations and foundations in unheated areas should be located at least 30 inches below final adjacent exterior grades to provide frost protection. We recommend formed continuous footings have a minimum width of 12 inches and isolated column foundations have a minimum width of 24 inches. Trenched foundations or grade beam foundations could be used in the sandstone/claystone bedrock. We recommend the foundation footing design loads be balanced to promote relatively uniform settlement, thereby reducing the potential for differential settlement. As an alternative to balancing the design loads solely on settlement, designing the foundation such that the dead-load pressure is balanced throughout the foundations could be considered. Balancing the dead-load pressure would also reduce the potential for differential settlement between adjacent footings. We estimate the long- term movement of footing foundations designed and constructed as recommended above would be less than 1 inch. No unusual problems are anticipated in completing excavations required for construction of the footing foundations. Some difficulty may be encountered in excavating the sandstone/claystone bedrock. Chipping or blasting may be necessary to excavate the cemented or hard portions of the bedrock. Care should be taken during construction to avoid disturbing foundation bearing materials. Foundation bearing materials which are loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced or reworked in place prior to placement of foundation concrete. While the site sandstone/claystone bedrock did not exhibit appreciable swell potential with variation in moisture content, some degree of swelling was observed in the sandstone/claystone bedrock samples tested on this lot. Close observation and testing will be needed to evaluate the volume change Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 5 characteristics of the in-situ soils at the time of foundation excavation. If moderately expansive sandstone/claystone bedrock are observed at that time, drilled pier type foundations along with an interior basement structural floor may be necessary to develop suitable foundation bearing. Groundwater was observed in one of the test borings at a depth of approximately 18 feet below present site grades. We recommend maintaining a minimum vertical separation of at least three feet between foundation bearing elevation and the peak seasonal groundwater levels. Close observation would be needed to evaluate the groundwater depths during the spring and summer months to determine the peak groundwater levels at the site. No unusual problems are anticipated in completing excavations required for construction of the footing foundations. Care should be taken during construction to avoid disturbing foundation bearing materials. Foundation bearing materials which are loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced or reworked in place prior to placement of foundation concrete. Floor Slab /Flatwork Subgrades Any existing vegetation and/or topsoil should be removed from floor slab areas. After stripping and completing all cuts and prior to placement of any floor slabs or fill, we recommend the exposed subgrades be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's maximum dry density as determined in accordance with ASTM Specification D-698, the standard Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the range of ±2% of standard Proctor optimum moisture at the time of compaction. Scarification and compaction of subgrades in the basement area of the structure would not be required. Fill soils required to develop the floor slab subgrades should consist of approved, low-volume change materials which are free from organic matter and debris. It is our opinion the on-site soils could be used as low-volume change fill in the floor areas. The on-site sandstone/claystone bedrock could be used for fill providing those materials are thoroughly broken up prior to use for backfilling. Those fill materials should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as recommended for the scarified soils and compacted to at least 95% of standard Proctor maximum dry density. Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 6 After preparation of the subgrades, care should be taken to avoid disturbing the in-place materials. Subgrade materials loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced or reworked in place prior to placement of the floor slab concrete. As a precaution, the floor slabs should be isolated from structural portions of the building to prevent distress to the structure due to differential movement of the structural elements. We also recommend isolating the basement floor slab from non-load bearing partitions to help reduce the potential for distress in upper sections of the building due to slab movement. That isolation is typically developed through the use of a voided wall which is suspended from the overhead first floor joist. Care should be exercised when framing doors, drywalling and finishing to maintain a voided space which will allow for movement of the floor slab without transmission of stresses to the overlying structure. While laboratory testing completed for this report indicated the site soils sampled exhibited relatively low swell potential, floor slab and exterior flatwork movement could occur and should be expected. Slab movement is common in Colorado even in areas with relatively low-swelling soils. Mitigation techniques to reduce the potential for post-construction movement, such as overexcavation, moisture conditioning and replacement could be considered; however, the risk for slab movement cannot be eliminated. Below Grade Areas We recommend a perimeter drain system be installed around all below grade areas to reduce the potential for development of hydrostatic loads on the below grade walls and to help prevent accumulation of infiltration water in below grade areas. In general, a perimeter drain system should consist of perforated metal or plastic pipe placed at approximate foundation bearing level around the exterior perimeter of the structure. The drainline should be surrounded by a minimum of 6 inches of appropriately sized granular filter soil and either the filter soil or drainline should be surrounded by a filter fabric to help reduce the potential infiltration of fines into the drain system. The drainline should be sloped to provide positive gravity drainage of water to a sump area or gravity outfall where reverse flow cannot occur into the system. Backfill placed adjacent to the below grade walls should consist of approved, low-volume change soils which are free from organic matter and debris. It is our opinion the on-site soils could be used as fill in these areas. The on-site sandstone/claystone bedrock could be used for fill providing those materials are thoroughly broken up prior to use for backfilling. If free draining granular soils are used Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 7 as backfill adjacent to the below grade areas, we recommend the top 2 feet of material be an essentially cohesive material to help reduce the potential for immediate surface water infiltration into the backfill. The backfill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to be at least 95% of the material's maximum dry density as determined in accordance with the standard Proctor procedure. The moisture content of the backfill soils should be adjusted to be within the range of -2 to +2% of standard Proctor optimum moisture. Care should be taken in placing and compacting the wall backfill to avoid placing undue lateral stress on the below grade walls. We recommend compaction using light mechanical or hand compaction equipment. For design of below grade walls where appropriate steps have been taken to eliminate hydrostatic loads, we recommend using an equivalent fluid pressure of 50 pounds per cubic foot. The recommended design equivalent fluid pressure is based on an active stress distribution case where slight rotation is expected in the below grade walls. The rotation expected to develop an active stress distribution case results in deflection on the wall of approximately 0.5% times the height of the wall. That deflection may result in stress cracks on the interior of the basement walls, particularly near the center of spans between corners or other restrained points. The recommended equivalent fluid pressure does not include an allowance for hydrostatic loads nor does it include a factor of safety. Surcharge loads placed adjacent to below grade walls or point loads placed in the wall backfill may add to the lateral pressures of below grade walls. Other Considerations Positive drainage should be developed away from the structure with a minimum slope of 1 inch per foot for the first 10 feet away from the building. Care should be taken in planning of landscaping adjacent to the residence to avoid features which would pond water adjacent to the foundations or stemwalls. Placement of plants which require irrigation system or could result in fluctuations of the moisture content of the subgrade material should be avoided adjacent to the structure. Lawn watering systems should not be placed within 5 feet of the perimeter of the building and spray heads should be designed not to spray water on or immediately adjacent to the structure. Roof drains should be designed to discharge at least 5 feet away from the structure and away from the pavement areas. Site Percolation Tests Two (2) test pits were completed in the identified area of the proposed individual sewage disposal system. The materials encountered in the test pits completed at the approximate proposed leachfield Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 8 consisted of brown sandy lean clay soils underlain by grey/brown and rust claystone bedrock at a depth of approximately 2 to 2½ feet below present site grades which extended to the bottom of the test pits at a depth of approximately 8 feet below present site grades. At the time of excavating, no groundwater was observed in the test pits. EEC personnel noted the ‘limiting zone’ of claystone bedrock was at a depth of approximately 2 to 2½’ below site grades. The near surface site sandy clay soils observed classify as Soil Type 3A and the claystone bedrock observed classify as Soil Type 5. Larimer County Health Department regulations require a percolation rate between 5 and 60 minutes per inch to use a conventional absorption system. Based upon the soils classification of Soil Type 5 percolation rate of greater than 120 minutes per inch should be assumed in the design. Larimer County standards also require that no limiting zone be encountered within 6 feet below ground surface in the area of a conventional absorption field. The test pits completed indicates the near surface site soils do not meet the limiting zone criteria. Based on the results as outlined above, it appears an engineered absorption system would be required for the residence. In siting of the absorption field, Larimer County criteria concerning proximity to drainage ways, property lines and other site features should be addressed. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings and test pits performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations which may occur across the site. The nature and extent of such variations may not become evident until construction. If variations appear evident, it will be necessary to re-evaluate the recommendations of this report. It is recommended that the geotechnical engineer be retained to review the plans and specifications so that comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Ms. Cassy Moorhead for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. In the event that any changes in the nature, design or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are Earth Engineering Company, Inc. EEC Project No. 19-01-060 June 10, 2019 Page 9 reviewed and the conclusions of this report modified or verified in writing by the geotechnical engineer. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report, or if we can be of further service to you in any other way please do not hesitate to contact us. Very truly yours, Earth Engineering Company, Inc. Michael J. Coley, P.E. Principal Engineer DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample ST: Thin-Walled Tube - 2" O.D., unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler - 2.42" I.D., 3" O.D. unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit = 4", N, B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.D. split spoon, except where noted. WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WS : While Sampling WCI: Wet Cave in WD : While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB : After Boring ACR: After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION Soil Classification is based on the Unified Soil Classification system and the ASTM Designations D-2488. Coarse Grained Soils have move than 50% of their dry weight retained on a #200 sieve; they are described as: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are described as : clays, if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse grained soils are defined on the basis of their relative in- place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense (SM). CONSISTENCY OF FINE-GRAINED SOILS Unconfined Compressive Strength, Qu, psf Consistency < 500 Very Soft 500 - 1,000 Soft 1,001 - 2,000 Medium 2,001 - 4,000 Stiff 4,001 - 8,000 Very Stiff 8,001 - 16,000 Very Hard RELATIVE DENSITY OF COARSE-GRAINED SOILS: N-Blows/ft Relative Density 0-3 Very Loose 4-9 Loose 10-29 Medium Dense 30-49 Dense 50-80 Very Dense 80 + Extremely Dense PHYSICAL PROPERTIES OF BEDROCK DEGREE OF WEATHERING: Slight Slight decomposition of parent material on joints. May be color change. Moderate Some decomposition and color change throughout. High Rock highly decomposed, may be extremely broken. HARDNESS AND DEGREE OF CEMENTATION: Group Symbol Group Name Cu≥4 and 1<Cc≤3 E GW Well-graded gravel F Cu<4 and/or 1>Cc>3 E GP Poorly-graded gravel F Fines classify as ML or MH GM Silty gravel G,H Fines Classify as CL or CH GC Clayey Gravel F,G,H Cu≥6 and 1<Cc≤3 E SW Well-graded sand I Cu<6 and/or 1>Cc>3 E SP Poorly-graded sand I Fines classify as ML or MH SM Silty sand G,H,I Fines classify as CL or CH SC Clayey sand G,H,I inorganic PI>7 and plots on or above "A" Line CL Lean clay K,L,M PI<4 or plots below "A" Line ML Silt K,L,M organic Liquid Limit - oven dried Organic clay K,L,M,N Liquid Limit - not dried Organic silt K,L,M,O inorganic PI plots on or above "A" Line CH Fat clay K,L,M PI plots below "A" Line MH Elastic Silt K,L,M organic Liquid Limit - oven dried Organic clay K,L,M,P Liquid Limit - not dried Organic silt K,L,M,O Highly organic soils PT Peat (D30)2 D10 x D60 GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line. GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line. GP-GM poorly-graded gravel with silt PPI plots on or above "A" line. GP-GC poorly-graded gravel with clay QPI plots below "A" line. SW-SM well-graded sand with silt SW-SC well-graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay Silts and Clays Liquid Limit 50 or more CGravels with 5 to 12% fines required dual symbols: Kif soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel", whichever is predominant. <0.75 OH Primarily organic matter, dark in color, and organic odor ABased on the material passing the 3-in. (75-mm) sieve 1000 SCENIC DRIVE LARIMER COUNTY, CO EEC PROJECT No. 19-01-060 MAY 2019 1000 SCENIC DRIVE LARIMER COUNTY, CO EEC PROJECT No. 19-01-060 MAY 2019 1000 SCENIC DRIVE LARIMER COUNTY, CO EEC PROJECT No. 19-01-060 MAY 2019 1000 SCENIC DRIVE LARIMER COUNTY, COLORADO PROJECT NO: 19-01-035 DATE: MAY 2019 LOG OF BORING B-1 RIG TYPE: CME 55 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 5/31/2019 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 5/31/2019 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 3 DAYS AFTER DRILLING 18' SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ SANDY LEAN CLAY (CL) 2 brown to brown/grey/rust CS _ _ 15 9000+ 15.7 124.8 < 500 psf None very stiff 4 silty with sand and gravel lenses SS _ _ 25/10" 5000 10.3 6 _ _ 8 SANDSTONE/CLAYSTONE _ _ grey/tan/rust CS 10 50/7" 9000+ 12.2 125.3 31 16 44.1 2800 psf 1.6% moderately hard _ _ 12 _ _ 14 SS _ _ 50/9" 9000+ 12.1 16 _ _ 18 _ _ CS 20 50/6" 9000+ 14.1 118.6 1800 psf 0.4%@1000 19.5' BOTTOM OF BORING _ _ 22 _ _ 24 _ _ 26 _ _ 28 _ _ 30 _ _ 32 _ _ 34 _ _ 36 _ _ 38 _ _ 40 _ _ 42 _ _ 44 _ _ 46 _ _ 48 _ _ 50 1000 SCENIC DRIVE LARIMER COUNTY, COLORADO PROJECT NO: 19-01-035 DATE: MAY 2019 LOG OF BORING B-2 RIG TYPE: CME 55 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 5/31/2019 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 5/31/2019 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 3 DAYS AFTER DRILLING 18' SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF SANDY LEAN CLAY (CL) _ _ brown 2 silty with gravel _ _ 4 SANDSTONE/CLAYSTONE CS _ _ 50 9000+ 12.8 grey/tan/rust 6 moderately hard _ _ with cemented sandstone lenses 8 _ _ CS 10 50/7" 9000+ 12.5 123.6 2000 psf 1.2% _ _ 12 _ _ 14 CS _ _ 50/7" 9000+ 12.4 123.6 4000 psf 1.1%@1000 16 _ _ 18 _ _ CS 20 50/6" 9000+ 10.9 122.0 2800 psf 0.9%@1000 _ _ 22 _ _ 24 CS _ _ 50/5" 9000+ 9.8 118.9 2600 psf 0.7%@1000 26 _ _ 28 _ _ 30 _ _ 32 _ _ 34 _ _ 35' BOTTOM OF BORING 36 _ _ 38 _ _ 40 _ _ 42 _ _ 44 _ _ 46 _ _ 48 _ _ 50 SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay with Gravel Sample Location: B-1, S-1 @ 2' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 15.2% Dry Density: 124.8 pcf Ending Moisture: 20.2% Swell Pressure: < 500 psf % Swell @ 500 psf: None Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Tan/Rust Sandstone/Claystone Sample Location: B-1, S-3 @ 9' Liquid Limit: 31 Plasticity Index: 16 % Passing #200: 94.1 Beginning Moisture: 12.3% Dry Density: 125.3 pcf Ending Moisture: 14.4% Swell Pressure: 2800 psf % Swell @ 500 psf: 1.6% Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Tan/Rust Sandstone/Claystone Sample Location: B-1, S-5 @ 14' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 11.8% Dry Density: 118.6 pcf Ending Moisture: 14.3% Swell Pressure: 1800 psf % Swell @ 1000 psf: 0.4% Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Tan/Rust Sandstone/Claystone Sample Location: B-2, S-2 @ 9' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 13.0% Dry Density: 123.6 pcf Ending Moisture: 15.5% Swell Pressure: 2000 psf % Swell @ 500 psf: 1.2% Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Tan/Rust Sandstone/Claystone Sample Location: B-2, S-3 @ 14' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 12.8% Dry Density: 123.6 pcf Ending Moisture: 14.8% Swell Pressure: 4000 psf % Swell @ 1000 psf: 1.1% Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Tan/Rust Sandstone/Claystone Sample Location: B-2, S-4 @ 19' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 11.0% Dry Density: 122.0 pcf Ending Moisture: 13.7% Swell Pressure: 2800 psf % Swell @ 1000 psf: 0.9% Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Tan/Rust Sandstone/Claystone Sample Location: B-2, S-5 @ 24' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 9.2% Dry Density: 118.9 pcf Ending Moisture: 13.7% Swell Pressure: 2600 psf % Swell @ 1000 psf: 0.7% Project: 1000 Scenic Drive Larimer County, Colorado Project No.: 19-01-060 Date: May 2019 -10 -8 -6 -4 -2 0 2 4 6 8 10 0.01 0.1 1 10 Percent Movement Load (TSF) Water Added Consolidation Swell 1000 SCENIC DRIVE LARIMER COUNTY, COLORADO PROJECT NO: 19-01-060 DATE: MAY 2019 LOG OF TEST PIT NO. 1 RIG TYPE: BACKHOE SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 5/20/2019 WHILE EXCAVATING None AUGER TYPE: N/A FINISH DATE 5/20/2019 AFTER EXCAVATING None SPT HAMMER: N/A SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF 6" TOPSOIL AND VEGETATION _ _ SANDY LEAN CLAY (CL) 1 brown _ _ Soil Type 3A 2 _ _ CLAYSTONE BS 3 -- -- 19.6 grey/brown/rust _ _ moderately hard 4 Soil Type 5 _ _ BS 5 -- -- 11.7 _ _ 6 _ _ BS 7 -- -- 11.8 hard _ _ 8 8' BOTTOM OF TEST PIT _ _ 9 _ _ 10 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 1000 SCENIC DRIVE LARIMER COUNTY, COLORADO PROJECT NO: 19-01-060 DATE: MAY 2019 LOG OF TEST PIT NO. 2 RIG TYPE: BACKHOE SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 5/20/2019 WHILE EXCAVATING None AUGER TYPE: N/A FINISH DATE 5/20/2019 AFTER EXCAVATING None SPT HAMMER: N/A SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF 6" TOPSOIL AND VEGETATION _ _ SANDY LEAN CLAY (CL) 1 brown _ _ Soil Type 3A 2 BS _ _ -- -- 8.7 33 18 51.2 3 CLAYSTONE _ _ grey/brown/rust 4 moderately hard to hard _ _ Soil Type 5 BS 5 -- -- 10.9 _ _ 6 _ _ BS 7 -- -- 13.5 _ _ 8 8' BOTTOM OF TEST PIT _ _ 9 _ _ 10 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 No. 4 4.75 No. 10 2 No. 40 0.425 No. 200 0.075 Project: City Location: Larimer County, Colorado Project Number: 19-01-060 Date: May 2019 Description: Earth Engineering Company, Inc. Summary of Laboratory Gradation Test Brown Sandy Lean Clay 1000 Scenic Drive Sample Location: TP-2, S-1 @ 2' No. 10 No. 200 51% Sieve Size Percent Passing No. 4 83% 88% No. 40 92% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 100 10 1 0.1 0.01 0.001 Percent Finer by Weight Grain Size in Millimeters Earth Engineering Company Earth Engineering Company Earth Engineering Company Earth Engineering Company ECu=D60/D10 Cc= HIf fines are organic, add "with organic fines" to group name LIf soil contains ≥ 30% plus No. 200 predominantly sand, add "sandy" to group name. MIf soil contains ≥30% plus No. 200 predominantly gravel, add "gravelly" to group name. DSands with 5 to 12% fines require dual symbols: BIf field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name. FIf soil contains ≥15% sand, add "with sand" to Unified Soil ClaSSifiCation SyStem Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests Sands 50% or more coarse fraction passes No. 4 sieve Fine-Grained Soils 50% or more passes the No. 200 sieve <0.75 OL Gravels with Fines more than 12% fines Clean Sands Less than 5% fines Sands with Fines more than 12% fines Clean Gravels Less than 5% fines Gravels more than 50% of coarse fraction retained on No. 4 sieve Coarse - Grained Soils more than 50% retained on No. 200 sieve Silts and Clays Liquid Limit less than 50 IIf soil contains >15% gravel, add "with gravel" to group name JIf Atterberg limits plots shaded area, soil is a CL- ML, Silty clay GIf fines classify as CL-ML, use dual symbol GC- CM, or SC-SM. 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 110 PLASTICITY INDEX (PI) LIQUID LIMIT (LL) ML OR OL MH OR OH For Classification of fine-grained soils and fine-grained fraction of coarse-grained soils. Equation of "A"-line Horizontal at PI=4 to LL=25.5 then PI-0.73 (LL-20) Equation of "U"-line Vertical at LL=16 to PI-7, then PI=0.9 (LL-8) CL-ML Limestone and Dolomite: Hard Difficult to scratch with knife. Moderately Can be scratched easily with knife. Hard Cannot be scratched with fingernail. Soft Can be scratched with fingernail. Shale, Siltstone and Claystone: Hard Can be scratched easily with knife, cannot be scratched with fingernail. Moderately Can be scratched with fingernail. Hard Soft Can be easily dented but not molded with fingers. Sandstone and Conglomerate: Well Capable of scratching a knife blade. Cemented Cemented Can be scratched with knife. Poorly Can be broken apart easily with fingers. Cemented Earth Engineering Company