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HomeMy WebLinkAboutCIRCLE C ADULT RESIDENTIAL SERVICES - PDP190009 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTMay 2, 2016 Nicky Galbraith (nickyinthefort@gmail.com) 2601 South Lemay Ave., #7-108 Fort Collins, Colorado 80525 Re: Geotechnical Subsurface Exploration Lot 2 – East Elizabeth Subdivision Fort Collins, Colorado EEC Project No. 16-01-062 Ms. Galbraith: Earth Engineering Company, Inc. (EEC) personnel have completed the geotechnical subsurface exploration you requested for the proposed multi-plex townhome building to be constructed at Lot 2 in the East Elizabeth Subdivision in Fort Collins, Colorado. Results of the subsurface exploration completed by EEC personnel are provided with this report. We understand the proposed two (2) multi-plex townhome buildings will be non-basement two or three-story wood-frame structures constructed with slabs-on-grade. We expect foundation loads for the structures will be light, with continuous wall loads less than 3 kips per lineal foot and individual column loads less than 50 kips. Small grade changes are expected to develop final site grades for the structure. The purpose of this report is to describe the subsurface conditions encountered in the test borings completed within the approximate building location on the referenced lot and provide geotechnical recommendations for design and construction of foundations and support of floor slabs. The lot is located at the southeast corner of the intersection of Patton and Elizabeth streets in Fort Collins, Colorado. The surrounding site infrastructure, including pavements and utilities, has already been installed. To develop information on existing subsurface conditions in the area of the proposed buildings, four soil borings were extended to a depth of approximately 25 to 35 feet within the approximate building envelopes. The locations of the test borings were established by pacing and estimating angles from site property pins and identifiable site features. The Earth Engineering Company, Inc. EEC Project No. 16-01-062 May 2, 2016 Page 2 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 encountered 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 can be generalized as follows. Brown fine sand materials were encountered at the surface at the boring locations. The fine sand materials were loose to medium dense in consistency, contained a slight amount of clay and exhibited a low potential for swelling with variation in moisture content at current moisture/density conditions. The fine sand materials were underlain by reddish brown sandy lean clay soils at a depth of approximately 13 feet below present site grades. The sandy lean clay soils were very stiff in consistency, contained gravel and exhibited a low potential for swelling with variation in moisture content at current moisture/density conditions. The sandy lean clay soils were underlain by brown sand and gravel materials at a depth of approximately 16 feet below present site grades. The sand and gravel materials were dense to very dense in consistency, contained cobbles and extended to the bottom of borings B-1 and B-3 at a depth of approximately 25 feet below present site grades. The sand and gravel materials encountered at borings B-2 and B-4 were underlain by grey claystone bedrock at a depth of approximately 27 and 25 feet below present site grades at borings B-2 and B-4, respectively. The claystone bedrock was moderately hard in consistency and extended to the bottom of borings B-2 and B-4 at a depth of approximately 35 feet below present site grades. Observations were made at the time of drilling and approximately 24 hours after drilling to evaluate the presence and depth to free water at the test boring locations. At the time of Earth Engineering Company, Inc. EEC Project No. 16-01-062 May 2, 2016 Page 3 drilling, free water was observed at a depth of approximately 19 feet below present site grades at borings B-1 through B-4. Approximately 24 hours after drilling, free water was observed at a depth of approximately 16 feet below present site grades at borings B-1 through B-4. 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 based on hydrologic conditions and 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 borings provide an indication of subsurface conditions at the test locations; however, subsurface conditions may vary in relatively short distances away from the borings. 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 borings appear evident at that time, it may be necessary to re-evaluate the recommendations provided in this report. ANALYSIS AND RECOMMENDATIONS Foundations Based on the materials observed at the test boring locations, it is our opinion the proposed lightly loaded multi-plex townhome structures could be supported on conventional footing foundations bearing on undisturbed natural fine sand materials. For design of footing foundations bearing in the medium dense, low volume-change, fine sand materials, we recommend using a net allowable total load soil bearing pressure not to exceed 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 should include full dead and live loads. Earth Engineering Company, Inc. EEC Project No. 16-01-062 May 2, 2016 Page 4 Exterior foundations and foundations in unheated areas should be located at least 30 inches below adjacent exterior grade to provide frost cover protection. We recommend formed continuous footings have a minimum width of 12 inches and isolated column foundations have a minimum width of 24 inches. 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 settlement of footing foundations designed and constructed as recommended above would be less than 1 inch. If settlement of the proposed structure cannot be tolerated, drilled pier foundations bearing in the deeper sandstone bedrock are recommended. Some zones of loose fine sand materials were observed in the completed borings. Care will be needed to avoid placing structural elements directly on any loose zones of material. Careful observation should be completed prior to placement of foundation concrete to evaluate the bearing materials. If loose zones are observed at that time, reworking of the subgrade or removal and replacement may be necessary to develop suitable foundation bearing. While the site cohesive soils did not exhibit appreciable swell potential with variation in moisture content, moderate consolidation potential was observed in a few of the near surface samples tested. Close observation and testing will be needed to evaluate the volume change characteristics of the in-situ soils at the time of foundation excavation. If moderately to highly compressible soils are observed at that time, reworking of the subgrade or removal and replacement may be necessary to develop suitable foundation bearing. No unusual problems are anticipated in completing the excavations required for construction of the footing foundations. Care should be taken to avoid disturbing the foundation bearing materials. The lean clay soils would be subject to strength loss and instability when wetted and may show some expansion from dry to moist conditions. Dry Earth Engineering Company, Inc. EEC Project No. 16-01-062 May 2, 2016 Page 5 and desiccated soils or soft and wet soils should be removed from the footing excavations prior to placement of foundation concrete. Floor Slab /Flatwork Subgrades After completing all cuts and prior to placement of any floor slabs or fill materials, 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. Fill materials required to develop the floor or exterior improvement subgrades should consist of approved, low-volume change materials which are free from organic matter and debris. Based on laboratory test results, it is our opinion the on-site soils could be used as fill in these areas. Those fill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as recommended for the scarified materials and compacted to at least 95% of the material's standard Proctor maximum dry density. After preparation of the subgrades, care should be taken to avoid disturbing the in-place materials. The lean clay soils may be subject to strength loss and instability when wetted. Soils which are loosened or disturbed by the construction activities would require removal and replacement or reworking in place prior to placement of the overlying improvements. Soils which are excessively dry and/or desiccated should also be reworked to increase moisture content prior to floor slab placement. As a precaution, the floor slabs should be isolated from structural portions of the building to prevent differential movement to those elements causing distress to the structure. We also recommend the garage floor slab be isolated from non-load bearing partitions to help reduce the potential for slab movement causing distress in upper sections of the building. That isolation is typically developed through the use of a voided wall which is suspended from the overhead first floor joist. Care should be taken in door framing, 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. Earth Engineering Company, Inc. EEC Project No. 16-01-062 May 2, 2016 Page 6 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. 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. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings 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. 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 LOT 2 EAST ELIZABETH SUB. FORT COLLINS, CO EEC PROJECT No. 16-01-062 APRIL 2016 LOT 2 - EAST ELIZABETH SUBDIVISION FORT COLLINS, COLORADO PROJECT NO: 16-01-062 DATE: APRIL 2016 LOG OF BORING B-1 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 4/25/2016 WHILE DRILLING 19' AUGER TYPE: 4" CFA FINISH DATE 4/25/2016 AFTER DRILLING 19' SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR 16' SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ FINE SAND (SP) 2 brown CS _ _ 7 8000 15.1 105.5 NL NP 61.8 < 500 psf None loose 4 with a slight amount of clay SS _ _ 3 < 500 15.2 6 _ _ 8 _ _ medium dense CS 10 15 9000+ 5.7 104.0 < 500 psf None _ _ 12 _ _ SANDY LEAN CLAY (CL) 14 reddish brown SS _ _ 15 6000 14.7 very stiff with gravel 16 _ _ SAND AND GRAVEL (SP-GP) 18 brown _ _ dense SS 20 50 -- 11.2 with cobbles _ _ 22 _ _ 24 BS _ _ -- -- 6.8 25' BOTTOM OF BORING 26 _ _ 28 _ _ 30 _ _ 32 _ _ 34 _ _ 36 _ _ 38 _ _ 40 _ _ 42 _ _ 44 _ _ 46 _ _ 48 _ _ 50 LOT 2 - EAST ELIZABETH SUBDIVISION FORT COLLINS, COLORADO PROJECT NO: 16-01-062 DATE: APRIL 2016 LOG OF BORING B-2 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 4/25/2016 WHILE DRILLING 19' AUGER TYPE: 4" CFA FINISH DATE 4/25/2016 AFTER DRILLING 19' SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR 16' SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ FINE SAND (SP) 2 brown _ _ loose 4 with a slight amount of clay CS _ _ 8 9000+ 7.9 95.4 < 500 psf None 6 _ _ 8 _ _ medium dense SS 10 13 2000 6.5 _ _ 12 _ _ SANDY LEAN CLAY (CL) 14 reddish brown CS _ _ 13 8000 17.8 110.4 < 1000 psf None@1000 very stiff with a slight amount of gravel 16 _ _ SAND AND GRAVEL (SP-GP) 18 brown _ _ dense SS 20 50 -- 11.9 with cobbles _ _ 22 _ _ 24 BS _ _ -- -- 10.2 26 _ _ 28 CLAYSTONE _ _ grey 30 moderately hard _ _ 32 _ _ 34 BS _ _ -- -- 25.4 35' BOTTOM OF BORING 36 _ _ 38 _ _ 40 _ _ 42 _ _ 44 _ _ 46 _ _ 48 _ _ 50 LOT 2 - EAST ELIZABETH SUBDIVISION FORT COLLINS, COLORADO PROJECT NO: 16-01-062 DATE: APRIL 2016 LOG OF BORING B-3 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 4/25/2016 WHILE DRILLING 19' AUGER TYPE: 4" CFA FINISH DATE 4/25/2016 AFTER DRILLING 19' SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR 16' SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ FINE SAND (SP) 2 brown CS _ _ 19 9000+ 4.4 106.6 < 500 psf None medium dense 4 SS _ _ 12 3000 6.4 6 _ _ 8 _ _ CS 10 12 9000+ 5.3 97.7 NL NP 49.3 < 500 psf None _ _ 12 _ _ SANDY LEAN CLAY (CL) 14 reddish brown SS _ _ 11 8000 13.6 very stiff with gravel 16 _ _ SAND AND GRAVEL (SP-GP) 18 brown _ _ very dense CS 20 50/6" -- 10.3 with cobbles _ _ 22 _ _ 24 BS _ _ -- -- 13.2 25' BOTTOM OF BORING 26 _ _ 28 _ _ 30 _ _ 32 _ _ 34 _ _ 36 _ _ 38 _ _ 40 _ _ 42 _ _ 44 _ _ 46 _ _ 48 _ _ 50 LOT 2 - EAST ELIZABETH SUBDIVISION FORT COLLINS, COLORADO PROJECT NO: 16-01-062 DATE: APRIL 2016 LOG OF BORING B-4 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 4/25/2016 WHILE DRILLING 19' AUGER TYPE: 4" CFA FINISH DATE 4/25/2016 AFTER DRILLING 19' SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR 16' SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ FINE SAND (SP) 2 brown _ _ medium dense 4 with a slight amount of clay CS _ _ 12 8000 7.0 94.1 < 500 psf None 6 _ _ 8 _ _ SS 10 17 1000 6.5 _ _ 12 _ _ SANDY LEAN CLAY (CL) 14 reddish brown CS _ _ 14 9000+ 14.4 116.5 < 1000 psf None@1000 very stiff with a slight amount of gravel 16 _ _ SAND AND GRAVEL (SP-GP) 18 brown _ _ dense SS 20 50 -- 6.7 with cobbles _ _ 22 _ _ 24 BS _ _ -- -- 10.6 26 CLAYSTONE _ _ grey 28 moderately hard _ _ 30 _ _ 32 _ _ 34 BS _ _ -- -- 25.5 35' BOTTOM OF BORING 36 _ _ 38 _ _ 40 _ _ 42 _ _ 44 _ _ 46 _ _ 48 _ _ 50 SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Fine Sand Sample Location: B-1, S-1 @ 2' Liquid Limit: NL Plasticity Index: NP % Passing #200: 61.8% Beginning Moisture: 15.4% Dry Density: 105.5 pcf Ending Moisture: 21.9% Swell Pressure: < 500 psf % Swell @ 500 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Brown Fine Sand Sample Location: B-1, S-3 @ 9' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 3.7% Dry Density: 104.0 pcf Ending Moisture: 23.4% Swell Pressure: < 1000 psf % Swell @ 500 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Brown Fine Sand Sample Location: B-2, S-1 @ 4' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 5.4% Dry Density: 95.4 pcf Ending Moisture: 30.1% Swell Pressure: < 500 psf % Swell @ 500 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Reddish Brown Sandy Lean Clay Sample Location: B-2, S-3 @ 14' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 17.5% Dry Density: 110.4 pcf Ending Moisture: 18.9% Swell Pressure: < 1000 psf % Swell @ 1000 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Brown Fine Sand Sample Location: B-3, S-1 @ 2' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 3.7% Dry Density: 106.6 pcf Ending Moisture: 21.5% Swell Pressure: < 500 psf % Swell @ 500 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Brown Fine Sand Sample Location: B-3, S-3 @ 9' Liquid Limit: NL Plasticity Index: NP % Passing #200: 49.3 Beginning Moisture: 9.3% Dry Density: 97.7 pcf Ending Moisture: 25.7% Swell Pressure: < 500 psf % Swell @ 500 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Brown Fine Sand Sample Location: B-4, S-1 @ 2' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 5.5% Dry Density: 94.1 pcf Ending Moisture: 26.2% Swell Pressure: < 500 psf % Swell @ 500 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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: Reddish Brown Sandy Lean Clay Sample Location: B-4, S-3 @ 14' Liquid Limit: -- Plasticity Index: -- % Passing #200: -- Beginning Moisture: 15.8% Dry Density: 116.5 pcf Ending Moisture: 20.1% Swell Pressure: < 1000 psf % Swell @ 1000 psf: None Project: Lot 2 - East Elizabeth Subdivision Fort Collins, Colorado Project No.: 16-01-062 Date: April 2016 -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 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