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Home My WebLink AboutHUNTINGTON HILLS PUD SIXTH - Filed SER-SUBSURFACE EXPLORATION REPORT -SUBSURFACE EXPLORATION REPORT HUNTINGTON HILLS 6T" FILING STREET SUBGRADES FORT COLLINS, COLORADO EEC PROJECT NO. 1972032 D) D EARTH ENGINEERING CONSULTANTS, INC. May 14, 1997 MSP Companies 650 South Cherry Street Suite 435 Denver, Colorado 80222 Attn: Mr. Marc Palkowitsh Re: Subsurface Exploration Report Huntington Hills 6`h Filing - Street Subgrades Fort Collins, Colorado EEC Project No. 1972032 Mr. Palkowitsh: Enclosed, herewith, are the results of the geotechnical subsurface exploration completed by Earth Engineering Consultants, Inc. personnel for the in -place subgrades in the Huntington Hills 6h Filing pavement areas. The pavement design for the roadways will be completed after we receive traffic loading information from City of Fort Collins Engineering Department. 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 Consultants, Inc. Lester t' lt-tM':`P.E. Principal Engineer LLL/dmf Centre For Advanced Technology 2301 Research Boulevard, Suite 104 Fort Collins, CO 80526 970) 224-1522 FAX 224-4564 SUBSURFACE EXPLORATION REPORT HUNTINGTON HILLS 6THFILING STREET SUBGRADES FORT COLLINS, COLORADO EEC PROJECT NO. 1972032 INTRODUCTION May 14, 1997 The subsurface exploration for the in -place street subgrades in the Huntington Hills 6h Filing P. U.D. has been completed. Seven soil borings were advanced in the area of the new streets to develop information on existing subsurface conditions. Individual boring logs and a diagram indicating the approximate boring locations are included with this report. Huntington Hills 6`h Filing is generally located north and east of Fossil Creek Parkway in Fort Collins, Colorado. Overlot grading and utility installation has been completed within the development area. Street subgrades have been cut to approximate final grade and the underground utilities installed in the road right-of-ways. The purpose of this exploration was to define the existing subsurface conditions in the street areas and provide remolded subgrade strength characteristics for use in the pavement design. EXPLORATION AND TESTING PROCEDURES Boring locations were selected and established in the field by Earth Engineering Consultants, Inc. EEC) personnel. Those field locations were established by approximating locations relative to identifiable site features. The locations of the field 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 hydraulic driven drill rig using 4-inch nominal diameter continuous flight augers. Samples of the subgrade materials were obtained from the auger cuttings. Field density testing has previously been completed in the overlot fill and utility backfill areas. Earth Engineering Consultants, Inc. EEC Project No. 1972032 May 14, 1997 Page 2 Moisture content tests were completed in the laboratory for each of the recovered samples. In addition, washed sieve analysis and Atterberg limits tests were performed on selected samples to evaluate the percent and plasticity of the fines in the subgrade. Swell/consolidation tests were performed on a selected sample to establish the soil's tendency to change volume with variation in moisture content. In addition, one Hveem stabilometer R-value test was completed on a composite sample to evaluate the remolded strength characteristics of the site soils. Results of the outlined tests are shown on the attached boring logs and summary sheets. As a part of the testing program, all samples were examined in the laboratory by an engineer and classified in accordance with the attached General Notes and the Unified Soil Classification System, based on the soil's texture and plasticity. The estimated group symbol for the Unified Soil Classification System is shown on the boring logs and a brief description of that classification system is included with this report. SITE AND SUBSURFACE CONDITIONS The Huntington Hills 6h Filing is located generally north and east of Fossil Creek Parkway in Fort Collins, Colorado. At this time, overlot grading and utility installations have been completed on the site. The roads are presently rough cut to approximate subgrade elevation. Field density tests have been completed on the overlot fill and utility backfill. Based on results of the subsurface exploration, subsurface conditions can be generalized as follows. Subsurface soils in the test borings consist of olive brown and light brown lean clays with silt and sand. Those materials are slightly to moderately plastic as indicated from the Atterberg limits tests. Those materials show low swell potential in their in -situ moisture condition. The subsurface soils have low to moderate remolded strength. The cohesive materials extended to the bottom of the borings at depths of approximately 40 feet below top of subgrade. 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. Earth Engineering Consultants, Inc. EEC Project No. 1972032 May 14, 1997 Page 3 Observations were made while drilling and after completion of the borings to detect the presence and depth to free water. No free water was observed in the borings at the time of drilling. Fluctuations in groundwater levels can occur over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. ANALYSIS AND RECOMMENDATIONS The subgrades for the roadways have been prepared in general accordance with the recommendations of our subsurface exploration report for the Huntington Hills 6h Filing. Field density tests have been completed on overlot fill materials and on the utility backfill materials within the roadway areas. Those fill and backfill materials were compacted to at least 95 % of standard Proctor maximum dry density. The subgrade soils in the pavement areas consist of lean clays with low swell potential given their in -situ moisture content. We expect those subgrades could be used for direct support of composite or full -depth asphalt concrete pavement sections. Those pavement sections will be designed after traffic loadings are provided by City of Fort Collins Engineering Department. GENERAL COMMENTS The preliminary 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 between borings or across the site. The nature and extent of such variations may not become evident until further exploration or 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 Earth Engineering Consultants, Inc. EEC Project No. 1972032 May 14, 1997 Page 4 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 MSP Companies 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 reviewed and the conclusions of this report modified or verified in writing by the geotechnical 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 WCL 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: 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. ale- adC a stone:ha a 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 Conelomerate: Well Capablie_oTscratching a knife blade. Cemented Cemented Can be scratched with knife. Poorly Can be broken apart easily with fingers. Cemented UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests' Coarse -Grained Gravels more than Cleans Gravels Less Soils more than 50% of coarse than 5% fines` Cu > 4 and 1 < Cc < 3E 50% retained on fraction retained No. 200 sieve on No. 4 sieve Cu < 4 and/or 1 > Cc > 3E Gravels with Fines Fines classify as ML or MH more than 12% fines` Fines classify as CL or CH Sands 50% or Clean Sands Less Cu > 6 and I < Cc < 3E more of coarse than 5% fines' fraction passes Cu < 6 and/or l > Cc > 31: No. 4 sieve Sands with Fines Fines classify as ML or MH more than 12% fines" Fines classify as CL or CH Fine -Grained Silts and Clays inorganic PI > 7 and plots on or above "A" line Soils 50% or Liquid limit less more passes the than 50 PI < 4 or plots below "A" line No. 200 sieve organic Liquid limit - oven dried Liquid limit - not dried Silts and Clays inorganic PI plots on or above "A" line Liquid limit 50 or more PI lots below "A" line organic Liquid limit - oven dried Liquid limit - not dried Highly organic soils Primarily organic matter, dark in color, and organic odor Based on the material passing the 3-in. (75- Cu=D /D Cc= (D3°) mm) sieve 60 , D X D If field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name. Elf soil contains> 15%sand, add "with sand" to Gravels with 5 to 12% fines require dual group name. symbols: If fines classify as CL-ML, use dual symbol GW-GM well -graded gravel with silt GC -CM, or SC-SM. GW-GC well -graded gravel with clay If fines are organic, add "with organic fines" to GP -GM poorly graded gravel with silt roue name. GP -GC poorly graded gravel with clay If soil contains > 15%gravel, add "with gravel" Sands with 5 to 12% fines require dual to group name. symbols: If Atterberg limits plot in shaded area, soil is a SW-SM well -graded sand with silt CL-ML, silty clay. SW -SC well -graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay 0.7 0.7 Soil Classification Group Group Name" Symbol GW Well -graded gravel GP Poorly graded gravel GM Silty gravel, G, H GC Clayey gravel""" SW Well -graded sand' SP Poorly graded sand' SM Silty sand`,'" SC Clayey sand"" CL Lean clay"Lm IvIL silt',,-, Organic clayKL 1,N 5 OL Organic silt',"" CH Fat clayK,L.1 MH Elastic SiltK L.M Organic clay"," L'' 5 OH Organic siltK•L"1e PT Peat KIf soil contains 15 to 29% plus No. 200, add with sand" or "with gravel", whichever is predominant. Llf soil contains _> 30% plus No. 200 predominantly sand, add "sandy" to group name. If soil contains _> 30% plus No. 200. predominantly gravel, add "gravelly" to group name. PI > 4 and plots on or above "A" line. PI < 4 or plots below "A" line. PI plots on or above "A" line. API plots below "A" line. Fcp cL.R FIeIM.x :< fixE-r,Isbl4 ;t: . HG IM!-GFI.iMEtfF<.:i:w Of avaxec a curt Txex P1 = :.77tLL 2 i e iCu <l LL • 16 +< Fi = I rx I I I 7 L BORING LOCATION DIAGRAM HUNTINGTON HILLS; FORT COLLINS, COLORADO PROJECT NO:1972032 DATE: MAY 1997 EARTH ENGINEERING CONSULTANTS HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-1 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05/05/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 05/05/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV NIA 24 HOUR N/A SOIL DESCRIPTION D N QU MC DO A-IJMITS 200 SWELL LL PI PRESSURE 8 500 PSFTYPEFEET) BLOWS/FT) PSF) PCF) SANDY LEAN CLAY (CL) AS 1 15.8 olive/light brown 2 12.0AS 3 4 5 14.8AS 6 7 8 9 16.2AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Earth Engineering consonants HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-2 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05/05/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 05/05/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N OU MC DD A -LIMITS 200 SWELL LL PI PRESSURE LID 500 PSFTYPEFEET) BLOWS/FT) PSF) PCF) I%) SANDY LEAN CLAY (CL) AS 1 16.3 38 20 86.5 800 psf 0.5 olive/light brown 2 16.5AS 3 4 AS 5 14.6 6 7 8 9 16.4AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Earth Engineering Consultants 1 HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-3 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05/05/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 05/05/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N OU MC DD A.LIMITS 200 SWELL LL PI PRESSURE @ 500 PSFTYPEFEET) BLOWS/FT) PSF) PCF) 1 SANDY LEAN CLAY (CL) AS 1 17.2 olive/light brown 2 15.8AS 3 4 AS 5 16.4 6 7 8 9 17.3AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 Earth Engineering Consultanis I HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-4 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05105/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 05/05/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR NIA SOIL DESCRIPTION D N OU MC DD A -LIMITS 200 SWELL LL PI PRESSURE LID 500 PSFTYPEFEET) BLOWS/FT) PSF) PCF) SANDY LEAN CLAY (CL) AS 1 14.6 olive/light brown 2 13.7 41 20 87.4 600 psi 0.3AS 3 4 AS 5 14.8 6 7 8 9 16.2AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Eartn Engineering uonsultants HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-5 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05/05/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 06/05/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV NIA 24 HOUR N/A SOIL DESCRIPTION D N OU MC DD ALIMITS 200 SWELL LL PI PRESSURE @ 500 PSFTYPEFEET) BLOWS/FT) PSF) I%) PCF) I%) SANDY LEAN CLAY (CL) AS 1 12.9 oliveAight brown 2 15.8AS 3 4 AS 5 16.4 6 7 8 9 17.0AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 tarn tnglneenng t,onsutranis HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-6 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05/05/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 05/05/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV N/A 5 DAYS AFTER DRILLING N/A SOIL DESCRIPTION D N OU MC DD ALIMITS 200 SWELL LL PI PRESSURE 500 PSFTYPEFEET) BLOWSIFT) PSF) PCF) SANDY LEAN CLAY (CL) AS 1 16.2 oliveAight brown 2 14.9AS 3 4 AS 5 15.9 6 7 8 9 17.1AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Earth Engineering Consultants HUNTINGTON HILLS 6TH STREET SUBGRADE FORT COLLINS, COLORADO PROJECT NO: 1972032 DATE: MAY 1997 LOG OF BORING B-7 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: START DATE 05/05/97 WHILE DRILLING None AUGER TYPE: 4" CFA FINISH DATE 05105/97 AFTER DRILLING None SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR NIA SOIL DESCRIPTION D N oU MC DO A -LIMITS 200 SWELL LL PI PRESSURE LID 500 PSFTYPEFEET) BLOWS/FT) PSF) PCF) SANDY LEAN CLAY (CL) AS 1 15.7 34 16 82.4 600 Psf 0.4 olive/light brown 2 12.2AS 3 4 AS 5 13.9 6 7 8 9 12.7AS 10 BOTTOM OF BORING 10' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Earth Engineering Consultants SWELL/CONSOLIDATION TEST RESULTS 12 I 10 i 8 a V) 6 i I 4E 0 c 2 a U U a Water 0 Added C 0 2 0 N CO U 4 6 0.01 0.05 0.1 0.5 1.0 5.0 10.0 Load (TSF) Material Description: Olive/Light Brown Sandy Leon Cloy Sample Location: Boring B-2 @1' Liquid Limit: 38 Plastic Limit: 18 Plasticity Index: 20 Passing 200: 86.5 Beginning Moisture: 17.1% Dry Density. 106.5 pcf Ending Moisture: 21.1% Swell Pressure: 800 psf Swell ® 500 psf 0.5% Project: Huntington Hills 6th St. Project No: 1972032 Fort Collins, Colorado Date: May 1997 SWELL/CONSOLIDATION TEST RESULTS Material 12 10 8 cn 6 c 0 E 4 a 0 c 2 U 0 Added c 0 2 o c0 U 4 6 0.01 0.05 0.1 0.5 1.0 5.0 10.0 Load (TSF) Description: Olive/Light Brown Sandy Lean Clay Sample Location: Boring B-4 p2' Liquid Limit: 41 Plastic Limit: 21 Plasticity Index: 20 90 Passing 200: 87.4 Beginning Moisture: 16.8% Dry Density. 102.7 pcf Ending Moisture: 21.4% Swell Pressure: 600 psf Swell ® 500 psf 0.37 Project: Huntington Hills 6th St. Project No: 1972032 Fort Collins, Colorado Dote: May 1997 L SWELL/CONSOLIDATION TEST RESULTS Material 12 10 8 Cn 6 c 0 4 0 U c 2 U Q 0 Added c 0 2 0 c0 U 4 6 I 0.01 0.05 0.1 0.5 1.0 5.0 10.0 Lood (TSF) Description: Olive/Light Brown Sandy Leon Cloy Sample Location: Boring B-7 @1' Liquid Limit: 34 Plastic Limit: 18 Plasticity Index: 16 Passing #200: 82.4 Beginning Moisture: 16.17 Dry Density. 103.4 pcf Ending Moisture: 18.8% Swell Pressure: 600 psf Swell C? 500 psf 0.4% Project: Huntington Hills 6th St. Project No: 1972032 Fort Collins, Colorado Date: May 1997 2( 15 10 v 1.24 5 100 200 300 400 500 Exudation Pressure SUMMARY OF HVEEM STABILOMETER TEST RESULTS Material: Olive/Light Brown Sandy Leon Clay Test No. 1 2 3 4 Moisture (%) 14.5 17.0 18.4 Density (pcf) 104.7 106.1 104.2 Exudation Pressure R—Value 173 6.7 238 8.6 387 9.7 300 9.0 Project: Huntington Hills 6th Street Subgrades Project No.: 1972032 Fort Collins, Colorado Date: May 1997