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Home My WebLink AboutFIRE STATION #12, FALCON RIDGE PUD - PRELIMINARY / FINAL - 2-94H - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTUNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Testa' Coarse -Grained Gravels more than Soils more than 50% of coarse 50% retained on fraction retained on No. 200 sieve No. 4 sieve Sands 50% or more of coarse fraction passes No. 4 sieve Fine -Grained Soils Silts and Clays 50% or more Liquid limit less passes the than 50 No. 200 sieve Silts and Clays Liquid limit 50 or more _. Highly organic soils Prim ABased on the material passing the 3-in. (75-mm) sieve Bit field sample contained cobbles or boulders, or both, add 'with cobbles or boulders, or both- to group name. "Gravels with 5 to 120% fines require dual symbols: GW.G1M well -graded gravel with silt GW-GC well -graded gravel with clay GP -GM poorly graded gravel with silt GP -GC poorly graded gravel with clay "Sands with 5 to 12% fines require dual symbols: 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 a., s0 Soil Classification Groupl Group Name' Clean Gravels c Less than 5% fines Cu > 4 and 1 < Cc <3' GW Well -graded gravel` Cu < 4 and/or 1 > Cc > 3' GP Poorly graded gravel' Gravels with n,6 finesines than 12c Fines classify as NIL or NIH GM Sifty graval,G,H more Fines classify as CL or CH GC Clayey gravely"m Clean Sands Less Cu > 9 and 1 < Cc < 3' SW 'b'/ell-graded sand' than 5% fines' Cu < 6 and/or t > Cc > 3' SP Poorly graded sand' Sands with Fines Fines classify as NIL or NIH SNI Sihy sand""' more than 12% fines° Fines Classify as CL or CH Sc Clayey sandc"' inorganic PI > 7 and plots on or above 'A line' CL Lean clay" PI < 4 or plots below 'A' line' NIL Silt`^" organic Liquid limit - oven dried Organic clay'.LN < 0.75 OL Liquid limit - not dried Organic silt'L'"0 inorganic PI plots on or above 'A' line CH Fat clay'A" PI lots below 'A' line MH Elastic Sih'L" organic ,..... Liquid limit - oven dried _ Organic clay',LH.y < 0.75 OH Liquid limit - not dried Organic silt'"'" ilv oreanic matter. dark in color, and organic odor PT Peat sCU'Dw1Dla Cc . (D30)s DLa x Dr, 'If soil contains > 15% sand, add "with sand' to group name. cif fines classify as CL-ML, use dual symbol GC -GM, or SC-SM. 'If fines are organic, add "with organic fines' to group name. 'If soil contains > 15% gravel, add "with gravel" to group name. 'If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. 'If soil contains IS to 299% plus No. 200, add .with sand' or "with gravel', whichever is predominant. 'if soil contains > 300% plus No. 200 predominantly sand, add "sandy" to group name. 'it soil contains > 30% plus No. 200, predominantly gravel, add "gravelly' to group name. "PI > 4 and plots on or above "A" line. OPI < 4 or plots below "A' line. "PI plots on or above "A" line. °PI plots below "A" line. For classlllcatlon at Ilne•gealned soils and Ilnrgrained /lichen of cause. grulnud sails Egaaaon of -A' - line Honroniat at PI . a to LL • 25 s. :J / than PI a 0.731LL - 201 / I e Egaaoon of'u' • line V•rtiul at LL - 16 to Pt 7, ' Ines PI . 0.91LL - 91 � t � I I C\' I' V MHoFtOH / � 1 ; IC full—r i�--..�--MIL II 0 to 16 20 30 40 so 60 70 60 90 100 Ila LIQUID LIMIT ILL) r. DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS:. SS : Split Spoon - 13L" 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 DC : Dutch Cone 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 groundwater. In low permeability soils, the accurate determination of groundwater 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-2437 and 0-2488. Coarse Grained Soils have more 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 < 500 500 - 1,000 .1,001 - 2,000 2,001 - 4,000 4,001 - 8,000 8,001 - 16,000 Consistency Very Soft Soft Medium Stiff Very Stiff Very Hard RELATIVE DENSITY OF COARSE -GRAINED SOILS: N-Blowslft 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. I 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. 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 Cemented Can be broken apart easily with fingers. i. • r y ( N° 4. S FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-22 SHEET 1 OF 1 RIO TYPE: DIETRICH D-50 ;: WATER _ DEPTH ELEV FOREMAN: SICK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D uEEq N mlows.rn QU �rsq MC ivi DD ,w:r, A LIMITS .200 1m SWELL ,nn L %@600PSF u n S" TOP SOIL 8 VEGETATION BROWN SANDY CLAY (CL), moist, soft to medium stiff SS 5 10 12 15.9 BROWN SANDSTONE , slightly hard, friable, highly weathered SS 25/5" 16.0 BOTTOM OF BORING 7- 5". 15 20 25 Earth Engineering Consultants FALCON RIDGE P.U.D. • FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-21 SHEET 1 OF 1 RIG TYPE: DIETRICH D•50 WATER DEPTH ELEV FOREMAN: SOCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D Off E rI N (0(O Ssrl QU IF'6f1 MC IMI DO CKFI A -LIMITS .200 IYI SWELL IPSrI %@600PSF U R 6" TOP SOIL 8 VEGETATION BROWN SANDY CLAY (CL), moist, medium stiff FSS SS 5 21 18.4 26 13 50 10 8 22.5 BROWN SANDSTONE, slightly hard, friable, highly weathered SS 15 25/7" 15.9 BOTTOM OF BORING 10' 7". 20 25 Earth Engineering Consultants FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B•20 SHEET 1 OF 1 RIG TYPE: DIETRICH D•50 WATER DEPTH ELEV_ FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4' CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR NIA SOIL DESCRIPTION TYPE D (FEET) N IBLOw%,PTI QU IP FI MC 4%1 DO IMFI A LIMITS .200 (%I SWELL Inn %Q600nF Ll F, 6" TOP SOIL 8 VEGETATION BROWN SANDY CLAY (CL), moist, stiff SS 5 31 *7000 12.9 _ _ 10 SS BROWN SANDSTONE, slightly hard, friable, highly weathered No Recovery in Sam le SS 25/7" 17.4 15 25/1" BOTTOM OF BORING 10' 1". •CHP 20 25 Larth Ln9lneefln9 uonsUILHntS FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-19 SHEET 1 OF 1 RIO TYPE: DIETRICH D-50 :::..'.::->;..:..-:.:.;. ...,..., WATER DEPTH ELEV_ FOREMAN: SCK START DATE 4/28194 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR 10' SOIL DESCRIPTION TYPE D 6LE0 N 19Wws411 ou IMF MC IYI DD W6I A -LIMITS .200 MI SWELL IMF) %@600PSF u n 6" TOP SOIL 8 VEGETATION DARK BROWN SANDY CLAY (CL), moist, medium stiff Ess SS _ 5 30 16.6 44 22 77 <500 NONE 10 15 20.6 MOTTLED BROWN GRAY -ORANGE ss SANDY CLAY (CL), moist, medium stiff 14 22.5 _ _ 15 BROWN SANDSTONE, slightly hard, friable, highly weathered ss 25/6" 1 17.7 BOTTOM OF BORING 14' 6". 20 25 Earth Engineering Consultants A FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-18 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 WATER DEPTH ELEV FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4- CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D IFEE rI N 10'l S,Frl OU ^FI MC M, DO IK11 A LIMITS .200 c.I SWELL Inn %0600PSF u n 6" TOP SOIL &VEGETATION BROWN CLAYEY SAND (SP), moist, medium dense _ _ 5 LIGHT BROWN GRAVELLY SAND (SP), SS moist, medium dense 28 5.0 10 LIGHT BROWN SANDY CLAY (CL), moist, medium stiff SS 19 7.3 _ _ _ 15 BROWN SANDSTONE, slightly hard, friable, highly weathered L.SS BOTTOM OF BORING 12' 1". 25/1" 20 25 tarin tnglneenng "nsulcanw FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-17 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 ;::' WATER DEPTH ELEV_ FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING ONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING ONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D (FEET) N 48LOwi6'1, GU inn MC iaE DD iKn A UMITS .200 00 sweu invi %@600PSF LL 6" TOP SOIL 8 VEGETATION AS BROWN SANDY CLAY (CL), moist, medium stiff SS 5 6.0 10 18 5.5 15 20 BROWN SANDSTONE, slightly hard, friable, highly weathered S 2611" 4.4 BOTTOM OF BORING 1T 1". 25 tarin engineering uonswidnis FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-1 6 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 .......`......::........::...::.:....::....::.;:::.........;::::::.'' WATER DEPTH ELEV_ FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D 6EEE1 N IOLO S:FII QU ,n111 MC 1%, DD JKFI A -LIMITS .200 i%i SWELL wsn %@600PSF U n 6" TOP SOIL &VEGETATION BROWN CLAYEY SAND (SP), moist, medium stiff SS 5 22 5.7 _ _ _ 10 BROWN SANDSTONE, slightly hard, friable, highly weathered 25/3" 8.3 SS BOTTOM OF BORING 9' 3". 15 20 25 Earth Engineering Gonsultants FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-15 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 ...:.;.?� WATER DEPTH ELEV FOREMAN: SICK START DATE 4/28/94 WHILE DRILLING NONE _ AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D IRV) N 1810W&Fq OU IMF) MC I%I DO ,ron A -LIMITS •200 011 SWELL MFj 1,6@600PSF u n 6" TOP SOIL 8 VEGETATION Ess BROWN SANDSTONE, slightly hard to hard, friable, highly weathered 5 25/5" 8.1 10 25/1" 7.4 SS BOTTOM OF BORING 8- 1". 15 20 25 Earth Engineering 4onsultants FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-14 SHEET 1 OF 1 RIG TYPE: DIETRICH 0-50........:..:::...........;..::.::.:;...::.-. ....; ... WATER DEPTH ELEV FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28194 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D IFEETI N (BLO SIFT) QU inn MC Irl OD QCFl ALIMITS -200 111 SWELL inn %@600PSF LL % 6" TOP SOIL & VEGETAION BROWN CLAYEY SAND (SP), moist, medium dense Ess _ _ _ 5 19 4.9 BROWN SANDY CLAY (CL), moist, medium stiff SS 13 5.6 BROWN CLAYEY SAND (SP), moist, medium dense SS _ 10 28 4.9 BROWN SANDSTONE, slightly hard, friable, highly weathered _ _ 15 BOTTOM OF BORING 12 FEET. 20 25 FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-13 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 WATER DEPTH ELEV__ FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4128194 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR 0' SOIL DESCRIPTION r/PE D IFEEtI N IBLO Wy) QU '1 F) MC IMI DO IKFI A -LIMITS 300 Iwl SWELL (P h %Q600PSF LL T 6" TOP SOIL 8 VEGETATION SS LIGHT BROWN SANDY CLAY (CL), moist, medium stiff [SS _ _ 5 33 *6000 3.8 27 9 50 <500 NONE 15 '3500 4.2 _ _ _ _ 10 BROWN SANDSTONE, slightly hard, friable, highly weathered BOTTOM OF BORING 9' 3". SS •CHP 2513" 9.0 15 20 25 tarn tngfneenng uonsunams FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-12 SHEET 1 OF 1 RIG TYPE: DIET RICH D-50 %<::: W ATER DEPTH E LEV FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D OECT) N IOLO S'"l OU IPYiI MC INI DD (MF) A LIMITS •200 INI SWELL I�,LI %n@600PSF LL n 6" TOP SOIL-9 VEGETATION LIGHT BROWN SANDY CLAY (CL), moist, medium stiff _ _ 5 LIGHT BROWN CLAYEY SAND (SP), moist, medium dense [Ss 18 4.7 19 3.9 10 LIGHT BROWN SANDY CLAY (CL), moist, medium stiff F 17 4.2 _ _ _ 15 BROWN SANDSTONE, slightly hard, friable, highly weathered Ss 28/8" 9.9 BOTTOM OF BORING 14' 8". 20 25 twin tngineenng t,onsuliants FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-11 SHEET 1 OF 1 RIO TYPE: DIETRICH D-50 WATER DEPTH ELEV_ FOREMAN: SICK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D Iaf cn N ,elows,v11 OU ,vsn MC IxI DD mcn A -LIMITS .200 SWELL %0600PSF u 6" TOP SOIL & VEGETATION LIGHT BROWN SANDY CLAY (CL), Fss moist, medium stiff _ 5 17 4.2 22 6 43 <500 NONE MEDIUM BROWN SANDY CLAY (CL), SS moist, medium stiff 23 4.9 _ _ 10 BROWN SANDSTONE, slightly hard, friable, highly weathered SS BOTTOM OF BORING 9- 3" 2513" 7.0 15 20 25 Earth Engineering Gonsuitants FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-10 SHEET 1 OF 1 .,. RIG TYPE: DIETRICH D-50 FOREMAN: SCK AUGER TYPE: 4" CFA SPT HAMMER: MANUAL SOIL DESCRIPTION TYPE .. .,_..: START DATE FINISH DATE SURFACE ELEV D N GU 6FE11 m,owsRn inn ......, ..; :> 4/28/94 4/28/94 MC DO ,*1 n:n WATER WHILE DRILLING AFTER DRILLING 24 HOUR A-UMITS 300 u n — _ DEPTH ELEV NONE NONE NIA Swell nsn %@600PSF 6" TOP SOIL S VEGETATION _ SS 2816" 8.6 5 BROWN SANDSTONE, slightly hard, friable, highly weathered SS _ _ 2511" 6.28 BOTTOM OF BORING 8' 1". 10 15 20 25 r_ rol UI cnyu"c 'u.y--- -..--•- No Text ' FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-8 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 .........:::::..:.: - '' WATER DEPTH ELEV FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4128/94 AFTER DRILLING NONE-- SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A SOIL DESCRIPTION TYPE D IFFEI) N IBLO S5 ) GU 'nn MC M DO 'KFl A -LIMITS -200 IA) SWELL 'Nn %@600PSF Ll fY 6" TOP SOIL 8 VEGETATION BROWN TO LIGHT BROWN SANDY CLAY (CL), moist, medium stiff AS _ 5 8.1 BROWN SANDSTONE, slightly hard, friable, highly weathered 2615 1/2" 4.5 SS BOTTOM OF BORING 4- 5". 10 15 20 25 Earth Engineering Consuitants No Text NO: 194201 AUGER TYPE: 4' CFA SPT HAMMER: MANUAL SOIL DESCRIPTION 6" TOP SOIL & VEGETATION BROWN SANDY CLAY (CL), moist, medium stiff BROWN SANDSTONE, slightly hard, friable highly weathered BOTTOM OF BORING 4' 2". FALCON RIDGE P.U.D. FORT COLLINS, COLORADO FINISH DATE 4/LifF��a SURFACE ELEV D N GU MC DD YPE IFEEII 18Ll Sn) IMF) 1%1 IICFl SS 21 9.7 SS _ 26/2" 7.6 5 10 15 20 DATE: APRIL 1994 SHEET 1 OF 1 4TER TH ELEV RILE DRILLING NE tNONE :TER DRILLING HOUR p LJMITS .20p EE n I%1 A SWELL Imn %@600F 29 12 I 44 <500 I NONE Earth Engineering Consultants FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-5 SHEET 1 OF 1 RID TYPE: DIETRICH D-50 �:.:.::.'.::> ..:... -c:; ...... i WATER DEPTH ELEV FOREMAN: SICK START DATE 4/28194 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4/28194 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR NIA SOIL DESCRIPTION TYPE D oim N IBI OWSO TI OU Inn MC Ixl DD IICFI A-UMITS .200 I%I SWELL Inn %@600PSF ll N 6" TOP SOIL & VEGETATION SS BROWN SANDSTONE, slightly hard triable, highly weathered AS 5 7.2 BOTTOM OF BORING 4 FEET. 10 15 20 25 Earth Engineering L.onsunams • FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-4 SHEET 1 OF 1 C D •50 • DIETRI H O TYPE: RI TY ` START DATE`'` FINISH DATE SURFACE ELEV :f:`: WATER R DEPTH ELEV 4/28/94`, 4/28/94 WHILE DRILLING AFTER DRILLING 24 HOUR NONE NONE-- 9' 3" FOREMAN: SCK AUGER TYPE: 4" CFA SPT HAMMER: MANUAL SOIL DESCRIPTION TYPE D JFEETI N Nlow5IR1 OU m5Fl MC 1%1 DD Imn A-UMrs .200 IXI MELL Imn %0600PSF EE R 6" TOP SOIL 8 VEGETATION SS BROWN SANDY CLAY (CL), moist to wet, soft [Ss _ _ 5 11 •3000 14.5 4 "2000 20.0 _ 10 BROWN SANDSTONE, slightly hard friable, highly weathered SS 25/3" 12.5 BOTTOM OFBORING 9' 3". •CHP 15 20 25 Caren enyulccnny a rj"Qul L,•..a� FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-3 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 >::::........ WATER DEPTH ELEV FOREMAN: SCK START DATE 4128/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA tTYPEIFEET) FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR NIA SOIL DESCRIPTION N tv'O S61I QU IMFI MC M1 DD mn A -LIMITS .200 SWELL M11 %@500PSF u 6" TOP SOIL & VEGETATION BROWN SANDY CLAY (CL), moist medium stiff 5 11.6 SS Ess BROWN SANDSTONE, slightly hard, friable, highly weathered SS 14 20.7 37 15.2 _ 10 2513" 14.1 BOTTOM OF BORING 9' 3". _ 15 20 25 rarLn Engrneenng %1U11SU %aUw ' FALCON RIDGE P.U.D. FORT COLLINS, COLORADO PROJECT NO: 1942016 DATE: APRIL 1994 LOG OF BORING B-2 SHEET 1 OF 1 RIG TYPE: DIETRICH D-50 -':..:...::..:........:::.........:::.':..;::.::::.,,.::.:.,:...:.,....:,...:....:.;...>.::;:.: WATER DEPTH ELEV FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4- CFA FINISH DATE 4/28/94 AFTER DRILLING NONE SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR N/A " SOIL DESCRIPTION TYPE D 6[Frl N ro[ow56f1 QU IMF) MC MI DO IKn A -LIMITS •200 M1 sweu Mn %@600PSF u n 6" TOP SOIL 8 VEGETATION BROWN SANDY CLAY (CL), moist, medium stiff FSS _ 5 16 '4000 11.7 1SS BROWN SANDSTONE, slightly hard, friable, highly weathered SS 25/6" 1 11.7 10 25/3" 11.8 BOTTOM OF BORING 9' 3". •CHP 15 20 25 Earth Engineering uonsultanis ' FALCON RIDGE P.U.D. FORT COLLINS, COLOF ADO DATE: APRIL 1994 PROJECT NO: 1942016 LOG OF BORING B-1 SHEET 1 OF 1 WATER DEPTH ELEV RIG TYPE: DfETRICH D-50 FOREMAN: SCK START DATE 4/28/94 WHILE DRILLING NONE AUGER TYPE: 4" CFA FINISH DATE 4128194 AFTER DRILLING NONE-- SPT HAMMER: MANUAL SURFACE ELEV 24 HOUR NIA D N QU MC DO A -OMITS .200 SWELL SOIL DESCRIPTION inn %@600PSF TYPE lif Efl BLOWS Tl inn IA) Imn P YI 6" TOP SOIL S VEGETATION BROWN SANDY CLAY (CL), SS _ 15 '3500 10.4 moist, medium stiff SS 5 14 '3500 15.8 LIGHT BROWN SANDY CLAY (CL), _ moist, medium stiff 10 BROWN SANDSTONE, slightly SS 58 15.1 hard, friable, highly weathered _ SS 2513" 11.0 15 BOTTOM OF BORING 14' 3". 20 •CHP 25 Earth Fnaineerin(a Consultants No Text Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 10 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 Sandstone Associates 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 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. Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 9 development of uplift loads on the basement slabs, as well as reduce dampness. We would be pleased to provide additional information concerning these systems, if desired. PAVEMENTS At the time of this report, testing of the expected pavement subgrade soils and information concerning anticipated traffic volumes on the site roadways was not available. An addendum report providing recommended pavement sections for this development will be provided once that information is available. OTHER CONSIDERATIONS Care should be taken in excavating below grade trenches for the installation of site utilities, particular in the northeast portion of the site. Stable side slopes should be developed in accordance with OSHA guidelines for open excavations. Auger refusal on well cemented sandstone was encountered at many of the test boring locations. Consideration should be given to the potential for difficult excavation. Blasting could be required in some areas of the site. 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 between borings or 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 Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 8 soils. Subgrade soils and bearing soils allowed to become wet and softened subsequent to construction could result in additional settlement of the foundations. FLOOR SLAB AND PAVEMENT SUBGRADES All existing vegetation and/or topsoil should be removed from beneath the building and roadway areas. After stripping and completing all cuts and prior to placement of any fill, floor slabs or pavements, we recommend the exposed subgrades be scarified to a minimum depth of 9-inches, adjust moisture content and compacted to at least 95 % of the materials' maximum dry density as determined in accordance with 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 for cohesive soils and to a workable moisture for granular soils. Higher silt content soils may be encounter in the subgrade soils and although those materials may be considered to be cohesive, it may be necessary to lower the required moisture content to develop stable subgrades. Scarification and compaction of subgrades in the basement areas would generally not be required. Fill required to develop the floor slab and pavement subgrades should consist of approved, low volume change material, free from organic matter and debris. Those soils should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as recommend for scarified soils and compacted to at least 95 % of the materials maximum dry density as determined in accordance with ASTM specification D-698, the standard Proctor procedure. Care should be taken during construction to avoid disturbing the in -place subgrades. Materials which are loosened or disturbed by the construction activities or materials which are dry and desiccated or wet and softened should be removed and replaced or, if possible, reworked in place prior to placement of the floor slabs and pavements. In the basement areas of the structure, we recommend a visqueen vapor barrier or underslab drain system be installed in the area in the northeast portion of the site. The vapor barrier would help reduce wetness in the basement area and the under slab drain system could prevent Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 7 or perimeter drain line be surround by filter fabric to reduce potential for an influx of fines into the system. Backfill placed around the perimeter of the structure should consist of approved, low -volume change material, free from organic matter and debris. Normally, soils with a liquid limit of 40 or less and plasticity index of 18 or less could be used as low volume change fill. Based on the materials observed at the test boring locations, it is our opinion the near surface soils could be used as low -volume change fill. The highly weathered sandstone bedrock could also be used as fill although care would be necessary to see that the bedrock material is thoroughly broken up prior to placement as fill. The well cemented materials would be difficult to break-up and use. The backfill soils adjacent to the below grade walls should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 90% of the materials' standard Proctor maximum dry density. The moisture content of cohesive backfill soils should be adjusted to be within the range of ±2% of standard Proctor optimum moisture. The moisture content of granular materials should be adjusted to a workable moisture. In areas were the backfill soils will support driveways, steps, patios or similar structures, the backfill should be compacted to at least 95 % of standard Proctor maximum dry density. For design of below grade walls where appropriate steps have been taken to eliminate hydrostatic loading, we recommend using an equivalent fluid pressure of 50 pcf. That recommended fluid pressure does not include a factor safety nor an allowance for hydrostatic loads. The lateral load recommendation is based on an "at -rest" distribution. We recommend the walls be appropriately braced or the flooring framing for the first floor in place prior to beginning the backfilling operations. Care should be taken during backfilling to be use lightweight hand or mechanical equipment to prevent putting excessive stress on below grade walls. Point loads adjacent to the below grade walls or surcharging placed near the tops of the walls could add the lateral stressed on the walls. Positive drainage should be developed away from the proposed structures to reduce the amount of infiltration water anticipated and to reduce the potential for wetting of bearing or subgrade Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 6 to the potential for encountering shallow groundwater during the construction of residences in the northeast portion of the site. Based on the observed surface topography, it would be postulated that groundwater enters the site from the north. One method of groundwater control would be to intercept groundwater coming into the site with a french drain system and gravity drain the groundwater from the area. Additional evaluation, including test pits along the north portions of the site should be considered prior to designing that system. As an alternative, use of an areal groundwater drain system, including a drain line constructed beneath the sanitary sewer line and tied in the perimeter drains for the housing, could be considered. That system would require gravity drainage and should be designed in accordance with interim guidelines from the City of.Fort Collins. It is possible that system would be constructed at a shallower depth than would be required for an interceptor system. Additional consideration will need to be given to the groundwater drainage system in final design of the project. BELOW GRADE AREAS Perimeter drain systems should be constructed around all below grade areas to remove water from the adjacent to the below grade walls. Water allowed to pond adjacent to the below grade walls could result in the development of hydrostatic pressures on those walls and would increase the potential for seepage of water into the below grade areas. In general, a perimeter drain system would consist of perforated metal or plastic pipe placed at approximate foundation bearing level around the exterior perimeter of the structure. The drain line should be sloped to a sump system or a groundwater drain system which doesn't have the potential for reverse flow into the system. The perimeter drain line should be surrounded by a minimum of 6-inches of appropriately sized granular filter soil. We recommend the filter soil Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 5 2000 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure; total load implies full dead and live loads. If the foundations for a residence will be supported entirely on the sandstone bedrock, a net allowable total load soil bearing pressure not to exceed 5000 psf could be used for design of the footings. The near surface cohesive soils and high weathered bedrock encountered at this site are essentially nonexpansive and a minimum dead load pressures for the footing foundations sizing would not be required. Exterior foundations and foundations in unheated areas should be located a minimum of 30 inches below adjacent exterior grade to provide frost protection. We recommend formed continuous footings have a minimum width of 16 inches and isolated column foundations have a minimum width of 30 inches. Grade beam foundations (trenched foundations) could be used in the near surface cohesive soils and highly weathered sandstone bedrock. Excavation of the sandstone using trenching equipment may be difficult. If used, we recommend the trenched foundations have a minimum width of 12 inches. Some difficulty may be encountered in completing the excavations required for construction of basement areas in the highly weathered sandstone. Well cemented zones of sandstone were encountered with depth at the test boring locations. In the silty clay areas, care should be taken to avoid disturbing the bearing soils. Materials which are loosened or disturbed by the construction activities, or materials which are extremely wet or dry, should be removed from the foundation excavations prior to placement of the reinforcing steel and foundation concrete. We estimate the long term settlement of footing foundations designed and constructed as recommended above would be small, less than 3/4 inch. GROUNDWATER CONTROL Shallow groundwater is possible in the northeast portion of the site. During test pit excavations, groundwater was encountered in depths as shallow as 3 to 4 feet. Groundwater depths at the time of our exploration were on the order of 9 to 10 feet. Consideration will need to be given J Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 4 at many of the boring locations. The sandstone extended to the bottom of the borings ranging at depths from approximately 4 to 15 feet. The stratification boundaries shown on the boring logs represent the approximate locations of changes in soil and rock types; in -situ, the transition materials may be gradual and indistinct. WATER LEVEL OBSERVATIONS Observations were made while drilling and after completion of the borings to detect the presence and level of free water in the borings. In addition, field slotted 2" diameter PVC piezometers were installed at four (4) boring locations to allow for longer term monitoring of groundwater levels. Groundwater was generally encountered in the northeast area of the project site and was encountered at depths ranging from approximately 9 to 10 feet. The water level measurements at the individual boring locations are indicated on the boring logs. When completing test pits on the site at an earlier date, groundwater was encountered at depths on the order of 4 feet in the same generally vicinity. Based on observation of the surface topography, it would appear the groundwater enters the site from the north as perched groundwater above the site bedrock. Zones of perched or trapped water may be encountered in more permeable zones throughout the near surface site cohesive material. The location and amount of perched water can vary over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. Groundwater levels can also vary over time. ANALYSIS AND RECOMMENDATIONS GENERAL Based on the materials observed at the test locations, it is our opinion the proposed residences could be supported on conventional footing foundations. We recommend those foundations extend through all existing vegetation and/or topsoil and bear in the natural, stiff to very stiff cohesive soils, medium dense granular soils, or underlying highly weathered sandstone bedrock. For design of footing foundation bearing in the near surface soils or underlying highly weathered bedrock, we recommend using a net allowable total load soil bearing pressure not to exceed s Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 3 on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. SITE AND SUBSURFACE CONDITIONS The Falcon Ridge Development will be constructed between Country Club Road and Spalding Lane and to the west of Ford Lane in Fort Collins, Colorado. This parcel is currently used as pasture with a farmstead located on the east edge of the property. Surface vegetation at this site is generally grass and scrubbrush. General site drainage in the area is to the south and the east with maximum difference in ground surface elevations across the site on the order of 15 to 20 feet. Expect for the existing residence, evidence of prior building construction was not observed at the site by Earth Engineering Consultants, Inc. personnel. An EEC field geologist was on site during drilling to direct the drilling activities and maintain a written log of the materials encountered in the test borings. Field classification of the subsurface materials was based on visual and tactual observation of disturbed samples and auger cuttings as well as observation of drilling progress. Final boring logs included with this report may contain modifications to those field logs based on the results of laboratory testing and engineering evaluation. Based on the results of the field borings and laboratory testing, subsurface conditions can be generalized as follows. Approximately 4 to 6 inches vegetation and/or topsoil was encountered at the surface at the boring locations. The topsoil/vegetation was generally underlain by brown or light brown sandy lean clay which was stiff to very stiff. Brown and light brown silty sand was encountered instead of the sandy clay at a few locations. The silty sand was medium dense. At some locations, the overburden soils were not observed. Where encountered, those overburden soils extended to depths ranging from approximately 1 to 15 feet. Tile overburdened soils at the site where underlain by brown and light brown lightly weathered sandstone. The sandstone was poorly cemented to cemented and auger refusal was encountered 1, 1 Earth Engineering Consultants, Inc. Proposed Falcon Ridge P.U.D. May 13, 1994 Page 2 locations of the borings should be considered accurate only to the degree implied by the methods used to make those field measurements. The borings were performed with a truck mounted, rotary -type drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using continuous flight augers and samples of the subsurface materials encountered were obtained using thin -walled tube and split barrel sampling procedures in general accordance with ASTM Specifications D-1587 and D-1586, respectively. In the thin -walled tube sampling procedure, a seamless steel tube with a sharpened cutting edge is pushed into the soil with a hydraulic pressure to obtain a relatively undisturbed sample of cohesive or moderately cohesive material. In the split barrel sampling procedure, a standard 2-inch OD split barrel sampling spoon is driven into the ground by means of a 140 pound hammer falling a distance of 30 inches. The number of blows required to advance the split barrel sampler is recorded and is used to estimate the in -situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and hardness weathered bedrock. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification and testing. Moisture content, dry density, unconfined strength and calibrated hand penetrometer tests were performed, as appropriate, on the recovered samples. Atterberg limits and washed sieve analysis tests were performed on representative portions of selective samples. Swell/consolidation test were also completed on selected samples. One Hveem stabilometer test was completed on a representative portion anticipated pavement subgrade material. Results of the outlined tests are shown on the attached boring logs. 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. The classification of the bedrock was based t M SUBSURFACE EXPLORATION REPORT PROPOSED FALCON RIDGE P.U.D. FORT COLLINS, COLORADO EEC PROJECT NO. 1942016 INTRODUCTION The subsurface exploration for the proposed Falcon Ridge Development near Country Club Road and Ford Lane in Fort Collins, Colorado, has been completed. Twenty-two (22) soil borings extending to depths of approximately 5 to 15 feet below present site grades were advanced to develop information on subsurface conditions in the proposed development area. Piezometers were installed at three (3) of those boring locations to allow for longer term monitoring of groundwater levels. Individual boring logs and a diagram indicating the approximate test locations are included with this report. We understand the proposed Falcon Ridge P.U.D. will involve the development of approximately 60 single-family housing lots on a 20 acre parcel. The proposed residences are expected to be one- and two-story, wood frame structures and will likely contain full basements. Foundation loads for those structures are expected to be light with continuous wall loads..less than 3 kips per lineal foot and column loads less than 30 kips. Floor loads will be less than 100 psf. Except for the basement excavations, it is expected the grade changes required to develop the final site grades will be less than 2 feet. The purpose of this report is the describe the subsurface conditions encountered in the borings, analyze and evaluate the test data and provide geotechnical recommendations concerning design and construction of the foundations and support of floor slabs and pavements. EXPLORATION AND TEST PROCEDURES The boring locations were determined and established in the field by Earth Engineering Consultants, Inc. (EEC) personnel. The field locations were determined by pacing and estimating angles from the site features indicated on the attached boring location diagram. The May 13, 1994 Sandcreek Associates 2002 Rollingwood Drive Fort Collins, Colorado 80525 Attn: Mr. Pete Sherman Re: Subsurface Exploration Report Proposed Falcon Ridge P.U.D. Fort Collins, Colorado EEC Project No. 1942016 Mr. Sherman: EEC EARTH ENGINEERING CONSULTANTS, INC. Enclosed, herewith, are the results of the Subsurface Exploration you requested for the referenced project. In summary, the near surface soils encountered at this site consist mostly of low plasticity sandy clays. Those materials were underlain by highly weathered to weathered sandstone bedrock. The bedrock was encountered at depths of less than 5 feet in some areas. Based on the materials we observed at the boring locations and the results of laboratory testing of those materials, it is our opinion the proposed residences could be supported on conventional footing foundations. The near surface materials could also be used for direct support of floor slabs and pavements for the development. Difficulty may be encountered in some areas in excavating the weathered sandstone bedrock. Geotechnical recommendations concerning design and construction of the foundations and support of floor slabs and pavements are presented in the text of the attached report. If you have any questions concerning the enclosed 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 L. Litton, P.E. Principal Engineer E. Principal Engineer 2600. Canton Ct, Suite A Fort Collins, CO 80525 (303) 224-1522 FAX 224-4564 SUBSURFACE EXPLORATION REPORT i PROPOSED FALCON RIDGE P.U.D. FORT COLLINS, COLORADO EEC PROJECT 1942016