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HomeMy WebLinkAboutSANDCREEK ESTATES - MINOR SUBDIVISION - 56-94 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTUNIFIED SOIL CLASSIFICATION SYSTEM Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Group Group Names Symbol Coarse -Grained Soils Gravels - Clean Gravels Cu a 4 and 1 < Cc s 3E GW Well -graded gravelF More than 50% retained on More than 50% of coarse Less than 5% finesc Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF No. 200 sieve fraction retained on No. 4 sieve Fines classify as ML or MH GM Silty gravelF. G, H Gravels with Fines More than 12% finesc Fines classify as CL or CH GC Clayey gravelF, o. H Sands Clean Sands Cu z: 6 and 1 s Cc s 3E SW Well -graded sand' 50% or more of coarse Less than 5% finesE Cu < 6 and/or 1> Cc > 3E SP Poorly graded sand No. 4 sieve Fines classify as ML or MH SM Silty sandG, "•' Sands with Fines More than 12% fineso Fines classify as CL or CH SC Clayey sands• "• Fine -Grained Soils Silts and Clays inorganic PI > 7 and plots on or above "A" line CL Lean clay K L. M 50% or more passes the Liquid limit less than 50 PI < 4 or plots below "A" line ML SIItK, L. M No. 200 sieve Liquid limit — oven dried Organic clayK L. M. N organic < 0.75 OL Liquid limit — not dried Organic silty L. M, o Silts and Clays Inorganic - PI plots on or above "A" line CH Fat clayK I- M Liquid limit 50 or more PI plots below "A" line MH Elastic silty I. M Liquid limit — oven dried Organic clay L, M. P organic < 0.75 OH Liquid limit — not dried Organic silty L, M, o . Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat "aon the material passing the 3-in. Based Bsed s (D��2 Klf sail contains 15 to 29% plus No. 200, add Cu = DdD10 Cc = "with "with whichever is ( sieve. _ sand" or gravel", D x D slf field sample contained cobbles or "with F ° t0 so predominant. If soil contains >_ 15 /° sand, add "with sand" to Llt soil contains >_ 30% plus. No. 200 boulders, or both, add cobbles or boulders, or both" to group name. group name. predominantlysand, add "sandy" to group °Gravels with 5 to 12% fines require dual GG fines classify as CL-ML, use dual symbol GC- name. n GM, or SC-SM. MY symbols: soil contains >_ 30% plus No. 200, "If "with GW-GM well -graded gravel with silt fines are organic, add organic fines" to predominantly gravel, add "gravelly" to group GW-GC well -graded gravel with clay group name. name. GP -GM poorly graded gravel with silt 'If soil contains a 15% gravel, add "with gravel" to "pI > 4 and plots on or above "A" line. GP -GC poorly graded gravel with clay group name. - °PI < 4 or plots below "A" line. °Sands with 5 to 12% fines require dual 'If Atterberg limits plot in shaded area, soil is a CL- PPI plots on or above "A" line. symbols: ML, silty clay. oPl 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 60 50 a x 40 I11 0 Z_ } 30 H U Q 20 a 10 7 4 For classification of fine-grained soils and fine-grained fraction of coarse- - / grained soils 4 Equation of "A" - iHorizontal at PI PI 0.73 `J /�Equation then = of "U" -OQ' Vertical at LL = / G.then Allne�� PI = 0.9 ( MH OR OH / GLOW ML OR OL %' 0 0 10 16 20 30 40 50 60 70 80 90 100 110 LIQUID LIMIT (LL) Form 111-6-85 1 rerracon SUMMARY OF TEST RESULTS Sandcreek Village Project No. 2092-9594 Boring No. Depth (Ft.) Moisture M Dry Density (PCF) Compressive. Strength (Psf) Swell Pressure (Psf) Soluble Sulfates M Liquid Limit M Plasticity Index M Classification AASHTO USCS Resistivity (ohm -cm) N (Blows/Ft) 5 4.0-5.0 10.1 7/12 7.0-8.0 1 15.9 112.7 6390 30 8.0-9.0 15.7 25/12 14.0-14.5 14.0 50/6 6 0.5-1.5 16.9 1 10/12 3.0-4.0 21.0 110.3 2500 4.0-5.0 22.9 2/12 8.0-9.0 26.3 2/12 14.0-14.8 18.4 50/9 7 0.5-1.5 14.7 10/12 3.0-4.0 17.4 104.8 580 4.0-5.0 17.2 4/12 9.0-10.0 12.4 21/12 14.0-14.5 14.0 50/6 0.5-4.0 25.3 8.7 0.8 A-4(I) SUMMARY OF TEST RESULTS Sandcreek Village Project No. 2092-9594 Boring No. Depth (Ft.) Moisture ( k) Dry Density (PCF) Compressive Strength (PSO Swell Pressure (Psf) Soluble Sulfates M Liquid Limit M Plasticity Index M Classification AASHTO USCS Resistivity (ohm -cm) N (Blows/Ft) 1 0.5-1.5 4.1 35/12 3.0-4.0 12.7 108.1 1 235 4.0-5.0 12.2 27/12 8.0-8.6 11.6 640* 50/7 14.0.14.4 13.5 50/5 2 0.5-1.5 5.0 14/12 4.0-5.0 22.0 4/12 7.0-8.0 22.1 107.6 560 8.0-9.0 25.3 4/12 I4.0-15.0 16.6 30/12 3 0.5-1.5 12.8 11/12 3.0-4.0 20.6 102.8 700 22.8 2.6 A-4(0) 4.0-5.0 18.1 5/12 8.0-9.0 20.8 7/12 14.0-15.0 17.5 42/12 4 0.5-1.5 13.4 8/12 3.04.0 21.7 101.3 950 4.0-5.0 22.1 3/12 8.0-9.0 21.5 16/12 14.0-14.5 15.5 .0022 50/6 5 0.5-1.5 10.1 18/12 3.0-4.0 8.4 101.1 1 1630 215 .0150 Kemoiaea aampie RESISTANCE R-VALUE AND EXPANSION PRESSURE OF COMPACTED SOIL RSTM — D 2844 CLIENT: FIRST INTERSTATE BANK PROJECT: SANDCREEK VILLAGE LOCATION OF SAMPLE: 7 @ 0.5 - 4.0 SAMPLE DATA TENT SPECIMEN 1 2 3 COMPACTION PRESSURE - PSI 0 80 110 DENSITY - PCF 110.5 114.3 118.0 MOISTURE - % 18.0 17.0 16.2 EXPANSION PRESSURE - PSI 0.00 0.00 0.00 HORIZONTAL PRESSURE @ 160 psi 160 152 140 SAMPLE HEIGHT - in. 2.53 2.53 2.59 EXUDATION PRESSURE - PSI 123 159 358 UNCORRECTED R-VALUE 0.0 2.9 6.4 CORRECTED R-VALUE 0.0 2.9 6.7 R-VALUE AT 300 PSI EXUDATION PRESSURE = 6.8 10 k7' 80 Ir 40 20 0 ......... ....... .................... ............. .............. ............. ............ _.............i............._... ....... ...... ...4... ..:... ....... ...4... ...:... ... _ ....... ......... p............. .............1............. ................. ............... j...........................1......................... ........................ ....... ......................... i............. _............ ........... ....j......... ....4............. .............. 1............. .............. ................... ....... _ ....... .........4............. .............1............. ............. y............. ............................ ..............1......................... ....... ........ ....... [.............. ........................... ........... ...i............. ............. ............ .............. ..... ........ ............. ............. ....... _ ....... ......... _......:...... c............ �............. ...:......................i............. �..... ...d.............i........... ....... _ ....... ........................... €1 .........i..............!.............. e............ ............... i............ .i.............o..........................b.......... _ ....... ....... _ ....... ....... .........�............. b........................... ............. ........ ......1.............. :............. 4. ....... ........ ....... _ ....... ........................... .........i.............. i......:......s......... ... ...... ........ i............ .?..... ....... b............. i... ... ... . ..... _ ....... ....... _...... ....... ....... 100 .200 300 '400 500 600 700 .800 EXUDRTION PRESSURE psi EMPIRE LABORATORIES INC. .Jo .55 .54 5j d H _ .52 A - 5L d c .49 .48 4 CONSOLIDATION TEST PRO. 2F7929594 BORING NO.: 6 DEPTH: 3.0 DRY DEN'SITY:1©6.4 PCF MOISTURE: 22.8% 0+ 0 0 0 00 0 0 ,0 r 0.1 w J J T UY I 0.0 I 4 -2 .0 H F' p -4 .0 " H J d z -6 .0 0 U 0.25 0.5 1.0 5 10 APPLIED PRESSURE - TSF 0.25 0.5 1.0 APPLIED PRESSURE - TSF EMPIRE LABORATORIES INC. 5 10 r 0.1 w J J T UY I 0.0 I 4 -2 .0 H F' p -4 .0 " H J d z -6 .0 0 U 0.25 0.5 1.0 5 10 APPLIED PRESSURE - TSF 0.25 0.5 1.0 APPLIED PRESSURE - TSF EMPIRE LABORATORIES INC. 5 10 J .OJ .62 .61 .60 4 H a:58 2 AM 5S O .57 .56 .55 54 CONSOLIDATION TEST PRO. 20929594 0 BORING N4.: 4 0 DEPTH: 3.0 DRY DENSITY:100.8 PCF MOISTURE: 23.7 0 0 0 0 0 0 0 0 0.1 4.0 'J J W 3 2.0 N 0.0 4 —2 .0 H F A -4 .0 H . J .. 6 2 —6 .0 8.0 0.25 0.5 1.0 5 1c+ APPLIED PRESSURE — TSF 0.25 0.5 1.0 APPLIED PRESSURE — TSF EMPIRE LHBORATORIES INC. 5 10 LOG OF BORING NO. 7 Page 1 of 1 OWNER ARCHITECT/ENGINEER FIRST INTERSTATE BANK SHERMAN HOMES LTD. srrEWILLOX LANE & BRAMBLEBUSH STREET PROJECT FORT COLLINS, COLORADO SAND CREEK VILLAGE DEVELOPMENT SAMPLES TESTS CD . _J O O F H O DESCRIPTION Z\ W HI— m(n H N w w L 2 2 W > iO F O ZZ 2F CL F (A co W O 3 N O W W H a. U E a. U HO H YLL UWLL FELL LD Approx. Surface Elev.: 4975.6 ft. o ch z ►}— z (nm E 00- =(na ¢tea "•""" 0.5 6" TOPSOIL 4975.1 CL 1 SS 12" 10 LEAN CLAY WITH SAND 14.7 Brown PA Moist 25/16/9 Soft Composite sample taken at 6" to 4' CL 2 ST 12" 17.4 105 4.0 ft. 4971.6 SC 3 SS 12" 4 17.2 580 5 PA CLAYEYSAND Brown Moist Loose i Q 8.0 4967.6 10 WEATHERED SILTSTONE/ SANDSTONE Tan/gray Moist Poorly cemented 11.5 4964.1 4 SS 12" 21 12.4 PA SILTSTONE/SANDSTONE Tan/gray Moist Cemented 14.5 4961.1 5 SS 6" 50/6" 114.0 END OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS _Empire Laboratories Incorporated Division of Tercacon BORING STARTED 1-19-93 WL y 7)4n W.D. IT 71-011 A.B. BORING COMPLETED 1-19-93 WL RIG CME-55 FOREMAN DR V- Checked 24 hrs A.B. APPROVED NRS JOB # 20929594 LOG OF BORING NO. 6 Page 1 of 1 OWNER ARCHITECT/ENGINEER FIRST INTERSTATE BANK SHERMAN HOMES LTD. srrEWILLOX LANE & BRAMBLEBUSH STREET PROJECT FORT COLLINS COLORADO SAND CREEK VILLAGE DEVELOPMENT SAMPLES TESTS o_ CO E z w o- r F- w o U w 0:: E— Z� � 3 �O n.J U) co \ W U H O s Y F (nn w o }LL MU oa- O Z 2 LL((D o w UXIL zf_In :Dcna C7 O J H (L ¢ a LO DESCRIPTION Approx. Surface Elev.: 4965.5 ft. .. I~L a w O J O E N cn U cn ^A"A" 0.5 6" TOPSOIL 4965.0 CL 1 SS 12" 10 16.9 LEAN CLAY WITH SAND PA Brown Moist Stiff CL 2 ST 12" 21.0 110 2500 4.0 4961.5 = SC 3 SS 12" 2 22.9 CLAYEY SAND SZ 5 PA Brown Moist to wet Very loose SC 4 ST 1 0" SC 5 SS 12" 2 �26.3 PA 10 12.0 4953.5 WEATHERED SILTSTONE/ SANDSTONE Tan/gray Moist 14.5 Poorly cemented 4951.0 6 SS 9" 50/9" 18.4 14.8 SILTSTONE/SANDSTONE 4950.7 Tan/gray, moist,hard .M=SANDSTON END OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS _Empire Laboratories Incorporated Division ofTeacon BORING STARTED 1-19-93 Q V-411 W.D. __ 41-5" A.B. BORING COMPLETED 1-19-93 IWLWL RIG CM E-55 FOREMAN DRn Checked 24 hrs. A.B. APPROVED NRS JOB N 209295 94 LOG OF BORING NO. 5 Page 1 of 1 OWNER ARCHITECT/ENGINEER FIRST INTERSTATE BANK SHERMAN HOMES LTD. SITEWILLOX LANE & BRAMBLEBUSH STREET PROJECT FORT COLLINS COLORADO SAND CREEK VILLAGE DEVELOPMENT SAMPLES TESTS \ >- J J LLL E Y Ld N Z= W DESCRIPTION Z\ X HLL � � H N w w = 2 W =0 i(n ♦— O Z Z J (A (L H N m W q 3 Cl) ow J (A cc n- U E a. U HO H YLL UW.LL WWLL CD Approx. Surface Elev.: 4979.5 ft. Wo z i Lu Mm z oa �U)(L (n(aa 0.5 6" TOPSOIL 4979.0 CL 1 SS 12" 18 10.1 LEAN CLAY WITH SAND PA Brown Moist Medium to stiff CL 2 ST 12" 8.4 101 1630 215 4.5 4975.0 5 SC 3 SS 12" 7 10.1 PA CLAYEYSAND Brown Moist Loose 7.5 4972.0 10 30 4 ST 12" 115.9 6390 WEATHERED SILTSTONE/ SANDSTONE Tan/gray Moist 10.0 Poorly cemented 4969.5 5 SS 12" 25 15.7 PA —_ SILTSTONE/SANDSTONE Tan/gray Moist =_ Cemented 14.5 4965.0 6 SS 6" 50/6" 14.0 END OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS __Empire Laboratories Incorporated Division of Ttrracon BORING STARTED 1-19-93 W- g None W.D.=11'-9° A.B. BORING COMPLETED 1-19-93 W1. RIG CME-55 FOREMAN DR � Checked 24 hrs. A.B. APPROVED NRS JOB a 20929594 LOG OF BORING NO. 4 Page 1 of 1 OWNER FIRST INTERSTATE BANK ARCHITECT/ENGINEER SHERMAN HOMES LTD. srrEWELLOX LANE & BRAMBLEBUSH STREET FORT COLLINS COLORADO PROJECT SAND CREEK VILLAGE DEVELOPMENT o J H d (DD DESCRIPTION Approx. Surface Elev.: 4980.0 ft. .. U-� H a. o o > In U SAMPLES TESTS m E z W a I- Y w O U W U. Z\ 3 1— O Cn03 W � fA H r_ N w O >- U. oa o Ld Z S HLL � zz ow U M LL pia """ 0.5 6" TOPSOIL 4979.5 LEAN CLAY WITH SAND Brown Moist Stiff 4.5 4975.5 5 10 CL I SS 12" 8 13.4 PA CL 2 ST 12" 21.7 101 950 SC 3 SS 12" 22.1 CLAYEY SAND Brown Moist to wet Loose to medium dense 8.5 4971.5 PA 4 ST 0" SC 5 SS 12" 16 121.5 WEATHERED SILTSTONE/ SANDSTONE Tan/gray Moist 11.0 Poorly cemented 4969.0 SILTSTONE/SANDSTONE Tan/gray Moist Cemented 14.5 4965.5 PA _ 6 SS 6" 50/6" 15.5 END OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS Empire Laboratories Incorporated Division ofTerracon BORING STARTED 1-19-93 N'I- Q 63-411 W.D. t W-211 A.B. BORING COMPLETED 1-19-93 WL RIG CME-55 FOREMAN DR I N1 Checked 24 hrs. A.B. APPROVED NRS I JOB k 20929594 j LOG OF BORING NO. 3 Page 1 of 1 OWNER ARCHITECT/ENGINEER FIRST INTERSTATE BANK SHERMAN HOMES LTD. SITEWILLOX LANE & BRAMBLEBUSH STREET PROJECT FORT COLLINS COLORADO SAND CREEK VILLAGE DEVELOPMENT SAMPLES TESTS o: w m E z w d w > o U W i— w Z\ (n 3 I—O WCJO •. M t- In H E >- F H w a YLL oa O w LLO z z ow UXLL =wa C9 mat Q� F- w H HELL ~¢_ja O J H x a cc DESCRIPTION Approx. SurfaceElev.: 4974.5 ft. H x I— d o O CO N N U = " " A " 0.5 6" TOPSOIL 4974.0 CL 1 SS 12" 11 12.8 LEAN CLAY WITH SAND PA Brown Moist Soft 23/20/3 CL 2 ST 12" 20.6 103 700 = CL 3 SS 12" 5 18.1 Q - 5 PA CL 4 SS 12" 7 120.8 PA 10 13.0 4961.5 15 WEATHERED CLAYSTONE Gray/brown Moist to wet 15.0 Poorly cemented 4959.5 END OF BORING 5 SS 12" 42 17.5 THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS Empire Laboratories Incorporated Division ofTerracon BORING STARTED 10-29-92 SZ V-1'1 W.D. t41-511 A.B. BORING COMPLETED 10-29-92 LWIL RIG CME-55 FOREMAN LRS Checked I Week A.B. APPROVED NRS JOB # 20929594 LOG OF BORING NO. 2 Page 1 of 1 OWNER ARCHITECT/ENGINEER FIRST INTERSTATE BANK SHERMAN HOMES LTD. sITEWILLOX LANE & BRAMBLEBUSH STREET PROJECT FORT COLLINS COLORADO SAND CREEK VILLAGE DEVELOPMENT SAMPLES TESTS I~i CO } Lu t~n z x DESCRIPTION z� X �ED H x N Lu w I<n w 0 zz CL d U CO U H UMLL cc OW.. HO YLL LD Approx. Surface Elev.: 4970.0 ft. o M z F- it CnCO E oa �(Da- "•""" 0.5 6" TOPSOIL 4969.5 CL 1 SS 12" 14 5.0 i FAN CLAY WITH SOFT PA Brown Moist to wet Soft = CL 2 SS 12" 4 22.0 5 PA Q CL 3 ST 12" 22.1 108 560 CL 4 SS 12" 4 25.3 PA 10 13.0 4957.0 15 WEATHERED SANDSTONE/ SILTSTONE Tan/gray 15.0 Poorly cemented 4955.0 END OF BORING 5 SS 12" 30 �16.6 THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS BORING STARTED 10-29-92 _Empire Laboratories Incorporated �)-1011W.D. _W-611 A.B. BORING COMPLETED 10-29-92 IL RIG CME-55 FOREMAN LRS Division ofTerracon Checked 1 week A.B. APPROVED NRS JOB# 20929594 LOG OF BORING NO. 1 Page 1 of 1 OWNER FIRST INTERSTATE BANK ARCHITECT/ENGINEER SHERMAN HOMES LTD. sITEWILLOX LANE & BRAMBLEBUSH STREET FORT COLLINS COLORADO PROJECT SAND CREEK VILLAGE DEVELOPMENT c� o H 2 a. Lo DESCRIPTION Approx. Surface Elev.: 4977.5 ft. 2 F- (L o J O N En U SAMPLES TESTS W co r_ z W (L w > O U W Z\ I V7 3 F-O Ln a. m v W F (n H E r r w O rLL M iL ❑ LH� _ ZZ ow L)WLL � u~i a. X Jfn J (n WWII WO- 0- """"" 0.5 6" TOPSOIL 4977.0 LEAN CLAY WITH SAND Brown Moist Very stiff 3.0 4974.5 5 10 CL 1 SS 12" 35 4.1 235 640 PA WEATHERED SANDSTONE/ SILTSTONE Tan/gray Moist Poorly cemented 6.0 4971.5 2 ST 12" 12.7 108 3 SS 12" 27 112.2 PA SANDSTONE/SILTSTONE Tan/gray Moist Cemented 14.4 4963.1 END OF BORING _ _— — 4 SS 7" 50/7" 11.6 PA = 5 SS 5" 5015" 13.5 THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS _Empire Laboratories Incorporated Division ofTerracon BORING STARTED 10-29-92 4 None W.D. t None A.B. BORING COMPLETED 10-29-92 IWL RIG CME-55 FOREMAN LRS Checked 1 week A.B. APPROVED NRS JOB# 20929594 to TEST BORING LOCATION PLAN L27 L2m \ L 24 -L22 P�oJ�c • n�ILL� l - i�-�2 • U°' ..,. .. Lia 49 L i7 -L,-7 - Lis L11 Lto �lo:� L Io GENERAL NOTES Sedimentary Rock Classification DESCRIPTIVE ROCK CLASSIFICATION: Sedimentary rocks are composed of cemented clay, silt and sand sized particles. The most common minerals are clay, quartz and calcite. Rock composed primarily of calcite is called limestone; rock of sand size grains is called sandstone, and rock of clay and silt size grains is called mudstone or claystone, siltstone, or shale. Modifiers such as shaly, sandy, dolomitic, calcareous, carbonaceous, etc. are used to describe various constituents. Examples: sandy shale; calcareous sandstone. LIMESTONE Light to dark colored, crystalline to fine-grained texture, composed of CaCO3, reacts readily with HCI. DOLOMITE Light to dark colored, crystalline to fine-grained texture, composed of CaMg(CO3)2, harder than limestone, reacts with HCI when powdered. CHERT Light to dark colored, very fine-grained texture, composed of micro -crystalline quartz (Si02), brittle, breaks into angular fragments, will scratch glass. SHALE Very fine-grained texture, composed of consolidated silt or clay, bedded in thin layers. The unlaminated equivalent is frequently referred to as siltstone, claystone or mudstone. SANDSTONE Usually light colored, coarse to fine texture, composed of cemented sand size grains of quartz, feldspar, etc. Cement usually is silica but may be such minerals as calcite, iron -oxide, or some other carbonate. CONGLOMERATE Rounded rock fragments of variable mineralogy varying in size from near sand to boulder size but usually pebble to cobble size (1/2 inch to 6 inches). Cemented together with various cementing agents. Breccia is similar but composed of angular, fractured rock particles cemented together. 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. Classification of rock materials has been estimated from disturbed samples. Core samples and petrographic analysis may reveal other rock types. Irerracon Form 109_685 GENERAL NOTES Sedimentary Rock Classification DESCRIPTIVE ROCK CLASSIFICATION: Sedimentary rocks are composed of cemented clay, silt and sand sized particles. The most common minerals are clay, quartz and calcite. Rock composed primarily of calcite is called limestone; rock of sand size grains is called sandstone, and rock of clay and silt size grains is called mudstone or claystone, siltstone, or shale. Modifiers such as shaly, sandy, dolomitic, calcareous, carbonaceous, etc. are used to describe various constituents. Examples: sandy shale; calcareous sandstone. LIMESTONE Light to dark colored, crystalline to fine-grained texture, composed of CaCo3, reacts readily with HCI. DOLOMITE Light to dark colored, crystalline to fine-grained texture, composed of CaMg(CO3)2, harder than limestone, reacts with HCI when powdered. CHERT Light to dark colored, very fine-grained texture, composed of micro -crystalline quartz (SiO2), brittle, breaks into angular fragments, will scratch glass. SHALE Very fine-grained texture, composed of consolidated silt or clay, bedded in thin layers. The unlaminated equivalent is frequently referred to as siltstone, claystone or mudstone. SANDSTONE Usually light colored, coarse to fine texture, composed of cemented sand size grains of quartz, feldspar, etc. Cement usually is silica but may be such minerals as calcite, iron -oxide, or some other carbonate. CONGLOMERATE Rounded rock fragments of variable mineralogy varying in size from near sand to boulder size but usually pebble to cobble size (1/2 inch to 6 inches). Cemented together with various cemen- ting agents. Breccia is similar but composed of angular, fractured rock particles cemented together. PHYSICAL PROPERTIES: DEGREE OF WEATHERING BEDDING AND JOINT CHARACTERISTICS Slight Slight decomposition of parent Bed Thickness Joint Spacing Dimensions material on joints. May be color Very Thick Very Wide >10, change. Thick Wide 3' - 10' Moderate Medium Moderately Close 1' - 3' Some decomposition and color Thin Close 2" - 1' change throughout. Very Thin Very Close .4" - 2" High Rock highly decomposed, may be ex- Laminated — .1" - .4" tremely broken. Bedding Plane A plane dividing sedimentary rocks of the same or different lithology. HARDNESS AND DEGREE OF CEMENTATION Joint Fracture in rock, generally more or Limestone and Dolomite: less vertical or transverse to bedding, along which no appreciable move - Hard Difficult to scratch with knife. ment has occurred. Moderately Can be scratched easily with knife, Seam Generally applies to bedding plane Hard cannot be scratched with fingernail. with an unspecified degree of Soft Can be scratched with fingernail. weathering. Shale, Siltstone and Claystone Hard Can be scratched easily with knife, SOLUTION AND VOID CONDITIONS cannot be scratched with fingernail. Solid Contains no voids. Moderately Vuggy (Pitted) Rock having small solution pits or Hard Can be scratched with fingernail. cavities up to 1/2 inch diameter, fre- Soft Can be easily dented but not molded quently with a mineral lining. with fingers. Porous Containing numerous voids, pores, or other openings, which may or may Sandstone and Conglomerate not interconnect. Well Capable of scratching a knife blade. Cavernous Containing cavities or caverns, some - Cemented times quite large. Cemented Can be scratched with knife. Poorly Can be broken apart easily with Cemented fingers. 1 rerracon. Form 110-885 GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS Split Spoon - 1%" I.D., 2" O.D., unless otherwise noted PS : Piston Sample ST Thin -Walled Tube - 2" O.D., Unless otherwise noted WS : Wash Sample 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 : Pressuremeter 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 OD 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 Casing Removal Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate deter- minati,.)n 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 ASTM Designations D-2487 and D-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 k200 sieve; they are described as: clays, if they are plastic, and silts if they are slightly plastic or non -plastic. Major con- stituents 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: RELATIVE DENSITY OF COARSE -GRAINED SOILS: Unconfined Compressive N-Blowslft. Relative Density Strength, Ou, psf Consistency 0.3 Very Loose < 500 Very Soft 4-9 Loose 500 - 1,000 Soft 10-29 Medium Dense 1,001 - 2,000 Medium 30-49 Dense 2,001 - 4,000 Stiff 50.80 Very Dense 4,001 - 8,000 Very Stiff 80+ Extremely Dense 8,001-16,000 Hard >-16,000 Very Hard GRAIN SIZE TERMINOLOGY RELATIVE PROPORTIONS OF SAND AND GRAVEL Major Component Descriptive Term(s) Of Sample Size Range (of Components Also Percent of Boulders Over 12 in. (300mm) Present in Sample) Dry Weight Cobbles 12 in. to 3 in. Trace < 15 (300mm to 75mm) With 15 - 29 Gravel 3 in. to N4 sieve Modifier > 30 (75mm to 4.75mm) Sand N4 to #200 sieve RELATIVE PROPORTIONS OF FINES (4.75mm to 0.075mm) Descriptive Term(s) Silt or Clay Passing #200 sieve (of Components Also Percent of (0.075mm) Present in Sample) Dry Weight Trace < 5 With 5-12 Modifier > 12 1 rerracon. Form 108-6-85 Job No. 20929594 January 25, 1993 Page 10 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 our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observation 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 our client 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. Job No. 20929594 January 25, 1993 Page 9 course. Other pavement sections could be considered and we would be pleased to evaluate any other desired alternatives, at your request. Aggregate base for the pavement should consist of high quality base course materials compatible with Colorado Department of Transportation (CDOT) standard specifications for Class 5 or Class 6 base. Those materials should be placed in loose lifts not to exceed 9 inches thick, adjusted to a workable moisture and compacted to a minimum of 100% of standard Proctor maximum dry density. Asphalt for use in the pavement section should be consistent with City of Fort Collins standard specifications for SC-1 or SC-2 surface course materials. Those materials should be placed and compacted as outlined in City of Fort Collins standard specifications for street construction. Other Considerations Positive drainage should be developed away from the buildings and across and away from all pavements. Water allowed to pond on or adjacent to pavements and/or foundations walls could result in softening of subgrade or bearing soils and result in premature failure of the pavement sections or settlement of foundations. Water could also accumulate in crawl space areas if proper drainage is not developed. A portion of the subsurface soils at this site were relatively soft and compressible. If grade changes involving the placement of over 2 feet of fill are designed for the project, we should be consulted regarding potential areal settlement caused by the weight of the fill. Job No. 20929594 January 25, 1993 Page 8 Fill soils beneath the on -grade slabs or pavements should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95% of the material's maximum dry density as determined in accordance with the standard Proctor procedure. The moisture content of the fill soils should be adjusted within the range of -1 to +3% of standard Proctor optimum moisture. After preparation of the subgrades, care should be taken to avoid disturbing those prepared subgrades. Materials which are disturbed by the construction activities or any materials which become extremely wet or dry prior to placement of the slabs or pavements should be reworked in place or, if necessary, removed and replaced prior to placement of the overlying concrete slabs or pavements. Pavements Traffic loads are estimated at 5 EDLA for the new cul-de-sacs. These estimates need to be verified by City of Fort Collins engineering personnel. A Hveem stabilometer R-value of 6.8 was determined in laboratory testing of a representative sample of the site materials. That R-value corresponds to a resilient modulus value of approximately 4,600 using the American Association of State Highway and Transportation Officials (AASHTO) correlation. The 1986 AASHTO "Guide for Design of Pavement Structures" was used to help evaluate alternative pavement sections for this project. A reliability of 70 percent and serviceability loss of 2.5 were used in the evaluation; consistent with City of Fort Collins .recommended parameters. Based on the outlined evaluation, we recommend the pavement sections used for the two cul-de-sacs consist of 3 inches of hot bituminous pavement overlying 7-inches of crushed aggregate base Job No. 20929594 January 25, 1993 Page 7 continuous foundations. to evaluate the near surface bearing materials. If soft or loose materials are observed in"those borings, it would be necessary to extend the foundations to bear on suitable strength materials or use overexcavation and backfill procedures to develop foundation bearing. We estimate the long-term settlement of footing foundations designed and constructed as recommended above would be small, less than 3a-inch. Concrete Slab and Pavement Subarades All existing vegetation and/or topsoil should be removed from beneath any on -grade slabs and/or pavements. After stripping and completing all cuts and prior to placement of any fill, concrete slabs or pavements, we recommend the exposed subgrades be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95 percent 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 within the range of -1 to +3% of standard Proctor optimum moisture. Fill required to develop the pavement subgrades should consist of approved, low -volume change material free from organic matter and debris and similar to the on -site, near surface cohesive materials. Normally, cohesive soils with a liquid limit of 40 or less and plasticity index of 18 or less could be used as low -volume change fill. We recommend the fill materials contain a minimum of 15% fines, material passing the No. 200 sieve, to reduce the potential for ponding of water within the fill. Job No. 20929594 January 25, 1993 Page 6 ANALYSIS AND RECOMMENDATIONS Foundations Based on the materials we observed at the boring locations, it is our opinion the proposed structures could be supported on conventional footing foundations. We recommend those footing foundations extend through all existing vegetation and/or topsoil and bear in the natural, medium to stiff lean clay containing varying amounts of sand. For design of footing foundations bearing in the natural, medium to stiff cohesive soil, we recommend using a net allowable total load soil bearing pressure not to exceed 1,500 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Exterior foundations and foundations in unheated areas should be located at least 30 inches below adjacent exterior grade to provide frost protection. Trenched foundations appear suitable for use in the near surface cohesive materials. The foundations should be sized to minimize differential settlement.' No unusual problems are anticipated in completing the excavations required for the construction of the footing foundations. Care should be taken to avoid disturbing the bearing soils and minimize moisture fluctuations in those materials. Any loosened or disturbed material, or any extremely wet or dry material should be removed prior to placement or reinforcing steel and foundation concrete. Occasional loose zones were observed in the subsurface soils. Care should be taken to see that footings are supported on suitable strength materials. As a minimum, hand auger borings shall be advanced at each column location and at regular intervals along Job No. 20929594 January 25, 1993 Page 5 Classification of the bedrock was based on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. WATER LEVEL OBSERVATIONS Observations were made while drilling and after completion of the borings to detect the presence and level of free water. In addition, the boreholes were left open and water level observations also performed at times ranging from 24 hours to approximately 1 week after completion of the drilling. The depth to free water observed at these times range from approximately 4 to 10 feet below existing ground surface; however, free water was not encountered in boring B-1. Based on those observations, we anticipate the depth to groundwater at the time of drilling was on the order of 4 to 6 feet below ground surface throughout most of the site. Fluctuations in groundwater levels can occur throughout time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. In addition, zones of perched and/or trapped water may be encountered in more permeable zones within the subgrade soils and perched water is often encountered in soils overlying less permeable weathered bedrock. The location and amount of perched water may also vary depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. Monitoring of site groundwater in piezometers or monitoring wells which are sealed from the influence of surface water would be necessary to more accurately evaluate groundwater levels and fluctuations. u Job No. 20929594 January 25, 1993 Page 4 contain descriptions of the recovered samples and the engineer's interpretation of subsurface conditions between samples based on visual and tactual observations. Final boring logs included with this report may contain modifications to those field logs based on the results of laboratory testing and observation. Based on results of our exploration and testing program, subsurface conditions can be generalized as follows: Approximately 6 inches of topsoil and/or vegetation was encountered at the surface at the boring locations. The topsoil/vegetation was underlain by low plasticity lean clay containing varying amounts of silt and sand. The cohesive materials were generally medium to stiff, were colored brown and were moist to wet. Those soils extended to depths ranging from approximately 3 to 13 feet at the boring locations. In borings B-4, B-51 B-6 and B-7, the lean clay was underlain by clayey sand. The essentially granular materials were loose to medium dense, brown and moist. In borings B-1, B-2 and B-3 beneath the lean clay and at the other boring locations beneath the clayey sand, weathered bedrock was encountered. The weathered bedrock consisted predominately of siltstone/sandstone; however, weathered claystone was encountered beneath a depth of approximately 13 feet in boring B-3. The siltstone/sandstone bedrock was colored tan and gray and the claystone bedrock was colored gray brown. The siltstone/sandstone was poorly cemented although became more well cemented and less weathered with depth. The borings were terminated at depths ranging from approximately 14 to 15 feet in the highly weathered to weathered bedrock. The stratification boundaries shown on the boring logs represent the approximate location of changes in soil and rock types; in - situ, the transition of materials may be gradual and indistinct. 0 Job No. 20929594 January 25, 1993 Page 3 observed. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification and testing. Moisture content, dry density and unconfined strength tests were performed as appropriate on the recovered discrete samples. In addition, Atterberg Limits, washed sieve analysis, swell/consolidation and soluble sulfate tests were performed on selected samples. One Hveem stabilometer R-value was performed on a sample of the near surface subgrade soils obtained from the auger cuttings. 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 in the appropriate column on the boring logs and a brief description of that classification system is included with this report. SITE AND SUBSURFACE CONDITIONS The Sandcreek Village P.U.D. will be located northeast of Willox Lane and north of Bramblebush in Fort Collins, Colorado. The site is presently an open field and evidence of prior building construction was not observed on the site by our field personnel. Site drainage is generally towards the south with a maximum difference in ground surface elevations across the site on the order of 20 feet. Field logs of the materials encountered during drilling were prepared by an Empire Laboratories field engineer. Those logs Job No. 20929594 January 25, 1993 Page 2 EXPLORATION AND TESTING PROCEDURES The boring locations were selected by Empire Laboratories personnel and located in the field by an Empire Laboratories field engineer. Boring layout was completed by pacing and estimating angles from the references shown on the attached boring location diagram. The surface elevations at the boring. locations were estimated by interpolation from plan contours. The locations and elevations of the borings should be considered accurate only to the degree implied by the methods used to make these measurements. The borings were performed with a truck -mounted, CME 55 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 hydraulic pressure to obtain a relatively undisturbed sample of cohesive or moderately cohesive material. In the split -barrel sampling procedure, a standard 2-inch O.D. 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 soil and, to a lesser degree of accuracy, the consistency of cohesive materials and hardness of weathered bedrock. An Empire Laboratories field engineer was present during the drilling operations to maintain a log of the materials encountered and establish the field sampling program based on the materials SUBSURFACE EXPLORATION REPORT PROPOSED SANDCREER VILLAGE WILLOX LANE AND BRAMBLEBUSH STREET FORT COLLINS, COLORADO Job No: 20929594 Date: January 25, 1993 INTRODUCTION The subsurface exploration for the proposed Sandcreek Village development near Willox Lane and Bramblebush Street in Fort Collins, Colorado, has been completed. Three (3) soil borings were performed in October of 1992 to develop preliminary subsurface information on the site. Four additional borings were completed in January of 1993 to provide additional design information. The results of those borings, along with a diagram showing the approximate boring locations, are included with this report. We understand the proposed Sandcreek Village will include the development of 28 single-family residential structures. New access roadways will also be constructed as a part of the development. - Foundation loads for the proposed wood frame buildings will be light with continuous wall loads less than 3 kips per lineal foot and column loads less than 30 kips. IBased on our verbal discussions since the preliminary exploration, we understand the buildings will likely be non -basement, crawl space construction. Small grade changes, cuts and fills less than 2 feet, will be required to develop the site grades for the new development. Traffic loads of five 18-kip equivalent daily load axle (EDLA) are estimated for the new streets although this estimate needs verification from the City of Fort Collins Engineering Department. The purpose of this report is to describe the subsurface conditions encountered in the borings, analyze and evaluate the test results and provide recommendations concerning design and construction of foundations and support of on -grade slabs and pavements. n Job No. 20929594 January 25, 1993 Page 2 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, EMPIRE LABORATORIES, INC. A DIVISION OF THE TERRACON COMPANIES, INC. Lester L. Litton, P.E. Principal Engineer Chester C. Smith, P.E. Division Manager LLL/dmf cc: Mr. Pete Sherman/Sherman Homes, Ltd. January 25, 1993 First Interstate Bank P.O. Box 578 Fort Collins, CO 80522-0578 ATTN: Mr. Larry Wood RE: Subsurface Exploration Report Proposed Sandcreek Village Willox Lane and Bramblebush Street Fort Collins, CO Job No. 20929594 Mr. Wood: Enclosed, herewith, are the results of the subsurface exploration performed for the proposed Sandcreek Village development. In summary, the overburden soils at this site consisted of low plasticity lean clay with varying amounts of silt and sand and fine to medium sand with varying percentages of silt and clay. These materials were overlying siltstone/sandstone bedrock which was encountered at depths of approximately 3 to 13 feet. Relatively shallow groundwater located at depths of approximately 4 to 6 feet below existing ground surface, was encountered throughout much of the site. Based on the results of our exploration, it is our opinion the ,proposed residences could be supported on conventional footing foundations bearing in the overburden soils. The overburden soils could also be used for direct support of slabs -on -grade and pavements. Geotechnical recommendations concerning design and construction of the foundations and support of at -grade slabs and pavements, are presented in the text of this report. SUBSURFACE EXPLORATION REPORT PROPOSED SANDCREER VILLAGE WILLOX LANE AND BRAMBLEBUSH STREET FORT COLLINS, COLORADO JOB NO. 20929594