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Home My WebLink About992552.tiff UNIFIED SOIL CLASSIFICATION SYSTEM Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Group Group Name° Symbol Coarse-Grained Soils Gravels Clean Gravels Cu a 4 and 1 s Cc s 36 GW Well-graded gravelF More than 50% retained on More than 50% of coarse Less than 5% finest No.200 sieve fraction retained on Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF No.4 sieve Fines classify as ML or MH GM Silty gravelF.G." Gravels with Fines More than 12% fines° Fines classify as CL or CH GC Clayey gravelF,G," Sands Clean Sands Cu ≥ 6 and 1 s Cc s 3E SW Well-graded sand' 50% or more of coarse Less than 5% finesE fraction passes Cu < 6 and/or 1> Cc > 3E SP Poorly graded sand No.4 sieve Fines classify as ML or MH SM Silty sandy.".1 Sands with Fines More than 12% fines° Fines classify as CL or CH SC Clayey sand°.", Fine-Grained Soils Silts and Clays inorganic PI > 7 and plots on or above"A" line'' CL Lean clay"L M 50% or more passes the Liquid limit less than 50 No.200 sieve PI < 4 or plots below"A" lined ML Silt"L.M g Liquid limit —oven dried Organic clay"'L M," organic < 0.75 OL Liquid limit — not dried Organic silt"L M.0 Silts and Clays inorganic PI plots on or above "A" line CH Fat clay"L M Liquid limit 50 or more PI plots below"A" line MH Elastic silt".L M g Liquid limit — oven dried Organic clay".L M'P organic < 0.75 OH Liquid limit — not dried Organic silt"'L M.0 Highly organic soils ' Primarily organic matter,dark in color,and organic odor PT Peat "Based on the material passing the 3-in. (030)2 "If soil contains 15 to 29% plus No.200, add 6 (75-mm)sieve. Cu = DOOID10 Cc = D X D "with sand"or"with gravel",whichever is 81f field sample contained cobbles or F 10 80 predominant. boulders,or both,add "with cobbles or If soil contains ≥ 15% Sand, add "with sand" to EIf soil contains ≥ 30% plus. No. 200 group name. boulders,or both"to group name. predominantly sand, add "sandy" to group °Gravels with 5 to 12% fines require dual °lf fines classify as CL-ML, use dual symbol GC name. symbols: GM,or SC-SM. Mif soil contains ≥ 30% plus No.200, GW-GM well-graded gravel with silt "If fines are organic,add "with 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 ≥ 15% gravel,add "with gravel"to "PI ≥ 4 and plots on or above"A" line. GP-GC poorly graded gravel with clay group name. GPI < 4 or plots below "A" line. °Sands with 5 to 12% fines require dual 31f Atterberg limits plot in shaded area, soil is a CL Ppl plots on or above "A" line. symbols: ML, silty clay. SW-SM well-graded sand with silt GPI plots below "A" line. SW-SC well-graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay 60 For classification of fine-grained soils / and fine-grained fraction of coarse- / 50 _grained soils / Equation of "A"-line \��/ 4. Horizontal at PI = 4 to LL = 25.5. J // �\C\ then PI = 0.73(LL-20) • / O� „P w ` x40 -Equation of"U" line ' / OP -- ---- -- O Vertical at LL = 16 to PI = 7, I '� Z_ then P1 = 0.9(LL-8) // )- 30 L I /_,. I 1- / / o F / Q 20_ _ / O� O a // City MH OR OH / 10 7 CL ,M ML0ROL EXHarr 0 I 0 10 16 20 30 40 50 60 70 80 90 100 110 LIQUID LIMIT (LL) 992552 1 lerracon_1 Form 111-6.85 Geotechnical Engineer,ng Exploration Quality Living Homes Terracon Project No. 21985073 SUBSURFACE CONDITIONS Soil Conditions As seen in the Logs of Borings presented in Appendix A of this report, the subsurface soils consist predominantly of a sand strata with a varying degree of silt and gravel sand content. l Field and Laboratory Test Results J Field and laboratory test results indicate the sand layer is medium dense in relative density, 7 exhibiting low swell potential and moderate bearing capacity characteristics. Percolation tests conducted in the area of the proposed soil absorption bed area are Jsummarized as follows: Percolation Test Results " Test Hole Depth (inches) Soil Percolation Rate Depth to Depth to Bedrock Classification (minutes/inch) Groundwater(ft) (ft) 2 30 SM 20 NA NA J3 30 SM 20 NA NA 4 30 SM 20 NA NA J Field test results indicate the soils in both areas of the proposed septic system have good percolation characteristics. Groundwater Conditions Groundwater was not observed in the test borings at the time of field exploration and when checked 2 days after drilling at maximum depths of exploration fifteen (15) feet below existing site grades. These observations represent only current groundwater conditions, and may not be indicative of other times, or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, as well as irrigation demands on and/or adjacent to the subject site. 4 Geotechnical Engineering Exploration Terracon Quality Living Homes Project No. 21985073 .] Septic System Construction jField test results indicate that construction of a standard septic system and leach field (soil absorption bed) is feasible for construction on the site in the general vicinity of percolation test holes 2 through 4. The system should be designed in accordance with applicable state and county requirements and should be located at the minimum distances from all pertinent ground features described in Weld County regulations. An average percolation rate of 20 minutes per inch is recommended for design purposes. J No groundwater or bedrock was encountered in the soil profile boring located at the proposed soil absorption bed. Therefore, the leach field should be constructed at a depth of one (1) to two (2) foot from existing site grade. Additional design criteria for standard septic system construction are as follows: • Based upon the proposed residence containing 4 bedrooms, the proposed soil absorption bed should include an approximate area of 1496 square feet of trench in plan view. • A minimum 1,250-gallon capacity septic tank should be used in the design and construction. • Distribution lines within the soil absorption bed should consist of 3- or 4-inch l diameter perforated plastic or similar pipe approved in governing J regulations. Distribution lines should be placed the full length of the proposed absorption bed or trench and should not exceed 100-feet in length. Distribution lines should be spaced at a maximum of 6-feet on center with the perimeter lines placed within 3 feet of all sides in the -i absorption bed. • Absorption beds should be backfilled with a minimum 12-inch thickness of clean graded gravel ranging in size from 1/2 to 2-1/2 inches in diameter. The gravel should extend a minimum of 6-inches below and 2- inches above the distribution pipes. • The gravel bed should be completely covered with untreated building paper prior to final soil cover. Final soil cover should be a minimum of 12-inches in 7 x Geotechnical Engineering Exploration Terracon Quality Living Homes Project No. 21985073 thickness and suitable for vegetative growth. The surface of the soil cover should be graded for positive surface drainage and to reduce the possibility of surface water infiltration. It is our understanding an "infiltrator" system may be utilized in place of the standard gravel and pipe leach field. An "infiltrator" system may reduce the required, soil absorption bed size by approximately 50%. However, approval by the Weld County Health Department (WCHD) is necessary. Earthwork ] • Site Clearing and Subgrade Preparation: 1. Strip and remove existing vegetation, debris, and other deleterious materials from proposed building areas. All exposed surfaces should be free of mounds and depressions which could prevent uniform compaction. 1 2. If unexpected fills or underground facilities are encountered during site clearing, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. All excavations should be observed by the geotechnical engineer prior to backfill placement. 1 3. Stripped materials consisting of vegetation and organic materials should be wasted from the site or used to revegetate exposed slopes after completion of grading operations. If it is necessary to dispose of organic materials on-site, 1 they should be placed in non-structural areas and in fill sections not exceeding 5 feet in height. 4. The site should be initially graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed building structures. 5. All exposed areas which will receive fill, floor slabs and/or pavement, once properly cleared and benched where necessary, should be scarified to a minimum depth of 8 inches, conditioned to near optimum moisture content, and compacted. 8 e. 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- mination 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 #200 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•Blows/ft. Relative Density Strength, Qu, 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 Present in Sample) Dry Weight Over 12 in. (300mm) Trace < 15 Cobbles 12 in. to 3 in. V`f!th 15 - 29 (300mm to 75mm) Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75mm) RELATIVE PROPORTIONS OF FINES Sand #4 to #200 sieve (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 • O. 0.2 0.4 0.6 0.8 1.0 1.2 R 1.4 A N 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 0.1 1 10 STRESS.TSF Specimen Identification Classification DD MC% • 1 3.0 SILTY, CLAYEY SAND (SC-SM) 108 8 PROJECT Single FAmily Residence with Septic System - JOB NO. 21985073 S/W/C OF WCR'S 39 & 100 DATE 7/30/98 CONSOLIDATION TEST TERRACON CONSULTANTS WESTERN INC./EMPIRE DIV. 1289 1ST AVENUE GREELEY, COLORADO 0.525 - 0.520 - - - 0.515 - 0.510 V 0.505 ' O I D R 0.500 A T I O 0.495 0.490 0.485 0.480 0.475 0.1 1 10 STRESS,TSF Specimen Identification Classification DD MC% • 1 3.0 SILTY, CLAYEY SAND (SC-SM) 108 8 PROJECT Single FAmilx.EesidenCC with Septic System - JOB NO. 21985073 S/W/C OF WCR'S 39 & 100 DATE 7/30/98 CONSOLIDATION TEST TERRACON CONSULTANTS WESTERN INC./EMPIRE DIV. 1289 1ST AVENUE GREELEY, COLORADO • f% LOG OF BORING NO. 1 • OWNER Page 1 of 1 ARCHITECT/ENGINEER Quality Living Homes SITE S/W/C OF WCR'S 39 & 100 PROJECT Weld County, Colorado Single FAmily Residence with Septic System SAMPLES TESTS . >1 0 Lji DESCRIPTION .c x w wF a z wtx- a X co en a. ] w Soil Description w `" N LU Ho O aU ZFti 3aen p per Depth of Exploration a a z h x mw Aa Dann. mean. 0.5 6" TOPSOIL �IeI/ SM 1 SS 12" 8 4 SILTY. CLAYEY SANQ — ��IIB Tan, light brown, moist, medium dense OI�I� OI�I� 2 sr 12" 8 106 15 PSF '$10 �I�Ir 4-5 3 SS 12' 6 8 SILTY SAND 5 Brown, rust, moist, medium dense — 4 ST 12" 5 SS 12" 1 3 • • 10— 14.0 a QTY SAND w n P G �M SW 6 SS 12" 30 3 15.0 Tan, gray, rust, moist, medium dense 15 BOTTOM OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES 'EFWEEN SOIL AND ROCK TYPES: IN-SITU.THE TRANSmON MAY BE GRADUAL. WATER LEVEL OBSERVATIONS BORING STARTED WL s 7-16-98 DRY WD•( DRY A-B• BORING COMPLETED 7-16-98 N- 1 irerracon RIG CME=55 FOREMAN J1{ Water Checked 2 Days A.B. APPROVED DAR JOB# 21985073 LOG OF BORING NO. 2 Page OWNER ARCHITECT/ENGINEER ag I of 1 Quality Living Homes SITE S/W/C OF WCR'S 39 & 100 PROJECT Weld County, Colorado Single FAmily Residence with Septic System SAMPLES TESTS O 02 • O x toil ZX DESCRIPTION w w - w a u F co co 2 w > z3 A oz o z W UWZ w ccnn ] F C.) Ci O aU ZF3 wiz c7 Soil Description per Depth of Exploration A A Z H x cnal 2 Aa Av�a aaG2 6" TOPSOIL _ 0.5 SILTY SAND Tan, light brown, moist, medium dense SM PA 20 2.5 BOTTOM OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: INSmm.THE TRANSTON MAY BE GRADUAL. WATER LEVEL OBSERVATIONS STARTED WL Q7-16 98 DRY WD• ? DRY BORING COMPLETEDli 7-16 98 erraconJBORING RIG Gym FOREMAN JK WL Water Checked 2 Days A.B. APPROVED DAR JOB a 21985073 I LOG OF BORING NO. 3 OWNER ARCHITECT/ENGINEER Page 1 of 1 Quality Living Homes SITE S/W/C OF WCR'S 39 & 100 PROJECT - Weld County, Colorado Single FAmily Residence with Septic System 8 SAMPLES TESTS a0i be H W O x DESCRIPTION x Wa h wx a x v� W ranJ 4 Z y W zC�7 7 P. U w c r w as O W V Zi,o, aHZ U aa Soil Description per Depth of Exploration C O Z l- a mm Ca acne. Ow _ A 6" TOPSOIL 0.5 SILTY SAND Tan, light brown, moist, medium dense SM PA 20 4.5 SILTY SAND with GRAVE'', 5— �.>' Tan, rust, gray, moist, medium dense 1 SS 12" 45 1 8.0 BOTTOM OF BORING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN-SITU,THE TRANSmON MAY BE GRADUAL. WATER LEVEL OBSERVATIONS BORING STARTED wt_ 4 DRY -16 98 W.D.• ? DRY A.B.A•B• BORING COMPLETED 7-16 98 wL ME RIG CME=55 FOREMAN JI{ WL Water Checked 2 Days A.B. APPROVED DAR JOB 4 21985073 Hello