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HomeMy WebLinkAbout1994 - Geotechnical Services Report GEOTECHNICAL SERVICES REPORT FOR PROPOSED HOUSE 1006 WILDHURST TRAIL ORONO, MINNESOTA AET #94-1805 PREPARED FOR: ROBERT WAADE & ASSOCIATES, INC. 1487 SHORELINE DRIVE WAYZATA, MN 55391 SEPTEMBER 14, 1994 AMERICAN CONSULTANTS •GEOTECHNICAL ENGINEERING • MATERIALS TESTING, INC. •ENVIRONMENTAL Emmu INC, September 14, 1994 Robert Waade & Associates, Inc. 1487 Shoreline Drive Wayzata, MN 55391 Attn: Mr. Robert Waade RE: Geotechnical Services Report Proposed House 1006 Wildhurst Trail Orono, Minnesota AET #94-1805 Dear Mr. Waade: American Engineering Testing, Inc. (AET) has completed services you authorized for geotechnical exploration and engineering services for your proposed house project at 1006 Wildhurst Trail in Orono, Minnesota. We are sending you three (3) copies of our report. Samples we recovered from the boring will be retained for thirty (30) days. We will then discard the samples unless you notify us to do otherwise. AET appreciates this opportunity to provide service to you. As your project proceeds to construction, we remain available to provide additional consulting and quality control testing services to you. Very truly yours, O /k Donovan K. Stormoe, PE Principal Phone: (612) 659-1300 Fax: (612) 659-1379 DKS/sm "AN AFFIRMATIVE ACTION EMPLOYER" 2102 University Ave. W •St.Paul,MN 55114 •612-659-9001 •Fax 612-659-1379 4431 West Michigan Street,Suite#4.Duluth,MN 55807 .218-628-1518 .Fax 218-628-1580 1730 First Avenue.Mankato,MN 56001 .507-387-2222 .Fax 507-387-6999 GEOTECHNICAL SERVICES REPORT FOR PROPOSED HOUSE 1006 WILDHURST TRAIL ORONO, MINNESOTA AET #94-1805 CONTENTS Page INTRODUCTION 1 AUTHORIZED WORK SCOPE 1 PROJECT INFORMATION 2 SITE CONDITIONS 2 Subsurface Soils 2 Ground Water 3 GEOTECHNICAL CONSIDERATIONS 3 CONCLUSIONS AND RECOMMENDATIONS 3 Discussion 3 Soil Correction Method 4 Pile Foundation 5 Construction Considerations 6 SUBSURFACE EXPLORATION 7 General 7 Drilling Methods 7 Sampling Methods 7 Classification Methods 8 Water Level Measurements 8 Sample Storage 9 EXPLORATION PROGRAM LIMITATIONS 9 STANDARD OF CARE 10 CLOSURE 10 CONTENTS PAGE 2 APPENDIX A Boring Location Sketch Log of Test Boring Boring Log Notes Classification of Soils for Engineering Purposes Soil Identification and Description GEOTECHNICAL SERVICES REPORT FOR PROPOSED HOUSE 1006 WILDHURST TRAIL ORONO, MINNESOTA AET #94-1805 INTRODUCTION You are planning to construct a new house at 1006 Wildhurst Trail in Orono, Minnesota. To assist you in planning and design of the project, you authorized AET to perform subsurface exploration and geotechnical engineering services for the project. This report presents our findings and recommendations To protect you, AET, and the public, we authorize use of opinions and recommendations in this report only by you and your project team for this specific project. Contact us if other uses are intended. Even though this report is not intended to provide sufficient information to accurately determine quantities and locations of particular materials, we recommend that your potential contractors be advised of the report availability. AUTHORIZED WORK SCOPE Our services were verbally authorized by you on August 29, 1994. Authorized services are limited to one boring to a depth sufficient to estimate pile capacity, if a deep foundation is needed, and then to prepare engineering recommendations on foundation alternatives for the proposed house. Our authorized work scope did not include determining the presence or extent of any ground contamination at the site. AET #94-1805 - Page 2 PROJECT INFORMATION We understand you plan to construct a 6,000 square foot rambler on the site. At this time, you have furnished us no additional information regarding the project. For purposes of our analysis and recommendations, we assume the structure will be a one story, wood-framed structure with or without a basement. We normally associated relatively light loadings with structures of this type. The above information is important to us in the analysis and recommendations we make. If there are changes, we suggest that we have the opportunity to review the impact of these changes on our recommendations or make additional recommendations which may be appropriate for such changes. SITE CONDITIONS Subsurface Soils One soil boring was drilled at the site at the location shown on the attached soil boring location drawing. The ground elevation at the boring location was referenced to the center of the intersection of Wildhurst Trail and the driveway to the house lot. The elevation at that point was taken as 100.0', an assumed elevation. The elevation of nearby Forest Lake is 95.8, referenced to this assumed benchmark and on the date the borings were made. The boring encountered about 3' of clayey fill overlying about 111/2' of peat and organic clay swamp deposits which are underlain by clayey glacial till which varies from medium to hard. It is difficult to generalize a soil profile on the site based on just one boring. Therefore, subsurface conditions at locations other than where this boring was put down can be significantly different from those conditions depicted by this boring. AET #94-1805 - Page 3 Ground Water Ground water was measured in the boring at a depth of about 7' below the ground surface. It is reasonable to expect that the ground water level would be at or above the level of nearby Forest Lake. Therefore, the water level at this site maybe higher than shown. Variations in ground water conditions can be expected seasonally and annually. GEOTECHNICAL CONSIDERATIONS For our analysis and recommendations, we have considered the following: • Wood-frame residential type construction with finishing materials that do not allow appreciable differential settlement without distress cracking; normal utility services to the structure. • Fill and soft organic deposits to a depth of nearly 15' and which are quite weak and compressible. • Underlying clayey glacial till soils which are quite firm at a depth of about 2' to 3' into the till formation. CONCLUSIONS AND RECOMMENDATIONS Discussion The existing fill and organic soils are not recommended for support of foundations for this structure. The organic deposits are quite weak, and more importantly, very compressible even under light loading conditions. These organic deposits can be expected to subside several inches during the normal life of 50 years or so for the proposed house. With the addition of even very little additional fill on the surface and the overall light loadings of a house, the organic deposits AET #94-1805 - Page 4 can be expected to settle in excess of 1' during a 50-year period. This amount of settlement is more than what is normally tolerable for construction of this type. We have considered surcharging the site to preconsolidate the existing fill and swamp deposits. Due to the highly organic nature of much of these materials, it is our judgment significant total and differential settlement of the structure could still occur even after surcharging. Soil Correction Method The building could be supported on footing foundations after soil correction. Based on the soil information at the boring location, it appears the unsuitable soils extend to a depth of about 141/2' below grade. Depending on the lateral extent of the organic deposits, it may be possible to replace the organic materials with compacted fill. For this method, the unsuitable existing fill and organic soils would have to be removed for their entire depth and laterally beyond the perimeter of the structure a minimum distance so adequate lateral support of replacement fill and the structure supported on that fill would be provided. For organic soils as soft and compressible as indicated in this boring, we recommend that the oversize be at least 11/2' laterally for each 1' of fill below normal depth foundations if the bottom of the organic soils is relatively level. If the surface of the underlying firm clay till materials are sloping downward, the lateral oversize should be increased to 2' horizontally for each 1' of fill required beneath foundations on the down slope side of the excavation bottom. The presence of ground water within the excavation, makes the excavation more difficult. In order to visually determine when the unsuitable soils are removed, you should plan on dewatering the excavation during the excavation operation. It may be difficult to dewater the excavation and maintain stability of the sideslopes without very flat backslopes or retention systems. Attempting to excavate under water is risky in that it is very difficult to determine if all unsuitable soils have been removed. Failure to excavate unsuitable would result in building settlement. AET #94-1805 - Page 5 For the soil correction method, clean granular fill soils are recommended for the entire depth of the fill sequence, due to the saturation which will occur after the fill has been placed. The granular fill should contain no more than 5% material finer than a #200 sieve and should preferably medium to coarse grained. We recommend compaction to a minimum 95% of standard Proctor density (ASTM:D698). After the building pad is brought to grade with compacted fill, the foundations can be supported at normal depth on the fill. All exterior foundations should be extended to a depth of at least 42" below exterior grade for frost protection. Interior footings in heated areas can be supported at minimum depth below the floor slab. In unheated building areas, foundations should extend to a minimum depth of 60" below grade. Based on the soil conditions encountered at the boring location, and on the minimum fill compaction levels recommended, it is our opinion the foundations can be designed based on a maximum allowable soil bearing pressure of 2,000 psf. It is our judgment this design will include a factor of safety of greater than three against sheer or base failure. It is also our judgment that total building settlement should be less than 1", and differential settlement should be less than lh". Pile Foundation An alternate foundation method will be to support the structure on a deep foundation system extending into the underlying clay soils. Considering the relatively low structural loads typical of construction of this type, driven timber piling may be the most practical deep foundation system. Such piling would derive their resistance by a combination of end bearing and side friction in the underlying clay till soils. If a deep foundation system is used, there will be additional load placed on the foundations due to subsidence and down drag of the compressible soils along the surfaces of the deep foundations above the underlying stiffer clay soils. For timber piling, we recommend that you allow at least 10 tons per pile for a drag load of this type. AET #94-1805 - Page 6 That load is in addition to the pile capacity needed to support the structure. Including drag load, we anticipate you may want to consider piles having a working capacity of 30 tons (20 tons building load and 10 tons drag load) per pile. We estimate pile lengths of about 40' to 45' below existing grade to attain a 30-ton capacity. We recommend the pile be driven with a hammer having a manufacturer's rated energy in the range of 15,000 to 25,000 foot-pounds. The pile lengths estimated above are based on static determinations from the boring log. We recommend the capacity be determined in the field with a driving formula such as the Engineering News Record formula. Our estimated pile lengths are based on attaining a factor of safety of about 2 against pile failure. It is also our judgment total and differential settlement of the recommended pile foundation should be less than 1/2". We recommend an experienced structural engineer be retained for design of the grade beam system. Construction Considerations Due to the compressible nature of the existing fill and swamp deposits, consolidation of the swamp deposits and subsequent settlement of lawn areas, driveways, sidewalks and other structures which are supported about the swamp deposits will occur. Utilities which are supported in or above the swamp deposits will also settle. Therefore, the design should include either supporting the utilities structurally or performing soil correction for support of the utilities. Another consideration when organic materials are present is the generation of methane gas. If these gases are trapped beneath an impervious surface layer, they will seek other paths to reach the atmosphere. If there are leaks into the structure, this gas can migrate into the building. Methane is heavier than air and is explosive. Therefore, sealing of the subsurface exterior and all service inlets through underground portions of the structure are important. You should also AET #94-1805 - Page 7 consider methane detectors and basement ventilation which will function if methane reaches concentrations where potential explosive conditions are incurred. SUBSURFACE EXPLORATION General The subsurface exploration program consisted of one (1) standard penetration test boring. The field work was performed on September 2, 1994. The approximate soil boring location is shown on the attached sketch. The boring location was located in the field by AET personnel by taping from nearby site features. Surface elevations were measured in the field by AET personnel using an engineer's level. Benchmark reference was the street elevation at the entrance of the driveway and Wildhurst Trail. This elevation was taken as 100.0', an assumed elevation. Drilling Methods The standard penetration test borings were drilled using hollow-stem augers. Where required by Minnesota Department of Health rules, the boreholes were grouted upon completion. Sampling Methods Split-Spoon Samples (SS) Standard penetration (split-spoon) samples were collected in accordance with ASTM:D1586. This method consists of driving a 2" O.D. split-barrel sampler into the in situ soil with a 140- pound hammer dropped from a height of 30". The sampler is driven a total of 18" into the soil. After an initial set of 6", the number of hammer blows to drive the sampler the final 12" is known as the standard penetration resistance or N value. AET #94-1805 - Page 8 Disturbed Samples I S Some of the samples taken within the upper portion of the profile were disturbed materials taken from the flights of the auger. Sampling Limitations Unless actually observed in a sample, contacts between soil layers are estimated based on the spacing of samples and the action of drilling tools. Cobbles, boulders, and other large objects generally cannot be recovered from test borings, and they may be present in the ground even if they are not noted on the boring logs. Classification Methods Soil classifications shown on the boring logs are based on the Unified Soil classification (USC) system. The USC system is described in ASTM:D2487 and D2488. Where laboratory classification tests (sieve analysis and Atterberg Limits) have been performed, classifications per ASTM:D2487 are possible. Otherwise, soil classifications shown on the boring logs are visual- manual judgments. We have attached charts (Appendix A) illustrating the USC system, the descriptive terminology, and the symbols used on the boring logs. The boring logs include judgments of the geological depositional origin. This judgment is primarily based on observation of the soil samples, which can be limited. Observations of the surrounding topography, vegetation and development can sometimes aid this judgment. Water Level Measurements The ground water measurements are shown at the bottom of the boring logs. The following information appears under "Water Level Measurements" on the logs: • Date and Time of measurement • Sampled Depth: lowest depth of soil sampling at the time of measurement AET #94-1805 - Page 9 • Casing Depth: depth to bottom of casing or hollow-stem auger at time of measurement • Cave-in Depth: depth at which measuring tape stops in the borehole • Water Level: depth in the borehole where free water is encountered • Drilling Fluid Level: same as Water Level, except that the liquid in the borehole is drilling fluid The true location of the water table at the boring locations may be different than the water levels measured in the boreholes. This is possible because there are several factors that can affect the water level measurements in the borehole. Some of these factors include: permeability of each soil layer in profile, presence of perched water, amount of time between water level readings, presence of drilling fluid, weather conditions, and use of borehole casing. Sample Storage We will retain representative samples of the soils recovered from the borings for a period of 30 days. The samples will then be discarded unless you notify us otherwise. EXPLORATION PROGRAM LIMITATIONS The data derived through this sampling and observation program have been used to develop our opinions about the subsurface conditions at your site. However, because no exploration program can reveal totally what is in the subsurface, conditions between borings and between samples and at other times, may differ from conditions described in this report. The exploration we conducted identified subsurface conditions only at those points where we took samples or observed ground water conditions. Depending on the sampling methods and sampling frequency, every soil layer may not be observed, and some materials or layers which are present in the ground may not be noted on the boring logs. Unless actually observed in a sample, contacts between soil layers are estimated based on the spacing of samples and the action of drilling tools. Thus, most contacts shown on the logs are AET #94-1805 - Page 10 approximate, with a possible upper and lower limits of contacts defined by the overlying and underlying samples. Cobbles, boulders, and other large objects generally cannot be recovered from test borings, and they may be present in the ground even if they are not noted on the boring logs. If conditions encountered during construction differ from those indicated by our borings, it may be necessary to alter our conclusions and recommendations, or to modify construction procedures, and the cost of construction may be affected. The extent and detail of information about the subsurface condition is directly related to the scope of the exploration. It should be understood, therefore, that information can be obtained by means of additional exploration. STANDARD OF CARE Our services for your project have been conducted to those standards considered normal for services of this type at this time and location. Other than this, no warranty, either express or implied, is intended. CLOSURE Report Prepared by: Report Reviewed by: OfYY1"nrt-, de2, J1,04:0 -� Donovan K. Stormoe, PE Steven D. Koenes, PE Principal Principal Engineer MN Reg. No. 10493 APPENDIX A Boring Location Sketch Log of Test Boring Boring Log Notes Classification of Soils for Engineering Purposes Soil Identification and Description ! G7 ! - - A `k 1 I 1. PROJECT PROPOSED HOUSE AET JOB NO. l AMERICAN WILDHURST TRAIL; ORONO, MINNESOTA 94-1805 AENGINEERING SUBJECT DATE TESTING, INC. BORING LOCATION SKETCH 9/14/94 ammimm SCALE DR.4 WN BY CHECKED BY PAGE NONE SK - 1 OF 1 AMERICAN AENGINEERING SUBSURFACE BORING LOG TESTING, INC. AET JOB NO: 94-1805 LOG OF BORING NO. 1 (p. 1 of 3) PROJECT: PROPOSED HOUSE, 1006 WILDHURST TRAIL; ORONO, MN FIELD&LABORATORY TESTS DEPTH SURFACE ELEVATION: 97 4 GEOLOGY N MC SAMPLE REC. FEET MATERIAL DESCRIPTION TYPE IN. WC DEN LL PL %-200 Fill, mostly lean clay, dark grayish brown 4 M 1 SS 20 I 2 - Fill, mostly sandy lean clay with a little gravel, FILL brown, gray and black 7 M I SS 12 3 Hemic peat, dark brown and black, moist _m 4 - (PT) 5 - 2 M ' SS 16 6 - Organic clay, dark brown to black, very soft, _ a few laminations of waterbearing sand 7 - below about 7' (OH/PT) SWAMP DEPOSIT WISS 4 8 s - 9 - 7 10 - AllrBoglime with shells, light gray, very soft(OL) 2 W I SS 18 11 — 12 .. 2 W SS 13 - Organic clay with shells, brownish gray, very 3,24 soft (OH) 14 - 15 - 5 M SS 18 16 - 17 - Sandy lean clay with a little gravel, gray to TILL brownish gray to gray, medium to hard (CL) 10 M ' SS 18 18 - 19 - 20 - 21 - / DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO DATE TIME SAMPLEDDEPTHCASING CAVE-IN DEPTH DEPTH FLUID LEVEL LEVEL RILLING WATER THE ATTACHED 0-14.5' 2.25" HSA 14.5- Rotary 9/2/94 12:15 11.0 9.5 9.5 7.2 SHEETS FOR AN 9/2/94 12:25 16.0 14.5 14.5 I 12.1 EXPLANATION OF BORING TERMINOLOGY ON COMPLETED: 9/2/94 _ CC: SG CA: DN Rig: 3 THIS LOG 4/90 AMERICAN AENGINEERING SUBSURFACE BORING LOG TESTING, INC. mom AET JOB NO: 94-1805 LOG OF BORING NO. 1 (p. 2 of 3) PROJECT: PROPOSED HOUSE, 1006 WILDHURST 'FRAIL; ORONO, MN DEPTHGEOLOGYSAMPLE RECFIELD&LABORATORY TESTS . III N MC TYPE IN. FEET MATERIAL DESCRIPTION WC DEN LL PL %-200 23 13 M ' SS 18 24 - 25 - 26 - 27 - 28 - 29 - 30 - 24 MSS 10 31 - / ' 32 - 33 - Sandy lean clay with a little gravel, gray to brownish gray to gray, medium to hard(CL) TILL 34 - 35 - 21 MSS 18 36 - II 37 - 38 39 40 - 23 MSS 18 41 - ' 42 43 - 44 - 45 - 30 MSS 18 46 - / ' 47 - 4/90 AMERICAN AENGINEERING TESTING, INC. SUBSURFACE BORING LOG AET JOB NO: 94-1805 LOG OF BORING NO. 1 (p. 3 of 3) PROJECT: PROPOSED HOUSE, 1006 WILDHURST TRAIL; ORONO, MIN DEPTH FIELD&LABORATORY TESTS IN GEOLOGY N MC SAMPLE REC. FEET MATERIAL DESCRIPTION TYPE IN. WC DEN LL PL %-200 49 - Sandy lean clay with a little gravel, gray to brownish gray to gray, medium to hard(CL) / TILL 32 M SS 18 50 END OF BORING I 4/90 BORING LOG NOTES DRILLING AND SAMPLING SYMBOLS TEST SYMBOLS Symbol Definition Symbol Definition B,H,N: Size of flush joint casing CONS: One-dimensional consolidation test BX: BX double tube core barrel DEN: Dry density, pcf AC: At completion of boring HYD: Hydrometer analysis CA: Crew assistant LL: Liquid limit, % CAS: Pipe casing, number indicates nominal PERM: Coefficient of permeability (K) test; F -Field; diameter in inches L -Laboratory CC: Crew chief PL: Plastic limit, % COT: Clean-out tube q,: Pocket penetrometer strength, tsf DC: Drive casing; number indicates diameter in q : Static cone bearing pressure, tsf DM: Drilling mud or bentonite slurry q : Unconfined compressive strength, psf DS: Disturbed sample from auger flights R: Electrical resistivity, ohm-cms FA: Flight auger; number indicates outside RQD: Rock Quality Designator in percent (aggregate diameter in inches length of core pieces 4" or more in length as a HA: Hand auger; number indicates outside diameter percent of total core run) HSA: Hollow-stem auger; number indicates inside SA: Sieve analysis diameter in inches VS: Vane shear strength(field), psf JW: Jetting water WC: Water content, as percent of dry weight MC: Column used to describe moisture condition of -200: Percent of material finer than#200 sieve samples and for the ground water level symbol N (BPF): Standard penetration resistance (N-value) in blows per foot (see notes) MOISTURE/FROST CONDITION (MC COLUMN) NQ: NQ wireline core barrel PQ: PQ wireline core barrel D Dry RD: Rotary drilling with fluid and roller or drag bit M Moist REC: In split-spoon(see notes) and thin-walled tube W Wet/Waterbearing sampling, the recovered length(in inches) of F Frozen sample. In rock coring, the length of core recovered (expressed as percent of the total STANDARD PENETRATION TEST NOTES core run). Zero indicates no sample recovered. REV: Revert drilling fluid The standard penetration test consists of driving the sampler SS: Standard split-spoon sampler (steel; 13/a" with a 140-pound hammer and counting the number of blows is inside diameter; 2" outside diameter); applied in each of three 6" increments of penetration. If the unless indicated otherwise sampler is driven less than 18" (usually in highly resistant TW: Thin-walled tube; number indicates inside material), permitted in ASTM:D1586, the blows for each diameter in inches complete 6" increment and for each partial increment is WASH: Sample of material obtained by screening on the boring log. For partial increments, the number of returning rotary drilling fluid or by blows is shown over a slash (/) and the partial penetration which has collected inside the borehole less than 6" is shown taking a split-spoon sample of after "falling" through drilling fluid material to the nearest inch below the slash. WAT: Water WH: Sampler advanced by static weight of drill The length of sample recovered, as shown on the "REC" rod and 140-pound hammer column, may be greater than the distance indicated in the WR: Sampler advanced by static weight of drill rod N column. The disparity is because the N-value is recorded 94 mm: 94 millimeter wireline core barrel below the initial 6" set (unless partial penetration defined • Water level indicated in boring in ASTM:D1586 is encountered)whereas the length of sample recovered is for the entire sampler drive. AMERICAN ENGINEERING TESTING, INC. CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES AMERICAN ENGINEERING ASTM Designation: D 2487 TESTING, INC. (Based on Unified Soil Classification System) Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests' Group Group Name3 Symbol Coarse-Grained Soils Gravels Clean Gravels Cu_4 and 1Cc53c GW Well graded graver More than 50%retained on More than 50%coarse Less than 5% fines: No. 200 sieve fraction retained on Cu-44 and/or 1>Cc>3E GP Poorly graded gravel(' No.4 sieve Gravels with Fines Fines classify as ML or MH GM Silty gravel':' More than 12%fines: Fines classify as CL or CH GC Clayey graver:.°'H Sands Clean Sands Cu>6 and 1-Cc-s3` SW Well-graded sand' 50%or more of coarse Less than 5%fines° fraction passes No. Cush and/or 1>Cc,.33 SP Poorly graded sand' 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand•"•' More than 12%fines° Fines classify as CL or CH SC Clayey sand•~'i Fine-Grained Soils Silts and Clays inorganic PI>7 and plots on or above CL Lean clay<LM 50%or more passes the Liquid limit less than 50 "A"lines No. 200 sieve PI<4 or plots below"A" ML SiltK.LM lines organic Liquid limit•oven dried <0.75 OL Organic clayt'L'w.N Liquid limit-not dried Organic silt4A-At° Silts and Clays inorganic PI plots on or above "A" line CH Fat cfay'cLM Liquid limit 50 or more PI plots below"A"tine MH Elastic siltKLM organic Liquid limit•oven dried OH Organic c1ay<•LM.P <0.75 Liquid limit-not dried Organic silf<LM.o Highly organic soils Primarily organic matter.dark in color.and organic odor PT Peat "'lased on the material passing the 3-in.(75-m d sieve. (D l2 if Anerberg limns plot in hatched area.soil is a CL-ML. I 31f field sample contained cobbles or boulders.or both,add -Cu - 040 1010 Co . ji"0 t° silty clay. "with cobbles or boulders.or bot"to group name. ro Kit sod contains 15 to 29%plus No.200.add-with sane" :Gravels with 5 to 12%tines reauire dual symbols: "it soil contains>15%sand,add''with sand"to group or"with gravel."wnit never is predominant. GW-GM well graded gravel with silt name. lit sal containsZ30%plus no.200.predominantly sand. GW-GC-well-graded gravel with clay Gil fines classify as CL•ML,use dual symbol GC-GM.or add"sandy'"to to group name. GP GM poorly graded gravel with silt SC-SM. ui}soil contatnsl-30%plus No.200.predominantly GP-GC poorly graded gravel with clay 'Ill tines are organic.add"wit organic fines"to group gravel.add"gravelly"to group name. Sands with 5 to 12%fines require dual symbols: name. NPtb4 and pots on or above"A•'line. SW-SM well-graded sand with slit 'If soil contains?t5%gravel.add"wit gravel"10 group °PI<4 or plots below"A"line. SW-SC well-graded sand with clay name PPI plots on or above"A-line. SP-SM poorly graded sand with silt °PI pots below"A"line. SP-SC poorly graded sand with day SIEVE ANALYSIS 60 / SCREEN-IN SIEVE N0. fine-"rained far classification of ine 3roined soils loo 3 z +, 0 20 w so •o 200 :00and f ineiroined fraction of coarse-gromed // ! 1 I l I I I — soils. M 50- I I ( a Equation of.A'-line ..{�I oto I r zo c Horizontal at PI-4 to LL-25.5. \�E z I i ! I I I I l l I = w then PI-0.73(LL-20) '^s/ 11S<\ •,\' a 4o- `r' lo.-isi.. l I I I t z Equation of.U'-line ,/ pP I i ac I , I1 I I .o W Vertical at LL=16 to PI=7 / I� r I I I ! x } then PI=0.9(LL-8) / G ~ �0 I I I I I I j 6O .- ~ 30- /1 = .. U I i I : I �a,.-2.5em , I U f- - // Lt . I l I CC In i t I I I "r < zo- / Q i 20 , ; l I l , Ie�."a.075 � /,/�G�ad' I MH °i OH I l• , l i l too i � l0- 1 v so .0 s ;.o 3.5 0.i0 7---/27;C1:: 04%// ML OR OL PARTICLE SIZE IN MILLIMETERS 4 I f I c i•. .a.ms-too 4.(0(.24- I z.f l' .S.6 00 10 16 20 30 40 50 60 70 a0 90 100 110 . aZ0�i 1T LIQUID LIMIT ILL) GENERAL TERMINOLOGY NOTES FOR SOIL IDENTIFICATION AND DESCRIPTION GRAIN SIZE GRAVEL PERCENTAGES Term ASTM AASHTO Term Percent Boulders Over 12" Over 3" A Little Gravel 3%-15% Cobbles 3" to 12" - With Gravel 15%-30% Gravel #4 sieve to 3" #10 sieve to 3" Gravelly 30%-50% Sand #200 to #4 sieve #200 to #10 sieve Fines (silt Pass #200 sieve Pass #200 sieve &clay) CONSISTENCY OF PLASTIC SOILS RELATIVE DENSITY OF NON-PLASTIC SOILS Term N-Value. BPF Term N-Value, BPF Very Soft less than 2 Very Loose 0-4 Soft 2-4 Loose 5-10 Medium 5-8 Medium Dense 11-30 Stiff 9-15 Dense 31-50 Very Stiff 16-30 Very Dense Greater than 50 Hard Greater than 30 FIBER CONTENT OF PEAT (ASTM D4427) ORGANIC DESCRIPTION (ASTM D2488) Term Fiber Content(Visual Estimate) Non-peat soils are described as organic, if soil is judged to have sufficient organic content to Fibric Greater than 67% influence the soil properties. Hemic 33-67% Sapric Less than 33% LAYERING NOTES Laminations - Layers less than 1/2" thick of differing material or color Lenses - Pockets or layers greater than 1/2" thick of differing material or color AMERICAN ENGINEERING TESTING, INC.