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HomeMy WebLinkAboutMINDYER MANORS Plat#78-294 No header sheet S-4880 DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION PLATTING OR PLANNING AND ZONING CASE REVIEW DATE RECEIVED CASE NUMBER S-488(~'~ ,\ PETITION FOR REZONING ~ OF SPECIAL EXCEPTION~ VACATION RE{3UBDIVISION COMMENT TO PLANNING BY ',IUd,,,V 19, ~1978 COMMENTS: ENVIRONMENTAL SANITATION: Youngs Subdivision; Tryck Nyman Hayes for Youngs FOR MEETING OF August 2, 1978 PUBLIC WATER NOT AVAILABLE of Cases PUBLIC SEwER':;NOT AVAILABLE TO SERVICE PETITION AREA. , ' , \ -f . ,' ¢, ii ENVIRONMENTAL ENGINEERING: 71-014 (9/76) 4040 "B" STREET ANCHORAGE, ALASKA 99503 (907) 278-1551 August 8, 1978 W.O. #A18567 Mr. Tod Youngs P.O. Box 4-2482 Anchorage, AK 99509 Subject: Subsurface Investigation for Youngs Subdivision Located in the SW 1/4, Section 3, T. 11N., R. 3 W., Seward Meridian, Alaska Dear Mr. Young: We were requested by Mr. Dave Grenier with Tryck, Nyman & Hayes to perform a preliminary subsurface investigation on the above referenced parcel to ascertain its suitability for construction of on-site sewage disposal systems in conjunc- tion with the development of R-6 type lots. A total of seven, 16' test holes were drilled on the site using a track mounted Mobile Drill B-50 drill rig owned and operated by Denali Drilling, Inc. The test holes were logged and the drilling supervised by Mr. Terry L. Barber, staff geologist with Alaska Testlab. Each hole was drilled using continuous, solid flight auger. As the drill bit was brought to the surface at 5' intervals, samples were taken directly off the drill bit, placed in sealed plastic bags and transported to the laboratory where their natural moisture content and dry strength were determined. Each sample was then visually classified with samples of similar color, texture, and grain size distribution being given an arbitrary group designation. Further testing was then performed on composite sample from. the group rather than on individual samples. Due to the necessity of getting this report out prior to the Municipal Planning meeting, we have not yet completed the laboratory testing on the soils samples. We have therefore, included with this report copies of the field logs and no laboratory test results. In a few days an addendum to this report will be issued with the final test hole logs, descrip- tion of soil types encountered and copies of the laboratory test results. Mr. Tod Youngs ~ugust 8, 1978 Page 2 Slotted, 3/4" PVC pipe was placed to full depth in test holes #1, #5, and #7 and a percolation test run in those holes° The results of those percolation tests are:· Test Hole 91: Test Hole #5: Test Hole #7: 10 minutes/inch 8 minutes/inch· 20 minutes/inch In addition, to drilling the holes and running a percolation test, our geologist walked the entire site, mapping out the paths of the two streams that transverse the site. It became obvious from the drilling, and from walking the site, that there were areas of poor drainage the ground surface and shallow soils were saturated. Four major areas where this occurred were identified and are mapped out by ~he geologist. These are shown on Figure 1. In addition, there were two areas where seepage was coming out of road cuts'and those were also identified on the enclosed Figure 1. It should be noted that shallow, subsurface water was encountered in test holes #4, #4A, #2, and #6. There is some problem with subsurface water on this site. Except in the areas immediately adjacent to the two streams, we do not feel that this shallow, subsurface water is true ground water, or even perched water. It is our opinion~.~·~_ that it is merely surface runoff associated With the heavy~ rains of the past two months that has not drained'properly and has saturated certain areas of the site. This saturation generally extends to a realtively shallow depth, i.e., less than ·10' In other cases, it is following more permeable seams and may exist relatively close to the surface, say less than 10'. Based on the data that we have collected there should be no problem, from a permeability standpoint, with constructing on-site sewage disposal systems to meet MUnicipal standards on all proposed lots within the subdivision. Additional soils and percolation data may be present to give specific design values for certain lots. We refer you to Table B included in this report, that is the summary listing of each lot of the subdivision with an estimated percolation rate. However, due to the presence in some areas, as identified on Figure ~ of shallow, subsurface water, it may be necessary to do additional testing to verify locations on specific lots where shallow, subsurface water will not affect the on- Mr. Tod Youngs ~ugust 8, 1978 Page 3 site disposal system. It may also be necessary to reduce the area of influence, and the amount, of shallow, .subsurface water through the use of improved drainage and ditching. This matter needs further consideration. If we can offer any clarification for any item discussed in this report or any data presented, please contact us. Very sincerely, ALASKA TESTLAB Melvin R. Nichols, P.E~ Laboratory Manager MRN:rb:mm Enclosures Lot' Block 1 Block 2 Percolation Rating 8 Min/inch 12 Min/inch 15 Min/inch 15 Min/inch 12 Min/inch 12 Min/inch 20 Min/inch 20 Min/inch 20 Min/inch 20 Min/inch TABLE B Comments Measured rating. Estimated rating. Keep system in SW portion of lot. Estimated rating. Keep system well above stream and wet area. May encounter shallow subsurface water. Estimated rating. Control shallow subsurface water or find a spot on the lot ' where it does not present a' problem. Visual rating. Control shallow subsurface or find an area on the lot where it does not present a problem. Visual rating. Control shallow surface water or find an area found on the lot where it does not present a problem. Measured rating. System needs to be kept to the rear of the lot to avoid problems with shallow subsurface water. Measured rating. Keep the system to the rear of the lot to avoid problem with shallow subsurface water. Measured rating. Keep the system mid-way between the two streams to avoid shallow subsurface water. Estimated rating. Keep the system mid-way'between the two streams on the rid~? to avoid problems with shallow subsurface water. (Continued) Table B (Continued) Lot (Block 2) 5 Block 3 1 Percolation Rating 12 Min/inch 20 Min/inch 20 Min/inch 10 Mifr/-i'Ach Co~,~,ents Estimated rating. Keep the system to the north portion of the lot to avoid shallow subsurface water problems. Estimated rating. Shallow subsurface water if encountered should be controlled or an area on the lot found where it does not present a problem. Estimated rating. Shallow subsurface water when encountered must'be controlled or found on ..an area of the lot where it does not present a problem. Measured rating. NOTES: Ail estimated ratings are from extropolated data and are intended to be quite conservative. It may prove economic on those lots to actually place a test hole and run a percolation test prior to constructing a system on the site. This is particularly true on Lots 3, 4, 5, 6, and 7, Block 2. 5 It is anticipated that shallow, subsurface water may present problems in Block 1, Lots 2, 3, 4, 5, and 6; Block 2, Lots 6 and 7. Test HOle Field Hole No. Location Water Level While Drilling Water Level After Drilling, Frost /"/ r~ ~, ~ Drill ,C~ .... /. Log Weather Project f,, '2 -~'i/'/. Hole No. ~ ~ Location Test H'~le Field- Log Water Level While Drilling ~/.¢;--,.- Logged By,&~/,'/ Water Level After Penetration Client Project Hole Locotion Test H61e Water Level While Drilling Water Level After Drilling Frost // .... u.: Drill ...... Field- Log W, O. No. Logged By--'v Driller Weather ,~/L/j/ -/ A-~TES~TLAB Client Project Ho~e No. ///~ Location Test Hole Field'Log W.O. Date III II I I I II I I II I Water Level While Drilling ~-"'--/'~ · _:. Logged By Water Level After Drilling Driller ;2, Frost /}}~, .~ '~ ~ /:~ ~- Drill ~_~-~9/J ~' Weather '-T-ESTLAB) Client Project Hole No. Location Test Hole Field' L'og W.O. No. /r- ,, , Date Water Level While Drilling -~>~,~ ._/.x~? Logged By---?' Water Level After Drilling. Driller .!-'~./'..~' Frost /-/~ ~' .~ "? ~ ~:Drill ./'/-:" ..'? "?~ Weather I Ill tl I II II I I II I Client '>%,..- ~ Project ~' Hole No. ~_~ -- Location Test H'O'I e Field-Log Water Level While Drilling Water Level After Drilling Frosf '; ' J Date ?- ~7- '-: :' ~;' - ~ Logged By ~': -'T /' Driller _,/~4~ Drill /~'L"'_'k½ -: Weather (ALAS ~KA~-TES.TLAB'') Client · .~/~a Project )'~O ..,..~ ~'¢T/~ ~ Hole No. 7 J Location Test Hole Field'L'og W.O. No.~ ~ ... ~-, / Date '~ -/- -?~' Water Level While Drilling //~?,-,, '? "~ '. Logged By. Water Level After Drilling Driller Frost: ~ '3 ~ , .: '~ ~.~Drill ~ ~-.": Weather Test Hole Lo~l - Description Guide The soil descriptions shown on the lugs are the best estimate of the soil's characteristics at the time of field examination and as such do not achieve the precision of a laboratory testing procedure. If the log includes soils samples, thom samples receive an independent textural classification' in the laboratory to verify the field examination. The logs often include the following items: Depth Interval - usually shown to 0.1 foot, within that zone no significant change in soil type was observed through drill action, direct observation or sampling, Frost Classification - NFS, FI, F2, F3, F4, see "Soil Classification Chart" Texture of Soi~ - An engineering classification of the.soils by particle stze and proportion, see "Soil Classification Chart", note the proportions are approximate and modifications to the soil group due to stratificatinn, inclusions and changes in properties are included. ;Moisture Con£ent this is a qualitative measure: dry, m~ or little apparent surface moisture, damp, moisture forms portion of color, less than plastic limit, wet, no frec water, often soft, ii' cohesive soil, saturated, free water may be squeezed out, ifa free draining soil; dilatent at natural moisture content, if a non-plastic silt or fine sand. (The moisture content is further defined by reference to PI, LW, NP. M%or dilatency.) Density - refers to more-or-less non-cohesive soils, such as sand gravel mixtures with or without a fine fraction, derived from drilling action and/or sample data: usually described as: very loose, loose, medium dense, very dense. General intent is to portray earthwork characteristics. Stiffness - refers to more-or-less cohesiv? soils and-fine grained silts of t e'"~y-silt groups. Derived from drill action and/or sample data. Very soft, soft, stiff, very stit'f and hard are commonly used serms. Particle size - The largest particle recovered by the split spoon is 1-3/8". Shelby tube Y'. auger (lights (minute-man) 2". Auger flights (13-50 hollow stem) b"-8". Larger particles are described indirectly by action of cite drilling and are referred to as cobbles, 3" to 8", or boulders 8"+. Therefore when reviewing the gradation sheets, if any, the description on'the hole log must be considered for an'indication of larger particles, Unified Soft Classification - This is a two letter code, See Unified Classification sheet t~r further definition. In some cases AASHO and/or FAA soil classifications may be shown as well as the unified. Atterberg Limits - useful for fine grained and other plastic soils. PI; natural moisture content believed to be less than plastic limit PI+; natural moisture content believed to be between plastic and liquid I-/mits L..~; natural moisture content believed to be greater than liquid limit - N.~.P; non-plastic, useful as a modifying description of some silty mat~ri~ls. Dilatencv, - is the abdity o( water to migrate to the surface of a saturated or nearly saturated soil sample when vibrated or jolted - used as an aid to determine if a fine grained soil is a slightly or non-plastic silt or a volcanic ash. Rock flour - finely ground soil that is not plastic but otherwise appears similar to a c~yey silt. Organic Content - usually described as Peat, PT, sometimes includes discrete particles such as wood, coal, etc. as a modifier to an inorganic soil. Quantity described as; trace, or an estimate of volume, or, in case of ail organic, - as Peat. This may include tundra, muskeg and bog material. Muck - a modifier used to describe very soft, semi-organic deposits usually occuring below a peat deposit. Amorphus peat - organic particles nearly or fully disintegrated. Fibrous Peat - organic particles more-or-less intact. Bottom ofTesthole - includes last sample interval. Frost Line - seasonal frost depth as described by drilling action and/or samples at the time of drilling. Frozen Ground - other than frost line. described by samples, usually includes description of ice content, often will include modified Unified Classification for frozen soils - this is a special case related to permafspst studies, Free Water Level -- The free water level noted during drilling. This is not necessarily the static water table at the time of drilling ot ~t other seasons. Static water table determination in other than very permeab e soils requires observation wells or piezometer installations, used only in special cases. Blow/6" - The number of blows of a 140 weight free falling 30" to advance a 2" split spoon 6"; the number of blows for a 12" advance is, by definition, thc standard penetration. .A% - natural moisture content of the soil sample, usually nnt pe--~r ormed on clean sands or gravels below the water table. Type of Sample - S__P, refers to 2" split spoon driven into the soil by la0 pound weight, a disturbed sample, _S, thin wall tube, "Shelby" Used to obtain undisturbed samples of fine grained soil, G, "grab" disturbed sample from auger flights or wall of trench. .~, cut sample, undisturbed sample from wall of trench. Dry Strength - a useful indicator of a soil's clayey fraction, N=None. L=Low, M~Medium, H=High - The samples are placed into apparently similar groups based or and texture and are arbitrarily assigned a group '.etter. Further disturbed tests including Atterberg Limits, grain size, moisture~tensity relationship, etc. may be performed on the group and are assumed to reflect the general distrubed characteristics of the soils assigned to the group. This is an important phase of the soil analysis and is used to standardize the various qualitative determinations and to reduce the number of quantitative tests necessary to describe the soil mass. SOIL CLASSIFICATION CHART 30% GRAVEL CLAY \ CLAYEY CLAYEY CLAYEY oR\ OR SI LTY SI LTY SILTY SAND GRAVELLY SAND CLAYEY SILTY SANDY GRAVEL GRAVEL GRAVEL (+#4 SCREEN) % BY WEIGHT NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN 0,02 mm. GROUPS OF FROST-SUSCEPTIBLE SOILS: F1 GRAVELLY SOILS CONTAINING BETWEEN 3 AND 20% FINER THAN 0.02 mm. F2 SANDY SOILS CONTAINING BETWEEN 3 AND 15% FINER THAN 0.02 mm. F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN 0.02 mm. AND SANDY SOILS {EXCEPT FINE SILTY, SANDS) CONTAINING MORE THAN 15% FINER THAN 0.02 mm. b. CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS. F4 aD ALL SILTS INCLUDING SANDY SILTS. b, FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN 0.02 mm. c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12. d. VARVED CLAYS, /\ SAND GRAVELLY SAND SANDY GRAVEL GRAVEL 0 10 20 30 40 50 60 70 80 90 100 ! 4040 "B" STREET ANCHORAGE, ALASKA 99503 (907) 278-1551 W.6. #A18~67 Mr. Todd Youngs P.O. Box 4-2482 Anchorage, AK 99509 Subject: Addendum to Subsurface Investigation for ~ubdivision ~'~ ~ Dear Mr. Youngs: As discussed 'in our original report to you dated August 8, 1978, we had not time to complete the laboratory analysis of the soil samples taken during the subsurface investigation for the above referenced project. That work has now been completed. This addendum is intended to give a detailed description of the major soil groups encountered during the exploration, present the final adjusted test hole logs, and present all of the results of the laboratory testing. Six major soil groups were identified and are described be'iow: Group A is a brown Sandy Gravel, it is non-frost suscep- tible, being rated NFS. Its unified classification is GW and its gradation is shown on Sheet 1. This material will be excellent for base material for road construction. Its permeability is high and it should prove excellent for disposal of effluent from on-site sewage disposal systems. Group B is a grey Silty Gravelly Sand that is highly frost susceptible, being rated F-3. Its unified class- ificatioh is SM and its gradation is shown on Sheet 2. This soil is moderately permeable. Group C is a grey to brown Silty Sandy Gravel that is moderately frost susceptible, being rated F-1. Its unified classification is SM. This is a borderline material between a gravel and a sand. The gradation for this group shown on Sheet 3 shows the soil as being a sand, however, this is probably incorrect in a strict sense in the native state, because the drilling does not pick up as much of the coarse fraction as usually exists. Therefore, on the test hole logs this material has been referred to as a gravel rather than a sand. Mr. Todd Youngs August 14, 1978 Page Two Group D is a brown Sandy Silt that is highly frost sus- ceptible being rated F-4. Its unified class- ification is ML. Group E is a brown Silty Sand that is mcderately frost susceptible, being rated F-2. Its unified class- ification is SM. Group F Ks a grey Sandy Silt that is highly frost sus- ceptible, being rated F-4. Its unified class- ification is SM. Its gradation is shown on Sheet 4. In reference to the Table B included in the initial report dated August 8, 1978, it listed an estimated, or actual, percolation rating for each lot of the subdivision. We would like to add to that a note of caution. These values obviously come from extrapolation of data. Indeed even where a single test hole is placed on one lot, that test hole represents a very small portion of the actual surface area of the lot. Therefore, the values listed in that table should only be used as an indicator and should be verified by visUal classification of the soils at the time the exca~ vation of the absorption trench is completed. If the soils appear to vary substantially from the descriptions given in the test hole logs, either much more permeable or much less permeable, the writer should then be contacted so that an adjusted rating of the soil be accomplished. If there are any further questions, please do not hesitate to contact us. Very sincerely, ALASKA TESTLAB Melvin R. Nichols, P.E. Laboratory Manager MRN:rb Enclosures Test Hole #1 Table A WO #Al 8567 Logged By: O.M. Hatch Date: 7-29-78 Depth in Feet From To 0.0' - 0.5' 0.5' - 3.0' 3.0' - 16.0' Soil Description Brown Peat, Pt, damp, soft. F-2, brown Silty Sand, SM, damp, medium density. NFS, brown Sandy Gravel, GW, damp, medium den- sity, Group A. Bottom of Test Hole: 'Frost Line: Free water Level: 16.0' None Observed None Observed Sample Depth 1 5.0' 2 10.0' Type of Dry M% Sample Strength Group Unified - G ..- A GW - G - A GW Remarks: 1. 3. 4. 5. 6. Type of Sample, G=Grab, 'SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #2 Table A WO #A18567 Logged By: O.M. Hatch Date: 7-29-78 p~pth in Feet From To 0.0' - 1.0' 1~0' - 7.0' 7.0' - 10.0' 10.0' - 16.0' Soil Description Brown Peat, Pt, damp, soft. F-3, brown Silty Sandy Gravel, SM, damp, medium density, particles to 3", Group B. F-4, brown Sandy Silt, ML, damp, stiff, NP, particles to 2", Group D. F-3, brown Silty Sandy Gravel, SM, damp, high density, particles to 12", Group B. Bottom of Test Hole: Frost Line: Free Water Level: 16.0' None Observed 3.0' two days after drilling Sample Depth I 5.0' 2 10.0' 3 16.0' M% Type of Dry Sample Strength Group Unified G - B SM G - D ML G - B SM Remarks: 1. 3. 4. 5. 6. Type of Sample, G=Grab, SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study Qnly. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #4 Table A WO #A18567 Logged By: T.L. Barber Date: 8-5-78 Depth in Feet From To 0.0' - 0.5' 0.5' - 12.0' 12.0' - 16.0' Soil Description Brown Peat, Pt, wet to saturated, soft. NFS, brown Sandy Gravel, GW, damp to saturated, high density,.Group A. F-3, grey Silty Gravelly Sand, SM, saturated, medium to high density, particles to 1", Group B. Bottom of Test Hole: Frost Line: Free Water Level: 16.0' None Observed 7.5' Sample Depth 1 5.0' 2 10.0' 3 16.0' Type of Dry.. M% Sample Strength Group Unified 4.2 G N A GW 8.7 G N A GW 12.3 G L B SM Remarks: 1. e 3. 4. 5. 6. Type of Sample, G=Grab, SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #4A Table A WO #A18567 Logged By: T.L. Barber Date: 8-5-78 Depth in Feet From To 0.0' - 3.0' 3.0' - 16.0' Soil Description Brown Peat, Pt, saturated, soft. F-l, grey to brown Silty Sandy Gravel, GM, damp to saturated, damp aT ]~.07~ ~-~up C. Bottom of Test Hole: Frost Line: Free Water Level: 16.0' None Observed 6.5'-12.0' Type of Sample Depth M% Sample 1 5.0' 7.7 G 2 10.0' 10.2 G 3 16.0' 11.6 G Dry Strength Group Unified N-L C GM L C GM L C GM Remarks: 1. '2. 3. 4. 5. 6. Type of Sample, G=Grab, SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #5 Table A WO #A18567 Logged By: T.L. Barber Date: 8-7-78 Depth in Feet From To 0.0' - 0.5' 0.5' - 6.5' 6.5' - 11.'5' 11.5' - 16.0' Soil Description Brown Peat, Pt,. damp, soft. F-l, brown Silty Sandy Gravel, GM, damp, high density, Group C. F-4, brown Sandy~Silt, ML, random gravel, damp, stiff, NP, Group D. F-2, brown Silty Sand, SM, damp, medium to high density, particles to 3/4", tight, Group E. Bottom of Test Hole: Frost Line: Free Water Level: Sample" Depth M% 1 2.5' 3.8 2 10.0' 11.7 3 16.0' 8.1 16.0' None Observed None Observed Type of Dry Sample Strenqth Group Unified G N C GM G L . D ML G L E SM Remarks: 1. e 3. 4. 5. 6. Type of Sample, G=Grab, SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #6 Table A WO #A18567 Logged By: T.L. Barber Date: 8-7-78 Depth in Feet From To 0.0' - 10.0' 10.0' - 15.0' Soil Description F-l, brown Silty Sandy Gravel, GM, damp to saturated, me~' density, Group C. F-3, brown Silty Gravelly Sand, SM, damp to wet, Group B. Bottom of Test Hole: Frost Line: Free Water Level: 15.0' None Observed Saturated 4.0' to 8;0' Sample Depth 1 2.5' 2 5.0' 3 10.0' 4 15.0' Type Of Dry M% Sample Strength Group Unified 9.0 G L C GM 9.3 G L C GM 10.2' G L-M B SM 10.2 G L B SM Remarks: 1. e 3. 4. 5. 6. Type of Sample, G=Grab, SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #7 Table A WO #A18567 Logged By: T.L. Barber Date: 8-7-78 Depth in Feet From To 0.0' - 0.5' 0.-5' - 7.0' 7.0' - 20.0' Soil Description Brown Peat, Pt, wet to saturated, soft. F-3, brown Silty Gravelly Sand, SM, medium density, Group B. F-4, grey Gravelly Sandy Silt, SM, damp to wet, stiff, NP, Group F. Bottom of Test Hole: Frost Line: Free Water Level: 20.0' None Observed None Observed Sample Depth I - 2.5' 2 5.0' 3 10.0' 4 15.0' 5 20.0' Type of Dry M% Sample Strength Group Unified 7.4 G L B SM 8.9 G N C GM 10.1 G L-M F SM -9.6 G N-L F SM 12.0 G L-M F SM Remarks: 1. m 3. 4. 5. 6. Type of Sample, G=Grab, SP = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. o ~ ~ o II II o~ ~ ~ ~ o Test Hole Lo~ - Description Guide The soil descriptions shown on the logs are the best estimate of the soil's characteristics at the time of field examination and as such do not achieve the precision of a laboratory testing procedure, If the log includes soils samples, those samples receive an independent textural classification in the laboratory to verify the field examination. The logs often include the following items: , Depth Interval - usually shown to 0.1 foot, within that zone no significant change in soil type was observed through drill action, direct observation or sam piing. Frost Classification - NFS, Fl, F2, F3, F4, see "Soil Classification Texture of Soil - An engineering classification of the soils by particle size and. proportion, see "Soil Classification Chart", note the proportions are approximate and modifications to the soil group due lo stratification, inclusions and changes in properties are included. Moisture Content this is a qualitative measure: d_[Z, no or little apparent surface moisture, damp. moisture forms portion of color, less than plastic limit, wet, no free water, often soft, if cohesive soil, saturated, free water may be squeezed out, ifa free draining soil; dilatent at natural moisture content, if a non-plastic silt or fine sand. (The moisture content is further defined by reference to PI, LW, NP, M%or dilatency.) Density - refers to more-or-less non-cohesive soils, such as sand gravel mixtures with or without a fine fraction, derived from drilling action and/or sample data; usually described as: very loose, loose, medium dense, very dense. General intent is to portray earthwork characteristics. Stiffness - refers to more-or.less cohesive soils and fine grained silts of ~silt groups. Derived from drill action and/or sample data. Very soft, soft, stiff, very stiff and hard are commonly used terms. Particle size -- The largest particle recovered by the split spoon is 1-3/8", Shelby tube 3", auger flights {minutc-manJ 2", Auger flights (13-30 hollow stem) 6"-g". Larger particles are described indirectly by actioh of tile drilling and are referred to as cobbles, Y' to 8". or boulders 8"+. Therefore when reviewing the gradation sheets, if any, the description on the hole log must be considered for an'indication of larger particles. Unified Soil Classification - This is a two letter code. See Unified Classification sheet lk)r further definition. In some cases AASHO and/or FAA soil classifications may be shown as well as the unified. Atterberg Limits - useful for fine grained and other plastic soils. Pl; natural moisture content believed to be less than plasti~ limit PI+; natural moisture content believed to be between plastic and liquid l~mits Rock flour - finely ground soil that is not plastic but otherwise appears similar to a clayey silt. Organic Content - usually described as Peat, PT, sometimes includes discrete particles such as wood, coal, etc. as a modifier to an inorganic soil. Quantity described as; trace, or an estimate of volume, or, in case of all organic, - as Peat. This may include tundra, muskeg and bog material. Muck - a modifier used to describe very soft, semi-organic deposits usually occuring below a peat deposit. Amorphus peat - organic particles nearly or fhlly disintegrated. Fibrous Peat - organic particles more-or-less intact. Bottom of Testhole - includes last sample interval. -. Frost Line - seasonal frost depth as described by drilling action and/or samples at the time of drilling. Frozen Ground - other than frost line, described by samples, usually includes description of ice content, often will include modified Unified Classification for frozen soils - this is a special case related to permafrost studies. Free Water Level - The free water level noted during drilling. This is not necessarily the static water table at the time of drilling or at other seasons. Static water table determination in other than very permeable soils requires observation wells or piezometer installations, used only in special cases.. Blow/6" - The number of blows of a 140 weight free falling 30" to advance a 2" split spoon 6"; the number of blows for a 12" advance is, by defi~tition, the, standard penetration. ,d% - natural moisture content of the soil sample, usually not pe~ormed on clean sands or gravels below the water table. Type of Sample - S.._P. refers to 2" split spoon driven into the soil by 140 pound weight, a disturbed sample, S, thin wall tube. "Shelby" used to obtain undisturbed samples of fine grained soil, G, "grab" disturbed sample from auger flights or wall of trench, C. cut sample, undisturbed sample from wall of trench. Dry Strength - a useful indicator of a soil's clayey fraction, N=None, L=Low, M=Medium, H=High L_._~; natural moisture content believed to be greater than Liquid limit Group - The samples a, re placed into apparently similar groups based .... on color and texture and are arbitrariiy'a~signed a group '.etter. Further NP; non-plastic, useful as a modifying description of some silty disturbed tests including Atterberg Limits, grain size, moisture4ensity materials, . relationship, etc. may be performed on the group and are assumed to reflect the general distrubed characteristics of the soils assigned to the Dilatency - is the abdity of water to migrate to the surface of a group. This is an important phase of the soil analysis and is used to saturated or nearly saturated soil sample when vibrated or jolted -- used standardize the various qualitative determinations and to reduce the as an aid to determine if a fine grained soil is a slightly or non-plaltic number of quantitative tests necessary to describe tile ~oil mass. silt or a volcanic ash, SOIL CLASSIFICATION CHART ! 30% GRAVEL ClAY OR SILTY SAND SAND:': CLAYEY CLAYEY /;:~CLAYEY :":SILTY;:::'.' .:.GRAVELLY SAND GRAVELLY 20 30 GRAVEL / SAND SILTY SANDY GRAVEL SANDY ;RAVEL :GRAVEL,: GRAVEL 0 1 0 40 50 60 70 80 90. (+#4 SCREEN) % BY WEIGHT NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN 0.02 mm. GROUPS OF FROST-SUSCEPTIBLE SOILS: F1 GRAVELLY SOILS CONTAINING BETWEEN 3 AND 20% FINER THAN 0.02 mm. F2 SANDY SOILS CONTAINING BETWEEN 3 AND 15% FINER THAN 0.02 mm. F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN 0.02 mm. AND SANDY SOILS (EXCEPT FINE SILTY, SANDS) CONTAINING MORE THAN 15% FINER THAN 0.02 mm. b. CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS. F4 a. ALL SILTS INCLUDING SANDY SILTS. bo FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN 0.02 mm. c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12. d. VARVED CLAYS. 1 O0 SUBSURFACE INVESTIGATION FOR YOUNGS SUBDIVISION SW1/4, Section 3, TllN, R3W, SM, Alaska. The subsurface investigation was conducted on July 3, 1978 using a Case 580 Backhoe to excavate the test pits. Test pit sites were chosen by the Engineer and logging was performed by Marvln Beyer, P.E. A total of 2 test pits were placed at locations on the property so as to reasonably represent the soils within the proposed subdivision. Test pits are located by pacing from topographic features determined from the topographic map of the area; therefore, locations are approximate. The proposed subdivision is located south of Anchorage on the eastern side of Turnagain Arm. The area is heavily tree covered with a small stream traversing the property. The soil consists of about 2 feet of black organic silt underlain with silty sandy gravel with lenses of clean sand and clean gravel. An existing road traverses the property and this road has been constructed by removing the black organic silt topsoil grading and using native material for a road bed. The free water level encountered in Test Pit No. 1 appears to be a localized occurrance and is not indicative of the ground water level of the area. All soils analyses were by visual classification. lmc Test Pit No. 1 Depth in Feet From To 0.0 o.5 0.5 2.2 2.2 4.8 4.8 I0.5 10.5 13.0 YOUNGS SUBDIVISION Date: 7-3-78 Logged by: M. Beyer, P.E. Soil Description Vegetation OL, black organic silt F4, CL, clayey silt, blue, plastic, some gravel and sand F2, GM, silty sandy gravel NFS, GP, fine sandy gravel 13.0 Free water level: Bottom of Hole 10.5' Test Pit No. 2 Depth in Feet From To 0.0 1.0 1.0 7.O 7.O 8.2 8.2 12.0 YOUNGS SUBDIVISION Date: 7-3-78 Logged by: M. Beyer, P.E. Soil Description Fl, GM, Silty gravel fill F2, GM, Silty sandy gravel, damp Fl, GM, Lens of cleaner sandy gravel, damp, loose F2, GM, Silty gravelly sand, hard, dry, occasional 4"+ boulder 12.0 Free water level: Bottom of Hole None ~ ~Test Hole Lo9 - Descrintlon Guide The ,'~ -h~criptions shown on the logs ate the hess estimate of the soil's .:haracterishcs at thc time of field examination and its such do no[ achieve th~ precision -.~ a laboralo~y tcs(ing procedure. I[ t~e log ~cludes soils samplc~, those samFs':s receive an independent textural classification in thc laboratory The logs. hen include the following items: usually shown to 0.! foot, within that zone no D,..k, th lnte_.r~a~l "itl s~d type was observed through drill action, d~ect observation or .ampling. F~v'~ chssific.ado~ '~ NFS, Fl, F2, F3, F4, see "Soft Classification -[, <~urc of soil -- An e.gincering classification of the soils by particle ~il~--~---~r~poruon: see "Soil Cl~sslfication Ch~r~", note thc p.%mttio.s arc approxlmdte and m.di[ic~cions to the soil group due to s-:~'t'i'~t"n mdusionsand ch~nges in properties ~re included' '-~y~V: o~ I~ttle appdrcm snrfacc moisture, ~p m~.i~mrc forms portion ot color, less th~n plastic limit, ~i.'~.~ hc~ wa:e~, often sofh if cohesive soil, saturated, free ~ater n ay be squeezed out, if~ free draining soil: ~l~c.~t ,,~t~al moisture corneal, if a non-plastic silt or fine ~nd (Thc moisture content is further definedby reference to ~1, D', si ~ ~t~crs to mme.~)t-less non-cohc;ive soils, such as sand gravel ~ .7~s .oh o~ w.heut a fine frac6on, derived from drilling action and/or ~ample da~a: o~'. a y described as: vury loose, loose, medium ~:Hffness ~- tefcr~ to more-o~-less cohesive soils and fine grained silts of ~l~-silt groups. Derived dom drill-action and/or s~mple data. Very sof~. ¥~tt, c~fff, very s~df and bard are commofily used terms. t~artide siz~ - Thc largest par6cl~ recovered by the split spoon is i.~.'~gL:~bv tube 3", auger ~igh~s (minute-man) 2", Auger fligh~s (B-50 holL~ ~tem~ b"8". Large: pi~6cles are described ind~ectly by action ol :be dfiHb~g an~ arc referred to as cobbles, 3" to 8", or boulders 8"*, Thecelorc whm~ ~eviewing the gradation shee~s, if ~n), - H:,: hole log taus: ~c consi~e~e~ for affindicadon of This is a wo totter code. See Unified Unified Soil Cl.~s~r~?~ - dcfini.on. In some cases AASHO and or FAA ~oil d~ssif~cadv-~ m~y be shown as well ~s ~he unified. fi~te~berg Limits -usctul For fine grained and other plastic sous. Dh r,~tmM moisture ~onte~t believed to be less th~n phs~ic ~mit PI~: nat~l moisture content believed to be between plastic ~nd liquid L~; n~tmal moisture content believed to be greater th~n liquid limit NP; no~ph~tic, uscml as a modifying description of some silty Ddatenc~ - is the ..bdity of wa~er to migrate to ~he surface of ~ saturated ar neatly ~aturatcd soil sample when vibrated or jolted -- used as an aid [o determine if a fine grained soil is a slighdy ot non.plastic Rock flour - finely ground soil that is not plastic but otber,.v~se :,irnil~r~ to a clayey silt. Organic Conical - usually described as Pe~t, PT. scmetime~ include: ~s~t~ partlc~ such as wood/coal, etc, as ~ modal;er to ,m inorgitm~. soil, Quantity described as; trace, or an estimate of ~oiumc, or, m case of all organic, - as Peat. This may include tundra, muskeg and brat material. Muck ~ a modifier used tn descril~e very sof~, semi.organic usu~ yoccurlngbelewa peatdepos~ Am..~orphus, c~ - organic particles nearly or f~,!h disl,steg:itted- Fibrous Peat - crgamc p~rticles more-or-less intac/.. Bottom of Tcsthole includes last sample interval. Frost Line - sea.nil frost depth as described ~ drdli~ ~dion ~m~'~-s'a~ the t.ne o( in~ dcscrip[~ot~ of ice content, often will r,:,.v~e mudO~cd Cl~ssil~cahon for frozen soils -- dos is a sr:c~al cay permaf[ost Free Water Level - The f~ee water level n-~ed during.: .~ "g not ~cessaril~ t~e stout v,'ate~ table ~t thc tbnc r,f dtt ,r a' ~oils requires observation wells o~ [,etomcter m~® o, ~ ! :~t~ special cases. ~1o~16" - The number o[ blov s of a 140 wegbt flee taql'~g 1W' ~'. advance a 2" split spoon 6"1 the number o( bl:3-'-'s for a 12'~ advance by definition, tbe ~andard pen~ ~ ~on. weight, a disturbed s~mple, ~, ddn wMl tube, "Shelby" esed to obtain undisturbed sampl' of fine g~amed soil, ~,"grab" disturbed sample from auger fllghtsor wall~a~trenc} ~, cut sample, undist,~bed s~mple (tom will of trench. ~ Strength - a useful indicator of a soil's clayey fi ~ction, N~Non L= ~ow, M'=Medium, ti=High - T~e sam les ~re placed n o a¢p~rently similar groups disturbed tes~sincludi"g Attctbc?g Limits, grain si;e. moistu~ed. reflccl the general distrubed characteristics al the sods ~ssiSi,cd m group. This Is ~n important phase of ,be soil andysis ~nrl Is number of quantitative tests necessary to describe the soil m~ss. SOIL CLASSIFICATION CHART 0 ~// /X ' ' y CLAYEY /~ X , t., CLAYEY SAND ~ [ / ~ANDQ GRAVEL 0 l0 z .... ~ % BY WEIGHT NONFROST SuscEPTIBLE SOILS ARE INORGANIC SOILS cONTAINING LESSTttAN 3 GROUPS OF [' ROST-SUSCEPTIBLE SOILS; GRAVELLY SOILS cONTAINING BETWEEN 3AND20% FINER THAN 0.02 mm. F2 SANDY SOILS coNTAINING BETWEEN 3 AND 15% FINER THAN 0.02 mm. F3 'a. GRAVELLY SOiLS CONTAINING MORE THAN 20% FINER flIANO~O2mm'ANDSANDYSOILS (EXCEPT FINE SILTY, SANDS) cONtAINING MORE TllAN 15% FINER Tt4&f4002 b, CLAYSW~TI4 pLASTICITY INDEXESOF MORE THAN t2. EXCEPT vARVEDCLAYS. F4 a. At;LSILTS iNCLUDING SANDY SILLS. b. FINE SILTY sANOSCONTAINING MORE~HAN t5% FINER THAN 0.02 mm. c t CAN CLAYS WFPt PLASTICITY INDEXESOF LESSTFIAN ]2' .d. VARVED CLAYS. ' _