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HomeMy WebLinkAboutSoils Report Small Log yard - GEO Geological Review - 2/15/1978 I RITTENHOUSE-ZEMAN & ASSOCIATES, INC. GEOLOGY & SOILS ENGINEERING 13240 Northrup Way,Bellevue,Washington 98005 (206)746-8020 8050 S.W. Cirrus Drive, Beaverton,Oregon 97005 (509) 644-9141 February 15, 1978 W-2634 Weyerhaeuser Company Cosmopolis, Washington 98537 Attention: Mr. Donald H. Jordan, P.L.S. Subject: Soils Investigation Report Belfair Small Log Sorting Yard Belfair, Washington INTRODUCTION In accordance with your request, we are pleased to present our soils investigation report on the above-mentioned project. This report summarizes our work to date, and presents conclusions and recommendations pertinent to future development. r The site is located approximately two miles northeast of the town of Belfair, in Mason County. It consists of 27. 5 acres of gently rolling terrain with a maximum vertical relief of twenty-six feet, and is bounded on the west by a Burlington Northern rail line. The north, south, and east boundaries all front on timberland owned by others. At present, no surface water is visible, and the two shallow drainage courses which cross the parcel show no evidence of flowing water having occurred during recent geological times. Planned development will consist primarily of grading, and the addition of a railroad spur track. Of the graded portions, ten acres will be paved Weyerhaeuser Company Page Two February 15, 1978 for log handling, and fourteen for possible log storage. The remaining acreage will be used for drainage, settling ponds, roads, and the rail line. Additional facilities will include an` office, well, and fuel .storage area. Our included site diagram shows these facilities, however, we understand that plans are presently under modification to accommodate a railroad spur paralleling the main track. SUBSURFACE INVESTIGATION Our investigation of the site consisted of digging twenty-six test pits using a tractor-mounted backhoe. Each of these pits penetrated from four to nine feet below the present ground surface, and permitted direct, visual evaluation of subsurface conditions. The inspection was performed by a qualified engineering geologist from our office who took representative samples for later laboratory analysis. In addition, three percolation tests were performed at the proposed settling pond, and two at the drainfield site. The results of these percolation tests and other laboratory tests are in the appendices. A site sketch showing the location of the field exploration is also enclosed. SUBSURFACE CONDITIONS Based on the results of our test pits, the site appears to be fairly uniform; consisting of either loose to medium dense sands and sands and gravels or very dense glacial till (hardpan). The till is a regional feature, and can generally be found underlying a thin surficial mantle on the high- lands throughout the Puget Sound Basin. It can be identified by its concrete- like texture and appearance, and although the composition may vary, will usually be a heterogeneous mixture of clay, silt, sand, and gravel-sized particles. The till was emplaced by and beneath glacial ice during the last glaciation some eleven to thirteen thousand years ago. Weyerhaeuser Company Page Three February 15, 1978 Our test pits encountered the till at relatively shallow depths (i. e. , less than five feet), along the eastern one-third of the parcel. Because of the tills' high density and impervious composition, it does not transmit ground water well, and as a result a "perched" water table will often develop on its upper surface during wet weather. On sloping ground, the perched water migrates downslope in the overlying sandy soils. Wherever the surface of the till is flat or depressed, water will tend to pond or saturate the overlying soils. Such is the case at test pits 10 and 21, where ground water was observed, and in the northeast corner, where wet surficial areas exist. Over the remaining two-thirds of the property, the near surface soils, to the limits of our equipment, are free draining sands and sands and gravels. We feel that these materials are representative of sediments emplaced in front of the receeding glacier. The upper one to two feet is silty, but as a rule, the materials become cleaner and coarser with depth. No ground water seepages were noted within these soils, nor were there any wet areas on the surface. CONCLUSIONS AND RECOMMENDATIONS 1. General The site appears to be well suited to the proposed development provided that adequate care is taken during the grading operation. Near surface materials on the eastern one-third of the parcel consist of glacial till, which may be compacted into a high strength fill at its optimum moisture content. However, if grading is performed in wet weather, the till will rapidly absorb an excess of water and will become nearly impossible to compact. The remaining soils , with the exception of the upper silty zone, consist of clean granular Weyerhaeuser Company Page Four February 15, 1978 material that can generally be compacted under most weather conditions using smooth drum vibratory compactors. 2. Grading It is our understanding that the paved portions of the site will be subject to moderately heavy wheel loads. Because of this, we feel that any fill placed as subgrade must be well compacted, and that the site be properly prepared prior to filling. As grading will likely be performed during late winter or early spring, we recommend that all structural fill be built using the clean granular materials found over the western two-thirds of the site. This material should be placed in eight-inch thick level layers, and compacted to at least 90 percent of laboratory maximum density, using ASTM:D-1557-70 (AASHTO:T-180), as a standard. We recommend that the upper one foot (compacted thickness), be compacted to at least 95 percent of the above standard to insure a firm, dense sub- grade for the overlying pavement section. Prior to filling, all stumps, large roots, organic rich topsoil, and debris subject to decomposition remaining from the burn piles, should be removed from the areas to recieve compacted fill and wasted. The ground surface should then be scarified and compacted during the proof rolling operation. Any soft areas discovered at that time should then be corrected. The finished base should then be inspected by a qualified soils engineer, and all fill placement should be under his full time supervision. Consideration should also be given to compacting the fill (minimum 90% density), placed under the 14 acres that will be used for possible log storage. This will result in much longer surface life, as well Weyerhaeuser Company Page Five February 15, 1978 as requiring much less rehabilitation should portions of it be paved at a later date. Unfortunately, much of this area (eastern one-third), is underlain by glacial till, which will be very difficult to work with at the time grading is anticipated. If at all possible, we suggest that grading of this portion be delayed until dry summer weather. Should this not be feasible, we recommend that compaction be attempted using non-vibratory "sheepsfoot" style compactors, which will give the best quality fill possible considering the anticipated weather conditions. 3. Disposal Drainfield A-.total of two percolation tests and three soil logs were performed at the proposed drainfield site. The results of this testing were sent out in a letter dated January 25, 1978, and have not been included in this report. 4. Settling Pond Three percolation tests were performed at the proposed settling pond area, and the results have been included in the attached appendices. All of the native soils in the area of the pond, below a thin silty zone, are well drained, and will provide as an effective ex-filtration basin if properly constructed and maintained. We expect that after a period of time, the bottom of the basin will plug due to silt and organic matter washing off of the paved log handling yard. When this occurs, or as part of a yearly maintenance program, the clogged surficial soils should be stripped by mechanical means, and replaced with a new sand filter. An attempt should be made to perform this work during summer to keep disturbance of the native Weyerhaeuser Company Page Six February 15, 1978 subgrade to a minimum. Because the native soils consist of poorly graded sands, they may be subject to erosion during heavy rains. We recommend keeping the side slopes of the pond at an angle less than 3H:1V, and that the transition from pavement to natural ground be lined with gravel or crushed rock. This will lower the velocity of water entering the pond and reduce the possibility of undercutting. 5. Ground and Surface Water Although we did not perform an extensive hydrologic study of the site and adjacent properties, we are able to present some general conclusions. We found no evidence of surface water on, or dis- charging from the property; the ground water we encountered consisted primarily of a limited perched water table on the glacial tills uper surface. Over the unpaved portions of the site we expect very little net change in ground or surface water conditions, except for that which occurs because of the land clearing and loss of vegetation. However, the paved area will channel runoff to the settling pond where the water will be absorbed in a localized area. We feel that this condition will result in an overall net increase in the amount of ground water leaving the site. The increase will be relatively minor, however, and should not visibly alter downslope springs or wells. APPENDIX A TEST PIT LOGS TEST PIT LOGS Depth (Feet) Soil Classification Test Pit No. 1 (Elevation 400') 0.0 - 0. 3 Sandy topsoil 0. 3 - 1.0 Loose to medium dense, moist, brown, silty sand with gravel 1.0 - 5.0 Medium dense, moist, brown, medium sand with gravel 5.0 - 8. 5 Medium dense, moist, light brown medium sand No seepage Root penetration to 5 feet Test Pit No. 2 (Elevation 38F) 0.0 - 0. 2 Topsoil 0.2 - 1. 5 Loose, moist, brown silt and fine to medium sand 1. 5 - 2.0 Medium dense, moist, brown silty sand with gravel and cobbles to 12 inches 2.0 - 7.0 Very dense, moist, gray silty sand with gravel (Glacial Till) No seepage, however, upper surface of till is wet Test Pit No. 3 (Approximate Elevation 396') 0.0 - 2. 5 Medium dense, moist, brown, silty sand and gravel 2. 5 - 8. 5 Dense to very dense, moist, gray, silty sand with gravel (Glacial Till) No seepage Test Pit No. 4 (Elevation 391') 0.0 - 1. 5 Loose to medium dense, moist, brown, silty sand with gravel 1. 5 - 7. 5 Dense to very dense, moist, gray, silty sand with gravel (Glacial Till) No seepage Depth (Feet) Soil Classification Test Pit No. 5 (Elevation 3901) 0.0 - 0.4 Topsoil 0.4 - 1. 5 Loose, moist, brown, silty, fine to medium sand 1. 5 - 3.0 Medium dense, moist, brown sand and gravel 3.0 - 6. 5 Very dense, moist, lavender, silty sand with gravel (Glacial Till) No seepage Test Pit No. 6 (Elevation 401') 0.0 - 0. 2 Topsoil 0.2 - 2.0 Loose to medium dense, moist, rust brown, silty fine to medium sand with gravel 2.0 - 5.0 Medium dense, moist, light brown, fine to medium sand with gravel 5.0 - 8. 5 Medium dense, moist, brown sand and pea gravel with larger gravel and occasional cobbles No seepage Test Pit No. 7 (Elevation 396') 0.0 - 0. 3 Topsoil 0. 3 - 3. 5 Loose to medium dense, moist, brown, fine to coarse sand with gravel and silt in upper one foot 3. 5 - 8.0 Medium dense to dense, moist, light brown sand and gravel No seepage Test Pit No. 8 (Elevation 400') 0.0 - 0. 2 Topsoil 0. 2 - 2. 5 Loose to medium dense, moist, brown, silty, fine to medium sand with gravel Depth (Feet) Soil Classification Test Pit No. 8 (continued) 2. 5 - 5.0 Medium dense, moist, tan, fine to medium sand with occasional gravel 5.0 - 9.0 Dense, moist, brown sand and gravel No seepage Test Pit No. 9 (Elevation 399') 0.0 - 0. 5 Medium dense, moist, rust, brown, silty sand and gravel 0. 5 - 1. 5 Medium dense, moist, brown, fine to medium sand 1. 5 - 9.0 Medium dense to dense, moist, tan sand and gravel No seepage Test Pit No. 10 (Elevation 382') 0.0 - 0. 5 Sandy topsoil 0. 5 - 2.0 Loose, moist, rust, brown, silty sand 2.0 - 6.0 Medium dense, moist, light brown, gravelly sand - wet below 5 feet 6.0 - 8. 5 Very dense, moist, gray, silty sand with gravel (Glacial Till) Slight to moderate seepage at 6 feet Test Pit No. 11 (Elevation 396') 0.0 - 1. 5 Loose, moist, rust, brown, silty, fine to medium sand with gravel 1. 5 - 3. 5 Medium dense to dense, moist, brown sand and gravel with cobbles to 6 inches 3. 5 - 9.0 Medium dense, moist, tan, fine to medium sand with gravel and a sandy silt lense from 3. 5' - 4.0' No seepage Depth (Feet) Soil Classification Test Pit No. 12 (Elevation 386') 0.0 - 1. 5 Loose, moist, brown, silty fine to medium sand 1. 5 - 5. 5 Medium dense, moist, tan, fine to medium sand with occasional gravel 5. 5 - 9.0 Dense, moist, brown, sand and gravel with cobbles to 6 inches No seepage Test Pit No. 13 (Elevation 386') 0.0 - 0. 2 Topsoil 0. 2 - 1. 5 Loose, moist, rust, brown, silty, fine to medium sand 1. 5 - 8.0 Medium dense, moist, brown, medium sand with gravel lenses No seepage Test Pit No. 14 (Elevation 397') 0.0 - 0. 5 Topsoil 0. 5 - 1.0 Loose, moist, rust, brown, silty, fine to medium sand 1.0 - 8.0 Medium dense, moist, light brown, fine to medium sand grading to medium sand with depth No seepage Test Pit No. 15 (Elevation 394') 0.0 - 0.2 Topsoil 0.2 - 1.0 Loose, moist, rust brown, silty fine to medium sand 1.0 - 2. 5 Loose, wet, brown silt and fine to medium sand 2. 5 - 6.0 Medium dense, moist, light brown, fine to medium sand 6.0 - 8.0 Medium dense to dense, moist, brown sand and gravel No seepage Depth (Feet) Soil Classification Test Pit No. 16 (Elevation 385') 0.0 - 2. 5 Loose, moist, rust brown, silty sand and gravel 2. 5 - 8.0 Medium dense to dense, moist, brown sand and gravel No seepage Test Pit No. 17 (Elevation 399') 0.0 - 1.0 Medium dense, moist, rust brown, silty sand and gravel with cobbles to 4 inches 1.0 - 2. 5 Medium dense to dense, moist, brown sand and gravel with cobbles to 6 inches 2. 5 - 8. 5 Dense, moist, brown, cobbly sand and gravel No seepage Root penetration to 5 feet Test Pit No. 18 (Elevation 404') 0.0 - 2.0 Loose to medium dense, moist, brown, silty fine to medium sand with gravel; one boulder approximately 2-1/2 x 4 feet 2.0 - 4.0 Medium dense, moist, brown sand and gravel with cobbles to 6 inches 4.0 - 7.0 Medium dense, moist, brown fine to medium sand 7.0 - 9. 5 Dense, moist, brown, medium to coarse sand and gravel No seepage Test Pit No. 19 (Elevation 385') 0.0 - 2.0 Medium dense, moist, rust brown, silty sand and gravel 2.0 - 5. 5 Dense to very dense, moist, gray, silty sand with gravel (Glacial Till) No seepage, however, top surface of till is wet Depth (Feet) Soil Classification Test Pit No. 20 (Elevation 403') 0. 0 - 1.0 Loose, moist to wet, rust brown, silty sand and gravel 1.0 - 4. 5 Dense to very dense, moist, gray, silty sand with gravel (Glacial Till) No seepage Test Pit No. 21 (Elevation 397`) 0.0 - 1.0 Sand, gravel and topsoil (Fill) 1.0 - 4. 5 Medium dense, wet, brown, silty sand and gravel 4. 5 - 6. 5 Very dense, moist, gray, silty sand with gravel (Glacial Till) Slight seepage at 3 feet Test Pit No. 22 (Elevation 404') 0.0 - 2.0 Loose to medium dense, moist, rust brown, silty sand and gravel 2.0 - 4.0 Very dense, moist, gray, silty sand with gravel (Glacial Till) No seepage Test Pit No. 23 (Elevation 402') 0.0 - 0. 2 Topsoil 0.2 - 1. 5 Loose to medium dense, moist, brown, silty fine to medium sand with gravel 1. 5 - 8.0 Medium dense to dense, moist, brown sand and gravel with cobbles to 6 inches No seepage Depth (Feet) Soil Classification Test Pit No. 24 (Elevation 393') 0.0 - 0. 4 Topsoil 0.4 - 1. 5 Loose, moist, brown, silty sand and gravel 1. 5 - 3.0 Medium dense, moist, brown sand and gravel 3.0 - 7. 5 Medium dense, moist, brown, fine to medium sand with gravel 7. 5 - 8. 5 Dense, moist, brown, sandy gravel No seepage Test Pit No. 25 (Elevation 400') 0.0 - 0. 2 Topsoil 0. 2 - 2.0 Medium dense, moist, rust brown, silty sand and gravel 2.0 - 6.0 Medium dense, moist, tan, fine to medium sand with gravel 6.0 - 8.0 Dense, moist, brown, coarse sand and gravel No seepage Test Pit No. 26 (Elevation 400') 0.0 - 0. 3 Topsoil 0. 3 - 2.0 Loose, moist, rust brown, silty, fine to medium sand 2.0 - 5.0 Medium dense, moist, tan, fine to medium'sand with gravel 5.0 - 8. 5 Medium dense to dense, moist, brown sand and gravel with cobbles to 6 inches No seepage APPENDIX B LABORATORY TESTING LABORATORY SUMMARY SHEET 1. Laboratory CBR Value: Soil Type CBR Value Sand with silt and gravel 35 2. Proctor Values: Soil Type Optimum Moisture Maximum Content (%) Density (lb/ft3) Glacial Till 7. 5 132 Sand with silt, gravel 5 113. 5 Gravelly sand 12 122 3. Percolation Tests - Drainfield: Test No. Depth Below Percolation Existing Grade (ft.) Rate (min/in) 1 0. 8 15 2 2.0 7 4. Percolation Tests - Settling Pond: Test No. Depth Below Location Percolation Existing Grade (ft.) Rate (minAn) 3 3. 5 See Plate 1/2 4 2. 5 See Plate 1/2 5 3 See Plate 3 U.S. STANDARD SIEVE SIZE 3in. 1i5in 3/4in. 3/8in.�*4 10 20 40 6�0 100 200 100 I HYDROMETER 90 80 w 3 70 m 60 w z 50 w z 40 w cr 30 w a 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND COARSE I FINE ICOARSOMEDIUM FINE SILT CLAY PROJECT Sel-L .5_-d Vk,_y WORK ORDER aC13y Boring Sample Depth ' -0'- PO' Dust Ratio % Passing 200 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN 8, ASSOC., INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 3in. 115in. 3/4in. 3/8in.-*4 10 20 40 60 100 200I 100 HYDROMETER 90 80 w 3 70 m 60 w - z 50 — w Z 40 w 30 w 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND COARSE FINE COARS MEDIUM FINE SILT CLAY PROJECT Hel4:. S--e� Ye'.1 WORK ORDER a&34/ Boring Sample oz Depth ° -3•� Dust Ratio % Passing 200 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN & ASSOC., INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 31n. 1.5in. 3/4 in. 3/b in.-4 10 20 40 60 100 200 , 100 HYDROMETER I I I I I I I I I I I 90 80 w 3 70 m � 60 w z 50 z 40 w a� 30 w 20 10 44-- 11 -21 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND SILT C L A Y COARSE I FINE COARS MEDIUM I FINE PROJECT �� %� S��z� Llama✓ WORK ORDER 163�1' Boring Sample 3 Depth -'D Dust Ratio % Passing 200 h!� GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN 8 ASSOC., INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 3in. 1i5in 3/4in. 3/8 in.�*4 10 2i0 4i0 60 100 2001 100 HYDROMETER 90 80 w 3 70 m I 6 0 r w z 50 w z 40 w x 30 w w 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL SAND COBBLES COARSE FINE COARS MEDIUM FINE SILT CLAY PROJECT WORK ORDER '71 Boring Sample -3 Depth sv G. Dust Ratio % Passing 200 /J. 9 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN a ASSOC., INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 31n. 1.5 i n. 3/4in. 3/8 in.�4 10 20 40 60 100 200 100 ' ' ' ' ' 1 1 1 1 1 1 HYDROMETER 90 80 w 3 70 m 60 w w 50 z 40 w a� 30 w 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND COARSE FINE COARS MEDIUM FINE SILT CLAY PROJECT -��-� �a-� WORK ORDER Boring Sample Cz Depth 3 Dust Ratio % Passing 200 9.3 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN 8, ASSOC, INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 3in. 1.5in 3/4in. 3/8in.-*4 10 20 40 60 100 2001 100 HYDROMETER i i i i I 90 80 w 3 70 m cr 6 0 w z 50 w z 40 w 30 w d 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND SILT CLAY COARSE I FINE JCOARS MEDIUM FINE PROJECT �E����'- -S-Z� �r� WORK ORDER ��3y Boring Sample Depth 70 Dust Ratio % Passing 200 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN a ASSOC , INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 3in. 1.5in 3/4in. 3/Bin.-*4 10 20 40 60 100 200I 100 HYDROMETER i i i i 90 80 w � 3 70 m 60 w z 50 w z 40 w cr_ 30 w a. 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND COARSE FINE COARS MEDIUM FINE SILT CLAY PROJECT �� -So�� `�a.-� WORK ORDER Boring Sample_ Depth 30'- y L " Dust Ratio % Passing 200 3. 5-7 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN 8, ASSOC , INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 3in. 1.5in 3/4in. 3/8in.�4 10 20 40 60 100 200I 100 HYDROMETER i i i i 90 80 w 3 70 m 60 w z 50 LL. z 40 w 30 w a 20 10 01000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES- ___ GRAVEL LLSAND COARSE I FINE JCOARS MEDIUM FINE SILT CLAY PROJECT WORK ORDER a&351 Boring Sample Depth 3.c)'— you Dust Ratio % Passing 200 a 9 GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN a ASSOC, INC. GEOTECHNICAL ENGINEERING U.S. STANDARD SIEVE SIZE 3in. 1.5in. 3/4 in. 3/b in.-*4 10 20 40 60 100 200I 100 ' ' ' I i i i HYDROMETER 90 80 w 3 70 m o_ 60 w 50 z 40 w NJ a� 30 w a_ 20 10 0 .11111 141 1 1 1000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL SAND COBBLES COARSE f FINE JCOARSd MEDIUM I FINE SILT CLAY PROJECT �f/�a/r So.z/ ���� WORK ORDER ­Ic-341 Boring Sample_ 7 Depth -3.0' Dust Ratio % Passing 200 dB GRAIN SIZE DISTRIBUTION RITTENHOUSE-ZEMAN & ASSOC., INC. GEOTECHNICAL ENGINEERING