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HomeMy WebLinkAboutSoils Report 02.23.2015Gtech HEPWORTH-PAWLAK GEOTECHNICAL Hepworth-Pawlak Geotechnical, Inc. 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 Email: hpgeoehpgeotech.com SUBSOIL STUDY FOR FOUNDATION DESIGN PROPOSED JOLLEY RESIDENCE PARCEL B, HUBER EXEMPTION 1793 COUNTY ROAD 245 WEST OF NEW CASTLE GARFIELD COUNTY, COLORADO JOB NO. 114 549A FEBRUARY 23, 2015 PREPARED FOR: BRETT JOLLEY 1288 COUNTY ROAD 245 NEW CASTLE, COLORADO 81647 biolley :soDris.net TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY ........... ..... f.. ........ .. •,...... ..- 1 - PROPOSED CONSTRUCTION - 1 - SITE CONDITIONS - 2 - FIELD EXPLORATION ,..........- 2 - SUBSURFACE CONDITIONS - 2 - FOUNDATION BEARING CONDITIONS - 3 - DESIGN RECOMMENDATIONS - 3 - FOUNDATIONS .,- 3 - FOUNDATION AND RETAINING WALLS - 5 - FLOOR SLABS - 6 - UNDERDRAIN SYSTEM - 7 - SURFACE DRAINAGE - 7 - LIMITATIONS - S - FIGURE 1 - LOCATION OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NOTES FIGURES 4 AND 5 - SWELL -CONSOLIDATION TEST RESULTS FIGURE 6 - GRADATION TEST RESULTS FIGURE 7 - USDA GRADATION TEST RESULTS TABLE 1- SUMMARY OF LABORATORY TEST RESULTS TABLE 2- PERCOLATION TEST RESULTS Job No. 114 549A Ggstech PURPOSE AND SCOPE OF STUDY This report presents the results of a subsoil study for a proposed residence to be located on Parcel B of the Huber Exemption, 1793 County Road 245, west of New Castle, Garfield County, Colorado. The project site is shown on Figure 1. The purpose of the study was to develop recommendations for the foundation design. The study was conducted in accordance with our proposal for geotechnical engineering services to Brett Jolley dated December 16, 2014. A field exploration program consisting of exploratory borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils obtained during the field exploration were tested in the laboratory to determine their classification, compressibility or swell and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation. This report summarizes the data obtained during this study and presents our conclusions, design recommendations and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION The proposed residence will be a one story, wood frame structure over a partial basement/partial crawlspace with an attached garage. Basement and garage floors will be slab -on -grade. Grading for the structure is assumed to be relatively minor with cut depths between about 4 to 8 feet. We assume relatively light foundation loadings, typical of the proposed type of construction. If building loadings, location or grading plans change significantly from those described above, we should be notified to re-evaluate the recommendations contained in this report. Job No. 114 549A -2 - SITE CONDITIONS The site is occupied by an existing one story residence over a full basement which will be razed prior to new construction_ The existing barn will remain. The lot slope is moderate down to the west toward East Elk Creek at grades of 5 to 15%. There are steeper slopes along East Elk Creek. Vegetation consists of scattered cottonwood and fir trees with grass and weeds. There is thick brush and trees along the creek banks below the building area. Above the building area, the property is mostly open irrigated pasture. FIELD EXPLORATION The field exploration for the project was conducted on December 30, 2014. Four exploratory borings were drilled at the locations shown on Figure 1 to evaluate the subsurface conditions. The borings were advanced with 4 inch diameter continuous flight augers powered by a truck -mounted CME -45B drill rig. The borings were logged by a representative of Hepworth-Pawlak Geotechnical, Inc. Samples of the subsoils were taken with 1% inch and 2 inch I.D. spoon samplers. The samplers were driven into the subsoils at various depths with blows from a 140 pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Graphic logs of the subsurface conditions encountered at the site are shown on Figure 2. The subsoils consist of up to about 1 foot of topsoil and 7 ". z to 11! i feet of medium stiff to stiff, sandy silty clay overlying relatively dense, silty sandy gravel with cobbles and Job No. 114 549A Gatech -3 - possible boulders down to the bottom of the borings at 10V2 to 13 feet. Drilling in the dense granular soils with auger equipment was difficult due to the cobbles and boulders and drilling refusal was encountered in the deposit. Laboratory testing performed on samples obtained from the borings included natural moisture content, density and gradation analyses. Results of swell -consolidation testing performed on relatively undisturbed drive samples of the clay soils, presented on Figures 4 and 5, indicate low to moderate compressibility under conditions of loading and wetting. The five-foot sample from Bring 5 showed a low swell potential when wetted under light loading. Results of gradation analyses performed on a small diameter drive sample (minus 1V2 inch fraction) of the coarse granular subsoils are shown on Figure 6. The laboratory testing is summarized in Table 1. No free water was encountered in the borings at the time of drilling or when checked the following day. The subsoils were slightly moist to moist. FOUNDATION BEARING CONDITIONS The shallow clay soils encountered at the site are suitable to support lightly loaded spread footing foundations with some risk of settlement particularly if the clay soils become wet. A lower settlement risk alternative is to extend the foundations down to the underlying relatively dense gravel soils. DESIGN RECOMMENDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the building be founded with spread footings bearing on the natural clay or granular soils. The fill around the existing Job No. 114 549A G - '1 -4 - residence and debris from the prior development should be completely removed from below the new residence area. The design and construction criteria presented below should be observed for a spread footing foundation system. 1) Footings placed on the undisturbed natural clay soils should be designed for an allowable soil bearing pressure of 1,500 psf and footings bearing entirely on the dense gravel soils should be designed for an allowable bearing pressure of 3,000 psf. Based on experience, we expect settlement of footings designed and constructed as discussed in this section will be about 1 inch or Less, Footings bearing entirely on the gravel soils should have only minor settlement. 2) The footings should have a minimum width of 20 inches for continuous walls and 2 feet for isolated pads. 3) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 36 inches below exterior grade is typically used in this area. 4) Continuous foundation walls should be reinforced top and bottom to span local anomalies such as by assuming an unsupported length of at least 14 feet. Foundation walls acting as retaining structures should also be designed to resist lateral earth pressures as discussed in the "Foundation and Retaining Walls" section of this report. 5) All existing fill, debris, topsoil and any loose or disturbed soils should be removed and the footing bearing level extended down to the undisturbed clay or relatively dense natural granular soils. The exposed soils in footing arca should then be moistened and compacted. If water seepage is encountered, the footing areas should be dewatered before concrete placement. 6) A representative of the geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions. Job No. 114 549A Ggestech 5 - FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 55 pcf for backfill consisting of the on-site fine-grained soils and at least 45 pcf for backfill consisting of imported granular materials. Cantilevered retaining structures which are separate from the residence and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 50 pcf for backfill consisting of the on-site fine-grained soils and at least 40 pcf for backfill consisting of imported granular materials. All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal back -fill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. Backfill should be placed in uniform lifts and compacted to at least 90% of the maximum standard Proctor density at a moisture content near optimum. Backfill placed in pavement and walkway areas should be compacted to at least 95% of the maximum standard Proctor density. Care should be taken not to overcompact the backfill or use large equipment near the wall, since this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall backfill should be expected, even if the material is placed correctly, and could result in distress to facilities constructed on the backfill. Job No. 114 549A eatech -6 - We recommend imported granular soils for backfilling foundation walls and retaining structures because their use results in lower lateral earth pressures. Imported granular wall backfill should contain Less than 15% passing the No. 200 sieve and have a maximum size of 6 inches. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.30. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 325 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The natural on-site soils, exclusive of topsoil, can be used to support lightly loaded slab - on -grade construction. There could be some potential for movement mainly for slabs bearing on clay soils. To reduce the effects of some differential movement, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be established by the designer based on experience and the intended slab use. A minimum 4 inch layer of free -draining gravel should be placed beneath basement level slabs to facilitate drainage. This material should consist of minus 2 inch aggregate with at least 500.o retained on the No. 4 sieve and less than 2% passing the No. 200 sieve. Job No. 114 549A iGegtech -7 - All fill materials for support of floor slabs should be compacted to at least 95% of maximum standard Proctor density at a moisture content near optimum. Required fill can consist of imported granular soils such as 3/4 inch road base devoid of vegetation, topsoil and oversized rock. UNDERDRAIN SYSTEM Although free water was not encountered during our exploration, it has been our experience in this area and where there are clay soils that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can also create a perched condition. We recommend below -grade construction, such as retaining walls, crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain system. The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free -draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1°o to a suitable gravity outlet. Free -draining granular material used in the underdrain system should contain less than 2% passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least 142 feet deep. SURFACE DRAINAGE The following drainage precautions should be observed during construction and maintained at all times after the residence has been completed: 1) Inundation of the foundation excavations and underslab areas should be avoided during construction. 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95% of the maximum standard Proctor density in pavement and slab areas and to at least 90°,6 of the maximum standard Proctor density in landscape areas. Job No. 114 549A Ggrytech -8- 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. Free -draining wall backfill should be capped with about 2 feet of the on- site soils to reduce surface water infiltration. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. PERCOLATION TESTING Percolation tests were conducted on December 31, 2014 to evaluate the feasibility of an infiltration septic disposal system at the site. One profile boring and three percolation holes were drilled at locations as shown on Figure 1. The test holes were drilled with 6 inch diameter auger and were soaked with water one day prior to testing. The soils encountered in the percolation holes are similar to those encountered in the Profile Boring shown on Figure 2 and consist of clay loam. The results of a gradation/hydrometer test performed on a combined sample from the Profile Boring are shown on Figure 7. The percolation test results are presented in Table 2. Based on the subsurface conditions encountered and the percolation test results, the tested area should be suitable for an infiltration septic disposal system. We recommend the infiltration area be oversized due to the relatively slow and variable percolation rate. A civil engineer should design the infiltration septic disposal system. Additional percolation testing and profile pits may be needed for design level recommendations. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 1, the proposed type of construction and our experience in the area. Job No. 114 549A -9 - Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Daniel E. Hardin, P.E. Reviewed by: Steven L. Pawlak, P.E. DEH/ksw cc: Jack Palomino iackpalomino55 a amail.com Job No, 114 549A 5670 1 so. w WELL O 5� P1 A P2 �,-- ( �• PROFILE BORING p 3 PROPOSED RESIDENC XISTING -RESIDENCE • BORING 1 / • BORING 2 / / Y 1 ' BORING 3• C:3( EXISTING BARN ( APPROXIMATE SCALE 1"= 100' WELL CD ( N. ♦J 568o 1 1 1 1 5710 COUNTY ROAD 245 5710 114 549A I-1 HBPWORTWPAW LAK GEOTECMNICA1. LOCATION OF EXPLORATORY BORINGS Figure 1 Elevation - Feel BORING 1 ELEV.= 5678' BORING 2 ELEV.= 5679' BORING 3 ELEV.= 5682' BORING 4 ELEV.= 5673' - 5690 5690 5685 - 5680 5675_ 7/12 • ']10/12 WC=20.9 • DD=103 -200=94 — , 13/12 r WC=20.7 6/12 ' DD=103 WC= 23,2 r 5670 . 4 . ,. DD x:98 90112 ,• 0 , WC=2.3 T — o" +4=59 r -200=11 , 5665 r 16/12 18/12 WC=8.3 DD=109 r r r 10/12 8/12 7/12 WC 153 DD -111 BASEMENT F.F. 5675 r � 5660 Note: Explanation of symbols is shown on Figure 3. 7/12 5685 5680 5675 WC=18.9 10/12 GRAVEL=1% --` SAND=32% 5670 SILT=35% 8/12 CLAY=32% — 7/12 6/12 5665 5660 Elevation - Feet 114 549A H HEPWORTH-PAWLAK GEOTECHNICAL LOGS OF EXPLORATORY BORINGS Figure 2 LEGEND: D M 10112 T TOPSOIL; organic sandy silty clay, firm, slightly moist, dark brown. CLAY (CL); silty, sandy, medium stiff to stiff, moist, brown. GRAVEL (GM); sandy. silty. cobbles, dense, slightly moist, brown. Relatively undisturbed drive sample; 2 -inch I.D. California liner sample. Drive sample; standard penetration test (SPT), 1 3/8 inch I.D. split spoon sample. ASTM D-1586. Drive sample blow count: indicates that 10 blows of a 140 pound hammer falling 30 inches were required to drive the California or SPT sampler 12 inches. Practical drilling refusal_ NOTES: 1. Exploratory borings were drilled on December 30, 2014 with 4 -inch diameter continuous flight power auger. 2. Locations of exploratory borings were measured approximately by pacing from features shown on the site plan provided. 3. Elevations of exploratory borings were obtained by interpolation between contours shown on the site plan provided. 4. The exploratory boring locations and elevations should be considered accurate only to the degree implied by the method used. 5. The lines between materials shown on the exploratory boring Togs represent the approximate boundaries between material types and transitions may be gradual. 6. No free water was encountered in the borings at the lime of drilling. Fluctuation in water level may occur with time. 7. Laboratory Testing Results: WC = Water Content (%) DD = Dry Density (pcf) +4 = Percent retained on the No. 4 sieve -200 = Percent passing No. 200 sieve Gravel = Percent retained on No. 10 Sieve Sand = Percent passing No. 10 sieve and retained on No. 325 sieve Silt = Percent passing No. 325 sieve to particle size .002mm Clay = Percent smaller then particle size .002mm 114 549A H HEPWORTH-PAWLAK GEOTECHNICAL, LEGEND AND NOTES Figure Compression % 0 1 2 3 4 2 c 0 c 1 0. • c 0 0 0 a� a 1 E 0 U 2 Moisture Content = 20.7 percent Dry Density = 103 pcf Sample of: Sandy Silty Clay From: Boring 1 at 5 Feet No movement upon wetting 0.1 .0 10 APPLIED PRESSURE - ksf 100 Moisture Content = 8.3 percent Dry Density = 109 pcf Sample of: Sandy Silty Clay From: Boring 2 at 5 Feet cIN\L\\ Expansion upon wetting 0.1 1.0 10 APPLIED PRESSURE - ksf 100 114 549A F-1 HEPWOR-PAWLAK GEOTECHNICAL SWELL -CONSOLIDATION TEST RESULTS Figure 4 Compression % Compression % 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 01 0 0 APPLIED PRESSURE - ksf 100 Moisture Content = 15.3 percent Dry Density = 111 pcf Sample of: Sandy Silty Clay From: Boring 3 at 5 Feet • • / 1 No movement upon wetting No movement upon wetting • N f 01 0 0 APPLIED PRESSURE - ksf 100 0.1 1 0 10 APPLIED PRESSURE - ksf 100 114 549A 1-1 HEPWORT*PAWLAK GEOTECHNICAL SWELL -CONSOLIDATION TEST RESULTS Figure 5 Moisture Content = 23.2 percent Dry Density = 98 pcf Sample of: Slightly Sandy Silty Clay From: Boring 3 at 10 Feet • No movement upon wetting f 0.1 1 0 10 APPLIED PRESSURE - ksf 100 114 549A 1-1 HEPWORT*PAWLAK GEOTECHNICAL SWELL -CONSOLIDATION TEST RESULTS Figure 5 I K31►laS31/1W2h: IHYDROMETER ANALYSIS I SIEVE ANALYSIS R1 22qq ��{{R 7 HR TIME READINGS U.S. STANDARD SERIES I CLFASQUARE OPENINGS 0 45 I N 15 MIN.60MIN19MIN 4 MIN. 1 MIN. *200 #100 #50 #30 X16 #f8 #14 318' 314' 1 1/2' 3' 5'6' 8' 100 10 20 30 40 50 60 70 80 so iaaaa-i aaa-a - a-�aaaa-� a�- :.Slam --- Iai aa- =SI ai as-r---- assa w--asaaa asoma -a Saar-rr asaNOS aai aa -a i a lb as aIMS, aa—aa--r as -a-a-wa=Ina MIMIMESIS ! SIM is .IAC a aa- -a -a- a-assswSION - --SSiS-i - a--i-aa- -a-S—ai--r— ISISS - a—a�i-aa- r-� aaa-aaaaaaaa-aaa aaaaaaaa-aaa aaa-aaaa-aaa- aaa-a�aaa �aaaa-aaa aa- -a, Smaate-- aaa-aaaa-aaa aaa aaa- asp^- aaa-aaaa- aaa-aaaa-aaa aiaaar--ate aiaaaa-aaa a�aaaa-aaa aaa-aaaa-aa- as�as�aw- -aaaa-aaa as�asa saaaa-s iaaaa-aaa Sinai i na asiaaa was aa�^- - SI! — aaa- - a a a as --a- - aaaaiaa-aaa- -a—a aS—ate-ate !SI III —aii-- ar -- aa—aaa---a- -`aaa al Sill! aa� , a—IIl nilaa—a !Sr -a- aaaaaaa-aa-a i-aa- aa- ----- --j----- -- - aaaa—Sias ----a --- ass—aaaaa—aaaalif as aa- - .a—ssss --- . --aiai—aaa- IMF Sr as-aaa- al_ aiaal aas-a—a r wSISIS Si I MSaSipIli iii IS waa—a� i AMIN a�a--a l Baas--waSaIMIFIS IN - -a--a—aa—rarrrar_s ass rviSISS---- Wiaiaaiaii ai Iii—ass Isli Si !Sail Elear!iSlail SI Ili Sw!l a.--aiaiaaa NWi !Saaa—il ai Wim—a—ai mills rat—a—SI! ai ai-a-a --- ---- ---- ------- --- --- ---- ---- - SINi �II a-Iail------- aiaa-I ais-�a�a�aai �_- a-- as�as�>_ss IM, -- SUS -iaiaiai-WS. a�—iaiaiaiaiV— �— a aaai—ate—'SI — SAM !- aaa- asa�a-asses - SI r-- -r✓rissa�iai ilei -a-Maar----i -a-aiaaa-aaa-i aa- a -a-aim SI la !IS in as --aa- as--- =�aa�asa-sal aaa- ri_ai -a-aiaaa-iaa� as--aa- �r-a ass !SI in - aa- i-'-- ==Mas-as�a—aa as-ai 100 .001 .002 .005 .009 .019 .037 .074 .150 .300 .600 1.18 2.36 4.75 9.512 519 0 37.5 76.2 152 203 CLAY TO SILT DIAMETER OF PARTICLES IN MILLIMETERS FINE GRAVEL 59 % LIQUID LIMIT % SAMPLE OF: Slightly Silty Sandy Gravel 114 549A I-1 HEPWORTH+PAw1.AK GEOSECHNICAL 1 1IEDMA 1 COARSE SAND 30 % GRAVEL FINE 1 COARSE SILT AND CLAY 11 % PLASTICITY INDEX % FROM: Boring 1 at 9 Y2 Feet GRADATION TEST RESULTS 90 80 70 60 50 40 30 20 10 0 .Mi]li7 ^i1 ? Figure 6 -4213•Tiff*E1E2f+. HYDROMETER ANALYSIS j q HH TIME READINGS . 0 45 MURN 15 MIN 60MINI9MIN.4 MIN 1 M1#325 10 20 30 40 50 60 70 80 90 100 SIEVE ANALYSIS 1 U S_ STANDARD SERIES 1 CLEAR SQUARE OPENINGS I #140 *60 #35 *18 #10 #4 318' 314' 1112' 3' 5'6' 8' i00 001 002 .005 .009 019 `: AY 114 549A SILT GRAVEL 1 % 045 .106 025 .500 1.00 200 DIAMETER OF PARTICLES IN MILLIMETERS SAND V. FINE 1 FRJE 1 MEDNM ICDAR E I1 caffmk. SAND 32 % USDA SOIL TYPE: Clay Loam H HEPWORTH-PAWL AK GEOTECHNICAL 4.75 9.5 19.0 37 5 76.2 152 203 GRAVEL SMALL 1 MEDIA 1 LARGE SILT 35 % CLAY 32 % 93 70 60 50 40 30 20 10 0 MI2C FROM: Profile Boring at 2 and 4 Feet Combined USDA GRADATION TEST RESULTS Figure 7 Job No. 114 549A SUMMARY OF LABORATORY TEST RESULTS SOIL OR BEDROCK TYPE Slightly Sandy Silty Clay Sandy Silty Clay 11 Slightly Silty Sandy Gravel 11 Sandy Silty Clay 11 Sandy Silty Clay Slightly Sandy Silty Clay Clay Loam* II UNCONFINED COMPRESSIVE STRENGTH (PSF) 1 ATTERBERG LIMITS r u * r F J xin 171 * M PERCENT PASSING NO. 200 SIEVE 01 .--i 01 0 4 g 0 Z i 30 N GRAVEL (%) O\ In * -. COI (pd) AJISN30 AN0 1YHf11VN 103 O i t - .--i 00 ON NATURAL MOISTURE CONTENT (%) 20.9 N M N M 15.3 N N Ch oci SAMPLE LOCATION DEPTH (ft) 21 vn 9'/z un vn O 2&4 Combined BORING —. N M Ill a O a 0 ro u H r. 0 1/7 a v7 HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE 2 PERCOLATION TEST RESULTS JOB N0.114 549A HOLE NO. HOLE DEPTH (INCHES) LENGTH OF INTERVAL (MIN) WATER DEPTH AT START OF INTERVAL (INCHES) WATER DEPTH AT END OF INTERVAL (INCHES) DROP IN WATER LEVEL (INCHES) AVERAGE PERCOLATION RATE (MIN./INCH) P-1 30 20 17% 1735 % 240 17% 17% 34 17% 17%s 0 17% 17% 34 17% 17% 0 17% 17% 0 P-2 32 1 20 18% 18% '4 1 160 1834 1835 0 1834 18% 4 18% 183. 0 18% 1834 % 18% 18 34 °-3 30 20 18 17% % 80 17% 1735 3 1734 17% 14 17% 17 34 17 16% 34 16% 1635 34 Note: Percolation test holes were drilled and soaked on December 30, 2014. Percolation tests were conducted on December 31, 2014. The average percolation rates were based on the last two readings of each test, except for P-1 which was the average of all the readings for that test.