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Home My WebLink AboutSoils Report 02.09.2015Gtech HEPWORTH-PAWLAK GEOTECHNICAL February 9, 2015 Aspen Signature Homes of Ironbridge, LLC Attn: Llwyd Ecclestone P.Q. Box 7628 Aspen, Colorado 81612 (leecle,,tone@ 01)111 l.nct) Subject: Gentlemen: 1kI twill' I' m1 J ( II. In, 50204..,wilt% l .•t.1 1i4 fly nt..,„I ynnu., 12.1L.r la • .11601 Plume 0i�} ")4i 7)'' 1 I\ 970-943 ti474 ,II 111 •:a.ri It 't. tr.lt Look Job No. 113 471H Observation of Excavation, Proposed Residence, Lot 292, Ironbridge Development, 1363 River Bend Way, Garfield County, Colorado As requested by Dave Guthrie with Silich Construction, a representative of Hepworth- Pawlak Geotechnical, Inc. performed compaction testing on February 4 and 5, 2015 and observed the building excavation at the subject site on February 4, 2015 to documcnt the soil conditions exposed for foundation support. The findings of our observations and testing, and recommendations for the foundation design are presented in this report. We previously conducted a subsoil study for design of foundations at the site and presented our findings in a report dated October 3, 2014, Job No. 113 471 H. The proposed residence is essentially the same as described in our previous report and will be supported on spread footings placed on compacted structural fill in the shallow footing, garage area and on the natural soils in the basement cut arca and sized for an allowable bearing pressure of 1,000 psf. At the time of our site visits on February 4 and 5, we observed and tested compaction of the backfill below the shallow footing, garage area. The compaction testing results are presented in the attached Earthwork Compaction Testing Reports and indicate satisfactory compaction. When observed on February 4, the basement area had been excavated which included the garage area. The excavation had been cut in one level from 7 to 9 feet below the adjacent ground surface. The deeper cut was along the uphill, west side. The soils exposed in the bottom of the excavation consisted of sandy silt. The exploratory boring drilled on the lot for the previous study showed the silt soils to extend to about 6 feet below basement cut depth and overlie dense river gravel soils. Results of a swell - consolidation test performed on a sample of the silt taken from the excavation bottom, presented on Figure 1, indicate low to moderate compressibility potential when wetted and loaded. The basement cut level was compacted concurrent with the backfill placement in the garage area. No free water was encountered in the excavation and the soils were generally moist. Parker 303-S41-7119 • (;o11•r:ikIt-Springy I9-633 5562 • .Sdverrhorne 971-46ti-19,59 Aspen Signature Homes of Ironbridge, LLC February 9, 2015 Page 2 The natural soils and compacted soils exposed in the excavation are consistent with those expected at the site and suitable for support of spread footings designed for the recommended allowable bearing pressure of 1,000 psf with the risk of settlement. Any remaining loose disturbed soils should be compacted in the footing areas. Other recommendations presented in our previous report which are applicable, especially those to keep the bearing soils dry, should also be observed. The recommendations submitted in this letter are based on our observation of the soils exposed within the foundation excavation and the previous limited subsurface exploration at the site. Variations in the subsurface conditions below the excavation could increase the risk of foundation movement. We should be advised of any variations encountered in the excavation conditions for possible changes to recommendations contained in this letter. 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. If you have any questions or need further assistance, please call our office. Sincerely, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Steven L. Pawlak, P.E. SLP/Ijf Attachments: Figures 1 and 1 A - Proctor Compaction and Particle Size Distribution Earthwork Compaction Testing Reports, February 4 and 5, 2015 Figure 2 - Swell -Consolidation Test Results cc: Silich Construction --• Dave Guthrie(d{=uthrie@silichconstruL1ion.com) Silich Construction - John Silich (john @ silichconvtruction.com) Silich Construction - Jodi Thimsen (Jodi@silichconstruction.com) Joh Islas 113 4711-1 G lertech Laboratory Proctor Compaction Test Report 117.5 \ I13. %, 112.7 115 Y23 Q.114.9 ocfl ... 112.5 U a 7+ C o 'd 0 110 • it• 107.5 ZAV for Sp.G. = 105 2.50 7 9 11 13 15 17 19 Water content, % —t- - Rock Corrected —0— - Uncorrected Test specification: ASTM D 698-00a Method B Standard Oversize corr. applied to each test point Elev! Depth Classification Nat. Moist. Sp.G. LL P1 % > 318 In. % < No.200 USCS AASHTO ML A-4(0) 7.0 1 65 ROCK CORRECTED TEST RESULTS UNCORRECTED MATERIAL DESCRIPTION Maximum dry density = 114.9 pcf Optimum moisture = 12.3 % 112.7 pcf 13.1 % Sandy Silt Project No. 113471H Client: Aspen Signature Homes oflronbridgc, LLC Project: Lot 292, Ironbridge Development, River Bend Way, Garfield County, Colorado o Location: Stockpile Sample Number. 006-15 Remarks: See Figure 1 A for classification results. Figure 1 Hepworth-Pawlak Geotechnical, Inc. Glenwood Springs, Colorado Tested By: KO Checked By: SLP PERCENT FINER Particle Size Distribution Report c GRAIN SIZE - mm. % +3" % Gravel % Sand % Fines Coarse Fine Coarse Medium Fine Silt 0 5 4 5 20 65 Clay SIEVE SIZE c 10 SPEC.* PERCENT ,6 ,E ,C a .a s N w x o oN a A a s app o a O ; v, 00 1.5 97 1 .75 95 I I I f I #4 91 1 1 1 1 1 1 #16 88 #30 86 #50 83 #100 76 #200 65 E 1 1 1 1 I' 90 i 1 1 1 1 I L i I i 1 I 1 ! 1 1 I I I I I I I I 80 I I 1 1 1 1 I I I I I I 1 1 1 1 1 1 t I I 1-1 1 1 1 1 1 1 I 1 E 1 1 70 I i I 11 I 1 I 1 1 I 1 1 1 1 1 1 1 1 1 1 I I 1 1 1 1 1 1 1 1 I I `r 60 1 { 1 1 1 I -1 I---1- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 50 i 1 1 1 1 1 1 1 1 1 1 1 I I 1 1 1 1 1 ! I 1 1 1 1 I I ! l I I I I 40 l I {{ I I I I 1 1 1 E I 1 1 1 1 1 1 1 1 1 1 .1, 1 1 1 1 1 1 1 i 1 1 1 1 30 1 1 1 I f 1 –I 1 : 1 1 7 I I 1111' 1 1 I 11 1 1 20 I I 1 1 1 1 I _.1 1 1 1 1 1. I I i 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 101 1, i 1 I t l I 1 ! 1 1 I 1 1 1 i 1 1 1 1 11 0 1 1 1 I I I I 100 10 1 01 am n.nn/ GRAIN SIZE - mm. % +3" % Gravel % Sand % Fines Coarse Fine Coarse Medium Fine Silt 0 5 4 5 20 65 Clay SIEVE SIZE PERCENT FINER SPEC.* PERCENT PASS? (X=NR) 3 100 1.5 97 .75 95 .375 93 #4 91 #8 90 #16 88 #30 86 #50 83 #100 76 #200 65 (no specification provided) Location: Stockpile Sample Number: 006-15 Material Description Sandy Silt Atterberg Limits PL= NP LL= PI= Coefficients D85= 0.4762 Do= D30= D15= Cu= Cc= Classification USCS= ML AASHTO= A-4(0) Remarks See Figure 1 for standard Proctor compaction results. D50= D10= Date: 2/2/2015 Hepworth-Pawlak Geotechnical, Inc. Glenwood Springs, Colorado Client: Aspen Signature Homes of Ironbridge, LLC Project Lot 292, Ironbridge Development, River Bend Way, Garfield County, Colorado Project No: 113471H Figure IATA Tested By: KO Checked By: SLP I-1Ptech HEPWORTH - PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 J1 Dn eo(athcae otech.com Earthwork Compaction Testing Report Client: Aspen Signature Homes of Ironbridge, LLC Job No.: Attn: Llwyd Ecclestone P.O. Box 7628 Aspen, Colorado 81612 Project: 113 471H Day: Date: Page: Lot 292, Ironbridge Development, River Bend Way, Garfield County, Colorado Wednesday 214115 1 of 1 Weather: Cloudy, calm, light rain Temperature: 38° at 1:20 pm Earthwork Contractor: Silich Equipment Used: Description of Earthwork Tested: Sample(s) Obtained: Verbal Communication: Track hoe, Wacker RT remote double drum roller, fire hose, insulated blankets First lift in sub -excavated area of garage footings was tested. Lift initially tested below specified compaction and high on moisture. Lift was then re - blended and re -compacted until an acceptable re -test was obtained. Standard Proctor and classification test sample was previously obtained on 2/2/15 by Steve Pawlak. Lab results are attached. Dave Guthrie with Silich and the crew were informed of our test results. Upon our second site visit we were informed that due to compactor breakdown, no additional backfill had been compacted. Placement and Compaction Procedure: Observed by HP Geotech. Lift Thickness: 1 foot loose Max. Rock Size: 3" Compactor(s) Used: Wacker RT remote double drum roller Moisture Fire hose and track hoe Conditioning: blending in stockpile Number of Passes: 8 minimum Test No. Location Nuclear Gauge Moisture/Density Test Results Backfill below garage footings Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) 1 6' S of NE garage corner 5' below footing grade 105.7 17.8 92 Min. Comp. Req. (%) 98 Proctor Lab No. 006-15 1A Re -test of #1 above 5' below footing grade 108.4 15.2 94 98 006-15 1B Re -test of #1 & I A above 5' below footing grade 112.4 14.4 98 98 006-15 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (%) 006-15 ASTM D 698 Sandy Silt 114.9 12.3 in�a noun i rncacn i urirvwrvs as A ntSULi ur ouRves VATI NSUF FlLL FL/4CEMENi, WE RAVE RELIED ON THE CONTRACTORTO CONTINUEAPPLYING THE RECOMMENDED COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938. Distribution: Aspen Signature Homes of Ironbridge, LLC - Uwyd Ecclestone (Iecclestonenoblhfl.net) Sillch Construction — David Guthrie(dauthrie(S?silichconstrucfion.com) SIIIch Construction — John Silich (iohn(sillchconstruction.com) Silich Construction —Jodi Thimsen (iodk5 silichconstniction.com) TJW/ Thomas J. Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By G&ech HEPWORTH-PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 P hone: 970.945.7988 Fax: 970-945-8454 hoaeoOlniaeotech,com Earthwork Compaction Testing Report Client: Aspen Signature Homes of Ironbridge, LLC Job No.: Attn: Llwyd Ecclestone P.O. Box 7628 Aspen, Colorado 81612 Project: 113 471H Day: Date: Page: Lot 292, Ironbridge Development, River Bend Way, Garfield County, Colorado Thursday 215115 1 of 1 Weather: Partly cloudy, calm, dry Temperature: 28° at 8:40 am, 52° at 2:40 pm Earthwork Contractor: Silich Equipment Used: Description of Earthwork Tested: Verbal Communication: Track hoe, Wacker RT remote double drum roller, fire hose, insulated blankets Four site visits were made today to test backfill placed in sub -excavated area of garage footings. Tests indicated acceptable compaction with moisture contents near optimum. The crew was informed of our test results. Placement and Compaction Procedure: Observed by HP Geotech. Lift Thickness: 1 foot loose Max. Rock Size: 3" Compactor(s) Used: Wacker RT remote double drum roller Moisture Fire hose and track hoe Conditioning: blending in stockpile Number of Passes: 8 minimum Test No. Location Nuclear Gauge Moisture/Density Test Results Backfill below garage footings Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) 1 10' S of NE garage corner 4' below footing grade 113.3 13.8 99 Min. Comp. Req. (%) 98 Proctor Lab No. 006-15 2 10' W of NE garage corner 4' below footing grade 112.3 12.4 98 98 006-15 3 6' S of NE garage corner 2' below footing grade 112.4 12.0 98 98 006-15 4 4' W of NE garage corner 2' below footing grade 112.2 12.3 98 98 006-15 5 7' W of NE garage corner footing grade 115.1 12.6 100 98 006-15 6 8' S of NE garage corner footing grade 112.5 13.6 98 98 006-15 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (%) 006-15 ASTM D 698 Sandy Silt 114.9 12.3 THIS REPORT r,aeaw',, OPENIONSASA RESULT OF OUR ue�tNVATIONSOF FILL PLACEMENT. WE WIVE RELIED DN THE CONTRACTOR TO CONTINUE APPLYING THE RECOIAMENDED COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6338. Distribution: Aspen Signature Homes of Ironbridge, LLC - Liwyd Ecclestone (Iecclestone@pblhfl.net) Silich Construction — David Guthrie (douthriet5 silichconstruction.com) Silich Construction —John Silich (iohnc8 silichconstruction.com) Silich Construction —Jodi Thimsen (iodi aesilichconstruction.com) TJWI Thomas J. Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By Compression % 0 1 2 3 4 5 6 7 8 Moisture Content = 15.3 percent Dry Density = 85 pct Sample of: Sandy Silt From: Bottom of Excavation at Southest Corner Compression upon wetting 0.1 11347'1H 1.0 H Hepworth—Pawlak Cootechntoal 10 APPLIED PRESSURE - ksf SWELL -CONSOLIDATION TEST RESULTS 100 Figure 2