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HomeMy WebLinkAboutObservation of Excavation 06.15.2015F� HEPWORTH-PAWLAK GEOTECHNICAL June 15.2015 Richard & Mary Jolley Family LLLP Attn: Kent Jolley 832 Canyon Creek Drive Glenwood Springs, Colorado 81601 kentjollevki sopri 5-nel -3.020( ittiti hi 1 I'li+ '170 ural 3rptit Job No. 115 10SA Subject: Observation of Excavation, Proposed Residence, Jolley Ranch, County Road 335, Between Divide and Garfield Creeks, Garfield County, Colorado Dear Kent: As requested, a representative of Hepworth-Pawlak Gcotechnical, Inc. observed the excavation at the subject site on June 11, 2015 to evaluate the soils exposed for foundation support. The findings of our observations 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 April 27, 2015, Job No. 115 108A. At the time of our visit to the site, the foundation excavation had been cut in one level from 2 to 5 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation consisted of stiff sandy silty clay. Results of swell -consolidation testing performed on samples taken from the site, shown on Figure 1, indicate the soils have low to moderate compressibility under conditions of loading and wetting and a minor swell or collapse (settlement under constant load) when wetted. No free water was encountered in the excavation and the soils were slightly moist to moist. The soil conditions exposed in the excavation are consistent with those previously encountered on the site and suitable for support of spread footings designed for the recommended allowable bearing pressure of 3,000 psf. Loose and disturbed soils should be removed in the footing areas to expose the undisturbed natural soils. Other recommendations presented in our previous report which are applicable 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 Iimited 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 I'.trLLL 303-S41-7119 • i',tltfr,itit)Sprint_s 719 633-5502 6 ilvertlu m 9770.4{,5 1989 Richard and Mary Jolley Family LLLP June 15, 2015 Page 2 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 consul ted. If you have any questions or need further assistance, please call our office. Sincerely, HEPWORTH -- PAWLAK GEOTECHNICAL, INC. Daniel E. Hardin, P.E. ;0 24443 41FSS�ONAL V Rev. by: SLP DEH/ksw attachment Figure 1 — Swell -Consolidation Test Results cc: Palomino Design -Build PC- Jack Palomino (o::k@palominodesignbuilct Job No. 115 I ORA eigtech Compression % Compression - Expansion % 0 1 2 3 4 0 1 2 0.1 Moisture Content = 16.9 percent Dry Density = 88 pcf Sample of: Sandy Silty Clay From: Footing Grade, East Side 1.0 10 APPLIED PRESSURE - ksf 0.1 115 108A • Expansion upon wetting Compression upon wetting Moisture Content = 12.6 percent Dry Density = 95 pcf Sample of: Sandy Silty Clay From: Footing Grade, North Side • 1.0 10 APPLIED PRESSURE - ksf H Hepworth—Pawlak Geotechnical SWELL -CONSOLIDATION TEST RESULTS 100 100 Figure 1