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HomeMy WebLinkAboutObservation of Excavation 02.10.2022lGrtiffirflffifffiniiiå'*" An Emdoycc olrncd Compony 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email : kaglenwood@kurnarusa.com www. kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado February 10,2022 Russell Cartwright 35 Willowview way Parachute, Colorado I ló35 rusÊecart@gmail.com Prqect No.2l-7-229.39 Subject: Observation of Excavation, Proposed Residence ,Lot 4, Block l, The Fairways, Battlement Mesa, 39 Hogan Circle, Garfield County, Colorado Dear Russell: As requested, a representative of Kumar & Associates, Inc. observed the excavation at the subject site on October 25,2021to evaluate the soils exposed for foundation support. The frndings of our observations and recommendations are presented in this report. The services are supplemental to our agreement for professional services to you dated March 1,2021. We previously conducted a subsoil study for design of foundations at the site and presented our frndingsinareportdatedJuly2l,202l,ProjectNo.2l-7-229. Theproposedconstructionis similar to that discussed in our report. Spread footings bearing on the natural soils sized using an allowable bearing pressure of 1,500 psf were designed for foundation support based on the recommendations in that report. At the time of our site visit, the foundation excavation which was essentially complete had been cut in two levels from nil to about 4 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation consisted of stiff, sandy silt. Results of swell-consolidation testing performed on samples taken from the site, shown on Figure l, indicate the soils are moderately compressible under conditions of loading and wetting with a low hydro-compression potential. The soils are not expansive. No groundwater was encountered in the excavation and the soils were slightly moist. The soil conditions exposed in the excavation are generally consistent with those previously encountered on the site and suitable for support ofspread footings designed for the recommended allowable bearing pressure of 1,500 psf. There is some risk of settlement if the bearing soils were to become wetted and precautions should be taken to prevent wetting. Loose and disturbed soils should be removed in the footing areas to expose the undisturbed natural soils and the subgrade compacted. 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 subsurface exploration at the site. Variations Russell Cartwright February 10,2022 Page2 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' If you have any questions or need further assistance, please call or¡r office. Sincerely, Kumrr & David A. Young, P DAYlkac attachment Figure I Test Results Inc. 6 "/l-z Kumar & Associates, lnc.6 Project t{o. 21 -7 -229.39 ¡ È i SAMPLE OF: Sondy Slll FRÒM: Bollom of NW Porlion of Excovolion WC = 6.0 %, DD = 95 pcf ñt b. ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE DUE TO WETTING 1 0 j-l l¿J =U) t_2 zotr ô¿oØzoQ-4 -5 -6 -7 t.0 - KSF IO 21-7-229.39 Kumar & Associates SWELL-CONSOLIDATION TEST RESULT Fig. 1