HomeMy WebLinkAboutObservation of Excavation 12.30.2021 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email: kaglenwood@kumarusa.com www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado December 30, 2021 SCIB, LLC Attn: Luke Gosda 0115 Boomerang Road, Suite 5201B Aspen, Colorado 81611 luke.gosda@sunriseco.com Project No. 20-7-784 Subject: Observation of Excavation, Proposed Residence, Lot 25, Ironbridge, River Bend Way, Garfield County, Colorado Gentlemen: As requested, a representative of Kumar & Associates, Inc. observed the excavation at the subject site on December 21, 2021 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 February 2, 2021, Project No. 20-7-784. The residence will be similar to that described in our previous report except that a partial basement has been included in the downhill, north part. Spread footings placed on the natural gravel soils and sized for an allowable bearing pressure of 2,500 psf were designed for the foundation support. At the time of our visit to the site, the foundation excavation had been cut in 2 levels from 4 to 10 feet below the adjacent ground surface. The step between levels was about 6 feet. The soils exposed in the bottom of the excavation consisted of relatively dense, sandy gravel with cobbles. No free water was encountered in the excavation and the soils were slightly moist and not frozen. 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 2,500 psf. Loose disturbed soils should be removed in the footing areas to expose the undisturbed natural soils. The bearing soils should be protected from frost and concrete should not be placed on frozen 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 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