Attachment 3 - Geotechnical AGEGC Report.pdf

This is a geotechnical investigation report dated October 30, 2013, prepared by Applied Geotechnical Engineering and Geologic Consulting LLC for a proposed 6,000 sq ft chapel building at the VA Domiciliary in White City, Oregon. The report details subsurface soil conditions based on three test pit excavations completed on September 25, 2013.

The investigation found that the site contains a 12-18 inch surficial layer of brown silt soils with moderate shrink-swell potential, underlain by medium dense to dense gravel/cobble. Key recommendations include: overexcavation of unsuitable soils to depths of 18-30 inches below grade; use of conventional spread footing foundations with a minimum depth of 18 inches; structural fills using imported granular material compacted to 95% maximum dry density; and a vapor-retarding membrane beneath the concrete slab-on-grade floor. The report indicates the site is suitable for the proposed chapel construction from a geotechnical standpoint, with a seismic Site Class C classification and low risk of earthquake-induced issues. Foundation loads are assumed to be up to 10 kips for columns and 3 kips/ft for walls.