10632 7TH AVE SE Geotech Report 2025-07-28

I June 6,2008 Serenity Meadows L&A Job No. 8A017 Page 14 construction settlement of the buildings should be 3/4 inch or less and the differential settlement across building width should be 1/2 inch or less. Lateral loads on buildings can be resisted by the friction force between the foundations and the subgrade soils or the passive earth pressure acting on the below-grade portion of the founds ions. For the latter, the foundations must be poured"neat"against undisturbed soils or backfilled with a clean, free-draining, compacted structural fill. We recommend that an equivalent fluid density I (EFD) of 325 pcf (pounds per cubic foot) for the passive earth pressure be used for lateral resistance. The above passive pressure assumes that the backfill is level or inclines upward behind the foundations for a horizontal distance at least twice the depth of the foundations below final grade. A coefficient of friction of 0.60 between the foundations and the subgrade soils may be used. The above soil parameters are unfactored values, and a proper factor of safety should be used in calculating the resisting forces against lateral loads on the buildings. SLAB-ON-GRADE FLOORS Slab-on-grade floors, if used, should be placed on firm subgrade soils prepared as outlined in the SITE PREPARATION AND GENERAL EARTHWORK.and the STRUCTURAL MI,sections repo rt.this r rt. Where moisture control is critical, the slab-on-grade floors should be placed on a capillary break which is in turn placed on the compacted subgrade. The capillary break should layer of free-draining of a minimum four-inch-thicky g gravel or crushed rock containing no more than 5%by weight passing the No. 4 sieve. We recommend that a vapor barrier, such as a 6-mil plastic membrane, be placed over the capillary break to keep moisture from migrating upwards. ROADWAY PAVEMENT Performance of roadway pavement is critically related to the conditions of the underlying subgrade soils. We recommend that the subgrade soils within the roadways be treated and LIU & ASSOCIATES, INC.