6301 36TH AVE W 2016-11-01 - Laserfiche WebLink

' June 23,2014 Project No. T-6241 ' If grading activities are planned during the wet winter months, or if they are initiated during the summer and extend into fall and winter, the owner should be prepared to import wet weather structural fill. For this purpose, ' we recommend importing a granular soil that meets the following grading requirements: U.S.Sieve Size Percent Passing ' 6 inches 100 No. 4 75 maximum No. 200 5 maximum* *Based on the 3/4-inch fraction. ' Prior to use, Terra Associates, Inc. should examine and test all materials imported to the site for use as structural fill. ' Structural fill should be placed in uniform loose layers not exceeding 12 inches and compacted to a minimum of 95 percent of the soil's maximum dry density, as determined by American Society for Testing and Materials (ASTM) Test Designation D-1557 (Modified Proctor). The moisture content of the soil at the time of ' compaction should be within two percent of its optimum,as determined by this ASTM standard. In nonstructural areas, the degree of compaction can be reduced to 90 percent. All structural fill in City of Everett rights of way must confonn to City materials and compaction specifications. ' 5.3 Excavations ' All excavations at the site associated with confined spaces, such as retaining walls and utility trenches, must be completed in accordance with local, state, and federal requirements. Based on current Washington Industrial ' Safety and Health Act (WISHA) regulations, loose to medium dense weathered soils and medium dense to dense outwash soils would be classified as Type C soils. The dense to very dense unweathered till soils would be classified as Type A soils. ' Accordingly, temporary excavations in Type C soils should have their slopes laid back at an inclination of 1.5:1 (Horizontal:Vertical)or flatter, from the toe to the crest of the slope. Side slopes in Type A soils can be laid back ' at a slope inclination of 0.75:1 or flatter. For temporary excavation slopes less than 8 feet in height in Type A soils, the lower 3.5 feet can be cut to a vertical condition, with a 0.75:1 slope graded above. For temporary excavation slopes greater than 8 feet in height, the slope above the 3.5-foot vertical portion will need to be laid ' back at a minimum slope inclination of 1:1. All exposed slope faces should be covered with a durable reinforced plastic membrane during construction to prevent slope raveling and rutting during periods of precipitation. ' The above information is provided solely for the benefit of the owner and other design consultants, and should not be construed to imply that Terra Associates, Inc. assumes responsibility for job site safety. It is understood that job site safety is the sole responsibility of the project contractor. Page No. 8