1010 N BROADWAY EVCC 2018-01-01 MF Import

PROPOSED LIBERTY HALL,EVERETT COMMUNITY COLLEGE „- Everett,Washington 1. Structural fill placed to construct parking areas, to backfill utility trenches and to support building and floor slabs should consist of imported gravel borrow as described in Section 9-03.14(1) of the 2010 Washington State Department of Transportation (WSDOT) Standard Specifications, with the additional restriction that the fines content be limited to no more than 5 percent.On-site silt and clay soils are not suitable for use as structural fill. 2. Structural fill placed immediately outside below-grade walls (drainage zone) or around footing drains should consist of washed 3/8 inch to No. 8 pea gravel per section 9-03.1(4)C Grading No. 8, or conform to Section 9-03.12(4) of the 2010 WSDOT Standard Specifications, as shown on Figure 4. 3. Structural fill placed as crushed surfacing base course below pavements should conform to Section 9-03.9 (3)of the 2010 WSDOT Standard Specifications. 4. Structural fill placed as capillary break below slabs should consist of 11/2-inch minus clean crushed gravel with negligible sand or silt in conformance with Section 9-03.1(4)C, AASHTO Grading No.57 of the 2010 WSDOT Standard Specifications. Reuse of On-site Soils. Most of the near surface on-site soils consist of fill, silts and clays, and native silty sand deposits, which contain a high percentage of fines. Consequently, most of the on-site soils will not be suitable for reuse as structural fill. Existing silt and clay deposits should not be reused as structural fill on the site. On-site native sand deposits are expected to be suitable for structural fill in areas requiring compaction to at least 90 percent of MDD (per ASTM D 1557), provided the work is accomplished . during the normally dry season (June through September) and that the soil can be properly moisture conditioned. It may be necessary to import sand and gravel with a low fines content to achieve adequate compaction for support of pavement areas, floor slabs and structures for wet weather construction. Imported structural fill consisting of sand and gravel (WSDOT gravel borrow) c 3 ,tye should be planned under all building floor slabs and foundation elements and if construction occurs during wet weather. The contractor should plan to cover and maintain all fill stockpiles with plastic sheeting if it will be used as structural fill. The reuse of on-site soils is highly dependent on the skill of the contractor and schedule, and we will work with the design team and contractor to maximize the reuse of on-site sandy soils during the wet and dry seasons. Reuse of Existing Asphalt and Concrete Rubble. Existing asphalt pavement, base course, and Portland cement concrete rubble may be reused as structural fill if properly crushed during demolition. Recycled asphalt pavement should not be used as structural fill under building foundations or in landscape areas. Portland cement concrete rubble and base course materials may be reused as structural fill throughout the project except in landscape areas. For use as structural fill, the asphalt and concrete rubble should be crushed or otherwise ground up and should meet the gradation requirements for gravel borrow as described in Section 9-03.14(1) of the 2010 WSDOT Standard Specifications. If recycled asphalt and/or concrete will be used under pavement areas, we recommend that it meet the gradation requirements for crushed surfacing base course as described in Section 9-03.9(3)of the 2010 WSDOT Standard Specifications. GEOENGINEERS� June 10,2010 I Page 7 File No.5636.010-00