2000 TOWER ST ARTS AND SCIENCES BLDG 2018-01-02 MF Import

Section 9-03.14(I) of the 2004 Washington State Department of Transportation (WSDOT) Standard Specifications, with the additional restriction that the fines content be limited to no more than 5 percent. If needed building foundations should also be supported on imported gravel borrow. It is possible to use on -site till soils during wet weather for areas requiring only 90 percent compaction provided the earthwork contractor implements good wet weather techniques. 2. Structural fill placed immediately outside below -grade walls (drainage zone) should consist of washed 3/8 inch to No. 8 pea gravel or conform to Section 9-03.12(4) of the 2004 WSDOT Standard Specifications, as shown on Figure 3. 3. Structural fill placed as crushed surfacing base course below pavements should conform to Section 9-03.9(3) of the 2004 WSDOT Standard Specifications. 4. Structural fill placed as capillary break below slabs should consist of I%: -inch minus clean crushed gravel with negligible sand or silt in conformance with Section 9-03.1(4)C, grading No. 57 of the 2004 WSDOT Standard Specifications. Reuse of On -site Native Soils. The till soils contain a high percentage of fines and will be sensitive to changes in moisture content and difficult to handle and compact during wet weather. The dense to very dense glacial till deposits are expected to he suitable for structural fill in areas requiring compaction to at least 95 percent of MDD (per ASTM D 1557), provided the work is accompli.,hed during the normally dry season (June through September) and that the soil can be properly moisture conditioned. It may be necessary to in,,-)ort sand and gravel with a low fines content to achieve adequate compaction for support of pavement areas, floor slabs and structures for we, weather construction. Imported structural fill consisting of sand and gravel (WSDOT gravel borrow) should be planned under all building floor slabs and foundation elements and if construction occurs during wet weather. The use of existing on -site till soils as structural fill during wet weather should be planned only for areas requiring compaction to 90 percent of MDD, as long as the soils are properly protected from wet weather and not placed during periods of precipitation. 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 till soils during the wet and dry seasons. Reuse of Existing Asphalt, Rase and Concrete Rubble. Existing asphalt pavement and Portland cement concrete rubble may be reused as structural fill if properly crushed during demolition. Recycled Portland cement concrete rubble and base course materials may be reused as structural fill throughout the project. Recycled asphalt may be used under new pavement and hardscape areas, in utility trenches, and against exterior below -grade walls. For use as general structural fill across the site, 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 2004 WSDOT Standard Specifications. If recycled asphalt and/or concrete will be used under pavement areas, we recommend that it meet the D3 G c o G n g i n e c r s 7 Pik No. 5836.002.00/040204