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

gradation requirements for crushed surfacing base course as described in Section 9-03.9(3) of the 2004 WSDOT Standard Specifications. ' Use of Recycled Glass. Recycled glass may also be used as structural fill in some areas. Based on the project location, it may be economical to use recycled glass in lieu of imported materials. We recommend that recycled glass meet the requirements of recycled glass aggregates as described in Section 9-03.21(4) of the 2004 WSDOT Standard Specifications. IFill Placemeni and Compaction Criteria. Structural fill should be mechanically compacted to a I firm, non -yielding condition. Structural fill should be placed in loose lifts not exceeding 8 to 10 inches in thickness. The actual thickness will be dependent or. the structural fill material used and the type and size of compaction equipment. Each lift should be conditioned to the proper moisture content and compacted to the sp �cified density before placing subsequent lifts. Structural fill should be compacted to the following criteria: 1. Structural fill placed behind below -grade walls should be compacted to between 90 to 92 percent of the MDD estimated in accordance with ASTM D 1557. Care should be taken when compacting fill near the face of below -grade walls to avoid over -compaction and hence overstressing the walls. Hand operated cowPactors should be used within 5 feet behind the wall. Wall backfill placed within the building footprint and under the second floor level should be compacted to between 90 to 92 percent of the MDD within 5 feet of the walls and to at least 95 percent of the MDD beyond 5 feet of the walls. The upper 2 icet of fill below floor slab subgradc should also be compacted to at least 95 percent of the MDD. The contractor should keep all heavy construction equipment away from the top of retaining walls a distance equal to %: the height of the wall, or at least 5 feet, which ever is greater. 2. Structural fill in new pavement and hardscape areas, including utility trench backfill, should be compacted to at least 90 percent of the NIDD estimated in accordance with ASTM D 1557, except that the upper 2 feet of fill below final subgradc should be compacted to at least 95 percent of the MDD, see Figure 4. 3. Structural wi placed below floor slabs and foundations shoul.l be compacted to 95 percent of the N'IDD estimated in accordance with ASTM D 1557. 4. Structural fill placed as crushed rock base course below pavements should be compacted to 95 percent of the MDD estimated in accordance with ASTM D 1557. 5. Non-structural fill, ,uch as till placed in landscape areas, should be compacted to at least 85 percent of the MDD estimated in accordance with ASTM D 1557. In areas intended for future development, a higher degree of compaction should be considered to reduce the settlement potential of the fill soils. Weather Considrt ations. Disturbance of near surface soils should be expected if earthwork is completed during periudn -if wet weather. During dD, weather ?,e soils will (1) be less susceptible to disturbance, (2) provide better support for construction equipment, and (3) be more likely to meet the required compaction criteria. uq G c o E n g i n c c r s File No. 5836-007.-00/040204