832 RUCKER AVE 2016-01-01 MF Import

� Proposed Modification to the Residence of Jcel 8 Kalhy Larsen February 12, 2004 Everett, Washington ORA Project Number: 04-065-Report 1 I thickness and compacted to at least 95 percent of the maximum laboratory dry density as determined by the modified Proctor test (ASTM D1557). The soils shouid be compacted at moisture contents within three (3) percent of optimum moisture. Placement of frozen soils or placement of soils on frozen ground should not be attempted. Structural bar,kfill behind basement or retaining walls should meet the gradation recommendations presented in Table 6.1 and should be compacted to 90 percent of the maximum density as determined by the modified Proctor (ASTM 1557) at moisture contents within two percent of optimum. The specified compacted density and moisture content of each lift should be verified by test, prior to placement of subsequent lifts. Placement on frozeri ground should not be attempted. Un!ess these walls are designed to withstand the additional lateral loads, heavy equipm�ant should not be operated behind the walis within a distance from the wall equal to the height of the wall. Lightweight equipment should be used to deliver ba�kfill soil behind t��e wall and hand operated equipment should be used for compaction. 6.5 Surface Drainage Good surface drainage is considered critical to the pertormance of earth-supported structures such as foundations, retaining walis, and pavements. Therefore, construction grades and final site grades should be designed to prevent water from entering the foundations or gravel drains behind any retaining walis or from ponding on or next to pavements. Where pavement does not immediately abut structures, slopes, with an outfall of at least three (3) percent for a minimum distance of ten (10) feet from exterior footfngs, should be provided. These slopes should be capped with relatively impervious soils to prevent infiltration of water into the foundation soils. 6.6 Groundwater Groundwater was encountered at approximate elevation 497 feet (plus or minus one- foot) above mean sea level (MSL.) If the basement floor elevation or any portion of the underdrain system will be at or below elevation 497 feet the groundwater level must be permanently lowered. Several methods of lowering the groundwater are available and include the use of perimeter well points and suction pumps and perimeter gravity drains. Depending upon the method selected and spacing of the components, the groundwater IOtto Rosenau 8 Associates, Inc. Page 11 0( 13 ��7