1600 MADISON ST 2016-01-01 MF Import

�i `I �� � � � f� Mr. Chris Lark February 20, 2001 C1.3 WET WEATHER EARTIIWORK AND EROSION CONSIDERATIONS The site soils contain a considera9le amount of fines, arid are therefore moisture scnsitivc. As a result, it may be more economical to perform earthwork in the diier summer months to pree ent thc site soils from becoming soft due to excessive moisture. Any sofiened soils should be removed and replaced with properly compacted granulaz structural fill. General recommendations relative to earihwork performed in wet weathcr or in wct conditions are presented below: • Earthwork should be perfornied in small areas to minimize exposure to wet weather. Excavation or the removal of unsuitablA soil shuuld be followed promptly by the placement and compaction of clean structural fil3. The size and fype of construction equipment used may have to be limited to prevent soil disturbance. Under somc circumstances, it may be necessary to excavate soils with a backhoe to minimize subgrade disturUance caused by equipment traffic. • During wet weather, the allowable fines content of the structural fill should Uc reduced to no more than 5 percent by weight based on Ute portion passing'/.,-inch sieve. The fines should be non-plastic. • The ground surface witUin the construction area should be graded to promote run-off of surface water and to prevent tl�e ponding of water. • A smooth drum vibratory roller, or equivalent should seal the ground surface within the construction area, and under no circumstances should soil be lett uncompactcd and exposed to moisture. • Bales of straw and/or geotextile silt fences should be strategically located to control erosion and the movement of'soil. 6.4 DRAINAGE CONSIDERATiONS Ade,�uate drainage provisions are imperative and �vc reconmiend botl� short and long tenn drainage measures be incorporated into the project design and construction. Surface rmioff can be controlled during construction by carefiil grading practices. Typically, t(tis includes the construction of shallow, upgrade perimeier ditches or low eartl�en bemis and the use of temporary sumps to collect runoff and prevent water from damaging exposed subgrades. All col(ected water should be directed under control to a positive and pennanent discharge system, such as a storm sewer. IFencountered, we anticipate that groundwater can be controlled in excavations by using ditches, sumps, and pumps. Permanent control of surface water should Ue incorporated in the final grading design. Water should not be allowed to pond immediately adjacent to huildings or paved areas. Perimeter 00-04G-100 Geotech Report PanGEO,lnc. �y