J_2024 05 09_West Orange Stormwater Management Plan

PSE&G Mav 17. 2011 Page 11 the majority of the settlement is expected to occur rapidly, practically upon application of load. Based on the information provided to us, it is our opinion that the lightly loaded foundations designed and installed in accordance with our recommendations would experience post construction settlements of about one-half of one inch. Information provided to us indicates that the transformers could weigh as much as 500 kips and would be supported on a mat with dimensions of 12 feet by 15 feet resulting in an applied pressure of about 2,800 pounds per square foot. The transformer pad would experience total settlements which are estimated to be about three-quarters of one inch. Calculations are presented in Appendix III. Seismic Design Criteria: Based on the results of our explorations and our review of the regional geology, it is our opinion that seismic design of the proposed improvements could be based on Site Class “C” as defined in the International Building Code 2009, New Jersey Edition. Lateral Earth Pressures: If required, excavation support systems, below grade structures or site retaining walls should be designed to resist lateral earth pressures imposed by the adjacent soils, as well as surcharge loads due to adjacent equipment, traffic, floor slabs or foundation loads, etc. We estimate that the following soil parameters could be used to design these systems: Soil Type .SISiw®:' S’" T?’-: Existing sandy and clayey fill materials Clean crushed stone backfill Natural silty and clayey sands or imported granular controlled compacted fill Total Unit Weight (pcf) AMpJjf fit internal friction (degrees) 120 30 0 0.333 105 38 0 0.238 125 34 0 0.307 Active Earth Pressure Coefficient (Ka> “ Corrosivity and pH Testing: Five samples of the soils in close proximity to the anticipated levels for shallow foundations (±2 to 2.5 feet) were submitted to an NJDEP certified laboratory and were subjected to laboratory tests to determine chloride, and sulfate levels to evaluate their potential