Surface Stabilization of Organic Silty Clay by Precompression

Field observations obtained at a 100-acre site near San Juan, Puerto Rico, indicate that (1) the use of surcharge is effective in eliminating post-construction settlement and (2) the use of sand drains shortens the length of the required precompression period. The amount of preload varied in various areas of the project to achieve negligible post-construction settlement under the design loads specified for each area. After removal of the surcharge load only a small amount of rebound was observed. Typical laboratory test results on organic silty clay and peat as well as settlement observations covering a period of 3 yr to 4 yr are presented. There is a continuing need for field observations taken over extended periods of time on projects in which the precompression technique is used.