Soft Soil Stabilization Study for Wilmington Harbor South Dredge Material Disposal Area

摘要

High-strength geotextiles coupled with polymeric vertical strip drains have essentially replaced the use of sand drains in the consolidation of soft clay deposits. Soft soils described in this report were saturated fine-grained organic silts and clays with an undrained shear strength of less than 100 lb/sq. ft. These materials were typical of maintenance dredged materials that are dredged by the US Army Corps of Engineers from rivers, port facilities, and harbors. This report contains a critique of the state of the art for soil stabilization using geosynthetic materials. It describes the implementation and performance of a high-strength geotextile and vertical strip drains in an ongoing project, Seagirt Project, being constructed by the Maryland Port Authority, Baltimore, Maryland. The Seagirt Stabilization Project consisted of a 113-acre dredged material containment area that contained 18 ft of fine-grained dredged material 50 to 150 percent above the liquid limit to depths of 20 to 33 ft. This surface contained alligator cracked crust 3 to 12 in. deep on the ground surface allowing one to walk on most of the areas to be stabilized. This report discusses the design philosophy, construction methodology, and development of new and innovative materials that are being developed for solving complex geotechnical problems. Purpose of this report was to evaluate the performance of the geotextile at the Seagirt Project and its bearing on the proposed Corps of Engineers project in the Port of Wilmington, Delaware, entitled Wilmington Harbor South Disposal Area, and other similar projects in the future.