真空预压发处理软土地基施工方案

Proposed Design Philosophy, Construction, Installation and Monitoring Method ( as per 22.1.7 of section 1.0)1. Source of borrows pit indicating the location and quantityWe have license given by Vietnam authority to exploit a quantity of 8, 400,000 m3 in Nha Be river and the location is in Nhon Trach district, Dong Nai province.2. Physical proprieties of proposed fill materialThe sampling test of sand proposed to use is carried out according to AASHTO M45-89, C144-88 (see Test Result of Analyses of Sand component). The specific weight of the sand is 2.634, unit weight 1.5g/cm3, organic content 2.87% and modules 2.52.3. Proposed method of statement and monitoring devices3.1 Method statementAccording to the geotechnical report of the site, the void ratio of the soft silty clay (e) is 2.377, and the permeability coefficient (Kv) 5.5*10-7cm/s. If we adopt “wick drains and pre-loading” method to reach a soil bearing capacity of 50Kpa, 75Kpa, 100Kpa under the site’s conditions, the consolidation period would be far beyond the proposed work period. For the purpose of reducing the consolidation period of foundation soil an overload should be added, though the loading would be 7.30m high to fulfill the bearing capacity of 100Kpa. Obviously, this technique would bear a tremendous number of loading and unloading, which would also mean a high construction cost. The stability of side slope would also be difficult to monitor.Based on our previous experience of soft soil improvement of China coastal and Hiep Phuoc Power Plant in Nha Be, 15km Southeast of Hochiminh City, the pre-loading method is appropriate only for general area. In process area we suggest to adopted the following method (details see drawings...