Studies On Treatment Techniques Of Soft Deposits Formed By Hydraulic Fills And Evaluation Of Engineering Effectiveness

The first-stage construction of Dayaowan has formed a region about 1 km2 by dredging. In this area, because the dredging points were set scarcely, soil formed becomes a regional and radial distribution, in which the soft deposits occupies about 40%. Through several years natural consolidation, this region begins to be backfilled and prepare to become the foundation for a district of substances exchange and a stack-up yard of container and general merchandise. Because the soft deposit contains silt, floury thin sand, medium thin sand, fill section and so on, the scheme of foundation treat can not be easily decided. Moreover, there will be a site about two million m2 formed by the oncoming second-stage project, which will be a mass of regions of soft base to wait for treat, and the method of dredging and the character of soil are the same as the former. For studying the scheme of treat and gaining experiences for the second-stage project, we select some regions to make experiments for comparing.Three experimental schemes were taken, including the draining plastic board and pre-compression with stacking load, the draining plastic board and punning, the replacement treat after punning. The deep horizontal movement of soil body, hyperstatic pore water pressure, the ground surface settlements and horizontal movements, dynamic detection and static load experiment were carried out in site.In this paper, the principles of several schemes of foundation treat and those related date were gained by the computation of those foundation treat schemes and analysis to the result of experiments. The feasibility and comparison of those several schemes are comprehensively and systemically understood. And many experiences were gained for the next stage construction. The achievement and ideas of the schemes were directed for the two following constructions of treating with stacking load two yards of Dayaowan dredging region. The scheme of natural draining and pre-compression with stacking load has not only treated the dredging region, but also prepared a great deal of rocks for the second-stage construction of Dayaowan and saved time for backfill work. And it will be possible that the Berth 11# of the second-stage construction is put into production as soon as possible. The scheme simplifies the unnecessary process of foundation treatment and its direct economic benefit and the social benefit are very remarkable.