Study On Theory And Application Of Vacuum Preloading With Long-short Plastic Drainage Board

In recent years, along with large-scale engineering construction in coastal areas, vacuum preloading method is frequently applied to the treatment of soft soil. Vacuum preloading method with the long-short plastic drainage board was proposed in some areas on the basis of reviewing the previous experience and technology in engineering. Nowadays, as there are few studies on the method, this paper carried out relevant study from the following aspects.Firstly, the variation patterns of surface subsidence, vacuum degree, layered settlement and pore water pressure were summarized and analyzed in detail, which were based on the monitoring data from a project using the vacuum preloading method combined with the long-short plastic drainage board. Besides, the effect of foundation treatment was evaluated, some improvement suggestions were proposed aiming at some problems in the process of construction and monitoring.Secondly, some new opinions were proposed from various aspects based on the field monitoring data. The concise consolidation calculation method of vacuum preloading with long-short plastic drainage board was proposed based on previous research work,and the feasibility of the calculation method had been verified by comparison with the field monitoring data.Finally, the method of vacuum preloading with long-short plastic drainage board was simulated by the large general finite element software ABAQUS. Two dimensional consolidation model was established by converting sand well foundation into sand wall foundation based on the formula of equivalent conversion. The variation patterns of the soil settlement, vacuum degree transmission and horizontal displacement were analyzed to draw some new conclusions.Meanwhile,the superiority of vacuum preloading method with long-short plastic drainage board was confirmed compared with the vacuum preloading method with equal-length plastic drainage board.