Settlement Caculation And Forecast Of Soft Soil Subgrade By Vacuum Preloading

Soft soil is widely distributed in China. Processing and settlement calculation are key issues of construction in soft soil area. Vacuum preloading, as a new method in lots of processing methods, is getting more and more research and application. Therefore, this paper mainly studies settlement calculation and forecast of soft soil subgrade by vacuum preloading. Details are as follows:(1) Based on previous studies, this paper, both macroscopicly and microscopicly, analyzes the consolidation mechanism of soft soil reinforced by vacuum preloading. So, feasibility of this method was explained in scientific theory.(2)Based on the analysis of consolidation mechanism of soft soil reinforced by vacuum preloading, an engineering case of vacuum preloading was simulated by FLAC3D,which is an excellent numerical calculation procedure. Simultaneous, ultimate settlement was calculated by FLAC3D. Vertical and horizontal displacement's characteristics were obtained through a relatively deep analysis.(3) This paper forecasts the soft soil settlement with hyperbolic method, exponential curve method and poisson's curve method, all of them are curve fitting method. Through the analysis of forecasting results, we learn how to getting accurater forecasting results. At the same time, we draw the conclusion that exponential curve method is the best forecast method during these methods.(4) This paper studies the Grey System Theory's application in the forecast of soft soil subgrade settlement. Settlement of soft soil was calculated by GM(1,1) model and the reason of low precision was analyzed.To sum up, this paper studies the settlement calculation and forecast of soft soil subgrade by vacuum preloading and obtains some useful conclusions which can guide construction better.