The Properties Of Vacuum-surcharge Preloading And Stability Of Soft Ground

Vacuum-surcharge preloading method as an effective software-based approach has been widely used in port construction, land reclamation from the sea, highway and other projects. Vacuum-surcharge preloading method has got great progress in reinforcement mechanism design theory, numerical simulation research, but still lags behind the theoretical study of engineering practice. There are still some issues of concern to academic research and to be resolved, including the distribution of the vacuum in soil, the variation of groundwater level on vacuum-surcharge preloading and its impact on the pore water pressure, vacuum-surcharge preloading process stability, simulating the vacuum load in numerical simulation, to complete the processing of soil liquefaction problems in the pre-press process, these problems have constrained vacuum-surcharge preloading method for further development. This paper has done some study in issues of the vacuum-surcharge preloading, based on previous studies, by field-testing, theoretical analysis and numerical simulation methods. Work include the following items:1) According to the field measurement data, study the variation and relationships of the vacuum, surface subsidence, soil layer settlement, horizontal displacement of soil, pore water pressure and groundwater level of vacuum-surcharge preloading, and study the effect of vacuum preloading and surcharge preloading on them separately.2) Study the strengthening mechanism of vacuum preloading and surcharge preloading, examined the differences and similarities between the two. With the measured data were calculated degree of consolidation and shear strength of soil estimated the growth.3) According to the principle of strength reduction, made analysis on soft ground slope stability by Flac3D.The slope stability safety factor is greater than1that the slope stability is good.4) Proposed liquefaction mechanism and control measures, and test the effects of dynamic compaction for soil liquefaction based on liquefaction discriminant methods.