淤泥地基处理中真空度和孔压变化规律研究

摘要

Analyzing the relations between the vacuum degree and pore water pressure in silt is of great significance to the research on vacuum preloading.According to the field measured data of vacuum-surcharge preloading,the change of the vacuum degree and excess pore water pressure in silt foundation is analyzed here,and the inquisition to the relevance of them is made.The test results show that the vacuum degree in silt has a start-up process,with the increase of vacuum time,its value falls gradually to a steady state;During vacuum pumping,the biggest dissipation values along the depth direction of pore water pressure are basically same,and the excess pore water pressure and vacuum degree are same above the groundwater level in silt,but below the groundwater level,the vacuum degree is smaller than the excess pore water pressure,the dissipation of pore water pressure is mainly caused by the drop of groundwater level due to vacuum pumping.%淤泥中真空度及孔隙水压力的关系分析对研究真空预压具有重要的意义。根据真空堆载联合预压现场实测资料,分析了淤泥中真空度和超静孔隙水压力的变化规律,并且对二者的相关性作了探究。监测结果表明：淤泥中的真空度存在一个启动过程,随着时间的增加,其值逐渐下降并趋于稳定;在抽真空阶段,孔隙水压力沿深度方向的最大消散值基本上相同,且淤泥中地下水位线以上的超静孔压值与真空度值一致,地下水位线以下的真空度值小于超孔压值,孔压消散主要是由抽真空导致的地下水位下降引起的。