真空预压与电渗固结联合加固技术的理论模型

真空预压和电渗固结是2种有效的软基加固技术,地基处理中阴极和阳极一般成梅花形布置,因此可以简化为轴对称问题进行研究。该文建立了真空预压-电渗固结问题的轴对称概化模型,研究地基加固过程中地基内超静孔压发展和地表沉降过程。在等应变假设的条件下,推导了轴对称一维模型的解析解。同时发展有限元计算软件,对软基加固过程进行数值模拟分析。真空预压、电渗固结和真空预压-电渗固结联合3种方法地基处理过程中的超静孔压发展情况的对比分析表明:真空预压-电渗固结联合时模型中负超静孔压最大,达到-90kPa,所产生的差异沉降最小,为0.01cm。因此,真空预压与电渗固结联合作用时地基中将形成更大的负超静孔压,达到更好的预压效果,同时有效地减小地表的差异沉降。

Analytical models of the coupling of vacuum preloading and electro-osmosis consolidation for ground stabilization

Vacuum preloading and electro-osmosis consolidation are two effective methods for soft ground stabilization.Those two techniques have been coupled in engineering practice,with analyses based on an axisymmetric model.This paper presents an analytical model in axisymmetric coordinate to predict the excess pore pressure and the ground settlement.An analytical solution is obtained based on an assumed equal strain condition for the 1-D axisymmetric model.A finite element model was developed to further investigate the development of the excess pore water pressure and the ground settlement during ground treatment.Numerical results show that vacuum preloading with electro-osmosis gives a larger negative excess pore water pressure to consolidate the ground and the differential settlement can be decreased to 0.01 cm.