基于Hansbo渗流的圆球土样Biot固结分析

Biot′s Consolidation Analysis for Spherical Soil Samples Based on Hansbo′s Flow

为考虑渗流的非Darcy特性对固结过程的影响,引入Hansbo渗流模型对圆球土样修正Biot固结方程,并给出方程的Crank-Nicolson有限差分格式.通过和Darcy渗流模式下Biot固结方程解析解的对比,验证了本文数值计算方法的有效性.在此基础上,讨论了Hansbo渗流参数对圆球土样固结过程的影响.计算结果表明,和Darcy渗流相比,在固结初期,Hansbo渗流将增强Mandel-Cryer效应,增大孔隙水压力的峰值,并延长孔隙水压力达到峰值的时间;在固结中后期,Hansbo渗流将使圆球土样内的孔压消散明显滞后.另外,Hansbo渗流会使整个固结过程中圆球土样的固结度减小,且这种影响会随着Hansbo渗流参数的增大而更加明显,但Hansbo渗流对圆球土样边界位移的影响很小.

In order to study the influence of the Non-Darcy flow in the consolidation process, the Hansbo＇s flow model was introduced to modity the Biot＇s consolidation equations for the spherical soil samples, and their numerical analyses were conducted by the Crank-Nicolson finite difference method. In order to verily its validity, the numerical solution for the spherical soil samples that the flow of pore water obeyed Darcy＇s flow was compared with the analytical solution based on the Biot＇s consolidation theory. Then, the ettects of Hansbo＇s flow parameters on the consolidation process of spherical soil samples were investigated. Compared with the consequence that considering the Darcy＇s flow,in the early stages of consolidation, numerical results showed that the Mandel-Cryer effect was enhanced by considering the behaviour of Hansbo＇s flow. The peak value of pore water pressure based on Hansbo＇s flow was also improved. Meanwhile the time that the pore water pressure reached its peak was extended. In the middle and later stage of consolidation,the appearance that Hansbo＇s flow delayed the dissipation of pore water pressure in the spherical soil samples was tound. In addition, the consolidation degree of the soil was reduced in the whole consolidation process when considering Hansbo＇s flow. Moveover,the above effects on consolidation were more observable with the increase of Hansbo＇s flow parameters. However,the effect on the spherical boundaiT displacement when considering Hansbo＇s flow was weak.