围压条件下原状花岗岩残积土细观渗流数值模拟

选取福州某地原状花岗岩残积土作为研究对象,基于计算机断层扫描(CT)图像与COMSOL Multiphyscis有限元软件,研究原状土样在考虑和不考虑围压时的细观渗流规律.结果表明:两种条件下,计算渗透率都随水压差的增加呈线性降低的关系;考虑围压时,计算渗透率随竖向力呈先急剧到平缓下降,再急剧上升,最后趋于平缓下降的规律.同一时刻,考虑围压时的渗流长度较未考虑时的减少了约16%,速度大小降低了约13%.应力敏感性指数主要受围压控制,水压差对其影响甚微,且不同围压作用下应力敏感性指数呈"Z"字型变化.

Numerical simulation of meso-seepage flow in undisturbed granite residual soil under confining pressure

In order to reveal the meso-seepage law of undisturbed granite residual soil, the undisturbed granite residual soil in Fuzhou was selected as the research object. Based on industrial CT scan images and COMSOL Multiphyscis finite element software, the meso-seepage law of undisturbed soil samples with and without confining pressure was studied. The results showed that the calculated permeability decreased with the increase of the differential water pressure in a line way under the above two conditions; when considering the confining pressure, with the verticle force the calculated permeability dropped sharply first, then dropped gently, after that rose sharply, and tended to decrease gently at last. At the same moment, taking the confining pressure into account, the seepage length was reduced by about 16%, and the velocity was reduced by about 13%. The stress sensitivity index was mainly controlled by the confining pressure, the differential water pressure had little effect on it, and the stress sensitivity index changed in a "Z" shape under different confining pressures.