荷载条件下原状与重塑泥岩渗透性试验研究

为模拟地基土普遍受上覆荷载等实际情况，研制了可加载渗透仪。文章以兰新铁路第二双线一处典型膨胀泥岩为研究对象，进行了原状土和重塑土不同荷载等级下渗透试验，荷载大小为0，0.1，0.2，0.3，0.4 MPa。试验结果表明:随着渗透时间变长，原状土和重塑土的渗透系数略微增大。原状土渗透系数随荷载增大而变小，为现场地基土随埋深增加渗透性变小提供依据；重塑土渗透系数随荷载增大而变小，对于高填方路基底层土而言上覆荷载对其渗透性产生影响。通过进一步对比原状土与重塑土渗透性差异，可知重塑土渗透系数比原状土渗透系数大1个数量级，且原状土渗透系数呈“外凸形”减小，重塑土渗透系数呈“内凹形”减小，荷载对两种土体渗透系数影响机理不同。

An experimental study of the permeability of undisturbed and remolded mudstones under the loading condition

In order to simulate the fact that the foundation soil is generally subjected to overlying loads and so on, a loadable osmosis apparatus is developed in this paper. The typical dilated mudstone at the second double line of the Lanxin railway is taken as the research object, and the permeability test under different load grades of the original and remolded soils is carried out. Value of the load is 0, 0.1, 0.2, 0.3 and 0.4 MPa. The results show that, the coefficient of permeability increases slightly with the increasing infiltration time. The coefficient of permeability of the undisturbed soil decreases with the increasing load. The results, provide a basis for analyzing the decrease in permeability of the foundation soil with the burial depth. The coefficient of permeability of the remolded soil decreases with the increasing load. For the high fill road foundation soil, the overburden load has an effect on the permeability. By further comparing the permeability of the intact soil and remolded soil, it is found that the coefficient of permeability of the remolded soil is 1 order of magnitude larger than that of the intact soil. The variation law of the coefficient of permeability is compared, and the reasons for the change in the permeability of the undisturbed soil and remolded soil are analyzed.