基于GDS的黏土非线性渗透特性试验研究

Experimental study on nonlinear permeability characteristics of Xiaoshan clay

基于黏土渗透性与孔隙比的非线性关系,讨论和总结了4种渗透模型,即lg[kv(1+e)]-lge渗透模型、e-lgkv渗透模型、lgkv-lge渗透模型和lgkv-lg(1+e)渗透模型。来用GDS高级固结仪,对萧山黏土8个试样进行了一维固结渗透联合试验,使用直接法整理固结压力作用下渗透系数等试验结果,分析了对应于4种非线性渗透模型的土性参数。试验与分析结果表明,萧山黏土渗透性随固结压力增加呈现非线性减少,在50～1600kPa压力作用下其的渗透系数从8×10-8cm.s-1减少为8×10-9cm.s-1;4种非线性渗透模型对萧山黏土都是适用的。

Based on nonlinear relationship between permeability and void ratio of intact natural clay, four theoretical permeability models, i.e. lg[k, （1 ＋ e）]-lg e model, e-lg k model, lg k -lg e model, and lg k -lg（1 ＋ e） model, are introduced and discussed. The 1-D consolidation and permeability combined tests on eight undisturbed Xiaoshan clay samples are carried out by GDS advanced consolidation testing system. Void ratio and directly-measured permeability coefficient obtained from the test results are analyzed to summarize clay parameters of four permeability models. Experimental results show that the permeability of Xiaoshan clay decreases nonlinearly with consolidation pressure increasing; and the permeability coefficient varies from 8×10^8 cm·s^-1 to 8×10^9cm·s^-1 . It is also shown that all the four nonlinear permeability models are suitable for describing the permeability of Xiaoshan clay.