逐级加载条件下低液限饱和黏土的渗透试验

发布时间：2018-11-05 19:03

【摘要】：为研究饱和黏土不同荷载下的渗透特性,利用改制的K_0固结仪进行逐级加载条件下的变水头渗透试验,考虑饱和黏性土的有效孔隙比概念,分析了逐级荷载条件下起始水头、有效孔隙比、渗透系数和有效渗透系数的变化规律。结果表明:原状土的起始水头变化可以分为快速增加和缓慢增加两个阶段;重塑土起始水头与总水头变化速率有一定关联;原状土样的有效孔隙随着固结压力的增加逐渐减小;重塑土无效孔隙比的变化规律类似于原状土;当土样的结构逐渐破坏,其结构差异性趋于一致,有效孔隙比大的土样,其有效渗透系数较大;黏性土的渗透系数不仅与土体结构相关,土样在固结过程中对应的初始孔隙比、有效孔隙比的变化规律、水头高度及水头高度变化速率也对其有重要影响。
[Abstract]:In order to study the permeability characteristics of saturated clay under different loads, the permeability test with variable head under the condition of step by step loading was carried out by using the modified Ks-0 consolidation instrument, and the concept of effective void ratio of saturated clay was considered. The variation rules of initial head, effective void ratio, permeability coefficient and effective permeability coefficient are analyzed. The results show that the initial head change of undisturbed soil can be divided into two stages: rapid increase and slow increase, the initial head of remolded soil is related to the change rate of total head, the effective porosity of undisturbed soil decreases with the increase of consolidation pressure. The variation of void ratio of remolded soil is similar to that of undisturbed soil, when the structure of soil sample is destroyed gradually, the difference of soil structure tends to be consistent, and the effective permeability coefficient of soil sample with large effective void ratio is larger. The permeability coefficient of clay soil is related not only to soil structure, but also to the change of initial porosity ratio, effective void ratio, water head height and water head height during consolidation.
【作者单位】：长安大学特殊地区公路工程教育部重点实验室;
【基金】：国家自然科学基金项目(51378004)
【分类号】：U412.22

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