摘要
已有的室内试验资料表明软黏土中的渗流会遵循指数形式渗流定律,并且土体压缩性、渗透性在固结过程中会表现出明显的非线性特性。在土中自重应力沿深度均匀分布的假定下,推导建立基于指数形式渗流的软土一维非线性固结控制微分方程,并利用有限差分法对其进行数值求解。将数值解与达西渗流下Davis解析解进行对比,验证数值计算结果的可靠性。最后,对基于指数形式渗流下的一维非线性固结性状进行分析。研究结果表明:土层的固结速率在固结初期随渗流指数的增大而加快;而当时间因子超过某一值后,在固结后期固结速率随渗流指数的增加而变慢;土的压缩指数与渗透指数的比值越大,则土层的固结速率越慢;此外,土层中最终有效应力与初始有效应力的比值以及外荷载的等效水头与土层厚度的比值均对固结速率有较大影响。
Experiments show that the water flow in soft soil may obey exponential flow law. Moreover, the soil exhibits an evident non-linearity in compressibility and permeability during the process of consolidation. By assuming a uniform distribution of initial self-weight stress, the differential equation governing one-dimensional non-linear consolidation was modified to consider exponential flow law, and numerical solutions were obtained by finite difference method. The reliability of numerical solutions was verified by comparing the numerical results with the analytical results obtained by Davis. Finally, one-dimensional non-linear consolidation behavior with exponential flow law was analyzed. The results show that the consolidation rate increases with the increase of the exponent at the early stage of consolidation, and decreases at the final stage of consolidation. The larger the ratio of compression index to permeability index, the slower the consolidation rate. In addition, both the ratio of the final effective stress to the initial one and the ratio of the equivalent water head of external loads to the thickness of a soil layer have great influences on the consolidation rate.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第7期2789-2795,共7页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(50878191
51109092)
关键词
一维固结
指数形式渗流
非线性固结
one-dimensional consolidation
exponential flow law
non-linear consolidation
