正交各向异性土石坝非饱和稳定渗流分析

The Analysis of the Orthogonal Anisotropic and Unsaturated Stability Seepage of Earth-rockfill Dam

基于固定网格有限元法和土体基质吸力与饱和度之间的相互关系,推导了基质吸力的渗流控制方程,对渗透系数各向同性与各向异性的均质土石坝进行了稳定渗流场的数值模拟,研究水—土特性模型参数对渗流的影响,分析了基质吸力、流速矢量、孔隙压力、渗流量、渗流速度的变化规律.结果表明,坝体内的渗流量和渗透速度与土体渗透系数各向异性关系密切,Van Genuchten模型中α对吸湿曲线的影响较大.提出了在实践工程中考虑土体的非饱和及各向异性更合理,且慎重确定土体吸湿曲线的各参数.

Based on the fixed mesh Finite Element Method and the relationship between soil matrix suction and saturation, this paper derives matrix suction on seepage control equation, simulates numbers of coefficient of permeability of isotropic and anisotropie homogeneous earth dam steady seepage on soil -water characteristics, studies the effect of the parameters in the model on the seepage, and analyzes the change rule of the suction, flow velocity vec- tor matrix, pore pressure and seepage flow, seepage speed. The results show that, in the dam, seepage flow and penetration speed and coefficient of permeability anisotropy are closely related. The α in the Van C, enuehten model influences the moisture absorption curve great. It also puts forward the idea of considering the soil unsaturated and anisotropy in practice, and carefully determining soil moisture curve parameters.