软岩各向异性渗透特征及力学特征的试验研究

【作者】 闫小波；

【导师】 杨林德；

【作者基本信息】 同济大学 ， 结构工程， 2007， 博士

【摘要】 沉积性软岩在渗流环境下的力学行为对工程稳定性起着关键作用。层理面引起的各向异性特征、渗流场与应力场的耦合作用等诸多因素使得软岩工程的稳定性分析变得异常复杂。本文从试验入手，着眼于软岩与水的作用，研究了不同层理方向上软岩的渗透特征及力学特征，进而对水一岩作用机理进行了定性分析，并建立了能够考虑含水化学作用的横观各向同性弹性损伤模型。 论文的主要成果有： (1) 通过压力脉冲试验，得出了泥质粉砂岩和褐红色泥岩分别在垂直及平行于层理方向、不同轴向应变下的渗透系数；对渗透系数与应力、应变的关系进行了研究，并对软岩渗透性随层理方向及应变变化的机理进行了探讨。 (2) 通过单轴压缩试验，得出了泥质粉砂岩和褐红色泥岩分别在垂直及平行于层理方向上、饱和及干燥状态下的变形及强度参数；对饱和及干燥状态下软岩的各向异性力学特征进行了分析、比较。 (3) 通过三轴压缩试验，得出了泥质粉砂岩和褐红色泥岩分别在垂直及平行于层理方向上、饱和及干燥状态下的变形及强度参数；总结了饱和及干燥状态下、不同方向上变形模量及强度随围压的变化规律；对软岩在饱和及干燥状态下的各向异性力学特征进行了分析、比较。 (4) 分别从力学作用、物理作用、化学作用等方面对水—岩相互作用的机理进行了定性分析。 (5) 从弹性余能定理出发，建立了能考虑水—岩作用的横观各向同性材料的弹性损伤模型。 最后，论文还对需要进一步深入开展的研究工作进行了讨论。更多还原

【Abstract】 The mechanical behavior of sedimentary soft rock environment coupling with seepage plays a crucial role to the stability of engineering. Anisotropy induced by the bedding surface, seepage coupled with the stress and many other factors make the stability analysis of soft rock extremely complex. In this paper, by the test, focusing on the interaction of soft rock and water, the permeability characteristics and mechanical properties of soft rock in different direction are studied, and the water-rock interaction mechanism of the qualitative are analyzed. Transversely isotropic elastic damage models that can take consider the effect of moisture is established in the paper.Among the main results are:(1) By pressure pulse test, the permeability of brown mudstone and siltstone in the vertical and parrallel direction to bedding different axial strain of the permeability coefficient; and the permeability coefficient of the stress-strain relationship of the sum, with stratification also soft rock permeability changes in the direction and contingency mechanism is discussed.(2) By uniaxial compression test, deformation and strength parameters of clayey siltstone and brown mudstone in the state of drying and saturation on the direction parallel and vertical to the bedding are determined respectively;Anisotropic mechanical properties of soft rock is analyzed and compared.(3) By triaxial compression test, deformation and strength parameters of clayey siltstone and brown mudstone in the state of drying and saturation on the direction parallel and vertical to the bedding are determined respectively; the relation of parameters of deformation and strength and confining pressure in different condition are generalized; Anisotropic mechanical properties of soft rock is analyzed and compared.(4)Qualitative analysis from the mechanism of mechanics, physics and chemistry interactive to water - rock is carried on.更多还原