损伤导致的节理岩体渗流模型

岩体内部含有大量节理裂隙，当岩体受到扰动后，这些节理裂隙将张开、扩展并贯通，形成渗流通道，这使得岩体渗透性发生急剧变化。为了描述这种由节理裂隙扩展导致的岩体渗流场发生的变化，将这些节理裂隙看作岩体内部损伤，假设渗透张量与损伤张量主轴重合。在渗透张量主空间内，认为岩体在一个主方向上的渗透系数决定于其它两个主方向上的损伤，建立了相应的损伤与渗透系数之间的关系。在外部荷载作用下，损伤将发生演化，从而导致渗透系数也发生演化。为了描述这种渗透系数演化过程，采用已有的损伤演化方程，通过渗透系数与损伤之间的定量关系，来刻划岩体扰动过程中渗透系数的变化规律。通过与已有数据对比分析，本文所发展的损伤导致的岩体渗流模型是合理的，能有效地反映节理裂隙发育对岩体渗透性的影响。

Damage-induced Seepage Model for Jointed Rockmass

The jointed rockmass contains numerous discontinuities, such as joints and cracks. Once the rockmass is disturbed, these discontinuities will open, propagate and coalesce, forming the fluid channels. These fluid channels lead to the abrupt increase of the seepage coefficient of rockmass. To describe the seepage field change induced by discontinuity evolution, these discontinuities are considered as the internal damage. It is assumed that the principal coordinate system of the damage tensor is aligned with that of the seepage tensor. In the principal coordinate system of seepage tensor, the seepage coefficient in one principal direction is determined by the damage in other two principal directions. The relationship between the damage and seepage is developed. Subjected to the external load, the damage will evolve, which causes the seepage coefficient evolve. To characterize the evolution of the seepage coefficient with damage, the existed damage evolution function is employed. Through the relationship between the damage and seepage coefficient, the seepage evolution is obtained. The analysis on the existed data by using the present method suggests that the present method is reasonable. It can reflect the impact of the discontinuity evolution on the seepage evolution of rockmass.