裂隙岩质边坡非饱和降雨入渗特征分析

Unsaturated Seepage Analysis of Fractured Rock Slope Under Rainfall Condition

[目的]研究降雨入渗过程中,裂隙岩质边坡渗流场和暂态饱和区的变化规律,为裂隙岩体降雨入渗规律、工程技术及水土保持方面的研究提供支持。[方法]基于非连续裂隙模型,采用Matlab编制裂隙岩体渗透张量的计算程序;基于等效连续介质渗流模型,采用FLAC3D内置的FISH语言编制程序进行非饱和渗流分析。[结果]依托实际工程分析得出了裂隙岩体的渗透张量,在降雨过程中随着降雨强度的增加或者降雨时间的延长,边坡表层区域零孔隙水压力面不断向内部发展,暂态饱和区的范围不断扩大,且暂态饱和区的出现发生在降雨强度大于边坡的入渗率的情况。[结论]采用非连续裂隙网络模型和等效连续介质渗流模型对裂隙岩质边坡降雨入渗分析能较好反映裂隙岩体各向异性和非饱和渗流的特点。

[Objective] Exploring the variation process of seepage field and transient saturated zone of fractured rock slope under the influence of rainfall to provide support for the study of the law of rainfall infiltration, engineering technology and water conservation. [Methods] Based on discontinuous fracture network model, a Matlab program was designed to calculate the permeability tensor. Based on equivalent continuous medium model, a program using FISH language was designed for unsaturated seepage analysis. [Results] Permeability tensor of fractured rock mass was obtained through the engineering case. With the increase of rainfall intensity and rainfall duration, the surface of zero pore water pressure will extend to the inside of the slope and the scope of transient saturated zone will expand. Moreover, the appearance of transient saturated zone will occur in the case when rainfall intensity is greater than the the infiltration rate of the slope. [Conclusion] The characteristics of anisotropic and unsaturated seepage in fractured rock mass can be better elucidated by using discontinuous fracture network model and equivalent continuous medium model and the models can be used to analyze the rainfall infiltration of fractured rock slope.