降雨入渗流量与压力控制边界双向转换机制及边坡裂隙渗流分析OA

Rainfall infiltration significantly affects slope stability.Accurately describing the dynamic behavior of the rainfall infiltration boundary is crucial for analyzing seepage and stability of slopes.Although the unidirectional con-version from flow-controlled to pressure-controlled boundaries has been achieved,several challenges remain.These include the unclear mechanisms in the governing equation and the lack of bidirectional conversion of boundary condi-tions,especially regarding treatment of the rainfall infiltration boundary in fracture-pore media.To this end,based on Darcy's seepage theory,this study reformulates the pressure governing equation,and establishes a rainfall infiltra-tion governing equation that can achieve bidirectional conversion between flow-controlled and pressure-controlled boundaries.Then,rainfall infiltration boundary treatment methods are proposed for discrete fracture-pore media and dual-permeability media.Three challenges are addressed:(1)a position head gradient is introduced to eliminate the influence of semi-permeable layer thickness on the depth of surface water accumulation;(2)a bidirectional conver-sion mechanism with two judgment conditions is developed to achieve adaptive control of the rainfall infiltration boundary;and(3)a rainfall infiltration boundary treating method is proposed to reveal the influence of rainfall inten-sity on the water exchange between the dual media.The results show that the proposed method can effectively allevi-ate the errors induced by the conventional rigid,one-way conversion between rainfall infiltration boundaries.Further-more,fractures are shown to play a significant role in the slope rainfall infiltration process.Under the low-intensity rainfall condition,the matrix dominates water transport,while the fractures become the primary seepage channels under the high-intensity rainfall.These findings provide theoretical support for studying slope fracture seepage and failure mechanism.