Seepage Evolution Model of the Fractured Rock Mass under High Seepage Pressure in Dam Foundation

Abstract

The seepage of the fractured rock mass in dam foundations involves complex fluid-structure coupling behavior, due to practical hydrogeological conditions. In this work, the seepage characteristics of the fractured rock mass and their correlations with the structural permeable mediums are experimentally explored to reveal the cracking effect on the hydromechanical properties firstly. Subsequently, the tangential and the compression creep damage constitutive models are, respectively, established by introducing a nonlinear viscoplastic body to improve the Nishihara model. Afterwards, an innovative evolution equation of the permeability coefficient considering the creep damage is proposed. It can indicate the time effect of the porosity, the permeability, and damage variables of the fractured rock mass under the long-term infiltration action of the hydraulic pressures. Ultimately, the proposed methods are applied to the seepage simulation on the dam foundation of the Longyangxia hydropower station and the significantly increased leakage is in good agreement with the measured values during the storage period. It was further confirmed that the crack expansion and penetration in the rock masses can be constantly intensified by the seepage pressures. The research results can provide a reference for engineering repair and supervision through controlling the permeability performance for long-term operations.

In-situ rock tests for fault gouge zone：A case in Fengman hydropower station, China

“…Therefore, both groundwater and surface water gather here. Considering the effect of artificial drainage and natural evaporation, the test rock mass gradually changes from relatively dense structure to loose irregular structure after the repeated soaking and drying cycles [16,17].…”

Prediction of the Long-Term Performance Based on the Seepage-Stress-Damage Coupling Theory: A Case in South-to-North Water Diversion Project in China

“…ε pl min (10) where ˆ. ε pl max is the maximum value the plastic strain rate tensor, ˆ. ε pl min is the minimum value of the plastic strain rate tensor, . ε pl t is the equivalent plastic strain rate in tension, and .…”

“…analyze the sudden pipeline crash of a specific project and derive its evolution process. Zhao et al [10] proposed an innovative permeability evolution equation. They found that the seepage pressure will continuously intensify fracture propagation and penetration in the rock mass due to the time effect of permeability and failure.…”

Effect of Contact Area on Deflection Flow Behavior in a Bifurcated Fracture

“…In many types of geological projects, such as the prevention and control of groundwater pollution [1,2] and seepage in a dam foundation [3,4], the contact deformation and development of mass fractures under in situ stress leads to sewage infiltration, and the collapse of the dam foundation is the key factor affecting the project. Therefore, fracture contact and seepage in rocks are the focus of engineering stability studies.…”