The Study On After-peak Seepage Flow Characteristics Of The Rock Specimen Under Three Dimensional Stress

Fractured rock-mass seepage is one of the main content of the rock-mass hydraulics research. It is a fluid in which flows through the crack, a phenomenon closely related to some human engineering activities. In petroleum engineering, construction engineering, environmental engineering, water and electricity engineering and mining engineering, etc, the relevant theories of fractured rock mass seepage has a very important guiding significance, it is also the project must face, study and solve the problem. Therefore this paper bases on the after-peak seepage test of the rock under the action of three dimensional loading, analysis to study the seepage characteristics.The paper research on the after-peak seepage rules of the rock specimens under the action of three dimensional stress by adopting the combination of experimental study and theoretical analysis method. In terms of experimental study, the paper studies on the rock-specimen test under uniaxial compression and the rock after-peak seepage test specimens under the action of three dimensional stress by using miniature triaxial loading seepage test machine.Baseon the uniaxial compression test results,The paper draw the stress-strain curve of the rock specimens and the fracture form,and analyzes the deformation and mechanical characteristics in the process of uniaxial compression. In addition,the paper draw and analyzes the curve between permeability and stress change based on the seepage test results under the action of three dimensional stress. In terms of theoretical analysis, from the aspects of rock mechanics and seepage mechanics for the analysis, the paper describes the rock specimen after-peak relationship between permeability and stress with the empirical formula, at the same time analyzing stress sensitivity of the rock specimen after-peak permeability. The paper compares and analyzes the sensitivity of permeability of the rock specimens of eaching to the stress, studies the relationship between permeability and peak strength, the relationship between the parameters and stress in the empirical formula,and the effect rock failure mode on permeability.This paper concludes that rock’s permeability and stress accords with exponential function relationship by the experimental study and theoretical analysis, when the rock structure damage is bigger, using the power function to describe the relationship between permeability and stress is more appropriate,fracture permeability sensitivity to normal stress on the surface of the perpendicular to its structure is high, fracture permeability increases first, then cuts in, finally gets bigger with rock peak strength.