Experimental Study And Engineering Application Of Coupled Seepage And Stress Fields In The Fracture Sandstone

This paper selected sandstone for tests investigation object in test segment, using three kinds of test programs to research the different axial pressure, confining pressure, filler size, crack depth of such factors as changes of their seepage. And it can mostly research couple seepage and stress field theory in theory segment. On the working group programs, Dagangshan slope unloading excavation stability analysis, carried out to consider the role of groundwater couple seepage and stress field analysis and calculation in application part at last relying.1) On the based reading references, summarized couple seepage and stress field of existing research results and to be further resolved so that make this the main research content and technical line.2) Sandstone specimen as the study object produced a diameter of 54 mm, a height of 110 mm of the test piece. Test pieces were made for artificial fractures, depth of 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm, 2.5 cm, open degree 0.3 cm. Relying on ELE instrument of the rock permeability testing equipment and RMT-150C rock mechanics test system, designed three reasonable programs of coupled seepage and stress field.3) Through the sandstone test analysis of seepage, educed the disciplinarian of fracture sandstone seepage during different axial compression, different confining pressure, fillers, non-fillers and various filler particle size range etc.4) The references were cited to introduce cracks, voids, permeability of rock mass, coupled seepage and stress field analysis of two types of problem, proposing mathematical model of continuum medium of coupled seepage and stress field analysis.5) Detailed description of FLAC-3D calculation and analysis software, explained that bulk modulus and shear modulus instead of Young's modulus and Poisson's ratio for constitutive relation of the Mohr Coulomb, and described the general process of the unbalanced force as convergence criterion and proposed solving slope stability.6) Taking example for the right bank slope of the Dagangshan hydropower station, the establishment of three-dimensional finite element model, this paper used the corresponding numerical simulation method to consider the role of groundwater six kinds of calculation conditions of coupled seepage and stress field analysis (initial condition, excavation unloading condition, rainfall condition of construction period, water storage condition of operation period, sudden lower in water level condition of operation period, seismic condition of operation period), and calculated the relative displacement field, seepage field, stress field and plastic zone distribution. In the process of the slope excavation unloading to monitor the unbalanced force, it drew the key point displacement curves to analyze visually deformation of each grade platform in slope excavation, using of three-dimensional finite element calculation results and the latest monitoring results to comparatively analyze and draw relevant conclusions.