Papers by Author: Wei Jia Guo

Abstract: In order to study permeability characteristics of low-strength coal under higher confining pressure, complete stress-strain permeability characteristics tests on 15# coal of Shanxi Province Qinshui Basin are conducted. Research shows that 15# coal manifests obvious plastic under 6MPa confining pressure whose uniaxial compressive strength is 7.43MPa; The saturated specimen’ permeability reduces provisionally during initial compression as the native fractures are closed; With the specimen compressed continuingly, new fractures appear and those fractures connect, then the permeability rapidly increase; But while the soft coal enters into plastic-flow state, because that the specimen becomes more homogeneous and fractures have closed, the permeability greatly reduces lower then the initial value. Research result has important guiding significance for reasonable retaining waterproof pillar in deep mining.

Abstract: At present, the mines in our country gradually shift from the shallow mining to the deep mining, but the deep well floor is particularly serious hazard by high pressure underground water.This article considers the high pressure underground water as three-dimensional transient flow, sets up mechanical model by combining mechanical knowledge and to analyze the destructive action on floor from two aspects. On the one hand, researching the impact destruction of high pressure water at different positions of floor ; the other hand, to analyze mechanical function on fracture development from high pressure water.

Abstract: The paper sets up mechanical model according to the characteristics of paste filling stope and determines the basic model units which are overlying strata, filling body, support and floor. The paper also establishes the mechanical parameters for controlling movement and deformation of overlying strata and sets up the relationship of all mechanical parameters. Based on this, the paper studies the stress evolution law under the condition of different filling ratio and filling step distance with the method of numerical simulation.

Abstract: In this paper, in order to get the mechanical properties of the different ratio similar material models and resolve the matching problem of pressure sensor and measured similar material, according to the similarity theories, the repeated loading tests on different ratio similar models were performed by multi-stage loading. This paper got the stress-pressure curve and the failure strength of each model. Test results show that there are significant differences in the matching abilities between different ratio similar materials and pressure sensors, and the matching abilities between different models of the same ratio and pressure sensors also have some differences. The matching ability between similar material and pressure sensor should be detected, so as to correct the experimental data. Test results also show that different ratio similar materials have stable and different mechanical properties. The mechanical properties of the similar material can be adjusted appropriately by changing the ratio. The mechanical properties of different ratio similar materials should be tested before the similar material simulation test.