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Influence of ground stress on Coal Seam Gas Pressure and Gas Content

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Fluid Dynamics & Materials Processing 2019年第1期15卷 53-61页

作者： Xuebo Zhang Zhiwei Jia The Collaborative Innovation Center of Coal Safety Production of Henan Province Jiaozuo45400China State Key Laboratory Cultivation Base for Gas Geology and Gas Control Jiaozuo45400China School of Safety Science&Engineering Henan Polytechnic UniversityJiaozuo45400China

The influence of ground stress was quantitatively analyzed on coal seam gas pressure and gas content in this *** activities in coal mine can result in stress concentration in the coal(rock)body around the mining space,but porosity of the coal seam would not change too ***,gas pressure and gas content in the coal seam are slightly *** showed that the free gas was gradually transformed into adsorbed gas,and the gas adsorption volume was small,and then gas pressure increases roughly linearly when the porosity decreased because of stress ***,when porosity of coal seam reduced to 40%,the amount of adsorbed gas accounted for no more than 10%of coal seam gas content,and the increase of gas pressure did not exceed 15%of the original gas pressure.

关键词： ground stress coal seam porosity gas pressure gas content stress concentration.

Combined back-analysis method of ground stress based on refined geological modeling

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Engineering Sciences 2012年第4期10卷 43-50页

作者： Liu Donghai Zheng Jiang Wang Qian School of Civil Engineering Tianjin University Tianjin 300072 China State Key Laboratory ofHydraulic Engineering Simulation and Safety Tianjin University Tianjin 300072 China

A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.

关键词： ground stress back-analysis combined method refined geological modeling artificial neural network(ANN) NURBS

Analysis of the dialectical relation between top coal caving and coal-gas outbtu rst

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Journal of Coal Science & Engineering(China) 2009年第2期15卷 181-187页

作者： MENG Xian-zheng XIAYongjun TANG Bing ZHANG Yong-jiang Chongqing Research Institute China Coal Research Institute Chongqing 400037 China School of Resources and Environment Engineering Anhui University of Science and Technology Huainan 232001 China

According to the different engineering mechanical states of top coal caving andnormal stoping of gaseous loose thick coal seams,the dialectical relation between thiscaving method and dynamic disasters was analyzed by simulating the change of stressstates in the process of top coal initial caving with different mining and caving ratios basedon the *** variation of elastic energy and methane expansion energy duringfirst top coal caving was analyzed by first weighting and periodic weighting and combiningwith coal stress and deformation distribution of top coal normal stoping as well as positiveand negative examples in top coal caving of outburst coal *** research shows thatthe outburst risk increases along with the increase of the caving ratio in the initial *** the period of normal stoping,when the mining and caving ratio is smaller than1:3 and hard and massive overlying strata do not exist (periodic weighting is not obvious),it is beneficial to control ground stress leading type ***,it is unreasonable toprohibit top coal caving in dangerous and outburst prone areas.

关键词： coal and gas outburst top coal initial caving mining and caving ratio ground stress

RESEARCH ON COMPLICATED DAM FOUNDATION DURING EXCAVATION WITH THREE DIMENSION VISCO ELASTIC PLASTIC CONDENSED FEM

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Transactions of Tianjin University 2000年第1期6卷 60-64页

作者：张兴强戚蓝天津大学建筑工程学院天津300072

On the basis of the two geological factors rock structure and ground stress environment,a visco elastic plastic model is established to analyze the rock stability of dam foundation and dam abutment during excavation by a kind of FE condensed *** mechanics is applied in analysing the dynamic process of displacements,stresses,yielding destruction of construction base level,soft interface of dam *** of the FE analysis indicate that theories and methods in this paper are reasonable and reliable.

关键词： condensed visco elastic plastic ground stress soft interface