Study On Foundation Deformation And Its Controll Under The Load In Coal Mine Subsidence Area

With the acceleration of China's urbanization construction process,coal mine subsidence area as construction land has great significance for alleviating the urban land demand,economic sustainable development and improving the ecological environment.Based on the geological and mining conditions of 22407 working face in halagou mine as the background,foundation redeformation and its control under the load in coal mining subsidence area was studied,which by means of data collection,theoretical analysis,mechanical modeling and simulation experiment,to provide the technical support for the construction of coal mining subsidence area.The main results are as follows:(1)According to the time characteristics about the movement and deformation of the mining rock mass,the empirical formulas was fitting about time influence parameter based on the measured data,the dynamic residual deformation model of the mining rock mass was established combined probability integral method,the method of determining the relevant parameters was given.Example analysis shows that the model can be effectively calculate the residual deformation at any period of time,combination with the practical situation of the subsidence area.(2)The determine method of the equivalent elastic modulus according to the mining rock porosity was proposed,on the basis of the correlation analysis with different rock porosity and elastic modulus.The rocks porosity was determined by calculation the strata limit subsidence space and actual subsidence space based on the space conservation theory.The result shows that the method can effectively determine the elastic modulus of each stratum.(3)The method of foundation redeformation was put forward by analyzing the stress condition and the instability condition of the mining rock mass structure.The gaps reconsolidation was the major factor of foundation redeformation in mining rock mass,through the analysis of the overlying strata gaps changes under the load by numerical analysis method.The similar simulation test shows that grouting of filling holes and gaps can effectively control the redeformation of foundation and reduce the rate of foundation redeformation,which reveals the mechanism of the foundation redeformation under load in the coal mining subsidence.(4)According to the experimental results of similar simulation,the influence of the mining degree,mining depth,load size,loading position and loading time were studied for foundation dynamic and static deformation,and discuss the general rule of foundation redeformation under load in coal mining subsidence area.(5)According to the layered distribution characteristics of mining rock mass,raise equivalent medium model composed of layered elastomer about the active rock mass generalized,analytical solution of the foundation redeformation under load,then the method of determining the additional coefficient of the foundation redeformation was presented combined with the residual deformation of subsidence area.The example shows that the mechanical model can be used to calculate the redeformation of the foundation effectively.(6)On the basis of systematical analysis about the influence factors and control technology of foundation redeformation under load in coal mining subsidence area,the comprehensive evaluation model of the foundation redeformation control was build,which takes into account the multi-level and multi-index factors.It shows that the comprehensive evaluation method was available to get suitable foundation redeformation control classification.