Disturbance Research Of Seismic Pertormance Of Buildings Caused By Coal Mining In Mining Areas

At present, research on seismic performance of the building in the mining areas, is based on the assumption of rigid soil. This paper considers the interact coordination of upperstructure, foundation and soil, further discusses on the seismic performance deterioration of buildings in the mining areas,under the combined effect of mining and earthquake. Based on the theory of damage mechanics, improved two parameter damage model is introducted to calculate the value of floor damage of buildings in the mining areas under eatthquake. On the basis of the existing research, quantitatively analysis of damage evolution law coal mining damaged buildings under earthquake, numerical calculation of The finite element analysis software ANSYS. The deterioration law of the seismic performance of buildings is analysised, to get the disturbance law of the seismic performance of the building in the mining areas. The calculation results show that:(1) Because of the existence of SSI (soil structure interaction, hereinafter referred to as SSI) effect, the high-frequency is filtered weakly, and low-frequency plays a dominant role, in the process of earthquake communication in the soil. Partly close to the resonant frequency of the structure is increased. Considering the SSI effect, self vibration characteristics of the structure is changed,and the dynamic response curve of the structure becomes more uniform;(2) Due to the presence of SSI effect, vibration cycle of become larger, self vibration frequency decreases,the overall stiffness soft. At the same time,combining with the time history curve of top displacement, top acceleration and base shear, The plastic damage at the bottom of the rigid foundation is earlier,to dissipat seismic energy, and the calculation result is significantly greater than the flexible foundation.(3) Owing to influence coal mining, seismic dynamic response increase,and the displacement curves increase generally moving in the direction of Inclined building. Because of the ground movement and deformation is caused by coal mining, building tilt lead to the position of the center of gravity shift, increase the adverse effects of gravity two order effect on the structural displacement under the action of horizontal forces. The bottom of the structure generate additional deformation and stress. The initial damage caused by coal mining make the structure form earlily "column hinge mechanism or beam hinge mechanism",and aggravate the destruction effect of earthquake on coal mining buildings.(4) Affected by the coal mining, stiffness distribution of the structure changes, the bottom of the structure stiffness speed up degradation and center of rigidity structure overall downward under the earthquake. Elastic-plastic displacement angle of first or second floor exceeds the standard value of 1/50, weak layer down mainly concentrated in first or second floor. Affected by the coal mining, Damage value and vulnerability, of the bottom floor increased sharply, seriously weakened the seismic performance of building.