Study Of The Relationship Between Dewater And Shaft Deformation Based On Fluid-solid Coupling

In the process of coal production, the shaft wall fracture poses a serious threat to safety coal production. Researches shows that the decline of the water table of bottom aquifer of the deep alluvium is the main reason of rupture of shaft lining. In order to prevent and control of shaft wall, this paper work with Taoyuan coal mine assistant well to study the relationship of the decline of the water table of bottom aquifer, ground surface settlement and shaft deformation by field measurement theoretical analysis and numerical computation.Through field measurement, acquired the law of shaft compression deformation and ground surface settlement. In the period of field measurement, the shaft compression deformation has little volatility with time increased, and almost increased lincarly with the incrcasing of time as a whole,the avcrage shaft compression deformation grow by a0.942mm annualized rate. The accumulative settlement of ground surface is5-6mm, the settlement increased linearly with the increasing of time, the average settlement grow by a2.095mm annualized rate, and the ground surface settlement is larger than shaft compression deformation.Through theoretical analysis, find a new Duncan-Chang model which fit to deep alluvium by modify the Duncan-Chang model, then embed it into FEM software Abaqus by further development to convenience to numerical simulation. Based on fluid-solid coupling theory, simulate the relationship of dewatering of the fourth aquifer and the shaft deformation by Abaqus. It is found that the dewatering of the fourth aquifer will lead to integral subsidence of the soil around shaft, and the main reason is the fourth aquifer compress and the third aquiclude compress partly. The total subsidence is about5.348cm,and the compression of the fourth aquifer is about4.62cm which reach to86.39%of total subsidence. The compression of the third aquiclude is about0.532cm which just to about10%of total subsidence. The settlement of the soil that near by the shaft is smaller than that far away the shaft as the result of the friction of the shaft. Meanwhile, the shaft have compression as the negative friction of soil, and the compression of shaft is much smaller than the settlement of soil. The stress is largest in the bottom of the shaft and the maximum principal stress in the bottom of the shaft is26.03Mpa, the minimum principal stress is2.317Mpa, the shaft will reach ultimate strength soon.This paper focuses on the relationship of the decline of the water table of bottom aquifer, ground surface settlement and shaft deformation and achieved certain results, that provides certain reference for the related theory and the similar engineering.