Analysis And Evaluation On The Surface Displacement And Deformation Of The Goaf

Underground mined-out area is a underground space formed by the humans exploitationof solid resources. The underground space is formed when the underground solid mineral istaken out, then the rock formations surrounding it lose support and gradually move to themined-out area. Thence the initial stress state of the overburden in the mined-out area wasbroken, and consequently, emerged deformation, separation, cracking or even destruction ofcollapse, until it reaches to a new balance. The process above is known as the “mine miningsubsidence”.Although the exploitation of coal resources plays an important role in the developmentof the national economy, the unconventional, disorder and extensive mining methods makesome areas appearing large-scale and large-range mining subsidence area. Due to the lack ofavailable building sites, we have to re-use the mined-out area, which can make the cavingzone rock with original state of equilibrium re-activation and the surface generating additionaldisplacement, led to the subsidence, local cracking,, tilt and other damage to the groundbuildings. The goaf has become a prominent issue in the surface infrastructure and at the sametime restricts the construction and operation of major projects in China.The the301coal goaf of the Cuncaota coalmine in Shendong mine area not only relatedto the smooth implementation of the slime comprehensive utilization power generation projectof Shenhua Buertai, but also affected the safe operation of the project. Therefore, we selectthe mined-out area for the study, and make a depth, systematic analysis and evaluation on itsdistribution characteristics, affected area and the surface displacement and deformation law, providing a theoretical basis for the selection of the proposed site and the reasonable choice ofdisaster prevention and mitigation measures.Facts have proved that the probability integration method can accurately calculate thesurface displacement and deformation of the overburden on the mined-out area, which is fullyvalidated by the measured data. This paper use the probability integration method to calculatethe maximum surface displacement and deformation values of the goaf and draw the surfacedisplacement and deformation curve. Estimated the affected area of the surface displacement and deformation by threedifferent numerical simulation methods, and compared with the predicted values, the authorfinalize the exploitation affected area of the mined-out area.According to the forecast and simulation results, the author takes the incline, horizontaldeformation and curvature of the surface as a control parameter to identify the correspondinghorizontal distance, accordingly determine the appropriate precincts for the ground buildingsand propose the disaster prevention and mitigation measures.