The Study On Geomechanics Model Test Of Zonal Disintegration In Deep Tunnel Of High Ground Stress

With the development of national economy, there are more and more deep underground rock mass engineering, the buried depth is more and more deep, an alternation of fracturing area and intact area phenomenon so-called zonal disintegration was monitored in a lot of engineering site. In order to simulate the phenomenon by experiment, the article was supported by National Natural Science Foundation of China, geo-mechanical model test research was done based on the deep mine roadway of Dingji coal mine in Huainan mining area, combining the in-situ monitoring result and model test result, the main characteristics and changing laws of zonal disintegration are summarized. The research results are important for the control design and construction of zonal disintegration in surrounding rock mass of deep mine roadways.The research work and research results are as follows:(1) Based on the mechanical parameters of original rock in the deep mine roadway of Dingji coal mine in Huainan mining area, plenty of test experiments of similar material were done, the optimal proportion of similar material for the model test was determined.(2) A 3D geomechanics model test loading system of high ground stress was developed, the loading system can load along pre and post, left and right, upper and lower, the loading system effectively guarantee the excavation under the axial-loading direction condition, the difficulty of excavationof axial-loading direction was solved.(3) A new geotechnical similar material and 3D geomechanics model test loading system of high ground stress were firstly applied in domestic, the zonal disintegration of surrounding rock mass in deep tunnel was reappeared by the 3D geomechanics model test.(4) The changing laws of strain and displacements of the surrounding rocks were got by means of various advanced and exact measurement methods, the layer number and distribution range of the zonal disintegration of surrounding rock mass in the model test are basically in accordance with the in-situ monitoring result, it indicates that the geomechanics model test can effectively reveals the nonlinear deformation features and the failure law in deep tunnel of high ground stress.(5) Based on the experimental phenomena and experimental results of the model test, the effects of axial stress, cavity form and tunnel diameter of the cavem, mining active process and time factors on zonal disintegration was analyzed, the forming features and failure laws of the zonal disintegration of deep tunnel have been premilinary revealed, which lays a solid test foundation for studying non-linear deformation and failure mechanism of deep tunnel.