Study on Non-Continuous Disintegrate in Surroundding Rock of Deep Roadway
|School||Shandong University of Science and Technology|
|Keywords||deep roadway Non-continuous disintegrate strongly rheological model numerical simulation weak structure|
Along with mining depth’s increasing, deformation of the rock around tunnels destroys seriously day by day and the supports become more difficult. Depth portion resources’ safe mining is threaten greatly by it. The research indicated:On mining condition of high stress in depth, the phenomenon which the complete area and the destruction area will be separated is presented in surrounding rock and called "Non-continuous disintegrate". It is not able to be explained complete clearly by traditional continuous medium elasto-plasticity mechanics and scientific research about mechanism of Non-continuous disintegrate becomes a hot spot in surrounding rock. The system analysis research to this phenomenon through methods of scene survey, theoretical analysis, numerical simulation and so on is conducted in this dissertation.(1) The survey to the different roof structure tunnel is carrried on by using rock layer drill hole survey recording instrument in Xinwen coal mine, Liangzhuang coal mine, Ezhuang coal mine, Xinwen Mining Group Co., Ltd. The survey result indicated:, the weak structure is the reason which leads to Non-continuous disintegrate on condition of the high stress function in deep roadway. At the same time, factor of creepage and so on also have a great influence.(2) Constitutive model with strong rheological properties is Established by Rheology knowledge and named "strongly rheological model". Nonlinear rheological components is increased in this model besides of traditional rheological mechanical components to describe accelerated creep stage of the rock which is provided to research creep buckling in high stress condition.This model is added in the Flac3D model base for numerical simulation use; Based on media ideal analysis model of circular tunnel, Stress distribution in the surrounding rock is discussed about Tunnel excavating in the initial period under the conditions of axial stress, and the failure criteria which determined mainly by the maximum tensile stress criterion and supplemented by maximum shear stress criterion and energy criterion by numerical simulation of the mechanical angle.(3) After reasonable numerical simulation method determined, the impact of non-continuous fracture phenomenon which is caused by mining depth, weak structure, the overall strength of rock, roadway shape, mining and creep is simulated in Flac3D. The results show that:Enough mining depth is precondition of Non-continuous disintegrate phenomenon. However, weak structure plays a key role. The overall strength of rock and mining affect the scope of the damage and destruction of the non-continuous fracture phenomenon, but roadway shape has small effects.(4) Take the radial strain as the clue, combining with mechanical model, to explain the theoretical mechanism about Non-continuous disintegrate. Based on affect of various factors on the phenomenon of Non-continuous disintegrate explain the phenomenon, Site mechanism is interpreted and critical role which "weak structure" plays is further defined.