| As everyone knows,large cut height fully-mechanized working face in special thick coal seam is high-outputs and high-efficiency mining face,it is serious for the pressure between coal mining and driving,and frequent for movement of combined driving workface,traditional technology can't achieve the aim that face withdraws fast and safely.It is a good measure to solve the difficulty to drive an equipment withdrawing roadway as an entry to withdraw equipments in advance.The roadway is laid out near stop line , paralleling with working face ,and often lying in coal seam,with a big section. Since affected by mining strongly during driving and serving,it is difficult for the roadway to be supported and stabilized.By synthetically using engineering analogy based on the classification of surrounding rock stability of roadway, design method of expert system, 3-dimention numerical simulation based on the geomechanics condition, physical simulation experiment and dynamic monitoring surrounding rock and information feedback and solving method,this paper solves the problem how surrounding rock of equipment withdrawing roadway in large mining height fully-mechanized coal face in special thick coal seam keeps stability.Practical plans are as follows: (l)Based on classification scheme on the stability of surrounding rock of coal roadway in China and seven indexes and their varying scopes connected with classification scheme found from geologic source of the equipment withdrawing roadway,its category is determined.Then referring to《rockbolt supporting technique specifications》,relevant bolt supporting form and parameters of the roadway are selected.(2)According to geomechanics condition of the equipment withdrawing roadway and《design method of Expert System on coal roadway support》, developed by Mining Technology Institute of TUT, basic support design is put forward.Then on the basis of basic support design the 3-dimention numerical simulation experiment is done with FLAC3D software,a three-dimensional explicit finite-difference program for engineering mechanics computation.Meantime,stress and displacement properties of rock around roadway in different burying depth before and after affected by mining action are calculated and analysed.On analysed simulation results,conclusion that mining action have a great role on surrounding rock stability of the equipment withdrawing roadway can be drawn.Before mining action plays a role surrounding rock is in stable state,but, after mining action does surrounding rock shifting quantity and roof bedding separation increase fast.As working face advances 20～30m distance from the equipment withdrawing roadway,coal pillar between working face and the roadway becomes to yield.Therefore,basic support design cannot reach roadway'stability and need to be revised.(3)On the base of the two works ahead,in the light of similarity theory,physical simulation experiment is conducted by virtue of large-scale 3000mm×3000mm×200mm plane strain flexible loading in the laboratory.Experiment result proves that the equipment withdrawing roadway must be strengthen to support when working face advance 20m distance from it;cable play a great role in maintaining roadway stability in later period,etc.(4)For complexity of geomechanics condition,there are always some errors between preliminary design and practical need,it cannot success to design at a time.In this paper,dynamic monitoring surrounding rock and information feedback and solving method will be used to dynamic monitor surrounding rock state.This method includes two parts:one is day-to-day check,the other is surrounding dynamic professional monitoring.It proves support design rational by getting and analyzing kinds of deformation and force informance about surrounding rock.If abnormal value (eg:it exceeds the range of monitoring informance feedback index) is monitored,it is necessary to analyse the design conversely and revise it.in addition, measures must be taken to strengthen the supported roadway as a remedy.
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