1、英文原文Study on mechanism and practice of surrounding rock control of high stress coal roadwayWANG Wei-jun(卫军)1,YANG Lei(杨磊)1, OUYANG Guang-bin(欧阳广斌)2(1. Department of Energy and Safety, Hunan University of Science and Technology, Xiangtan 411201, China； 2. No.4 Coal Mine, PingdingshanMining Group Comp
2、any, Pingdingshan 467000, China)AbstractThe mechanical principle and surrounding rock deformation feature of high stress coal roadway was analyzed. The condition of stress balance of the kind of the roadway was put forward. The surrounding rock control principle and supporting technique of high stre
3、ss coal roadway were discussed. It was very important to control early period deformation of coal sides. The supporting strength is should increased, so the strength loss of coal sides is decreased. The range of plastic fluid zone is reduced. The above mentioned principle is applied in industrial te
4、st, and the new supporting technique is applied successfully.Key words: high stress; coal roadway; surrounding rock controlIntroductionWith the increasing of mining depth, the surrounding stress of the roadway is heightening and the loosened area is enlarging. Many obvious softening properties of me
5、chanical feature of surrounding rock are taken on. Not only is there subsidence of roof，but also severe deformation of coal sides, intense floor heave, and continued deformation. So it is very difficult to control the surrounding rock of coal roadway. And the expense for maintenance is up to 35 time
6、s of digging for it for footage in many roadways 1. It is always in state of repairing or waiting to repair most of the time, which even the consequence of the roadways being abandoned and dig it again will be lead to. So it is already becomes the urgent problem to be solved of surrounding rock cont
7、rol in deep roadways.1 Deformation characters of the deep coal roadwayAccording to the scene, the deformation characters of the deep coal roadway as follow 2, 3:the speed of deformation is very fast and amount is large, especially sides and floor rock , and sides will heave in 515 days with supporti
8、ng system though it is supported in time after digging；roadways have become maintenance difficult from the time during utilization to excavation, so the number of roadways having to be abandoned after digging just now increases greatly； the deformation of roadway lasts long time, and rheology has be
9、come the main deformation characteristics of deep coal roadway. As time goes on, the deformation speed does not converge in most of soft rock roadways and extraction opening, and until it closed absolutely. For a long time, surrounding rock control in soft rock is well studied by the domestic and in
10、ternational scholars, and many supporting theories are put forward, for example, New Austrian method, the theory of broken rock zone, the theory of combining support, the theory of bolting, grouting and arc armor and so on. The basic points of all these theories are that it is difficult to solve the
11、 supporting problem by increasing rigidity only in soft rock supporting, so flexibility should be put before rigidity, keep a certain distance first and then resist, suitably flexible and keeping, and support steadily4. These theories all play an important role in soft rock supporting. However, with
12、 the increase of in-situ rock stress, there are many differences between the surrounding of roadway in deep and the one in shallow in mechanical characters. For example there arc two roadways in the Ji 3 coal seam No.4 Coal Mine in Pingdingshan, one is the mining area substation situating in the lev
13、el of-200metres which is supported by arc armor of heavy reinforced stern concrete, and the surrounding rock of the roadway is steady at all times. But the other one situating in the level of -500 m which is supported by the same ways has to he abandoned in one year. So it is impossible to solve the
14、 supporting problem in the coal roadways in deep by using the existing soft rock supporting theories simply.2 Deformation mechanism of deep coal roadway surrounding rockThe stress distribution of deep coal roadway surrounding rock is showed in Fig. 1Fig.1 Stress distribution of deep coal roadway sur
15、rounding rockAs shown in Fig. l，the surrounding rock is divided into four zones in the course of stress adjusting after the roadway is dig, which are plastic flow zone, plastic softening zone, plastic stiffening zone, and elastic zone. The rock in zones of plastic softening and plastic stiffening pl
16、ay an important role of carrying.2.1 Stress analyzing of surrounding rock For example, the in-situ rock stress of the roadway whose depth is 900 m with 22.5 MPa in PingdingShan No.4 Coal Mine, and it is easier to concentrate with the increase of mining depth in deep mining. Generally, the parameter of stress concentration of the surrounding rock is 23. If the parameter of stress concentration is 2, the
