1、翻译部分英文原文2011International Conference on Computer Distributed Control and Intelligent Environmental MonitoringSurrounding rock deformation and its controlling technology gob-side entry at isolated island coal faceZha Wen-hua Hua Xin-zhu Liu ShuKey Laboratory of Coal Mine Safety and High Efficient Min
2、ing Co-sponsored by Province and Ministry of EducationCollege of Energy Resources and Safety Engineering,Anhui University of Science and TechnologyHuainan, ChinawhzhalAbstractBased on voussoir beam structure theory of the overlying strata, deformation mechanism of surrounding rock of gob-side entry
3、at isolated island coal face was analyzed, principles for deformation controlling of surrounding rock were established.According to engineering geological conditions in return airway of 1251(3)Pansan colliery,and distribution of advance abutment pressure,roadways supporting scheme during the tunneli
4、ng and zoning advance reinforcement plans for roadways before mining.Field practice shows that supporting scheme is feasible for stability of surrounding rock. Keywords:isolated island coal face;gob-side entry;surrounding rock deformation;ground strata control I. INTRODUCTION Isolated island coal fa
5、ce appears stress concentration, its strata behaviors are obvious, surrounding rock occur and larger deformation and severe damage1-5; Roof-to-floor and sides convergence are larger, floor heave in roadways is strong, coal seams are prone to spontaneous fire, these cause hidden troubles for safety m
6、ining,therefore,it was found that how to control surrounding rock deformation effectively and understanding of strata behaviors deeply was key factors to quick mining and isolated island coal face safety. II. DEFORMATION MECHANISM OF SURROUNDING ROCK OF GOB-SIDE ENTRY AT ISOLATED ISLAND COAL FACE Du
7、ring the mining,voussoir beam structure6 produces sliding instability or rotation instability because superposition action of abutment pressure results from working face and gob,narrow coal pillars will lose the protection from voussoir beam structure.When narrow coal pillars suffered from damage, m
8、ain roof produces toppling rotation, subsidence.Main roof near the coal wall also produces toppling rotation and subsidence.This changes voussoir beam structure stability of the overlying strata in gob-side entry to cause stress in surrounding rock to increase sharply. In Fig.1, balance state of vou
9、ssoir beam structure in the overlying strata was strongly influenced during the mining are summarized as follow: 1)When the face is mining,main roof in the gob produces new fracture, the new rock block C and B connects with the original key rock block B. 2)After the main roof rupture, the block C su
10、bside toward the face and key block B in the action of rotary moment and m1,thereby undermining the original balance of the voussoir beam structure in overlying strata, articulated rock block C and key block B are in motion and instability state, which causes some subsidence of block B or higher abu
11、tment pressure occurs in m is rotary moment of rock block C in main roof (rock block C rotates in a clockwise direction or rock block C rotates toward the rear of the goaf ); m1 is resultant moment of rock block B in main roof of upper face.Fig.1. Gob-side entry and voussoir beam structure theory in
12、 the overlying stratathe front of face.3)voussoir beam structure of overlying strata is under higher abutment pressure , rock block C and key block B will produce rotary subsidence.Instability of voussoir beam structure results in stress redistribution and concentration of surrounding rock of gob-si
13、de entry again, its impact is much larger than that of the tunneling. 4)when face mining,the surrounding rock of gob-side entry occur high stress concentration, coupled with the soft surrounding rock,so gob-side entry produces deformation;at the same time,voussoir beam structure results in heterogen
14、eous stress redistribution of surrounding rock, this shows that there is a big difference the deformation and its mode of roof, floor, sides of solid coal and coal pillar in the roadway. 5)loads on overlying strata of voussoir beam structure in the mining increase continuously,but because thesupport
15、ing conditions between blocks does not change,it will remain random balance, the difference is between the block loading situation has changed. Therefore, before the face is advanced,the voussoir beam structure stability will not have fundamental changes, so long as the roadway supporting is reasona
16、ble, bolts and surrounding rock form stable structures,roadway damage is small; steady equilibrium state of voussoir beam structure in overlying strata is destroyed only after the working face is advanced, then instability occurs, resulting in the complete failure of roadway. The above analysis shows that the overlying strata of gob-side entry will remain in the random equilibrium in the process of extra
