1、英文原文Mechanism and control of ground residual deformation over longwall goafGUO Guang-li, WEI Kuang-ling, MU Bin-shan, GAO Jing-xiang, H E Guo-qing(1. China University of Mining and Technology, Xuzhou 221008, China;2. Chongqing University, Chongqing 400044, China;3. Qiwu Coal Mine, Jining 277606, Chi
2、na)Abstract: The deformation of rupture rock mass in goaf is the main reason for ground terrene residual deformation. Based on field measurement and similar material simulation, the rupture strata structure and its residual deformation characteristics in the long wall goaf and its overburden are poi
3、nted out. On the basis of these achievements, the authors propose the mechanism of strengthening rupture rock mass ground and the control measures of deformation resistant structure. Using the case of main coal building in Xinzhuangzi Coal Processing Plant, this paper introduces the influence of str
4、engthening rupture rock mass and deformation resistant structure.Key words: abandoned goaf; residual deformation; rupture rockmass; deformation mechanism; deformation control1 INTRODUCTIONThe movement and destruction of overburden layers caused by underground mining changed overburden engineering ge
5、ology characteristics and formed the engineering geology condition of extraction subsidence rupture rock mass ground. Even by long time natural pressure after mining, these phenomena of residual cavity, bed separation, mining-induced fissure can be seen in goaf and overburden. Sub-compaction and gap
6、 with saturated water can also be seen in caved goaf. Under the influence of inner and external factors (for example, ground stress, underground water, superimposed load of new building), the rupture rock mass will produce second movement and deformation, which is a serious threat to ground building
7、s safety. This is the main potential safety hazard that restrains large scale application of terrene in abandoned goaf.The deformation of rupture rock mass in goaf is the main reason for residual deformation in collapsed area terrene. Clarifying structure and deformation characteristic of rupture ro
8、ck mass in goaf, predicting terrene residual subsidence and deformation, adopting suitable measures to strengthen rupture ground and designing reasonable building structure are the basic research directions to guarantee the safety of the buildings above abandoned goaf.2 RUPTURE ROCK MASS STRUCTURE A
9、ND RESID UAL DEFORMATION CHARACTERIS TIC OVER LONGWALL GOAFAfter extracting underground ore body, the overburden will move and deform t hat induces the great change of the property and forms of rock, and will form a new goaf rupture rock mass structure system composed of caving zone, fracture zone a
10、nd inflection subsidence zone (Fig. 1).Fig. 1 Rupture rock mass structure over long wall goafAccording to a large amount of field inspection and simulation research results, abandoned goaf liven up and the mechanism of extraction rupture ground unstability can be analyzed as follows:1) The rupture r
11、ock pieces above the edge of long wall goaf articulate wit h each other and form a construction similar to half arch structure with one of it s foot t rending to coal wall. In t his structure, the first and second rupture rocks play key role in the relatively stable structure of rock mass above goaf
12、. If these key rocks lose their stability, they will influence overburden, and produce strata movement and deformation again, then extent terrene further.2) The block beam above long wall goaf results in the difference of the crack rocks compactivities in various positions of caving zone. There is u
13、nstowed cavity around open-off cut, terminal line, up and down crossheading (around the edge of goaf). From edge to center of goaf, caving zone can be divided into sub-compaction area, caving rock accumulated area, caving rock compaction area and full compaction area.3) In the super-critical extract
14、ion area above the middle of goaf, caving rupture rock mainly supports s vertical pressure stress. It can be compacted by natural pressure as time passing, but since rupture rocks are beyond retrieve, the fissures among rocks will exist forever. It will be compacted again when being suffered additio
15、nal burden.4) For the difference of stratum bedded deposit characteristic and each rock formation mechanical property, a large amount of bedded separation fissure will be produced in inflection zone of overburden. Under the influence of underground water and external force, especially vertical burde
16、n, these bed separation fissures may be compacted and closed, which will lead to the subsidence of terrene. Based on the analyses above, we can divide the “liven up” of rupture rock mass in abandoned goaf into four types:1) Under the effect of overburden, the rupture rock in goaf body has long-term slow creeping deformation.2) Under the effect of underground water and air, the rupture rock in goaf will be effloresced, it sIntensity will be attenu
