Observation and Numerical Analysis of the Scope of Fractured Zones Around Gateroads Under Longwall Influence

摘要

There exists a trend in China that high productivity long-wall face which produces 8.0-10.0 million tons of raw coal per annum is widely employed. The stability of the gate-roads during the life of longwall mining is the main concern of the success of high-production longwall face. After a gateroad is driven into rock strata, the primary equilibrium state is disturbed and, as a result, the surrounding rocks are unavoidably broken or fractured (Dong et al. 1994). The extent of the fractured zones mainly depends on: stress characteristics where the gateroad is located; physical, mechanical and rheological properties of rocks; tectonic structure of the rock mass; and an applied extraction and support system (Cai 2008; Chu et al. 2007; Coggan et al. 2012; Feng et al. 2012; Wang et al. 2000). In the case of longwall gateroads, the SFZ can rapidly develop with the influence of longwall mining (Esterhuizen and Barczak 2006; Hao et al. 2004; Walentek et al. 2009). Accurately evaluating the SFZ under the influence of excavation and longwall mining is an important issue for support design and gateroad maintenance.