再生顶板的结构形式及其顶板控制

Constitution and Control of Regenerated Roof

现场实测和分析表明,再生顶板以“类拱”结构随工作面推进而产生周期性的失稳来压,来压步距及强度取决于类拱结构的跨度、岩块的块度及强度,并随分层次数的增加而衰减并趋于稳定,表现为静载荷作用。根据再生顶板的力学结构特征,工作面应以护顶为主、支为辅的控顶准则进行支护设计。

Based on survey in the field and theoretic analysis and by means of rock behaviour principle, periodic unstable weighting phenomenon of quasi-arch constitution of regenerated roof, which phenomenon is accompanied with face advance, is drawn. Weighting distance and weighting strength depend on span of quasi-arch constitution, rock fragmentation degree and strength. and the phenomenon is getting weak and stable while slicing number increasing, lastly it is similar to static load. According to mechanical performance of regenerated roof constitution, supporting design of face must suit the following requirements; protection of roof is the first and supporting roof is the second; reasonably decreasing supporting density is to get good supporting results under the condition of keeping to have certain area of protective roof. Setting load, max. unsupported distance, min. supported distance and control method are main parameters of roof control. The paper presents calculation formulas and methods of determinating roof support and points out safety technical measures to prevent from roof accidents. Theory described in the paper has been verified at No. 6 seam of Hongwei Colliery, where roof is regenerated roof by aids of injecting water.