断裂带老顶的判别准则及在浅埋煤层中的应用

The criterion on determining main roof in breaking zone and its application to the shallow seam

从 2 0世纪 5 0年代的铰接岩块假说到砌体梁理论的建立 ,都把断裂带老顶结构作为主要研究对象 .在讨论有关断裂带老顶结构假说和理论的基础上 ,根据老顶初次断裂拱式平衡和周期断裂砌体梁平衡条件 ,考虑到岩块间铰点挤压接触面的实际高度 ,推导出了断裂带老顶判别的理论公式 ,即老顶分层厚度大于其下自由空间高度 1 5倍时该分层进入断裂带 .通过与实际观测值及所建立的经验公式比较 ,证明理论公式的计算值与实际一致 ,从而使长期悬而未解的断裂带老顶层位问题在理论上得以解决 .同时也进一步说明了浅埋煤层组合关键层覆岩全厚切落的必然性 .

From the hinged rock block hypothesis to the voussoir beam theory, main roof structure in breaking zone have been regarded as major object.Having considered arch balance on rock blocks in first breaking of main roof, voussoir beam balance of periodic breaking and interface highness among rock blocks,theoretical formula of determining main roof in breaking zone is deduced in this paper, based on the hypothesis and the theory.It is that layering of main roof in breaking zone when its thickness is 1.5 times higher than free space under the layering.A comparison of theoretical values with practical one proves that theoretical formula is consistent with practice.Thus, position problem of main roof in breaking zone, that had no ideal answer for a long time, has theoretically been solved.It is inevitable to show that integral breaking of the whole overlying strata in shallow coal beam occur.