岩层移动离层演化规律及其应用研究

Study and application of bed separation distribution and development in the process of strata movement

通过试验与理论分析 ,对岩层移动过程中的离层位置与离层量、离层动态发育特征及其影响因素进行了深入研究。结果表明 :覆岩离层主要出现在各关键层下 ,覆岩离层最大发育高度止于覆岩主关键层。当相邻两关键层复合破断时 ,尽管上部关键层的厚度与硬度比下部关键层大 ,其下部也不会出现离层。关键层初次破断后的离层区长度和最大离层量仅为关键层初次破断前的2 5 %～ 3 3 %。因此 ,离层区充填应在关键层初次破断前进行 ,并保持关键层不破断。针对目前覆岩离层区充填工艺不能阻止覆岩关键层初次破断的问题 ,提出了离层区充填与留设煤柱相结合的“覆岩离层分区隔离充填减沉法” 。

The position, size, development characteristics and their influence factors of bed separations have been analyzed deeply by experimental and theoretical methods. The results show that bed separations mainly occur below the key strata, and the highest bed separation space is right below the primary key stratum. When a combined breakage occurs on two adjacent key strata, even if the upper stratum is thicker and stronger than the lower one, there will be no bed separations below the upper key stratum. The largest width and size of bed separations after the key stratum breaks for the 1st time only reach to about 25%～33% of those occurred before the breakage. Therefore, grouting is best done before the key stratum breaks for the 1st time, and ensure that the key stratum would never break. In order to deal with the problem that the current bed separation grouting technology can not prevent the key stratum from breakage, the authors proposed the isolated section-grouting method for overburden bed separations by composing bed separation space grouting and pillar. This would be a technical progress in the bed separation grouting.