采场“砌体梁”结构的关键块分析

ANALYSIS OF KEY BLOCK IN THE STRUCTURE OF VOUSSOIR BEAM IN LONGWALL MINING

在“砌体梁”全结构力学分析基础上，将影响采场工作面安全生产的“砌体梁”关键块体部分简化为三铰拱式结构。此结构的基本失稳形式有两种，即滑落（Ｓ）失稳和回转（Ｒ）变形失稳。块体的回转角、长高比、岩性及负载岩层的高度是影响结构稳定的主要因素。在详细分析这些影响关键块体结构稳定性因素及范围基础上，初步建立起了采场围岩结构的Ｓ－Ｒ稳定理论。用此理论可就开采时上覆岩层对工作面的影响、压力变化及需控岩层范围等问题进行定量分析。文中还给出了“砌体梁”关键块体结构的稳定范围及在各种条件下应采取的相应措施。

Based on mechanical analysis of a complete structure of voussoirbeam in longwall mining, the key block, which affects safety of production at work face, is simplified into an arch with three articulations. Basically, there are two modes of instability, namely instability due to sliding(S), and instability dueto rotation (R). The major factors that affect the stability of the structure are rotational angle of the voussoir beam, ratio of length and height, rock type and height of carrying rock strata. And based on detailed analysis of these factors and their range, the theory of 'S-R' stability for rock structure in the workings is preliminary established. And it can be applied to quantitative analysis of many problems,such as, effect of overlying strata on workface in mining, changes of ground pressure and extent of area to be controlled. The paper also gives the range of stability of key block of voussoir beam and measures to be taken in various conditions.