晋城成庄矿煤层中节理研究及其意义

INVESTIGATION ON JOINTS IN THE COAL BEDS IN CHENGZHUANG COAL MINE OF JINCHENG COAL-BEARING DISTRICT AND ITS SIGNIFICANCE

煤层中的节理裂隙构造在很大程度上决定着煤层的结构构造和物理性质,对煤层和煤层气的生储、 聚集及可采性等起着直接或间接的控制作用。通过对成庄煤矿二盘区、三盘区和四盘区的巷道及多个开采面上的 节理裂隙构造进行详细的观察、统计与分析,节理裂隙有成带分布的特点,频度最高达60条/m,单个节理裂隙带中 煤层被切成薄片状,在两个或多个节理交汇地带,煤层被切成碎块,造成不稳定因素。构造应力场可分为4期:① 主应力σ1方向垂直,σ2、σ3水平;②σ1近S—N水平,σ3水平,σ2垂直;③σ1近E—W水平,σ3水平,σ2垂直;④σ1 方向135∠10°,σ3NE,σ2近垂直。构造因素是控制瓦斯突出分布的主导性因素,节理裂隙发育、应力集中、煤层破 碎地段是瓦斯突出的部位。

The structure and petrophysical property of coal bed are related to the joint fissures in coal to a great extent, which controls the coal bed and the source-reservoir-accumulation and recoverability of coalbed methane directly or indirectly. Throug the detailed observation, statistics and analysis of the joint fissures on many coalfaces and in tunnels of the Panel-2, Panel-3 and Panel-4 in Chengzhuang coal mine, it was pointed that the joint fissures are of the character of zonal distribution, the maximum frequence being up to 60 fissures permeter; and the coal beds in individual joint fissure belt were cut into slices, however, in the intersecting zone of two or several joint fissure belts, the coal beds were cut into shivers, an unstable factor being caused. The tectonic stress field may be divided into four stages according to stress directions. The structural condition is the principal factor of controlling the distribution of gas outbursts and the area of joint fissure development, stress centralization and coalbed crash is the portion of gas outburst.