承压水上厚煤层底板变形破坏特征实验研究

采场底板稳定性影响因素很多,其中高承压水作用是底板隔水层裂隙发生、发育、扩展及造成底板变形失稳的关键因素之一。我国华北型矿区均受石炭二叠纪煤系底部的太灰、奥灰含水层影响,为此,分析承压水作用下采场底板矿压显现规律意义重大。通过相似材料模拟,分析承压水作用下底板岩层变形及裂隙发育规律。结果表明:沿工作面推进方向,按煤层底板变形特征可划分为5个区,依次为稳定区、压缩区、压缩-膨胀过渡区、离层膨胀区及压实稳定区;按底板破坏特征,自上而下依次为竖向张裂隙带、斜向穿层裂隙带、顺层裂隙带。研究结果可为承压水上开采底板失稳机理研究提供参考。

Deformation and Failure Characteristics Research on Thick Seam Mining Floor above Confined Water

Many factors affect the stability of stope floor.Effect of high pressure water is one of the key factors to cause crack occurrence,development and expansion of water resisting floor and eventually lead to floor information and instability.The North China type coal mine are generally influenced by Carboniferous Permian coal bottom ash and Ordovician limestone aquifer.Therefore,it's of great significance to analyze mine pressure appearance law of stope floor with confined water.According to the simulation of similar meterial,laws of deformation and fracture development of stope floor with the action of confined water are analyzed.The results show that:along the working face advancing direction,it can be be divided into 5 regions according to the deformation characteristics of coal seam floor,followed by the stable region,the compression zone,compression-expension transition zone,separationexpansion zone and steady compacted stable area.According to the floor failure features,there are vertical tensile crack failure zone,oblique wear layer crack zone and the bedding fault zone from top to bottom.The research results can provide reference for the failure mechanism of floor in coal mining above aquifer.