摘要
为研究采掘应力作用下工作面煤体瓦斯压力的变化规律,借鉴土力学渗流固结模型,设计了一种由钢筒、活塞、弹簧组成的试验装置,形象地模拟采掘应力作用下瓦斯和煤体骨架的受力过程及相互作用,进而提出超静瓦斯压力与超静瓦斯压力系数。通过对轴对称应力状态下瓦斯和煤体骨架的应力、体积应变及相互关系进行理论分析,结合井下煤体采掘应力分布规律,得出超静瓦斯压力与支承压力的关系式。研究结果表明:超静瓦斯压力不同于静瓦斯压力,其是由采掘应力引起的瓦斯压力增量。采掘应力刚发生时,超静瓦斯压力达到最大,随着渗流的进行,超静瓦斯压力不断消散,附加应力逐步转移到煤体骨架上,煤体有效应力增大。超静瓦斯压力与煤体支承压力呈正比关系,比例系数即为超静瓦斯压力系数,其与煤体骨架体积压缩系数呈正比关系,与孔隙率、瓦斯体积压缩系数呈反比关系。
In order to study the change law of coal gas pressure in working face under mining stress,based on the seepage consolidation model of soil mechanics,a test device composed of steel cylinder,piston and spring is designed.The device vividly simulates the force process and interaction of gas and coal body skeleton under mining stress,and then proposes excessive gas pressure and excessive gas pressure coefficient.Through theoretical analysis of the stress,volume strain and mutual relationship between gas and coal body skeleton under axisymmetric stress state,the relation between excess static gas pressure and abutment pressure is obtained based on the stress distribution law of underground coal mining.The results show that the excess static gas pressure is different from the static gas pressure,which is the gas pressure increment caused by mining stress.When the mining stress just occurs,the excess gas pressure reaches the maximum.With the progress of seepage,the excess static gas pressure is continuously dissipated,additional stress is gradually transferred to the coal skeleton,and the effective stress of the coal increases.The excess static gas pressure is directly proportional to the abutment pressure of the coal body,and the proportional coefficient is called the excess static gas pressure coefficient,which is directly proportional to the volume compression coefficient of the coal body skeleton and inversely proportional to the porosity and the gas volumetric compressibility.
作者
张士岭
ZHANG Shiling(State Key Laboratory of the Gas Disaster Detecting,Preventing and Emergency Controlling,Chongqing 400037,China;CCTEG Chongqing Research Institute,Chongqing 400037,China)
出处
《矿业安全与环保》
北大核心
2021年第6期1-5,共5页
Mining Safety & Environmental Protection
基金
国家重点研发计划项目(2018YFC0808305)。
关键词
采掘应力
超静瓦斯压力
有效应力
支承压力
体积压缩系数
mining stress
excess static gas pressure
effective stress
abutment pressure
volumetric compressibility
