不同掘进工艺煤与瓦斯流固耦合数值模拟研究

井下瓦斯事故严重威胁着煤矿的安全,研究煤与瓦斯耦合作用规律并采取相应措施可以有效地防止事故发生。考虑瓦斯气体的可压缩性和吸附、解吸特性,假设瓦斯气体在煤体孔隙中的流动遵循D arcy定律,建立了考虑爆破因素的煤与瓦斯流固耦合数学模型,并利用com so l对其求解。结果表明：炮掘对煤体的破坏能力大于机掘;炮掘工艺下,爆破应力对煤体应力、位移的作用大于应力耦合的作用,机掘工艺应该考虑应力耦合的作用;煤层瓦斯压力随着煤壁暴露时间的增加而发生改变,整个巷道附近的瓦斯压力有降低的趋势,呈现漏斗状分布;煤层上表面煤体竖向位移边界呈以巷道顶端为中心的＂O＂型分布,且以＂O＂型中心处的位移值最大。

Numerical Simulation of Fluid-solid Coupling of Gas in Coal Face under Different Tunneling Technics

The accident of coal methane gas is always to threaten the safety in coal production.Researching the interaction law between coal and gas can prevent occurrance of accident effectively.Considering compressibility,adsorption and desorption of gas,and supposing that the gas flow in pore of coal follows Darcy low,we built up a gas-solid coupling mathematical model with consideration of blasting factors.Results solved by comsol show that coal is easily destroyed by blasting excavation than machnical excavation;contrasting to stress coupling blasting load action,coal stresses and displacements is large and coupling effects should not be neglected in mechancal mining;gas pressure changes with time increase of coal rake exposure and has a decrease trend near tunnel,it looks like a funnel distribution;the contour of displacement on top of the tunnel assumes an ＂O＂ type distribution and the maximum displacement is the centre of the ＂O＂ type distribution.