引入煤体孔隙率、渗透率的动态演化模型及D-P准则,建立高压水射流割缝后低透气煤层瓦斯渗流的流一固耦合模型,运用该模型优化重庆某矿W2704S回风巷条带下段预抽钻孔布置.结果表明,条带预抽达标时间与钻孔间距呈显著的指数关系,与实际达标时间的最大相对误差为5.8%,验证了流-固耦合模型的工程适用性;高压水射流割缝优化钻孔布置后,煤巷条带的预抽钻孔数量减少了27.3%、预抽达标时间缩短了69.6%,煤巷月平均掘进进尺提高了1.6倍.
Dynamical evolution model of permeability and porosity as well as D-P criterion were introduced to build the fluid-solid coupling model of methane seepage in the lower permeability slotted coal seams, and subsequently, the coupling model was used to optimize borehole layout of the W2704S return airway's lower stripe in a coal mine in Chongqing. Results show that there is an obvious exponential correlation between pre-drainage time of the stripe and borehole spacing. The maximum relative error between the numerical calculation time and the actual time is 5.8%, which verifies the engineering feasibility of the coupling model. With the appli- cation of high-pressure water jet slotting technology drilling quantity and pre-drainage time are respectively reduced by 27.3% and 69.6%, while average month development rate of the coal roadway is increased by 1.6 times.