深部巷道顶板层状岩体双向聚能切缝裂隙扩展机理研究

The mechanism of crack propagation in deep layered stratified rock mass with bilateral cumulative cutting to cutting roof and release pressure was investigated using the “110 construction method.” In this project, the failure behavior of deep layered stratified rock mass under bilateral cumulative impact loading is investigated through five typical angle split Hopkinson pressure bar (SHPB) experiments. Experimental results revealed the failure mode and fractal characteristics under different strain rates. Through physical simulation experiment, 3D refinement numerical experiment contrast, and typical engineering application, the crack evolution, stress evolution, acoustic emission, and fracture partition characteristics of two typical stratified rock masses under different cutting seam parameters are revealed. The crack evolution laws of high geostress of stratified rock mass are proposed under different cutting parameters. The 3D fine numerical simulation methods for crack propagation under bilateral cumulative cutting in deep layered stratified rock mass are established, the rules of crack propagation process and energy distribution are revealed, and the optimization control model of parameter design on stratified rock mass under bilateral cumulative cutting is established. All of these experiments and methods can help us understand the crack propagation characteristics of ductile to brittle transformation under bilateral cumulative cutting in deep layered stratified rock mass. Moreover, these experiments and methods can provide effective and accurate analytical theories and calculation methods to control the large deformation of surrounding rock, gas explosion, and rock burst.

针对“110工法”（指回采1个作面，只掘进1条顺槽，无需留设煤柱的采煤工艺和方法）中采用顶板双向聚能切缝切顶卸压的深部巷道层状岩体，本项目通过五类典型层面倾角的霍普金森压杆（SHPB）试验研究双向聚能冲击荷载下深部层状岩体破坏特性，提出不同应变率下层状岩体的破坏模式与分形特征；并通过物理模拟试验、三维精细化数值试验对比及典型工程应用，揭示不同切缝参数下两类典型层状岩体的双向聚能切缝裂隙演化特征、应力演化规律、声发射特性和裂隙分区，提出高地应力层状岩体双向聚能切缝裂隙演化规律，建立深部层状岩体双向聚能切缝三维精细化模拟方法，揭示不同控制因素对双向聚能切缝裂隙扩展过程和能量分布的规律，建立层状岩体双向聚能切缝参数设计优化控制模型。本项目研究有助于深入认识深部岩体在双向聚能切缝作用下延性-脆性转化的裂隙扩展特性，为控制围岩大变形、瓦斯爆炸、岩爆等重大灾害提供有效、准确的分析理论和计算方法。

本项目采用浙江科技学院自主研发的岩土体动态冲击力学试验系统和MST-600大型地质模拟试验台，对双向聚能冲击荷载下层状岩体破坏特性、高地应力层状岩体双向聚能切缝裂隙演化规律、深部层状岩体双向聚能切缝精细化数值模拟进行了系统研究。主要进行了以下几项工作：（1）研发了三轴岩土体动态冲击力学试验系统，以泥岩与砂岩组成的典型层面倾角的层状岩体为研究对象，利用岩土体动态冲击力学试验系统的冲击杆提供能量以模拟炸药爆炸产生的能量，设有聚能孔的双向聚能材料粘贴于试件的冲击端，研究了双向聚能冲击荷载下典型层面倾角的层状岩体的力学特性，提出了不同应变率下层状岩体的能量耗散规律，探究了层状岩体破坏特性的应变率效应，揭示了不同应变率下层状岩体的破坏模式与分形特性；（2）利用自主设计的MST-600大型地质模拟试验台，研发了典型岩体的相似模拟材料，探究了典型层状岩体在不同的切缝位置、切缝长度、切缝深度条件下的裂隙演化特征以及应力演化规律，揭示了不同切缝参数条件下典型层状岩体破裂全过程的声发射特性，提出了典型层状岩体在不同切缝参数下的裂隙分区及裂隙范围；（3）基于LS-DYNA动力分析软件，研究了典型层状岩体在典型层面倾角作用下的双向聚能切缝裂隙扩展过程，揭示了各个因素对双向聚能切缝裂隙扩展过程和效果的影响，探究了不同控制因素下双向聚能切缝的能量分布与切缝参数的优化设计。在基金委的支持下，通过资助人及其合作者的共同努力，本项目得以顺利完成，形成了24篇标注了基金号的已发表论文和5项已经授权的国家发明专利。