深部岩巷爆破掘进卸荷动态效应与围岩深浅层承载机理研究

Drilling and blasting is applied in the deep rock roadway as a main way for excavation. However, as the rock mass is excavated using this method, the stability of surrounding rock will be influenced, the damage of surrounding rock may occur, and some geological disasters, such as rock burst, groundwater inrush and gas outburst, may be induced. In order to better study the dynamic unloading effect on blasting excavation and deep-shallow bearing mechanism of surrounding rock for deep roadway (DUDSB), the excavation process in the deep rock roadway (EPR) is taken as the primary research objective. In this project, the three-dimensional geomechanics model (3DG) is used, and a combination of experiments with three-dimensional model of rock under the unloading disturbance, theoretical analysis and numerical simulations are employed. Then, the response of surrounding rock to blasting loading and transient unloading, as well as the influence on the stability of surrounding rock can be probed with a consideration of in-situ stress, loading and unloading condition, unloading rate, along with nonlinear constitutive performance of rock under unloading. Considering that the rock is subjected to dynamic loading in DUDSB, the damage and strength of rock is related to the strain rate. Therefore, the damage property and strength change under different strain rates should be considered in the constitutive model. In the project, based on the damage and strength characteristics under different strain rates, an interaction model between surrounding rock and support is developed. With the proposed interaction model, the time-space bearing structure stability of surrounding rock and damage evolution law under cyclic loading with blasting-unloading-re-blasting is analyzed, and then the bearing mechanism under the action of blasting vibration, transient unloading and support can be revealed.This research will promote the development of unloading and control theory for surrounding rock, and provide theoretical support for the safe excavation and support of deep rock roadway.

深部岩巷爆破掘进是目前巷道掘进主要方式，爆破带来围岩损伤或工程失稳，同时也易诱发岩爆、突水及瓦斯突出等事故。项目以深部岩巷爆破开挖过程为研究对象，采用三维地质力学模型、三维岩石卸荷扰动等试验手段、理论分析和数值模拟等方法, 考虑不同地应力、加卸荷条件与速率、扰动等因素下岩石非线性卸荷本构特性，探索高地应力岩巷开挖过程中爆破振动荷载与地应力瞬态卸荷效应对保留围岩响应与稳定作用，基于围岩损伤动载、岩体强度应变率特性，构建爆破掘进中巷道围岩-支护相互作用结构模型，分析爆破-卸荷-再爆破循环过程中围岩时空承载结构稳定性和围岩损伤演化规律，揭示深部岩巷爆破掘进过程中振动效应、卸荷效应、支护效应下动态围岩深浅层承载机理。对巷道围岩卸荷和控制理论具有推动作用，为深部岩巷安全掘进、支护提供理论支持。

深部岩巷爆破掘进是目前巷道掘进主要方式，爆破带来围岩损伤或工程失稳，同时也易诱发岩爆、突水及瓦斯突出等事故。.本项目通过四年的研究，已经圆满完成了申请计划书所规定的研究内容，在深部高应力巷道围岩开挖卸荷及动力扰动下岩体力学特征和损伤模型、围岩动态变形开裂机理和时空演化规律、巷道围岩深浅承载结构及承载效应的动态演化机制等方面取得一些新的研究成果。.项目掌握了卸荷条件下变形特征、强度特性及破坏特征，建立了加卸荷条件下高应力岩体本构模型；掌握了爆破振动应力波传播规律，构建了其围岩损伤模型，弄清了卸荷围岩应力和应变能调整机制及巷道围岩体应力场分布特征；构建围岩开挖、破坏和支护平衡的演化模型，提出深部岩巷围岩深浅层承载原理，形成深部岩巷爆破掘进和支护深浅层承载机理理论。.项目按计划正常进行，完成了预期目标。在本项目的资助下，已在国内外核心期刊和重要学术会议上发表署名国家自然科学基金项目资助的研究论文53篇（SCI、EI收录38篇），出版著作2部，获得申请授权国家专利11项，在本项目的支持和引导下获得其它各类科研项目5项，获得人才称号等13人次。研究内容和项目组成员均未进行大调整。