穿越断层破碎带深埋洞室爆破开挖围岩破坏机理研究进展

Research Progress on Failure Mechanism of Surrounding Rock in Deep Cavern Blasting Excavation Crossing Fault Fracture Zone

我国西部大开发战略正进一步实施,西南高山峡谷地区正在或即将在密集展开一大批大型水电工程.然而受复杂地形条件限制,工程建设中将导流、引水、发电等水工建筑物布置在地下,这就涉及到具有埋深大、地应力高典型特征的地下洞室群开挖工程,并且相当一部分地下洞室群不可避免地穿越断层破碎带.本文总结了近年来工程师和学者重点关注的围岩变形破坏成因以及降低围岩变形破坏发生风险和保障深埋洞室施工安全的方法与技术.诸多研究从理论上阐明了爆破-瞬态卸荷力学作用过程,明确了爆炸应力波和地应力瞬态-卸荷应力波产生机理;从爆破-瞬态卸荷反复扰动激发应力波传播规律、应力波与含断层破碎带岩体的相互作用、含断层破碎带岩体强度特征等方面深入研究爆破-瞬态卸荷反复扰动下穿越断层破碎带深埋洞室变形破坏机理.并结合现场试验、数值模拟和室内试验的方法研究提出了爆破-瞬态卸荷扰动作用下围岩破坏预报及其控制措施.最后提出了关于爆破-瞬态卸荷扰动对含断层破碎带岩体复杂相互作用及控制技术的深入研究方向.

China's western development strategy is being further implemented,and a large number of large-scale hydropower projects are being or will be intensively carried out in the southwest alpine valley area.However,due to the limitation of complex terrain conditions,hydraulic structures such as diversion,water diversion and power generation are arranged underground in the project construction,which involves the excavation of underground cavern groups with typical characteristics of large buried depth and high ground stress,and a considerable number of underground cavern groups inevitably cross the fault fracture zone.This paper summarizes the causes of surrounding rock deformation and failure that engineers and scholars have focused on in recent years,as well as the methods and techniques to reduce the risk of surrounding rock deformation and failure and ensure the safety of deep buried cavern construction.Many studies have theoretically clarified the process of blasting-transient unloading mechanics,and clarified the mechanism of explosion stress wave and ground stress transient-unloading stress wave.The deformation and failure mechanism of deep buried caverns crossing fault fracture zone under repeated disturbance of blasting-transient unloading is studied from the aspects of propagation law of stress wave excited by repeated disturbance of blasting-transient unloading,interaction between stress wave and rock mass containing fault fracture zone,and strength characteristics of rock mass containing fault fracture zone.Combined with field test,numerical simulation and laboratory test,the prediction and control measures of surrounding rock failure under blasting-transient unloading disturbance are proposed.Finally,the further research direction of blasting-transient unloading disturbance on the complex interaction and control techniques of rock mass with fault fracture zone is put forward.