基于CT扫描与3D打印的深部硐室裂隙围岩动态破裂机理研究

Taking the dynamic disaster of deep buried chamber, e.g. rock burst, as the background, according to the method combining true triaxial unloading, SHPB dynamic impacting, theoretical analysis and discrete element simulation, the key scientific problem of dynamic fracture mechanism of deep rock mass after strongly unloading under dynamic loading is closely payed attention to, based on CT scanning 3D printing. Firstly, the true triaxial unloading tests are conducted on rock specimens to obtain the evolution characteristics of strength. The propagation rules of cracks in rock are also revealed by CT scanning and three-dimensional reconstruction. Secondly, based on the numerical information of main cracks, the specimens containing true cracks are made by 3D printing. The SHPB dynamic impacting tests are carried out with different tectonic stress and strain rate to obtain the evolution rules of strength and deformation. Finally, according to the numerical information of cracks from CT images, the fractal dimension of rock mass is calculated, and the relationship between fractal dimension and dynamic response is established. The failure process and dynamic fracture mechanism of rock mass of deep chamber under dynamic load is revealed by UDEC discrete element simulation and fish secondary development, which could provide certain theoretical guidance for dynamic disaster prevention of deep underground engineering.

以岩爆、冲击地压等深部硐室动力灾害为背景，基于CT扫描和3D打印技术，采用真三轴卸荷、SHPB动力冲击、理论分析和离散元模拟相结合的方法，紧紧围绕深部强卸荷破裂围岩在冲击载荷下的动态破裂机理这一关键科学问题开展研究。通过真三轴卸载试验，获得岩石的强度演化特征，结合CT扫描和三维重构，掌握岩石内部的裂隙扩展规律；然后，基于卸荷破坏主裂隙的数字信息，采用3D打印技术制作含真实裂隙面的岩体试样，并进行不同构造应力和应变率条件下的SHPB动力冲击试验，获得冲击载荷作用下深部裂隙岩体的动态强度、位移场演化规律；进而，通过统计CT图像的微裂隙数字信息，计算破裂岩体的分形维数，建立岩体分形维数与动力学响应的联系，并通过fish语言二次开发，采用UDEC离散元程序，再现动载荷下深部硐室的失稳破坏过程，揭示深部裂隙围岩的动态破裂机理，为深部地下工程动力灾害防治提供一定的理论基础。

以岩爆、冲击地压等深部硐室动力灾害为背景，基于CT扫描和3D打印技术，采用峰前三轴卸荷、SHPB动力冲击、理论分析和离散元模拟相结合的方法，对深部开挖卸荷裂隙围岩的强度演化与动态破裂机理开展研究。首先，基于SHPB试验系统，获得了裂隙岩体试样的动态强度及应变场演化过程；然后，采用峰前三轴卸荷、CT扫描、三维扫描等方法，获得了裂隙面的数字信息，并基于3D打印技术和类岩石材料制备了含真实粗糙裂隙面的岩体试样；其次，分析了围压、裂隙面倾角、尺度对裂隙岩体力学特性的影响规律，并借助数字图像相关方法和声发射技术，揭示了复杂应力环境下裂隙岩体试样的破裂演化过程；最后，采用原位钻孔剪切技术，获得了深部硐室裂隙围岩强度的空间分布和开挖时间效应，并基于离散元数值模拟方法，研究了不同支护条件下深部硐室围岩的破裂演化特征。研究成果可以为深部地下工程稳定性分析、动力灾害防治等提供一定的理论基础。