边坡爆破损伤岩体力学参数协调弱化效应及协调折减方法研究

The problem of slope stability under blasting load has always been an important research field in geotechnical engineering. The attenuation rate of the rock mass strength and deformation parameters are different from each other caused by the excavation blasting damage, and there is a difference in the order and degree of influence of mechanical parameters on the slope stability. So, it is urgent to study the coupling mechanism and coordination weakening behavior of mechanical parameters of rock mass. First, a similar model test of slope excavation blasting will be designed to reveal the tempo-spacial evolution law of the non-continuous damage of the slope. Secondly, the coupling theoretical model of mechanical parameters for rock mass will be established based on the Tension-Mohr-Coulomb Criterion and mechanics performance test results of rock sample, the mathematical model of coupling relationship between mechanical parameters of rock mass will be established, and the coupling mechanism of mechanical parameters of rock mass will be explored. At the same time, particle swarm-wavelet neural network and finite difference method will be used to inversion and analysis tempo-spacial distribution characteristics and weakening law of elastic modulus of rock mass with damage. And the coordination weakening effect of local damage on mechanical parameters of rock mass will be analyzed. At the same time, method for determining the calculation area of slope degradation and reduction will be researched, and the failure criterion of slope based on energy conversion and mutation will be established. Finally, the mechanism of deformation and failure in the process of slope instability evolution will be systematically revealed through the Global-Local degradation calculation. The research results will provide a theoretical basis for the study of stability and early warning of the open pit slope from a new perspective.

爆破荷载作用下的边坡稳定性分析一直是岩土工程界一个重要研究领域。开挖爆破损伤导致边坡岩体强度与变形参数的衰减速度各不相同，二者对边坡稳定性影响的顺序与程度亦存在差异，因此亟需进行岩体力学参数耦合赋存机理与协调弱化行为的研究。设计开展边坡开挖爆破损伤相似模型试验，研究循环爆破作业条件下边坡岩体非连续损伤时空演化机制；基于张拉-摩尔-库伦剪切复合屈服准则与岩样力学性能测试，建立岩体力学参数耦合关系数学模型，揭示参数间耦合赋存机理；利用粒子群-小波神经网络与有限差分计算方法，反演分析边坡损伤岩体弹性模量时空分布特征与弱化规律，解析局部损伤对岩体力学参数的协调弱化效应，并研究边坡劣化折减计算区域的确定方法，构建基于能量转化与突变的边坡失稳判据，进而通过多参数协调的边坡全-局部强度折减数值计算，系统揭示边坡失稳演化过程中变形破坏机理，研究成果将从新的角度为边坡稳定性分析与失稳预警研究提供理论基础。

本项目主要针对边坡台阶爆破振动传播规律和协调劣化折减计算方法进行研究，采用理论分析、现场测试、模型试验和数值计算等方法，系统研究了边坡爆破振动沿坡面传播衰减机制、预测方法及围岩劣化折减计算方法。首先设计并开展循环爆破作用条件下矿山边坡振动响应模型试验，研究了爆破参量及边坡损伤程度对振动响应特征变量的影响规律，得到了考虑高程差因素的爆破振动速度预报模型。创新性提出了修正单响药量概念及计算方法，建立了精度较高的露天边坡台阶爆破振动速度预测方法。提出了考虑地震波传播距离差异因素的延期识别修正方法，并给出了一种电子雷管延期时间优选方法。开展了类岩石材料混凝土试件爆破荷载失效试验，建立了一种基于小波包能量理论的岩石脆性材料智能损伤判定方法。基于简化的Bishop法原理建立目标函数，利用麻雀搜索算法搜寻边坡滑动面的最佳圆心位置确定最危险滑动面，提出了一种基于麻雀搜索算法与蒙特卡洛模拟的边坡稳定性计算方法。基于张拉-摩尔-库伦剪切复合屈服准则，建立了岩体力学参数间的耦合赋存关系，提出了考虑多参数协调的边坡劣化折减计算方法。研究成果将从新的角度为边坡稳定性分析提供理论基础，为矿山、交通、水电等边坡工程动力失稳灾害预警与振动效应控制研究提供借鉴。