灰岩地区危岩激振解体机制研究

China is a nation with wide distributed carbonate rock, and the perilous rock collapse disaster is in a severe situation. The failure disintegration of perilous rock becomes an important basic scientific problem and the weakest research link for perilous rock collapse mitigation in limestone area. According to failure disintegration of perilous rock in limestone area, this project takes a deep analysis on Zhen Zi Yan perilous rock failure as the breakthrough point, adopts research methods such as laboratory model test, impact dynamics, vibration mechanics, fracture mechanics, etc. and carries out research on the excitation disintegration mechanism of perilous rock in limestone area. In the research, perilous rock in limestone area is equivalent to quasi-masonry structure, and by the study on toppling-sliding coupling rupture of perilous rock, the method to determine impact force spectrum of perilous rock is proposed. By using the impact force spectrum of perilous rock to act on quasi-masonry structure, its vibration mechanics model is established, and hereby to analyze the impact excitation characteristics of quasi-masonry structure. By constructing the excitation fracture mechanics model of quasi-masonry structure, its excitation fracture characteristics are analyzed and the method to determine its disintegration scale under the act of excitation fracture is proposed. Assuming disintegration parts of quasi-masonry structure are the remainder vertical drop height, to re-determine the impact force spectrum of perilous rock and to use former research results to analyze remainder excitation characteristics and fracture characteristics until the quasi-masonry structure is totally disintegrated. The achievements offer a technological support for promoting the cognitive level of perilous rock failure in limestone area.

我国是一个碳酸盐岩广布的国家，危岩崩塌灾情严重。危岩破坏解体是灰岩地区危岩崩塌减灾重要的基础科学问题，也是最薄弱的研究环节。本项目针对灰岩地区危岩破坏解体问题，以深入解剖甄子岩危岩破坏事件为着力点，采用室内模型试验、冲击动力学、振动力学和断裂力学等研究方法，开展灰岩地区危岩激振解体机制研究。研究中，将灰岩地区的危岩等效为类砌体结构，通过对危岩倾倒-滑动耦合破坏问题的研究，提出危岩冲击力谱确定方法；将危岩冲击力谱作用于类砌体结构，建立其振动力学模型，据此分析类砌体结构的冲击激振特性；通过构建类砌体结构激振断裂力学模型，分析类砌体结构激振断裂特性，提出类砌体结构激振断裂解体规模确定方法；假定类砌体结构解体部分为剩余部分的垂直落距，重新确定危岩冲击力谱，并利用之前的研究成果分析类砌体结构剩余部分的激振特性和断裂特性，直到类砌体结构全部解体为止。研究成果为提升灰岩地区危岩破坏认知水平提供技术支撑。

我国中西部地区碳酸盐岩广布，危岩崩塌灾情严重，其危岩破坏解体是灰岩地区危岩崩塌减灾重要的基础科学问题。本项目针对灰岩地区危岩破坏解体问题，研究过程中，以重庆南川金佛山甄子岩危岩破坏事件和其现场监测资料为依托，分析了灰岩地区危岩地质模型和力学模型，采用室内模型试验、数值模拟试验和冲击动力学、振动力学和断裂力学等多学科交叉融合研究方法，开展了灰岩地区危岩激振解体机制研究。研究发现，石灰岩地区的危岩具有类砌体结构特征，基座软质岩体的软化是致危岩破坏的重要诱因；获得了危岩倾倒-滑动耦合破坏中危岩倾倒过程中基座软质岩体突发滑动破坏时产生危岩弹冲速度计算方法，刻画了危岩由倾倒破坏模式转变为滑动破坏模式的物理描述和力学表达。把危岩冲击力谱作用于类砌体结构，建立了其振动力学模型，分析了危岩类砌体结构冲击激振特性；通过构建的类砌体结构激振断裂力学模型，分析了类砌体结构下部碎裂解体规模。利用已构建的危岩振动力学模型分析了类砌体结构剩余部分的振动特性，利用已建立的类砌体结构激振断裂力学模型量化了类砌体结构剩余的进一步碎裂解体规模，直到类砌体结构全部解体。该研究项目完全解译了重庆南川甄子岩破坏解体的科学问题，研究成果为提升灰岩地区危岩破坏认知水平提供技术支撑。