层状岩质边坡倾倒破坏的塑性极限分析法研究

Toppling failure is a typical form of loss of stability for layered rock slopes, some mechanical behaviors , such as sliding, rotation, bending, fracture and toppling, will be occurred simultaneously in rock layers and rock blocks. And there are many kinds of failure modes, and its instability mechanisms are very complicated. The layered rock slopes are regard as subject investigated in this project. The mechanics mechanism of the interaction between structural plane and rock block will be researched, and the mechanical process of toppling failure of slope will be revealed. Based on the theorem of plastic limit analysis, and numerical discrete technology to discrete layered rock slope, statically admissible stress fields and kinematically admissible velocity fields of slope will be obtained, the mathematical model of plastic limit analysis for layered rock slope toppling failure will be established, while the technology of composite element method will be put forward. And then, the solution strategy of model will be discussed. Finally, physical model experiment and practical engineering examples will be used to verify the correctness of the methods. The project will be started which is aimed at providing new methods for stability analysis of layered rock slope toppling failure, and it is valuable that using research production to evaluate stability of slopes in large geotechnical engineering,such as mining engineering , transportation engineering and hydropower project engineering.

倾倒破坏是层状岩质边坡失稳的一种典型形式，其失稳过程表现为岩层或岩块同时发生滑移、旋转、弯曲、断裂和倾倒变形，其破坏模式具有多样性、失稳机理复杂。本项目以层状岩质边坡为研究对象，基于塑性极限分析理论，开展岩块与结构面之间相互作用的力学机理研究，掌握层状岩质边坡弯曲倾倒破坏的物理和力学过程，研究层状岩质边坡塑性极限分析的复合单元法技术、倾倒破坏的静力许可应力场、机动许可速度场的构建技术，建立层状岩质边坡倾倒破坏的塑性极限分析法理论体系，并提出相应的数值实现策略，进而揭示倾倒破坏极限状态下边坡的静力场、运动场的分布规律，最后结合物理模型试验和实际工程算例进行理论与方法的验证。研究旨在为层状岩质边坡倾倒破坏的稳定性分析提供新方法。研究成果对矿山开采、交通运输、水利水电等大型岩土工程的稳定性分析具有重要的理论和应用价值。

本项目基于塑性极限分析理论、混合数值离散技术、数学规划方法进行了层状岩质边坡倾倒破坏的稳定性分析方法的系统性研究，本项目在以下6个方面取得了创新性成果：（1）研究了层状岩质边坡中岩块发生滑移、旋转、断裂等行为的力学机理；（2）提出了模拟岩体同时发生平动-倾倒破坏的塑性极限分析混合单元离散技术，实现了在下限法、上限法中模拟层状岩质边坡连续与非连续变形的力学特性；（3）提出了层状岩质边坡塑性极限分析的静力许可应力场的构造技术，建立了层状岩质边坡倾倒破坏的塑性极限分析下限法理论框架，并开发了岩质边坡倾倒破坏的下限法计算程序；（4）提出了层状岩质边坡塑性极限分析的机动许可速度场的构造技术，建立了层状岩质边坡倾倒破坏的塑性极限分析上限法理论框架，并开发了岩质边坡倾倒破坏的上限法计算程序；（5）提出了层状岩质边坡倾倒破坏塑性极限分析大规模数学规划模型的求解策略；（6）提出了层状岩质边坡中孔隙水压力、地震载荷的模拟技术，获得了地下水和强地震对倾倒岩块的力学作用机理。本项研究建立了一整套能够模拟层状岩质边坡的从连续到不连续倾倒破坏的塑性极限分析法体系，可以同时考虑岩体的滑移、旋转、弯曲、断裂、倾倒的变形过程，研究成果对边坡工程的稳定性分析具有重要的理论和应用价值。课题组按既定研究计划完成了研究任务内容，项目研究达到预期目标。截止目前，本项目成员共发表学术论文11篇，所发表的学术论文被SCI/EI/ISTP检索6篇，其中SCI检索3篇、EI检索3篇；授权发明专利4项、申请发明专利11项、登记软件著作权2项；培养博士研究生1名、硕士研究生6名；主要成员中有2人晋升副教授、1人晋升教授。