岩质边坡块状-弯曲复合倾倒破坏机理研究

Toppling failure is a serious and frequent instability in natural and manmade rock slopes, which often occurs in a variety of geotechnical engineering such as water resources and hydropower engineering, expressway project, opencast mining and so on. Most real toppling instabilities are of the block-?exure type because rocks are brittle and their discontinuities are irregular.But the research on toppling failures concentrates mostly on blocky and flexural types, few pay attention to the block-flexure types at present. After establishing typical conceptualization geomechanical model of rock slopes that most prone to block-?exure toppling failure and based on the stability study of Yunfu pyrite open-pit slope, Study on the mechanism of rock slopes against block-flexure toppling failure will be conducted through theoretical analysis ,model test and numerical analysis. The mechanism of rock slopes against block-flexure toppling failure will be clarified and the controlling factors for Toppling failure will be determined. The analysis method of rock slopes against block-flexure toppling failure will be proposed. In order to getting a rapid assessment of rock slopes stability against block-flexure toppling failure, computer program will be developed based on MATLAB. The project possesses significant theoretical and engineering application value to the stability analysis of rock slopes against toppling failure.

倾倒破坏是一种典型的岩质边坡失稳模式，大量存在于各种岩土工程如水利水电、高速公路以及露天矿开采等。由于岩石的脆性和节理的不规则性，块状-弯曲倾倒破坏是最常见的倾倒失稳类型，但是目前对倾倒变形的研究主要集中于块状倾倒和弯曲倾倒，鲜有学者研究块状-弯曲倾倒。本项目在概化出最易发生块状-弯曲倾倒破坏的边坡的典型地质力学模型的基础上，依托广东云浮硫铁矿露天采场边坡稳定性研究，通过理论分析、模型试验、数值分析，开展岩质边坡块状-弯曲倾倒破坏机理的研究，阐明岩质边坡块状-弯曲倾倒破坏机理，确定倾倒失稳控制因素，提出岩质边坡块状-弯曲倾倒分析方法，并以大型数学计算软件MATLAB为平台编写计算程序，实现块状-弯曲倾倒稳定性的快速评价。本项目对于岩质边坡倾倒稳定性分析具有重要的理论及工程实际应用价值。

由于节理分布的随机性和岩石的脆性，块状-弯曲倾倒是最常见的倾倒破坏类型，常见于水利水电、高速公路、露天矿等各类工程边坡中，给工程建设和人们的生命财产造成了严重的危害。本项目通过现场地质调查、室内试验、离心机模型试验、数值模拟和理论分析等综合研究手段，总结出了发生块状-弯曲倾倒破坏的典型工程地质条件及变形破坏模式，建立了块状-弯曲倾倒破坏的地质力学模型；弄清了横向节理间距（岩块高度）、岩层倾角、边坡坡度、岩层厚度以及层面强度等不同因素对块状-弯曲倾倒破坏的影响规律及岩层间作用力的分布特征，确定了破坏主控因素，揭示了破坏面的产生、发展及贯通机制；借助光纤光栅、激光和图像散斑识别等先进测量手段，获取了破坏过程中边坡的变形破坏规律和岩层内部拉伸应力的分布特征，得到了破坏面的起裂、发展及贯通全过程，弄清了块状-弯曲倾倒破坏机理；采用极限平衡方法和叠合梁理论，建立了柱-柱模型（短岩块不承担荷载，视为连续岩层间的传力构件）和柱-块模型（破坏面以上数个短岩块类似一个连续岩层，整体处于极限平衡状态）两种岩质边坡块状-弯曲倾倒破坏分析方法。项目研究成果将为反倾岩质边坡倾倒破坏的防治提供理论基础，对减少和控制倾倒型滑坡灾害的发生，具有十分重要的科学和实践意义。