坡体多期次滑移条件下滑带软岩特性变化规律研究

Under the certain slope structure conditions, there are some higher stablity slopes (such as the slope of dipping oblique introversion) slide many times along with the slip zone. There are some mirror materials in the slip zone, and its mechanical strength parameters will reduce with the slope slipping number of times and lead to slope failure. Combined with the stablity of typical cases, the analysis results of the formation mechanism and the macro characteristics of the slip zone, the evolution mechanism and the change of characteristics of the slip zone soft rock of slop multi-periods sliding were studied by using the research methods of field investigation, experimental study, theoretical study and comprehensive analysis of combining. The project is expected to reveal the characteristics of the linear striae of the slip zone soft rock and mirror material, clay mineral alignment, micro structure change of micropore and microfissure, and then comparative the mineral composition and the change law of macro structure. Under the instantaneous strength, residual strength and long-term strength and repeated shear strength of the soft rock condations, the slope stablity was inversed and the stress size of formation mirror material and depth with this type of mirror material slope were determined. Fininay, the mathematical model of mechanical strength parameters and repeated shear times was established, and the evolution model and formation-evolution mechanism were constructed. The research results provide a scientific basis and theoretical basis for the large consequent rock landslide assessment, forecasting and early warning, and mangement. There are important significances for the disaster prevention and mitigation.

在特定坡体结构等条件下，部分稳定性高的坡体（比如斜内倾）沿滑带软岩多期次剪切滑移。滑带软岩发生演化产生镜面物质且力学强度参数衰减导致坡体失稳。项目采用现场调查、实验研究、理论研究和综合分析相结合的研究方法，同时结合典型滑坡案例稳定性、形成机制分析结果以及滑带宏观结构特性，开展坡体多期次滑移条件下滑带软岩特性变化规律及形成机制研究。项目预期揭示滑带软岩和镜面物质的线型擦痕、粘土矿物呈定向排列、微孔隙和微裂隙等微观结构变化特征，比较矿物成分及宏观结构变化规律；反演滑带软岩瞬时强度、残余强度、长期强度和反复剪切强度等条件下坡体稳定性状，确定滑带软岩生成镜面物质的正应力大小及生成这类镜面物质坡体的深度；建立力学强度参数与反复剪切次数的数学模型，构建滑带演化模式和形成演化机制。研究成果为顺层大型岩质滑坡评估、预警预报和治理提供科学依据和理论基础，具有重要防灾减灾意义。

在特定坡体结构等条件下，部分稳定性高的坡体（比如斜内倾）沿滑带软岩多期次剪切滑移。滑带软岩发生演化产生镜面物质且力学强度参数衰减导致坡体失稳。项目采用了现场调查、实验研究、理论研究和综合分析相结合的研究方法，同时结合典型滑坡案例稳定性、形成机制分析结果以及滑带宏观结构特性，开展坡体多期次滑移条件下滑带软岩特性变化规律及形成机制研究。项目揭示了滑带软岩和镜面物质的线型擦痕、粘土矿物呈定向排列、微孔隙和微裂隙等微观结构变化特征，比较矿物成分及宏观结构变化规律；反演滑带软岩瞬时强度、残余强度、长期强度和反复剪切强度等条件下坡体稳定性状，确定了滑带软岩生成镜面物质的正应力大小及生成这类镜面物质坡体的深度；建立了力学强度参数与反复剪切次数的数学模型，构建软岩滑带s型劈理演化模式和形成演化机制。顺层破劈理型，当沿厚层坚硬岩石与软弱岩石的层面发生错动时，由于强烈挤压摩擦，在软岩石中通常产生密集的顺层破劈理，劈理面光滑，表面呈弧形，将岩石切割成鱼鳞片状。这类错碎带强度由原来的残余强度逐渐较低，在一定条件下，形成近滚动摩擦基础，为坡体提供了极低的强度，容易产生滑动失稳。研究成果为顺层大型岩质滑坡评估、预警预报和治理提供科学依据和理论基础，具有重要防灾减灾意义。