次生充填型断续夹层岩质边坡的参数多重共线性表征及可靠度分析

Huge disasters may be caused by rock slope failures, it is of significance to study the causing mechanisms and the features of developing process of landslides, so that sustainable economic and social development of China can be ensured. The soft interlayers play an important role in rock slopes. It is a great challenge to analyze the reliability of rock slopes with intermittent filled interlayer. The deformation and failure mechanism of rock slopes with secondary backfilled intermittents are investigated by similar model experiments, the sliding morphology and mechanical characteristics are determined and the potential sliding surfaces of the secondary filled interlayer rock slopes are find out finally. The velocities of P-wave and S-wave of the slope rock mass are detected by the ultrasonic wave detectors, the laws of the changing probability density of the parameters of rock mass are revealed. Furthermore, the detection methods of collinearity(multicollinearity) of the low-order terms, interaction terms and high-order terms of rock mass density, dynamic elastic modulus, Poisson's ratio and wave velocities before and after disturbed by using the variance expansion factor are performed. Finally, a design matrix considering collinearity is established based on the principle of non-collinearity. The Cox-LASSO regression model and the stochastic response surface method are combined to study the probability of failure of rock slopes. The influences of different factors on the probability of failure of rock slopes, such as the interlayer strength and the number of interlayers are investigated, and the theory of slope reliability analysis is improved.

岩质边坡滑坡危害巨大，深入研究滑坡的致灾机理及灾害发展规律，对保证我国经济和社会的可持续发展有着重要的意义。软弱夹层在岩质边坡失稳起重要作用，分析次生充填型断续夹层岩质边坡滑坡风险充满挑战。利用相似模型实验，分析次生充填型断续夹层岩质边坡的变形和破坏机制，确定滑动形态及力学特征并最终判断含次生充填型夹层岩质边坡潜在滑裂面。利用声波检测仪对边坡岩体进行纵波和横波波速测定，揭示多项岩体参数概率密度演化规律。在此基础上，利用方差膨胀因子对岩体密度、动态弹性模量、泊松比和扰动前后纵横波波速等岩体参数低阶项、交互项和高阶项进行(多重)共线性探测。最后基于非共线性原理建立考虑(多重)共线性的设计矩阵，提出Cox-LASSO回归模型和随机响应面法结合，深入研究不同夹层数目和夹层强度等因素对岩质边坡失效概率影响，得出边坡破坏的失效概率，完善边坡可靠度分析理论。

软弱夹层在岩质边坡失稳起重要作用，分析次生充填型断续夹层岩质边坡滑坡风险充满挑战。首先为克服传统遗传算法的缺点，在遗传算法的基础上，提出了一种改进的遗传算法，能够快速准确地定位三维边坡的临界滑动面。进一步，利用方差膨胀因子发现岩体参数低阶项、交互项和高阶项存在(多重)共线性，提出了LASSO回归方法和随机响应面法结合，得到精确回归系数和回归模型。其次利用相似模型实验，分析了次生充填型断续夹层岩质边坡的变形和破坏机制，确定了滑动形态及力学特征并最终判断含次生充填型夹层岩质边坡潜在滑裂面。最后，统计分析了国内外80多个边坡变形监测实例并建立了蠕变型滑坡数据库，基于边坡变形位移、速度和加速度3个无量纲参数，利用概率统计理论，确立了二级无量纲滑坡失稳阈值准确的阈值设定，为滑坡监测预警提供准确阈值。本项目完成学术论文10余篇，其中SCI、EI收录论文8篇，专著1部；正申请地方标准1项，取得了良好的社会和经济效益。