Slope reliability and back analysis of failure with geotechnical parameters estimated using Bayesian inference

A Bayesian approach is proposed for the inference of the geotechnical parameters used in slope design. The methodology involves the construction of posterior probability distributions that combine prior information on the parameter values with typical data from laboratory tests and site investigations used in design. The posterior distributions are often complex, multidimensional functions whose analysis requires the use of Markov chain Monte Carlo (MCMC) methods. These procedures are used to draw representative samples of the parameters investigated, providing information on their best estimate values, variability and correlations. The paper describes the methodology to define the posterior distributions of the input parameters for slope design and the use of these results for evaluation of the reliability of a slope with the first order reliability method (FORM). The reliability analysis corresponds to a forward stability analysis of the slope where the factor of safety (FS) is calculated with a surrogate model from the more likely values of the input parameters. The Bayesian model is also used to update the estimation of the input parameters based on the back analysis of slope failure. In this case, the condition FS = 1 is treated as a data point that is compared with the model prediction of FS. The analysis requires a sufficient number of observations of failure to outbalance the effect of the initial input parameters. The parameters are updated according to their uncertainty, which is determined by the amount of data supporting them. The methodology is illustrated with an example of a rock slope characterised with a Hoek-Brown rock mass strength. The example is used to highlight the advantages of using Bayesian methods for the slope reliability analysis and to show the effects of data support on the results of the updating process from back analysis of failure.     

边坡稳定性研究综述

介绍了边坡稳定性研究中的基础理论和分析方法，综合评述了这些分析方法的特点和不足，并着重探讨了在边坡稳定性分析中的数值分析法和可靠度法今后的研究方向及发展趋势，有助于边坡稳定性研究工作的开展。     

固定帮无台阶非平面露天底开采境界

传统的露天矿开采境界为固定帮有台阶、露天底平面型。本文以四川会理岔河锡矿露天采场边坡为工程实例,介绍了露天矿无台阶边坡、非平面露天底开采境界的研究与设计过程和方法;论证了该种开采境界的适用条件及生产过程中应采取的安全措施;阐述了其技术经济效果。     

GPS在深凹露天矿高陡边坡位移动态监测中的应用

回顾了矿山边坡变形监测技术的发展历程，结合水厂铁矿的实际，建立了GPS边坡位移动态监测系统，包括基准点和监测点的确定，边坡GPS基线向量网的布设，监测方式，监测周期与数据的输入输出及处理等。实践表明GPS完全能够满足矿山边坡变形监测的需要，该系统的建立是成功的、有效的。     

岩体质量的可拓学评价方法在边坡工程中的应用

可拓工程评价方法是在解决矛盾问题的过程中，既可利用物元的可拓性确定定性因素，又可利用可拓集合论，通过关联函数可取负值这一特点进行定量计算，使评价方法能较全面地分析对象属于集合的程度，较好地解决了岩体质量评价中定性与定量因素综合评价的问题。     

三峡库区巫山新县城库岸再造模式及塌岸预测

简要介绍了三峡库区巫山新县城地质环境，分析了库岸再造模式，对最终库坡塌岸宽度进行了预测。     

边坡稳定性的动态规划研究及其工程应用实例

研究了动态规划法确定边坡非圆临界滑动面的方法，并应用于大新锰矿边坡稳定性研究，取得良好效果，工程应用实例表明该方法对复杂地质条件的边坡稳定性分析具有广泛的应用前景。     

浅谈反算C、ф值在露天矿山边坡设计中的应用

以歪头山铁矿深部开采设计为例，在边坡研究报告来不及提出的条件下，设计利用上部开采暴露边坡出现的滑体要素反算Ｃ．ф值求边坡角。其值与后来研究报告推荐的边坡角值基本吻合。从１９７６年大冶铁矿边坡加固实例和本例设计边坡角结果看，文中介绍的方法有其实际应用意义。     

露天转地下矿山边坡稳定性的数值模拟与敏感度分析

露天转地下矿山边坡稳定性是一个当前广泛存在的问题.依据经验类比和正交试验原理,针对某铁矿工程地质条件,通过正交试验设计出了9种地下采场结构参数方案.采用有限元法,建立了矿区的有限元数值模型,通过数值模拟得出9种方案开采下边坡和采场围岩内的应力、应变数值.在此基础上,通过方差分析,对影响露天边坡稳定性的主要应力、应变指标进行了敏感度分析,得出了边坡稳定性对地下矿房各参数变化的敏感程度,据此确定了确保边坡稳定性的合理矿房结构参数,并初步应用到开采设计中.     

Enhanced performance in the deteriorated area of multicrystalline silicon wafers by internal gettering

The deteriorated area of the multicrystalline silicon (mc‐Si) ingots grown by directional solidification, commonly known as the Red Zone, is usually removed before wafering. This area, characterized by poor minority carrier lifetime, is located on the sides, at the top, and the bottom of the mc‐Si ingots. In this study, the effect of internal gettering by oxygen precipitates and structural defects has been investigated on the bottom zone of a mc‐Si ingot. Nucleation and growth of oxygen precipitates as well as low temperature annealing were studied. Photoluminescence imaging, lifetime mapping, and interstitial iron measurements performed by μ‐PCD reveal a considerable reduction of the bottom Red Zone. An improvement of lifetime from below 1 µs to about 20 µs and a reduction of interstitial iron concentration from 1.32 × 10¹³ at/cm³ to 8.4 × 10¹⁰ at/cm³ are demonstrated in this paper. Copyright © 2013 John Wiley & Sons, Ltd.