【作者】 安淑红；

【导师】 张正雄；

【作者基本信息】 福建农林大学 ， 森林工程， 2003， 硕士

【摘要】 边坡稳定性验算是公路边坡设计的关键，要提高所设计公路边坡的稳定性，首要问题是选择适宜的分析方法和参数的合理取值。目前工程中使用的定值分析方法由于忽略了荷载效应(滑动力矩)及抗力(抗滑力矩)计算中各要素实际存在的随机性质对工程结构安全性的影响，所以分析结果与边坡稳定的实际工作状态不符，所得安全系数与真正的边坡稳定安全性水平之间存在一定的误差。可靠性分析方法弥补了这种不足，是应用前景广阔和值得推广的一种方法。但由于可靠性理论涉及到较深的数学理论，而且土性参数数据的收集、处理以及可靠性指标的计算都较为麻烦，以致于可靠性方法在边坡工程实践中广泛推广应用有一定的难度。 论文针对目前边坡稳定分析计算中存在的问题，将边坡定值分析方法同可靠性分析方法相结合，利用定值分析方法的简便，考虑土性参数的变异性和不确定性，对边坡进行稳定性和可靠性评价，考虑了荷载效应及抗力计算中各因素实际存在的随机性质对工程结构安全性的影响，更接近边坡的实际工作状态。并且在进行边坡稳定可靠性分析时，用传统的定值分析方法确定公路边坡的临界滑裂面(即最危险滑裂面)，然后以此为基准计算边坡的稳定可靠指标及边坡失效概率，与以往寻找临界滑裂面的试算法相比，大大减少了计算时间，提高了计算效率，可以同时求得边坡稳定安全系数和边坡失效概率。 本文以简单粘土边坡为例，用边坡稳定可靠性分析方法分析边坡的稳定性，揭示边坡模型中土性参数的变异性与安全系数及可靠指标之间的内在联系：(1)土性参数的变异性对可靠性指标值有很大的影响。可靠性指标β值随土性参数c，φ变异性的增大而呈现下降的总趋势；在土性参数变异性较小时，一般在δ＜0.2时，对β的影响特别敏感；而在δ＞0.3时，β受δ的影响则明显减小。(2)β值在不同的变异系数δ_c和δ_φ组合下，所受的影响程度是不一样的。土性参数变异系数δ_c和δ_φ都较大组合时相对变异系数δ_c和δ_φ都较小组合时对β的影响要大。(3)土性参数变量c，φ的变异系数δ_c、δ_φ对β的敏感性程度是不一样的。δ_c、δ_φ对β的敏感性同c，φ均值相对大小有关；当某一土性参数均量明显大时，另一土性参数变量的δ对可靠性指标β的敏感性明显增大。(4)在其它变量保持不变的情况下，粘土边坡的可靠性指标β受土性参数c，φ均值的影响程度是不一样的，β对μ_c的敏感性 公路土质边坡稳定可靠性分析及综合防护体系研究明显要强于声，。(5)可靠指标卢随安全系数变异系数今的增大而呈下降趋势;不同均值指标下的刀一公关系曲线有一定差异，在其它条件相同的情况下，相对于内摩擦角必，粘聚力。均值大小对土坡稳定性和可靠性起着更大的作用。 在南方，降雨是公路边坡稳定性的主要影响因素之一。在非饱和土坡稳定性验算中，由一于非饱和土体中基质吸力对边坡稳定性有利，故不考虑孔隙水压力的影响。然而降雨使土体含水量增加，导致粘聚力、内摩擦角和基质吸力降低，从而在整体上‘降低了土体的抗剪强度;降雨使三非饱和土坡重度增加，下滑力增大;雨水入渗产生渗透力等这些因素都对边坡的稳定性不利。根据调查分析，降雨量、地下水位与边坡的稳定性之间都存在着密切的关系，但以往人们对这种关系的认识和理解仍很不充分。 论文从.分析降雨诱发边坡失稳的原因入手，研究雨水入渗引发滑坡的物理过程，建立定量的分析模型。根据建立的分析模型，研究降雨与边坡稳定性之间的关系。结果表明:对稳定性可靠指标(不考虑降雨作用时)较大的边坡，滑坡主要发生在降雨初期，降雨引起局部稳定性降低;对稳定性可靠指标(不考虑降雨作用时)较小的边坡，既可能在降雨初期发生局部失稳，也可能在长期降雨作用下发生整体失稳。 边坡防护工程是保证边坡稳定，维持与恢复因公路建设而破坏的生态系统平衡、改善沿途景观的重要工程。过去，边坡防护多以工程防护为主，不但投资大，造价高，还留下了许多“地球伤疤”，几乎无.生态效益可言。近年来，人们的环境保护意识逐步提高，审美观念逐渐加强，公路工程的概念不再局限于坚固、耐用、安全畅通，还应考虑沿路景观，高度重视公路建设对沿途生态环境的破坏。为此，要求工程建设人员对边坡的防护技术进行重新认识，对公路项目的环境影响做出评价，并提出相应的补偿措施，建设景观公1络和生态公路。 在调查分析目前各种边坡防护技术(工程防护技术、植物防护技术和综合防护技术)措施的特点、防护机理、防护效果和适用性的基础上，根据稳定边坡、可能失稳边坡和失稳边坡的防护要求和特点，提出相应的边坡防护技术原则及措施，提出应建立以适应.可持续发展及建设生态公路要求的综合防护体系，即把植物防护措施与工程防护措施相结合对边坡实施防护;研究综合防护工程的生态恢复原理、稳定加固原理，提出了公路边坡综合设计与选择防护技术的一般原则。 福建农林大学2003届硕士学位论文 根据国家关于《路基设计》和《公路建设项目环境影响评价》等规范要求，更多还原

【Abstract】 Checking computations of Stability of slope is the key of design of slope by the highway, if you want to improve stability of the slope by the highway designed. Primary problem is choose suitable analysis method and fetch rational parameter. Analysis result of the definite value analysis method used in the project at present doesn’t correspond to the steady real work state of slope, it’s income safety coefficient and real security competence of slope stabilize exists certain error. Because definite value analysis method neglects influence to engineering structure of random existing of the effect of loading (slippery moment) and resists strength (resist the slippery moment). Reliability analysis method have considered the comprehensive influence of the uncertain factor, So it’s analysis result accords comparatively with the real work state that the slope is steady, is a kind of method having a bright future and being worth of popularize. But, because dependability theory involves deeper mathematics theory, and soil parameter’s collection and treatment of data, dependability’ calculation of index has a little trouble, Dependability method doesn’t still apply extensively and isn’t be popularize in practice of slope project.Aiming at existing problem in analysis calculating of slope stability at present, thesis combines slope definite value analysis method with reliability analysis method, and carries on appraisal of stability and dependability of slope, that utilizes simple and convenient of definite value analysis method, considers soil variability and uncertainty of parameter. It considers the influence of random of loading and resistance in calculating that impact on structure security of the project, closes to the real work state sloping. And when going on reliability analysis of slope stability, confirm with critical split surface using traditional definite value analysis method (namely most dangerous sliding surface), then calculate reliability index and failure probability of slope in this sliding surface. Compare with using trial method to look for critical sliding surface in the past, it reduces time of calculating greatly, improves computational efficiency, can get safety coefficient and failure probability of slope stability at the same time.Thesis vise reliability analysis method of stability analyze the stability of the simple clay slope, announce inner link of soil parameter’s variability and safety coefficient, reliability index of slope in the model: (1) The variability of the soil parameter has very great influence on value of dependability index Dependability index Value appears the total trend dropped along with the variability of soil parameter increasing; When the variability of soil parameters is less, about δ<0.2, it’s influence to β is more sensitive; When δ>0.3, it’s influence to β reduce obviously. (2) When the combination of coefficient of variation is in different, the influence degree that received is different. Coefficient of variation of soil parameter have more heavy influenceWhen and is high all than c and is light all. (3) The sensitiveness degrees of C and to are different. The right sensitiveness is relevant to the mean value. Whether mean value of soil parameter is obviously heavy, comparatively speaking, sensitiveness obviously increases of another soil parameter to dependability index as a certain soil. (4) In the situation mat other variables keep unchanged, the sensitiveness degrees of and to are different, the sensitiveness of C to should obviously be stronger than to . (5) shows a tendency to drop when F increases. - F is different under different mean value. When other conditions are the same, to the interior angle of friction, mean value of glue and gather play a bigger role to stability and dependability of slope.In the South:, the rainfall is one of the main influence factors of the stability of slope by the highway. The stability checking computations in slight saturate slope doesn’t consider the influence of the更多还原