【作者】 童志怡；

【导师】 陈从新；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2009， 博士

【摘要】 岩质边坡滑动面力学参数的变化规律及其对应的取值理论和方法研究是边坡稳定性分析和防护设计工作中的重要环节。现有的岩质边坡滑动面力学参数取值只是孤立地给出试验数据和反算结果,往往忽略了边坡的实际地质状态及相应的破坏模式,因此有必要在分析各类滑动面变形和破坏特征的基础上,选用与之相适应的力学分析方法,研究取得滑动面的特征力学参数,从而较为真实地反映岩质边坡的受力状态,用以指导边坡的稳定性分析和防护设计。论文主要研究内容和结论如下:(1)阐明了边坡滑动面力学参数取值的研究对象、重点及其研究意义,简要回顾了滑动面分类、结构面强度取值、滑动面试验强度取值和力学参数反算的研究现状,针对目前研究中存在的一些问题,提出了本文的主要研究内容。(2)分析了岩质边坡的几种主要破坏模式,在此基础上对岩质边坡滑动带进行分类研究,从大的方面主要分为自生型滑动面、依附型滑动面和混合型滑动面三类,总结与各类滑动面相适应的力学参数取值方法,从而建立岩质边坡滑动面的力学分析模型,讨论水、风化和沉积环境对岩质边坡的影响,归纳了顺层岩质边坡、反倾岩质边坡和破碎岩质边坡滑动面的成因。(3)介绍了岩石强度理论中的粘接摩擦模型,运用此模型分析依附型滑动面的演化过程,并将其推广到边坡岩土体抗剪强度的选取,讨论了不同法向应力下峰值强度和残余强度随法向应力的变化规律,在此基础上给出抗剪强度的选取模式,讨论了对实际取值结果的影响,并与传统的Coulomb准则进行了比较分析,指出直剪试验的法向应力在小应力区的点较多且抗剪强度结果差异不大时,不宜直接运用最小二乘法回归抗剪强度参数,此时应结合粘接摩擦模型对结果进行线性分段。(4)详细研究了依附型滑动面中的硬性结构面和软弱结构面力学特性和破坏模式,对硬性结构面引入摩擦学中的粘着摩擦理论,着重研究结构面在剪切过程中实际接触面的变化规律,提出实际接触面积的最大点即为强度破坏点,并结合实际数据进行了验证;对软弱结构面则从其基本强度的组成、内部剪切面的形成机理和破坏模式入手,研究了结构面的几何特性、夹层厚度和强度关系对软弱结构面综合强度值的影响,并给出了定量关系式。(5)讨论了滑动面力学参数反算的原理,分析了常用的传递系数法存在的问题,提出了边坡稳定性分析的条块安全系数法,并简要介绍该方法的基本原理和操作过程,提出了条块安全系数法的反算取值依据,并运用此方法对沪蓉西高速公路沿线的典型边坡进行了强度反算,并与传递系数法的结果进行比较,结果证明条块安全系数法的力学概念更清晰,在反算取值的应用中可操作性更强。(6)讨论了混合型滑动面的成因条件、演化过程和强度估算方法,提出了混合型滑动面力学参数反算的双状态法,假定边坡在倾倒前和倾倒后处于两种不同的稳定状态,而且两种状态下的层面应采用不同的抗剪强度参数,然后运用边坡稳定性分析的Sarma法对滑动面的力学参数进行了计算,并结合沪蓉西高速公路的典型边坡进行了实例验证和分析。更多还原

【Abstract】 The variation rules and selection method of mechanics parameters of rock slope are important in the stability analysis and slope design. The current selection of mechanics parameters of slope only presents the testing data or results of counter-analysis, often ignoring the geological state and failure model of slope. Thus the mechanic parameters of slope must be selected on the basis of deformation and failure characters of each sliding plane in order to obtain the actual state of slope and to direct the stability analysis and design of slope. The main aims and conclusions of this thesis are as follows:(1) State the research subject, focus and significance of selection theory and methods of sliding plane mechanics parameters of slope; review briefly the classification of sliding plane, strength selection of structural plane, selection method by testing and counter analysis of strength in the literature; and introduce the main parts of this thesis, relating to the problems of existing research.(2) Analyze the failure models of rock slope, and then classify the sliding plane, the sliding plane can be divided into self-born sliding plane, appendiculate sliding plane and mixed sliding plane, furtherly summarize the selection method of mechanics parameters to each types. Based on the classification, the author establishes the mechanics model of each sliding plane. Discuss the influence of water and weathering and sedimentation conditions on rock slope, and then specify the geological cause of rock bedding slope, counter-tilt rock slope and cracked rock slope.(3) Introduce the cohesion-friction model of rock strength theory, and extend the model to select the strength of sliding plane, discuss the variation rules of peak strength and residual strength under different normal stress, and then present the selection model of shearing strength. After the result of cohesion-friction model is compared with Coulomb Criterion, it is found that when the results of shearing strength are many and adjacent the strength parameters can not be regressed by least square method, instead the results should be divided into some beelines at that time according to the cohesion-friction model.(4) Discuss the characters of hard structural plane and weak structural plane: The adhesive friction theory is applied to research the changing course of shear area of hard structural plane and its influence on shear stress. The shearing failure of structural plane is considered to be corresponding to the maximum of real contact area, a criterion is given to distinguish the shearing failure of structural plane and a new select method of shear strength is brought forward subsequently; Examine the influence of geometrical features and thickness of weak intercalation on the integrative strength of weak structural plane based on the composing of basic strengths, formative mechanism of shearing plane and failure pattern; and present the quantitative relation between the strength and thickness.(5) Discuss the counter-analysis method of strength of sliding plane; point out some problems of imbalance thrust force method; introduce the elements and operation of slice-stability method; and present the selection gist of strength in counter analysis by slice-stability method. The strength of slopes along the Hurong Highway in Hubei province are respectively obtained by imbalance thrust force method and slice-stability method, with the result showing that the mechanics conception of slice-stability method is clearer and much easier to operate.(6) Discuss the forming conditions, evolution process and the method to obtain strength of toppling-sliding plane. Based on the forming course the fore-toppling state and post-toppling state are selected, and the factor of safety and its corresponding strength of the two states are presented, then the two variables equations about the parameter of sliding plane are established by Sarma’s method, and the parameter of slip plane c andφcan be obtained by solving the equations.更多还原