多元结构边坡抗剪强度参数协同反分析及稳定性研究

发布时间：2018-05-10 19:14

本文选题：多元结构边坡 + 抗剪强度参数　；参考：《长沙理工大学》2015年硕士论文

【摘要】：边坡岩土体抗剪强度参数是稳定性定量评价的重要参数,工程中常常出现φ值相差仅1-2°,边坡稳定性出现急剧变化的情况。确保岩土体抗剪强度参数取值的准确性,是边坡稳定计算和工程设计的首要任务。本文利用协同优化层次性和并行性思想,针对边坡潜在滑动面未知,且潜在滑动面穿越多种待反演土体的多元结构边坡的土体抗剪强度参数反演问题,提出了协同反分析的新思路。依据某实际工程对边坡典型剖面内的抗剪强度参数在天然工况和暴雨工况下进行反分析研究。根据反演推荐抗剪强度参数,采用极限平衡法和有限元法两种方法分析了蓄水前后边坡稳定性,并对边坡加固措施的力学特性进行分析和评价,得出以下结论:(1)天然工况和暴雨工况反分析得到的抗剪强度参数值极为相识,同时两种工况反演得到的抗剪强度参数值与地质推荐的土体抗剪强度参数值也基本一致,表明协同反分析的层次性和并行性思想在解决边坡土体与土体之间、计算剖面与剖面之间的相互影响以及抗剪强度参数反分析解的不唯一性等方面具有一定的成效,为多元结构的边坡抗剪强度参数的反分析提供了一条新的有效途径。(2)边坡稳定分析结果表明:无论采用极限平衡法还是有限元法,水库蓄水均为影响边坡失稳的主要因素;水库蓄水后,边坡遭遇各种设计工况时,(如:水位骤降、设计暴雨以及设计地震工况),暴雨工况对稳定性产生的影响最大,边坡稳定性最低。因此当边坡在遭遇设计暴雨工况时,需特别加强对边坡稳定性的安全监测。(3)预应力锚索力学特性分析结果表明:二维和三维数值分析中,预应力锚索的轴力大小和变化规律基本一致。暴雨工况下预应力锚索轴力增加幅度最大,部分预应力锚索出现不同程度的预应力松弛现象,总体而言预应力锚索基本都能正常发挥支护功。(4)抗滑桩力学特性分析结果表明:抗滑桩内力和变形最大值分别出现在不同的设计工况,其中暴雨工况内力值最大,地震工况变形量最大;抗滑桩受力情况亦随空间位置的不同而不同,边坡中心剖面部位的抗滑桩受力最大,两侧抗滑桩内力相对较小。总体而言,边坡支护措施合理有效。
[Abstract]:The shear strength parameter of rock and soil mass is an important parameter in the quantitative evaluation of slope stability. In engineering, the difference of 蠁 value is only 1-2 掳, and the slope stability changes rapidly. To ensure the accuracy of shear strength parameters of rock and soil is the primary task of slope stability calculation and engineering design. In this paper, based on the idea of synergetic optimization hierarchy and parallelism, the shear strength parameter inversion problem of multi-structural slope with multiple structures that the potential slip surface is unknown, and the potential slip surface passes through a variety of soil layers to be retrieved, is discussed. A new idea of collaborative inverse analysis is put forward. According to a practical project, the parameters of shear strength in typical section of slope are studied under natural and rainstorm conditions. According to the inversion recommended shear strength parameters, the stability of slope before and after water storage is analyzed by using limit equilibrium method and finite element method, and the mechanical characteristics of slope reinforcement measures are analyzed and evaluated. The following conclusions are drawn: (1) the parameters of shear strength obtained by inverse analysis of natural and rainstorm conditions are very familiar, and the parameters of shear strength obtained by inversion of the two conditions are basically the same as those of soil mass recommended by geology. The results show that the hierarchy and parallelism of synergetic inverse analysis is effective in solving the interaction between slope soil and soil, the interaction between profile and section, and the non-uniqueness of back analysis solution of shear strength parameter. This paper provides a new effective way for the back analysis of shear strength parameters of multi-structure slope. The results of slope stability analysis show that: whether using limit equilibrium method or finite element method, reservoir water storage is the main factor affecting slope instability; After the reservoir impoundment, the slope encounters various design conditions (such as sudden drop of water level, design rainstorm and design earthquake condition). The rainstorm condition has the biggest influence on the stability, and the slope stability is the lowest. Therefore, when the slope is subjected to heavy rain, it is necessary to strengthen the safety monitoring of slope stability. The analysis results of the mechanical characteristics of prestressed anchor cable show that: in two-dimensional and three-dimensional numerical analysis, The axial force of prestressed Anchorage cable is basically the same as the law of change. Under rainstorm conditions, the axial force of prestressed anchor cable increases by the largest extent, and some prestressed cables show different degree of pre-stress relaxation phenomenon. In general, prestressed anchor cables can basically give full play to the support work. 4) the analysis results of the mechanical properties of anti-slide pile show that the maximum internal force and deformation of anti-slide pile appear in different design conditions respectively, and the maximum value of internal force in rainstorm condition is the largest. The deformation of anti-slide pile under earthquake condition is the largest and the stress of anti-slide pile varies with the space position. The anti-slide pile in the central section of slope has the largest force and the internal force of the anti-slide pile on both sides is relatively small. Overall, the slope support measures are reasonable and effective.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43

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