新疆G557线高填方路堤边坡稳定性及抗震性分析

发布时间：2019-06-25 20:05

【摘要】：近年来,我国高填方路堤频繁发生滑坡、崩塌等事故,这与不合理的路堤设计方法有较大关联。现阶段采用的极限平衡理论和竖向条分法虽然计算简明,但是存在两个缺陷。(1)无法估计高填方路堤发生破坏的概率;(2)地震力,尤其是水平地震力计算方法不合理,导致安全系数计算不准确。为解决上述两个问题,本文结合国道G577线旱田至特克斯段高填方路堤设计要求,提出了边坡破坏概率计算模型和改进拟静力法模型。通过将高填方路堤内部抗滑力和滑动力作为两个独立的随机变量建立安全系数计算方程。在此方程的基础上,采用边坡破坏概率计算模型分析边坡发生破坏的概率并运用于在国道G577线旱田至特克斯段。同时本文分析了传统拟静力法进行地震动力分析时的主要缺陷。在此基础上,通过水平条分改进拟静力法,避免传统拟静力法的缺陷,为工程运用提供了理论基础。最后以国道G577线旱田至特克斯段为研究对象,结合路段的地形地貌、气候、水系分布、水文地质条件、地质构造和地层岩性,提出了适用于国道G577线旱田至特克斯段高填方路堤的正常工况稳定性可靠度模型和抗震拟静力法分析模型并通过实例计算论证了两个模型的准确性。结果表明边坡破坏概率计算模型可以准确的估计出边坡发生破坏的概率。同时本文提出仅有当安全系数N1.2且边坡发生破坏的概率小于1.25%时,高填方路堤才能在全寿命周期内不发生失稳破坏。改进拟静力法模型通过水平条分避免了ai取值不合理的问题,更好的计算了地震力作用下的边坡安全系数。今后应考虑将边坡破坏概率计算模型和改进拟静力法模型运用于更多高填方路堤设计中,进一步验证其准确性。
[Abstract]:In recent years, landslides and landslides often occur in high fill embankment in China, which is closely related to unreasonable embankment design method. Although the calculation of limit equilibrium theory and vertical slice method is simple at present, there are two defects. (1) the probability of failure of high fill embankment can not be estimated; (2) the calculation method of seismic force, especially horizontal seismic force, is unreasonable, which leads to inaccurate calculation of safety factor. In order to solve the above two problems, this paper puts forward the calculation model of slope failure probability and the improved quasi-static method model according to the design requirements of high fill embankment from dry field to Tex section of national highway G577 line. The calculation equation of safety factor is established by taking the anti-skid force and sliding force in the high fill embankment as two independent random variables. On the basis of this equation, the probability of slope failure is analyzed by using the slope failure probability calculation model and applied to the dry field to Tex section of the national highway G577 line. At the same time, the main defects of the traditional quasi-static method in seismic dynamic analysis are analyzed in this paper. On this basis, the quasi-static method is improved by horizontal section to avoid the defects of the traditional quasi-static method, which provides a theoretical basis for engineering application. Finally, taking the dry field to Tex section of National Highway G577 as the research object, combined with the topography and geomorphology, climate, water system distribution, hydrogeological conditions, geological structure and strata lithology, the normal working condition stability reliability model and seismic quasi-static method analysis model suitable for the high fill embankment of G577 national highway are put forward, and the accuracy of the two models is verified by an example. The results show that the calculation model of slope failure probability can accurately estimate the failure probability of slope. At the same time, it is proposed that only when the safety factor N1.2 and the probability of slope failure are less than 1.25%, the high fill embankment can not cause instability failure in the whole life cycle. The improved quasi-static method avoids the unreasonable value of ai by horizontal segmentation, and calculates the slope safety factor under seismic force better. In the future, the probability calculation model of slope failure and the improved quasi-static method model should be applied to more high fill embankment design to further verify its accuracy.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.1

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