基于响应面法的土质边坡可靠度数值模拟研究

发布时间：2018-01-05 09:39

  本文关键词：基于响应面法的土质边坡可靠度数值模拟研究　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 边坡可靠度 有限元强度折减法 响应面法 变异系数 敏感性评价指标

【摘要】：自岩土力学建立以来,边坡稳定性问题便一直受到学术界与工程界的广泛关注。在过去很长一段时间内,用一个确定的值来对边坡稳定程度进行描述是唯一能够选择的方法,但在19世纪50年代可靠度理论诞生之后,一种新的边坡稳定性分析方法进入了人们的视野,这种方法弥补了之前确定性分析方法的不足,在概率论的基础上,将边坡工程中各种影响因素的不确定性加以量化从而进行更加深入的分析。本篇文章的主要研究内容为：一、根据边坡工程的特点,对已有的相关理论加以优化,从而提出一种兼容性好、计算精度高、并且实用性较强的边坡可靠度计算方案；二、分析可靠概率Ps对抗剪强度参数变异系数δ_φ和δ_c的敏感性,并对其敏感程度进行量化评估。在前者中,本文首先总结了部分岩土体物理力学参数变异系数的取值范围,然后运用响应面法结合少量基于有限元强度折减法的边坡稳定性模拟实验,获得了边坡的近似极限状态函数,最后通过联合概率密度函数积分法对边坡可靠度进行了求解；在后者中,本文通过matlab软件,建立起了可靠概率P_s与变异系数δ_φ和δ_c间的函数关系,以此为基础就可靠概率P_s对抗剪强度参数变异系数δ_φ和δ_c的敏感性进行了分析,并总结了其变化规律,最后提出将Ps≥99.65%所对应的区域与整个分析区域的比值S_A/(S_A+S_B)作为其敏感性强弱程度的评价指标,并在某高速公路第11标K49+080-K49+250右侧边坡的可靠度分析中做了应用。此指标的计算结果能够较好的反应边坡的可靠度是否稳定,从而在一定程度上指导设计人员对边坡工程进行更加合理的设计。
[Abstract]:Since the establishment of geotechnical mechanics, slope stability has been widely concerned by the academic and engineering circles, in the past a long time. Describing the slope stability by a certain value is the only method that can be chosen, but after 1850s, the reliability theory was born. A new method of slope stability analysis has entered the field of vision. This method makes up for the shortcomings of the previous deterministic analysis method and is based on probability theory. The uncertainty of various influencing factors in slope engineering is quantified to make more in-depth analysis. The main contents of this paper are as follows: first, according to the characteristics of slope engineering. The existing related theories are optimized, and a slope reliability calculation scheme with good compatibility, high calculation precision and strong practicability is put forward. Secondly, the sensitivity of reliability probability Ps to shear strength parameter variation coefficient 未 _ 蠁 and 未 -ac is analyzed, and its sensitivity is evaluated quantitatively in the former. In this paper, the range of variation coefficient of physical and mechanical parameters of some rock and soil is summarized, and then the slope stability simulation experiment based on finite element strength reduction method is carried out by using response surface method and a small amount of finite element strength reduction method. The approximate limit state function of the slope is obtained, and the reliability of the slope is solved by the joint probability density function integration method. In the latter case, the functional relationship between reliable probabilistic PHS and coefficients of variation 未 _ 蠁 and 未 -C is established by means of matlab software. On the basis of this, the sensitivity of the coefficient of variation (未 _ 蠁) and the coefficient of variation (未 _ (c)) of the reliable probabilistic PSAs to shear strength parameters are analyzed, and the variation rules are summarized. Finally, it is proposed that the ratio of regions corresponding to Ps 鈮，

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