土体参数空间分布对边坡稳定性影响研究

发布时间：2018-11-17 06:58

【摘要】：土体性质与参数具有显著的时空变异性,人们在一些实际的边坡工程案例中发现“安全系数大于1的边坡失稳了,而安全系数小于1的边坡却异常稳定或者具有相同安全系数的两个边坡却具有不同稳定状态”现象,未考虑土体参数的随机性、变异性、概率分布形式等参数空间分布不确定性因素就是导致这些现象的原因之一。本文在现有的确定性方法的基础上,引入变异系数、相关距离、参数分布形式、软硬成层组合等土体参数空间分布的不确定性因素,研究这些土体参数空间分布的不确定因素对边坡稳定性的影响,得到土体参数对边坡安全系数影响的一般规律。主要研究内容及成果如下:(1)总结了边坡土体参数空间分布的一般规律,主要有土体参数空间分布随机性(土体参数空间变异性、土体参数概率分布随机性)和边坡层状分布这两种分布规律,并进一步对其特点剖析。(2) 土体参数空间分布随机性对边坡安全系数有显著的影响:随着变异系数和相关距离的各自增加,其对边坡安全系数的影响均越来越大,进而导致边坡失稳的概率越来越大,且相关距离对边坡安全系数的影响大于变异系数对边坡安全系数的影响。(3)当土体参数服从不同概率分布形式时,边坡的安全系数是不同的,其对安全系数影响的大小依次是正态分布、“内摩擦角正态+黏聚力对数正态”组合分布、“黏聚力正态+内摩擦角对数正态”组合分布、对数正态分布。(4)边坡软硬成层分布形式对边坡安全系数均有相当大的影响,且安全系数从大到小的软硬分布顺序依次为:下硬上软分布、硬软互层分布、中间硬两边软分布、软硬互层分布、下软上硬分布、中间软两边硬分布。
[Abstract]:The properties and parameters of soil have significant temporal and spatial variability. In some practical slope engineering cases, it is found that "the slope with a safety factor greater than 1 is unstable." However, the slope with safety factor less than 1 has abnormal stability or two slopes with the same safety factor have different stability states, which does not take into account the randomness and variability of soil parameters. The uncertainty of spatial distribution of parameters such as probability distribution is one of the causes of these phenomena. On the basis of the existing deterministic methods, the uncertainty factors of spatial distribution of soil parameters, such as coefficient of variation, correlation distance, parameter distribution form, soft and hard stratified combination, are introduced in this paper. The influence of the spatial distribution of soil parameters on the slope stability is studied, and the general law of the influence of soil parameters on the slope safety factor is obtained. The main research contents and results are as follows: (1) the general laws of the spatial distribution of slope soil parameters are summarized, including the randomness of the spatial distribution of soil parameters (the spatial variability of soil parameters). The probability distribution of soil parameters and the stratified distribution of slope are two kinds of distribution laws. Further analysis of its characteristics. (2) the random distribution of soil parameters has a significant impact on slope safety factor: with the increase of variation coefficient and correlation distance, the influence on slope safety factor is more and more great. Furthermore, the probability of slope instability becomes larger and larger, and the influence of correlation distance on slope safety factor is greater than that of variation coefficient. (3) when soil parameters are in different probability distribution forms, The safety factor of slope is different, and its influence on safety factor is normal distribution, combination distribution of "logarithmic normal cohesion force of normal cohesion of internal friction angle" and "logarithmic normal distribution of internal friction angle of cohesion force". Logarithmic normal distribution. (4) the distribution of soft and hard layers of slope has a great influence on the safety factor of slope, and the order of soft and hard distribution of safety factor from large to small is as follows: the distribution of soft and hard layers, the distribution of soft layer between hard and hard layers, the distribution of soft and hard layers in order. Soft distribution between middle and hard, soft and hard interlayer distribution, lower soft and upper hard distribution, middle soft and hard distribution.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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