IMHE OpenIR  > 山地灾害与地表过程重点实验室
Alternative TitleStudy on Slope Reliability Considering Spatial Variability of Rock and Soil Strength Parameters
Thesis Advisor苏立君
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Discipline岩土工程
Keyword边坡可靠度 强度参数 空间变异性 随机场 遗传算法
Abstract滑坡灾害突发性强、破坏力大,常会造成巨大人身财产损失。若能合理评价边坡的稳定性,及早给出防治措施,能显著降低滑坡发生的概率。目前边坡稳定性分析多采用确定性的安全系数法,其不考虑边坡工程中的各种不确定性,导致安全系数相同的边坡可能具有完全不同的失效水平。为此本文在可靠度理论的基础上,主要考虑岩土体强度参数的空间变异性,分别采用随机变量模型、一维随机场模型和二维随机场模型对边坡可靠度进行了研究。首先采用随机变量模型对边坡可靠度进行了分析。利用均匀设计生成随机变量样本,基于强度折减法求出对应的安全系数,通过BP神经网络构造响应面函数,结合蒙特卡罗模拟计算边坡的失效概率与可靠度指标。然后对于只在竖直方向存在变异性的边坡,提出了一种基于遗传算法和一维随机场的边坡可靠度分析方法。讨论了c、φ的空间变异性对边坡可靠度的影响,发现:随着土体相关距离的增大,边坡失效概率逐渐增大,可靠度指标则减小,且逐渐趋于随机变量模型的结果;此外边坡失效概率还与c、φ间相关系数、变异系数成正比,可靠的指标规律则相反。 最后对于各向异性的边坡土体,采用二维随机场模型来模拟岩土体强度参数的空间变异性,基于蒙特卡罗随机有限差分法对边坡可靠度进行了分析。发现,忽略了岩土体强度参数的空间变异性,常会高估边坡的失效概率。一维随机场模型和随机变量模型均可看作二维随机场模型在相关距离较大时的一种特例。对于边坡失效概率,总有:二维随机场模型≤一维随机场模型≤随机变量模型。当相关距离远大于该方向边坡尺寸时等号成立,可对随机场模型进行简化处理。
Other AbstractLandslide is one of natural disasters, which outbreaks of a sudden and has a strong destructive force. And it will often cause huge loss of the personal and property. If the stability of slope can be evaluated reasonably and the control measures are given as early as possible, the probability of landslide occurrence can be significantly reduced. At present, most of the analysis of slope stability is based on the deterministic safety factor method, which does not take into account the uncertainty of slope, resulting in the slope which has the same safety factor may have a different level of failure. Therefore, in this paper, the spatial variability of strength parameters of the rock and soil is mainly considered based on the theory of reliability, and the reliability of the slope is studied by using the random variable model, the one-dimensional random field model and the two-dimensional random field model respectively.Firstly, Analysing the reliability with random variable model. Using uniform design to generate samples of random variables, obtaining the corresponding safety factor based on the strength reduction method, constructing the response surface function through BP neural network, then calculating failure probability and reliability index of slope based on Monte Carlo simulation.Secondly, propdsing a new method of slope reliability analysis based on genetic algorithm and one-dimensional random field. Discussing the implications of spatial variability of c and φ on slope reliability and the research shows that: with the increase of the soil correlation distance, the failure probability of slope increases gradually, while the reliability index decreases, which tends to be the result of the random variable model; in addition, the failure probability of slope is also proportional to the correlation coefficient and coefficient of variation between c and φ.Finally, using the two-dimensional random field model to simulate the spatial variability of rock and soil strength parameters and analyzing the reliability of slope based on Monte Carlo stochastic finite difference method. It is found that the failure probability of slopes will be overestimated if ignoring the spatial variability of the strength parameters of rock and soil. The one-dimensional random field model or the random variable model can be regarded as a special case of the two-dimensional random field model when the correlation distance is very large. For the failure probability of the slope, there will always be such a relationship established: two-dimensional random field model≤one-dimensional random field model≤random variable model. When the correlation distance is much larger than the size of slope in the direction, the sign is established, and the random field model can be simplified at this point.
Document Type学位论文
First Author Affilication中国科学院水利部成都山地灾害与环境研究所
Recommended Citation
GB/T 7714
宋永东. 考虑岩土体强度参数空间变异性的边坡可靠度研究[D]. 北京. 中国科学院大学,2017.
Files in This Item:
File Name/Size DocType Version Access License
考虑岩土体强度参数空间变异性的边坡可靠度(12285KB)学位论文 开放获取CC BY-NC-SAView Application Full Text
Related Services
Recommend this item
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[宋永东]'s Articles
Baidu academic
Similar articles in Baidu academic
[宋永东]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[宋永东]'s Articles
Terms of Use
No data!
Social Bookmark/Share
File name: 考虑岩土体强度参数空间变异性的边坡可靠度研究.pdf
Format: Adobe PDF
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.