基于山东省黄泛区典型土体参数的空间相关性研究

发布时间：2018-05-22 12:18

本文选题：分层土 + 静力触探数据　；参考：《山东建筑大学》2017年硕士论文

【摘要】：众所周知,岩土材料具有空间结构性和随机性双重特征,是结构性与随机性的统一。因此在考虑岩土相关分析时,需要考虑随机性以及土体参数的空间相关性。最初将岩土设计参数假设为随机变量来处理,忽略土体参数的空间相关特性。本文重点分析土体参数的空间相关性。以收集的山东省黄泛区6个不同场地的静力触探试验(CPT)数据为基础,对数据进行整理、分析,计算得到了其常用随机参数,如均值、方差以及相关距离。同时研究发现,不同土层之间没有明显的沿深度方向增加的规律,将场地根据土层情况进行分层研究。将6个场地中常见的土层分为粉质粘土、粘土、粉土以及砂土,研究了各种土层的参数均值、方差,对四种土类进行了平稳性和各态历经性检验。从研究结果来看,在进行去趋势项处理后,数据的平稳性要更好,可以视为平稳随机场。在此基础上,采用相关函数的矩计算方法,得到了粉质粘土、粉土、粘土和砂土这四种土层的空间分布相关函数。对相关函数随距离增加,尾部出现波动明显的情况,采用了三种处理方法:(1)对离散度大的无效点进行弱化或删除,(2)对所选取的拟合相关函数加权,(3)有效数据点法。处理后拟合函数相关性有显著提高。对相关函数进行模型化分析,在分析土体参数时在超过一定距离后,存在负相关的情况,在现有相关函数模型基础上,提出了可以考虑土体相关函数负值的修正相关函数模型,从而分别利用四种不同的相关函数模型对四种土类数据进行了拟合,得到了相关函数参数,并推导了相关距离的求解方法,从而得到山东黄泛区四种典型土类的相关函数、相关距离及相关函数模型,为典型土层的工程应用提供参考,同时为后续随机场分析提供基础。
[Abstract]:It is well known that geotechnical materials have the dual characteristics of spatial structure and randomness, which are the unity of structure and randomness. Therefore, when considering geotechnical correlation analysis, the randomness and spatial correlation of soil parameters should be considered. At first, the geotechnical design parameters are assumed to be random variables, and the spatial correlation characteristics of soil parameters are ignored. This paper focuses on the spatial correlation of soil parameters. Based on the CPT data collected from six different sites in the Yellow River flood area of Shandong Province, the data are arranged and analyzed, and the common random parameters, such as mean value, variance and correlation distance, are calculated. At the same time, it is found that there is no obvious law of increasing along the depth between different soil layers, and the site is stratified according to the soil conditions. The common soil layers in 6 sites were divided into silty clay silt and sandy soil. The mean and variance of the parameters of each soil layer were studied and the stability and ergodic tests of four kinds of soils were carried out. The results show that the data is more stable and can be regarded as a stationary random field. On this basis, the spatial distribution correlation functions of silty clay, silty soil, clay and sandy soil are obtained by using the moment calculation method of correlation function. For the case that the correlation function increases with the distance and the tail fluctuates obviously, three processing methods: 1) are used to weaken or delete the invalid points with large dispersion degree) the selected fitting correlation function is weighted / 3) the effective data point method is used. The correlation of fitting function was improved significantly after treatment. The correlation function is modeled and analyzed. When the soil parameter is analyzed beyond a certain distance, there is a negative correlation. On the basis of the existing correlation function model, a modified correlation function model considering the negative value of the soil correlation function is proposed. Four kinds of soil data were fitted with four different correlation function models, and the correlation function parameters were obtained, and the solution method of the correlation distance was deduced, thus the correlation functions of four typical soil types in the Yellow River flooding area in Shandong Province were obtained. The correlation distance and the correlation function model provide reference for the engineering application of typical soil layer and provide the basis for the subsequent random field analysis.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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