Efficient random field modeling of soil deposits properties
Efficient random field modeling of soil deposits properties
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DOI：
10.1016/j.soildyn.2018.01.036
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发表时间：
2018-05
影响因子：
4
通讯作者：
Q. Yue;Jingru Yao;A. Ang;P. Spanos
中科院分区：
文献类型：
--
作者：
Q. Yue;Jingru Yao;A. Ang;P. Spanos
利用静力触探试验资料，对山东中国等地土壤剖面的自相关函数进行了研究。这是在土壤沉积物的随机场建模的背景下完成的。研究发现，不同类型的土壤剖面具有不同的随机参数，且沿深度方向没有明显的变化趋势。因此，在每一层内都要检查土壤剖面。利用最小二乘法对现有的三种解析(ACF)模型进行了数值模拟，得到了不同类型土的数值结果。此外，还比较了端部阻力和套筒摩擦之间的自相关函数。在自相关数据分析的基础上，提出了一种新的自相关模型--线性指数余弦模型(LNCS)，该模型在空间滞后轴的原点具有可微性，沿该轴具有交替符号。对于所有四个ACF模型，都数值求解了一个相关的积分方程，以确定相关的Karhuen-Love(K-L)表示。在这方面，值得注意的是，新的模型不仅具有更好的物理一致性，而且产生了相当好的计算效率。最后，在假设二维可分离性的前提下，利用二维K-L展开对土体剖面的随机场进行了模拟。
The autocorrelation function (ACF) of the soil profile in some sites in Shandong province, China is studied using cone penetration test (CPT) data. This is done in the context of a random field modeling of the soil deposits. It is found that the different types of soil profile have different stochastic parameters, and there is no obvious trend along the depth of the soil profile. Thus, the soil profile is examined within each layer. Numerical values for three existing analytical (ACF) models are derived by the least squares fitting approach for the different types of soil. Further, comparisons of the autocorrelation function between the tip resistance and sleeve friction were examined. Based on the autocorrelation data analysis, a new autocorrelation model, named linear-exponential-cosine (LNCS), is considered with differentiability at the origin of the spatial lag axis, and alternating sign along this axis. For all of the four ACF models, a related integral equation is numerically solved for determining the associated Karhunen-Loeve (K-L) representation. In this regard, it is noted that the new model is not only more physics-consistent, but also yields quite good computational efficiency. In the end, the random field of the soil profile is modeled using a two-dimensional K-L expansion with the new model, assuming separability in two dimensions.