Probabilistic analysis of overall strength of a cement-treated soil column considering statistical uncertainty and spatial variability
Probabilistic analysis of overall strength of a cement-treated soil column considering statistical uncertainty and spatial variability
复制标题
考虑统计不确定性和空间变异性的水泥处理土柱整体强度的概率分析
DOI：
10.1002/nag.3182
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发表时间：
2021
影响因子：
4
通讯作者：
Tsutomu Namikawa
中科院分区：
文献类型：
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作者：
崎元 和樹;毛利 惇士;菅沼 亮輔;迫田 由華;菊池 喜昭;野田 翔兵;及川 森;Tsutomu Namikawa
结合随机场理论的有限元分析方法是预测具有空间变异性的深层水泥搅拌改善地基性能的有力工具。在分析中，强度的统计参数（即均值、方差和自相关距离）通常保持不变。然而，当从水泥处理过的土柱中提取的岩心样品进行强度评估时，这些参数涉及统计不确定性。本研究提出了一个概率分析框架来评估水泥处理土柱的整体强度，考虑到核心强度的统计不确定性和空间变异性。在蒙特卡罗框架中结合贝叶斯推理分析和随机场理论的有限元分析，同时考虑了统计不确定性和空间变异性。采用贝叶斯推理方法评估堆芯强度的统计不确定性，其中统计参数的概率分布是从观测数据中推断出来的。利用推断的强度统计参数生成随机场实现，并对生成的随机场实现进行有限元分析。通过一个实例分析来说明该方法的细节。算例仿真结果表明，在考虑柱核强度的统计不确定性和空间变异性的情况下，所提出的框架能够提供水泥处理柱整体强度的概率特征。
A finite‐element method (FEM) analysis incorporating with random field theory is a powerful tool to predict the behavior of ground improvement by deep cement mixing with spatial variability. In the analysis, statistical parameters of the strength (i.e., mean, variance, and autocorrelation distance) are normally held constant. However, these parameters involve a statistical uncertainty when evaluated from strengths of core samples retrieved from the cement‐treated soil columns. This study presents a probabilistic analysis framework to evaluate the overall strength of a cement‐treated soil column considering the statistical uncertainty and spatial variability of the core strength. A Bayesian inference analysis and an FEM analysis incorporating with the random field theory are combined in a Monte Carlo framework to simultaneously consider the statistical uncertainty and spatial variability. The statistical uncertainty of the core strength is evaluated by the Bayesian inference approach, where the probability distribution of the statistical parameters is inferred from the observation data. The inferred statistical parameters of the strength are used for generating random field realizations, and the FEM analysis is conducted on the generated realizations. An example analysis is conducted to illustrate the details of the approach. The results of the example simulation demonstrate that the proposed framework can provide the probabilistic characteristic of the overall strength of the cement‐treated column when the statistical uncertainty and the spatial variability of the core strength need to be simultaneously considered.