基于BCS-KL方法的地层边界不确定性研究
Uncertainty analysis on stratigraphic boundary based on BCS-KL method
张久龙 1张均 1陶永智 1李冰冰1
作者信息
- 1. 中国电建集团江西省电力设计院有限公司,江西南昌 330096
- 折叠
摘要
在工程建设中获取的现场钻孔数据有限,利用钻孔数据解释地下地层不可避免地存在不确定性,进而影响桩基础等工程设计的可靠性.对此,提出了从有限钻孔数据中量化地层边界不确定性的方法,并研究地层边界不确定性对单桩竖向承载力特征值的影响.首先依据钻孔数据,通过贝叶斯压缩采样-KL展开(BCS-KL)方法重建地层边界,并生成大量随机场数据量化地层边界的统计不确定性;然后依据地层边界数据,对单桩竖向承载力特征值进行不确定性分析.分析结果表明:BCS-KL方法生成的大量随机场数据能很好地表征地层边界的不确定性;在钻孔间距较大时,单桩竖向承载力特征值在95%置信区间内相差4 660.88 kN,差距较大.通过BSC-KL方法科学评估地层边界不确定性对单桩竖向承载力的影响,对确保工程设计可靠性具有重要意义.
Abstract
Due to the limited borehole data obtained during constructions,it is inevitable to interpret the underground strati-graphic boundary with uncertainty,which affects the design reliability of pile foundation and other engineering projects.In this pa-per,a method was proposed to quantify the uncertainty of stratigraphic boundary with limited borehole data,and the influence on the characteristic value of the vertical bearing capacity of a single pile was discussed.Firstly,based on the borehole data from a power plant,the stratigraphic boundary was reconstructed and a large number of random field data was generated to quantify the statistical uncertainty of the stratigraphic boundary by Bayesian compressive sampling-KL expansion(BCS-KL)method;then,according to the stratigraphic boundary data,the uncertainty analysis on the characteristic value of vertical bearing capacity of a single pile was carried out.The results showed that a large amount of random field data generated by the BCS-KL method can well characterize the uncertainty of the stratigraphic boundary;when the borehole spacing was sparse,the characteristic value of vertical bearing capacity of single pile has difference of 4 660.88 kN in the 95%confidence interval,showing great difference.It is of great significance to evaluate the influence of stratigraphic boundary uncertainty on the characteristic value of the vertical bearing capacity of a single pile for engineering design by BSC-KL method.
关键词
地层边界不确定性/BCS-KL方法/钻孔数据/单桩竖向承载力特征值Key words
stratigraphic boundary uncertainty/BCS-KL method/borehole data/characteristic value of the vertical bearing capacity of a single pile引用本文复制引用
基金项目
中国电建集团江西省电力设计院有限公司科技创新项目(2019-yk-18)
国家自然科学基金项目(42162023)
出版年
2024
国家科技期刊平台
NSTL
万方数据