基于Pair-Copula贝叶斯模型的基坑支护可靠度分析  

Reliability analysis on deep foundation pit support structures using Pair-Copula Bayesian Network

作　　者：吴大炜 江钰鑫 梁广林 林越翔 WU Dawei;JIANG Yuxin;LIANG Guanglin;LIN Yuexiang(Wuhan Engineering Co.,Ltd.,China Railway Seventh Engineering Bureau Group,Wuhan 430000,China;School of Civil Engineering,Sun Yat-Sen University,Guangzhou 510275,China;School of Aeronautics and Astronautics,Sun Yat-sen University,Shenzhen 518107,China)

机构地区：[1]中铁七局集团武汉工程有限公司,湖北武汉430000 [2]中山大学土木工程学院,广东广州510275 [3]中山大学航空航天学院,广东深圳518107

出　　处：《人民长江》2025年第1期140-146,163,共8页Yangtze River

基　　金：国家自然科学基金青年基金项目(52208381)。

摘　　要：为准确判定基坑安全状态,保障基坑安全建设,对影响基坑安全的关键因素展开时程监测,以Pair-Copula贝叶斯(Pair-Copula Bayesian Network, PCBN)模型为基础,结合Pair-Copula处理复杂多变量数据的灵活性和贝叶斯网络处理不确定性的优势,对深基坑支护结构的可靠性进行了深入分析,构建了一套较为完善的可靠度评价体系,实现了考虑监测数据复杂相关性的基坑安全状态量化评价。研究结果表明:监测数据之间存在相关性,其中桩顶竖向位移、桩体水平位移、地表沉降、支撑轴力、桩(墙)体深层水平位移之间的Kendall秩相关系数均超过0.5,存在较强正相关性。地下水位与桩顶竖向位移、桩体水平位移、地表沉降、支撑轴力、桩(墙)体深层水平位移皆为负相关,且相关性较弱,地下水位与地表沉降之间Kendall秩相关系数为-0.361 7,相关性最弱。PCBN模型具有良好的精度,基于PCBN模型计算得到的新塘互通立交路段明挖法市政隧道深基坑工程可靠性指标β值为4.056,基坑支护结构位于安全范围。研究成果可为深基坑支护结构安全量化评价提供有效参考。To accurately assess the safety status of foundation pits and ensure their safe construction,this study conducted a time-series monitoring on key factors affecting the safety of foundation pits.Based on the Pair-Copula Bayesian Network(PCBN)model,which combines the flexibility of Pair-Copula in handling complex multivariate data with the advantages of Bayesian Network in dealing with uncertainty,a comprehensive reliability evaluation system has been established.This system enabled a quantitative assessment of the safety status of foundation pits,considering the complex correlations within monitoring data.The results indicated that there was a correlation between monitoring data such as vertical displacement at the pile top,horizontal displacement of the pile body,ground settlement,support axial force,and deep horizontal displacement of the pile(wall)body,and the Kendall's rank correlation coefficients all exceed 0.5 among them,indicating a strong positive correlation.The groundwater level was negatively correlated,however relative weak,with vertical displacement at the pile top,horizontal displacement of the pile body,ground settlement,support axial force,and deep horizontal displacement of the pile(wall)body,and the weakest correlation was found between groundwater level and ground settlement,with Kendall's rank correlation coefficient of-0.3617.The PCBN model demonstrates good accuracy,the calculated reliability indexβvalue is 4.056 for the deep foundation pit engineering of the Xintang Interchange section of the open-cut municipal tunnel,indicating that the foundation pit support structure is within the safe range.The research findings can provide an effective reference for the quantitative safety evaluation of deep foundation pit support structures.

关 键 词：深基坑支护 Pair-Copula贝叶斯模型 风险评价 可靠度分析 

分 类 号：TU753[建筑科学—建筑技术科学]