洛阳龙门综合交通枢纽深大基坑开挖对邻近管线的影响

Impact of Deep Foundation Pit Excavation for Luoyang Longmen Comprehensive Transportation Hub on Adjacent Pipelines

以洛阳龙门综合交通枢纽工程为依托,运用Midas-GTS/NX有限元软件与现场监测数据相结合,揭示不同管线埋深、埋距、管径、材质及内支撑架设位置条件下基坑施工对管线变形的影响规律,通过变量归一化分析基坑施工时各因素对管线的影响程度,并对热力管线进行安全性能评价。结果表明:在坑角效应作用下,管线在2个坑角处的受力变形基本吻合,管线中部竖向位移、水平位移和弯矩分别是坑角处的1.36倍、1.14倍和1.19倍;不同影响因素下管线最大位移均发生在管线中部位置,通过变量归一化发现管线竖向位移和水平位移对管线埋距最敏感,相对敏感度分别为0.78和0.60,对管径敏感度最低,敏感度仅为0.12和0.08;对热力管线进行安全性能评估,最大相对转角小于容许值0.1°,强度安全系数达到10.52,评估结果为安全。

Taking the Longmen Comprehensive Transportation Hub Project in Luoyang as an engineering background,we employed the Midas-GTS/NX finite element software in association with on-site monitoring data to investigate the impact of foundation pit construction on pipeline deformation.We considered various factors of pipeline such as buried depth,buried distance,pipe diameter,pipe material,and the position of internal support.By normalizing variables,we evaluated the influence of these factors on pipeline behavior during foundation pit construction and assessed the safety performance of thermal pipelines.The outcomes reveal that,under the pit angle effect,the deformations at both pit corners are essentially consistent,with vertical displacement,horizontal displacement and bending moment in the middle of the pipeline reaching 1.36 times,1.14 times,and 1.19 times that of the pit corners respectively.Furthermore,the maximum displacement of the pipeline occurs in its middle part under diverse influencing factors.Through variable normalization,we identified that vertical displacement and horizontal displacement of pipeline exhibits the highest sensitivity to buried distance,with relative sensitivities of 0.78 and 0.60,respectively,and conversely,the lowest sensitivity to pipe diameter,with sensitivity values of only 0.12 and 0.08.Evaluation of the safety performance of thermal pipeline reveal that the maximum relative rotation angle remains below 0.1° and the stress safety coefficient reaches 10.52,indicating a satisfactory level of safety.