双向起伏地表浅埋盾构隧道开挖面三维被动失稳极限支护压力上限解  

Upper Bound Solution of Ultimate Support Pressure for 3D Face Passive Failure of Shallow Shield Tunnel Under Bidirectional Undulating Ground Surface

作　　者：钱伟丰 黄明[1] 曾子圣 王禹 胡艳峰 QIAN Weifeng;HUANG Ming;ZENG Zisheng;WANG Yu;HU Yanfeng(School of Civil Engineering,Fuzhou University,Fuzhou 350108,China;CCCC First Highway Xiamen Engineering Co.,Ltd.,Xiamen 361021,China)

机构地区：[1]福州大学土木工程学院,福建福州350108 [2]中交一公局厦门工程有限公司,福建厦门361021

出　　处：《应用基础与工程科学学报》2025年第1期273-288,共16页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(41972276);福建省“雏鹰计划”青年拔尖人才项目(00387088);福建省自然科学基金项目(2020J01310246)。

摘　　要：海域吹填砂地层在自重固结作用下易产生差异沉降形成起伏地表,浅埋盾构隧道在该类地层掘进时开挖面常处于被动土压模式,传统开挖面稳定性理论分析模型欠缺对以上两类影响因素的综合考虑,亟需探索针对起伏地表情况下更为精确的开挖面被动破坏分析模型.通过数值模拟研究了地表纵向坡度δ_(1)和横向坡度δ_(2)对极限支护压力和破坏区的影响,并根据数值模拟得到破坏区的范围.然后采用空间离散化技术,提出一种三维被动破坏模型,通过极限分析法推导了极限支护压力的上限解.分析结果表明:在实际工程中起伏地表双向坡度的影响不可忽略,地表纵向坡度δ_(1)比横向坡度δ_(2)对极限支护压力的影响更为明显;横向坡度δ_(2)对破坏区范围的影响比纵向坡度δ_(1)更为显著.最后,通过与数值模型和现有方法比较并结合工程实例验证,发现所提出的理论模型与数值模型模拟的结果更为接近.上述研究成果可为复杂地形下盾构法施工提供理论指导.Hydraulic fill sand strata in coastal areas were prone to differential settlements under the self-consolidation to form undulating ground surfaces.Shallow tunnel faces were often in passive failure modes when shield tunneling in hydraulic fill sand strata.However,traditional tunnel face stability analysis models lacked a comprehensive consideration of above two factors.More accurate passive failure analysis models of tunnel face under undulating ground surfaces urgent need to be explored.The influence exerted by longitudinal slopeδ_(1) and transverse slopeδ_(2) on the ultimate support pressures and the failure zone was investigated by numerical simulations.According to the failure zone obtained from numerical simulations,a 3D passive failure model was proposed by using the spatial discretization technique,and ultimate support pressure upper-bound solutions were derived based on limit analysis methods.The results demonstrated that the influence of bidirectional slopes cannot be ignored in practical engineering,the longitudinal slopeδ_(1) has a more significant impact on the ultimate support pressure than the transverse slopeδ_(2),the effect of transverse slopeδ_(2) on the extent of the failure zone was more important than that of longitudinal slopeδ_(1).Finally,validated by comparison with numerical models and existing analytical models and with a case study.The proposed results were closer to numerical results.The results can provide theoretical guidance for shield tunneling under complex terrain conditions.

关 键 词：浅埋盾构隧道 起伏地表 双向坡度 吹填砂地层 被动破坏 上限法分析 

分 类 号：TU921[建筑科学—建筑设计及理论]