双线盾构隧道近距离下穿施工对既有线路影响分析  

Impact of Short Distance Underpass Construction of Double Line Shield Tunnels on Existing Lines

作　　者：麻凤海[1] 闫盼 董博 王其 MA Fenghai;YAN Pan;DONG Bo;WANG Qi(School of Architectural Engineering,Dalian University,Dalian 116622,China)

机构地区：[1]大连大学建筑工程学院,辽宁大连116622

出　　处：《信阳师范学院学报（自然科学版）》2024年第4期508-515,共8页Journal of Xinyang Normal University(Natural Science Edition)

基　　金：国家自然科学基金项目(51474045)。

摘　　要：为研究新建双线隧道近接下穿施工对既有隧道的影响,以大连市地铁5号线下穿2号线工程为依托,通过有限元软件建立盾构穿越施工的三维数值模型,研究了新建隧道穿越对既有运营隧道拱顶、拱底竖向位移及附加应力的变化规律,并分析了新旧隧道净距、土仓压力、注浆压力等因素对既有线路的影响。研究结果表明:新建双线盾构隧道使既有隧道拱顶、拱底产生不同的沉降槽曲线,拱顶沉降小于拱底,新建左线穿越对既有隧道的影响要大于新建右线,约占最终沉降量的87%;既有隧道的附加应力整体表现为受拉,且随着开挖的推进其取值区间不断扩大,拱顶部位应力持续增大;既有线路竖向位移随新旧隧道净距增大而增加,在注浆压力上同样表现出该趋势,但既有线路竖向位移并不随土仓压力的改变而发生显著变化。研究结果可为类似工程提供参考。In order to study the impact of new double-line tunnel underpass construction on existing tunnels,based on the project of Dalian Metro Line 5 underpassing Line 2,a three-dimensional numerical model of shield crossing construction was established by finite element software,and the change law of vertical displacement and additional stress of new tunnel crossing on the vault and arch bottom of existing operating tunnel was studied.The impacts of the new and old tunnel clearances,soil chamber pressure and grouting pressure on the existing line were analyzed.The results showed that:The new double-lane shield tunnel caused different settlement trough curves in the vault and vault bottom of the existing tunnel,the settlement of the vault was smaller than that of the vault bottom,and the impact of the new left line crossing on the existing tunnel was larger than that of the new right line,accounting for about 87%of the final settlement;The additional stress of the existing tunnel was generally tensile,and the value range was expanding as the construction step advances,and the stresses in the vault part continued to increase;The vertical displacement of the existing line displacement increased with the increase of the net distance between the old and new tunnels,and the same trend was shown in the grouting pressure,but the vertical displacement of the existing line did not change significantly with the change of the soil chamber pressure.The research results could provide reference for similar projects.

关 键 词：双线盾构隧道 近距离下穿 附加变形 数值模拟 

分 类 号：TU473[建筑科学—结构工程]