摘要
济南市双线明挖隧道和双线盾构隧道先后下穿既有铁路桥梁。为保护既有铁路桥墩和桥桩,拟定采用隔离桩和不采用隔离桩两种方案,通过数值模拟研究了明挖隧道和盾构隧道施工时铁路桥梁的桥墩、桥桩位移变化规律及隔离桩的隔离效果。结果表明:明挖隧道围护桩施工+基坑开挖、主体结构施工+覆土回填、盾构隧道下穿引起的桥墩竖向位移分别占桥墩总竖向位移的60.14%、27.07%、12.79%;受围护桩与隔离桩桩长的影响,明挖隧道及盾构隧道施工对24.5 m深以下桥桩的保护作用减弱;与未采用隔离桩相比,采用隔离桩后桥墩最大累计竖向位移与桥桩最大水平位移分别减小了68.5%、60.7%,隔离桩对变形的控制效果明显。
The twin-line open-cut tunnel and the twin-line shield tunnel in Ji’nan city successively crossed existing railway bridges.In order to protect the existing railway piers and bridge piles,two schemes with isolation pile and without isolation piles were proposed.The displacement variation laws of railway pier and bridge piles during the construction of open-cut tunnel and shield tunnel were studied by numerical simulation,as well as the protection effect of the isolation piles.The results show that the vertical displacements of railway piers caused by the process of the construction of enclosure piles and the excavation of foundation,the construction of main structure and the backfilling of overburden,and the crossing of shield tunnel account for 60.14%,27.07% and 12.79% of the total vertical displacement of pier,respectively.Limited by the length of the piles,the protective effect of enclosure piles and isolation piles on the bridge piles below 24.5 m is weak.Compared with no isolation piles,the maximum cumulative vertical displacement of the railway pier and the maximum horizontal displacement of the bridge pile after isolation piles are reduced by 68.5% and 60.7%,respectively.Thus,the isolation piles have obvious control effects on deformation.
作者
吕昌怀
刘燕
张亮亮
杜昌言
LYU Changhuai;LIU Yan;ZHANG Liangliang;DU Changyan(School of Civil Engineering and Architecture,University of Ji’nan,Ji’nan 250022,China;The Engineering Technology Research Center for Urban Underground Engineering Supporting and Risk Monitoring of Shandong Province,Ji’nan 250022,China;China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430063,China;China Railway 14th Bureau Group Corporation Limited,Ji’nan 250101,China)
出处
《铁道建筑》
北大核心
2022年第11期118-121,共4页
Railway Engineering
基金
国家自然科学基金(51979122)。
关键词
隧道
变形分析
数值模拟
铁路桥梁
加固措施
明挖法
既有桩基
隔离桩
tunnel
deformation analysis
numerical simulation
railway bridge
reinforcement measures
open-cut method
existed pile foundation
isolation piles
