摘要
以双线盾构隧道近距离平行下穿浅基础石拱桥及桩基础板桥为研究对象,建立三维有限元数值模型,并对现场监测数据进行分析,总结出盾构隧道施工对桥梁产生的影响及风险应对措施.研究表明在未考虑加固措施条件下,盾构通过后旧拱桥的最大差异沉降计算值为4.8 mm、监测值为4.5 mm;板桥的最大差异沉降计算值为7.3 mm、监测值为7.7 mm,均能满足桥梁正常使用要求.从现场监测数据看,为了进一步减小桥梁墩台的差异沉降,可以在施工过程中,采取降低风险的被动补偿的措施,如交通管制、对桥台围堰成岛、预埋注浆管等.隧道下穿拱桥桥台结构时会产生差异沉降,该沉降会引发拱桥拱圈结构受力改变,从而引发拱桥整体破坏;而板桥受差异沉降影响相对较小,故可重点针对拱桥采取保护措施.
In the example of double-line shield tunnel underpass shallow foundation stone arch bridge and pile foundation slab bridge at close distance with parallel,the three—dimensional finite element numerical model is established,and the field momtoring data are analyzed,and the influence of shield tunnel construction on the bridge and the risk countermeasures are summarized.The results show that the maximum differential settlement of the old arch bridge after shield tunneling is 4.8 mm,the monitoring value is 4.5 mm,the maximum differential settlement of the new bridge is 7.3 mm and the monitoring value is 7.7 am without considering the reinforcement measures,which can meet the requirements of the normal use of the bridge.From the field monitoring data,in order to further reduce differential settlement of bridge piers and abutments,passive compensation measures can be taken to reduce risk during construction,such as traffic control,island formation of abutment cofferdam,pre-embedded grouting pipe.The differential settlement will occur when the tunnel passes through the abutment structure of the arch bridge.The settlement will cause the stress change of the arch ring structure,which will cause the overall damage of the arch bridge,while the slab bridge is relatively less affected by the differential settlement.Therefore,protection measures Can be taken for the arch bridge.
作者
苏鹏
Su Peng(China Railway Fifth Survey and Design Institute Group Co.Ltd.,Beijing 102600,China)
出处
《铁道建筑技术》
2019年第S02期168-171,210,共5页
Railway Construction Technology
基金
中铁第五勘察设计院集团有限公司科研项目(Y2011012-1).
关键词
平行下穿
拱桥
数值模拟
监测
保护措施
passing underneath with parallel
arch bridge
numerical simulation
monitoring
protection measure
