桥梁施工对既有区间隧道结构的影响分析研究

Analysis&Research on Influence of Bridge Construction on Existing Interval Tunnel Structure

随着城市地下结构空间开发利用的不断发展,新建桥梁与既有区间隧道结构之间的交叉、并行现象日益增多。因此,在桥梁施工时,不可避免地会对邻近区间隧道结构产生一定的影响。文章以广东省广州市黄埔区某中桥为研究背景,针对隧道上方大规模土方开挖和桥梁桩基施工2个不利因素,通过Midas GTS实体有限元软件进行3D建模分析,研究土方开挖的卸载效应和邻近桩基施工对隧道的影响。研究结果表明,新建桥桩施工和河涌拓宽对区间隧道结构内力变形的影响,均满足规范控制标准要求;采用钢护筒跟进的施工措施能够减小桩基施工对区间隧道结构的影响,但其主要作用侧重于控制局部扰动、预防塌孔等不利影响。

With the continuous development and utilization of urban underground structure space,the phenomenon of intersection and parallelism between newly built bridges and existing interval tunnel structures is increasing day by day.Therefore,during bridge construction,it is inevitable to have a certain impact on the adjacent tunnel structures.It takes a certain medium bridge in Huangpu District,Guangzhou,Guangdong as the research background.In response to two unfavorable factors of largescale earthwork excavation above the tunnel and bridge pile foundation construction,3D modeling analysis is carried out using Midas GTS solid finite element software to study the unloading effect of earthwork excavation and the impact of adjacent pile foundation construction on the tunnel.The research results indicate that the construction of new bridge piles and the widening of river channels have an impact on the internal force and deformation of interval tunnel structures,both of which meet the requirements of regulatory control standards.The use of steel casing follow-up construction measures can reduce the impact of pile foundation construction on the structure of interval tunnels,but its main function focuses on controlling local disturbances and preventing adverse effects such as collapse of holes.