新建地铁车站及区间对紧邻既有线影响性分析

INFLUENCE OF EXISTING METRO LINES CAUSED BY CONSTRUCTION OF NEW METRO STATION AND SHIELD TUNNEL

新建明挖地铁车站及区间施工时对邻近的既有车站和区间隧道产生不利影响,建立了临近既有线的新建车站及区间隧道三维数值计算模型,对不同施工步序下既有线位移、应力及承载力变化特征进行了详细分析。研究结果表明,既有线位移以竖向位移为主;既有线位移主要发生在基坑开挖阶段,回筑施工影响小;B出入口及2号风道施工时,既有线位移存在明显波动和正负转换,是位移监测的关键阶段;综合计算结果,既有线相关位移未超过控制值,可认为新建地铁车站和区间设计参数保护要求。可为类似条件下既有线保护提供借鉴与参考。

The existing metro tunnel and shield tunnel are affected by new metro station and shield tunnel construct-ed with exaction method.A 3D numerical model with metro station and interval tunnel was established.The displace-ment,stress,and bearing capacity under different construction steps are analyzed.The displacement of existing line is mainly vertical displacement.The displacement of existing line mainly happens in the excavation step,and the ef-fect of backfill construction is not apparent.During the construction of the entrance of exit B and the air duct of 2rd,the displacement of the existing line has obv ious fluctuation and positive-negative conversion.Thus,it is the key stage of displacement monitoring.Finally,the maximum displacements of the existing line are smaller than the rele-vant value.Therefore,the design scheme of new metro station and shield tunnel is feasible.The conclusion can be re-ferred under similar conditions.