临近高架桥初支拱盖法车站施工影响分析

INFLUENCE ANALYSIS OF METRO STATION ADOPTING PRIMARY ARCH COVER CONSTRUCTION METHOD ADJACENT TO VIADUCT

初支拱盖法地铁车站及区间施工时临近城市高架桥产生不利影响,在车站设计方案和高架桥保护措施的基础上,建立了临近桥梁的车站及区间隧道三维有限元模型,详细分析了不同施工步序下桥桩水平位移、竖向位移及差异沉降变化特征。研究表明桥桩位移以竖向和向地铁方向的横向水平位移为主;桥桩位移变化特性与空间位置关系有关;车站拱部CD开挖引起的桥桩竖向位移约占总竖向位移的2/3,是桥梁监测的关键阶段;综合计算结果,高架桥相关位移未超过控制值,可认为车站设计参数和桥梁保护措施符合市政桥梁保护要求。为类似条件下初支拱盖法地铁车站施工中临近桥梁保护提供借鉴与参考。

The viaduct is affected by construction metro of station adopting primary arch cover construction method.A 3D numerical model was established based on the station design scheme and the protective measures of Xinguan viaduct,in which the changing characteristics of horizontal displacement,vertical displacement,and the settlement of bridge piles under different construction steps are analyzed in detail.Some conclusions have been drawn.Firstly,the displacement of bridge pile is mainly vertical and transverse horizontal displacement.Secondly,the displacement characteristics of the bridge piles is related to the spatial position.Thirdly,the vertical displacement caused by CD method part is about 2/3 of the total vertical displacement.Thus,the construction of CD method part is the key stage of bridge protection.Finally,the relevant displacements of Xinguan viaduct are smaller than the allowable value.Therefore,the design scheme and the protection measures is feasible.The conclusion can be referred in bridge protection under similar conditions.