复合地层盾构机连续下穿高架桥梁施工技术研究

STUDY ON CONSTRUCTION TECHNOLOGY OF CONTINUOUS TRAVERSING OF SHIELD TUNNELING MACHINE UNDER VIADUCT IN COMPLEX STRATUM

以南京地铁某区间连续侧穿、下穿高架桥和高架桥路基段为基础,建立高架桥及周边土体的三维数值模型,在不同的施工参数下对盾构机下穿风险源期间情况进行模拟,根据模拟结果对施工进行指导,并将施工过程中的监测情况和数值模拟情况进行对比、分析,验证数值模拟结果的可靠性。施工过程中盾构机优化掘进参数,隧道内部进行二次注浆和深孔注浆可以有效减小桥梁及路面的变形量,并降低桥桩之间的差异沉降值;通过合理设置盾构施工参数可将桥梁及路面的变形控制在允许范围之内,减小桥梁及路面的变形量,为类似工程提供参考依据和经验。

Based on the continuous lateral traversing through a viaduct,traversing under the viaduct and subgrade of the viaduct in one section of Nanjing Metro,a three-dimensional numerical model of the viaduct and surrounding soil was built.With different construction parameters,risks in under-traversing of the shield tunneling machine were simulated,and simulation results were used for guidance in construction.In addition,the reliability of numerical simulation results was verified through comparison and analysis with monitoring data in the construction process.The tunneling parameters of the shield tunneling machine were optimized in the construction process.Secondary grouting and deep hole grouting can be carried out inside the tunnel to effectively reduce the deformation of the viaduct and pavement and the settlement difference of piers.The construction parameters of the shield tunneling machine can be set reasonably to control the viaduct and pavement deformation within an allowable range,reduce the deformation of the viaduct and pavement and provide the reference and experience for similar projects.