临近高速门架墩及互通匝道桥柱式墩段路基设计方案研究

Study on Design Scheme of Subgrade at Sections Adjacent to Expressway Portal Pier and Interchange Ramp Column Pier

随着经济和社会的发展,交通项目占用的土地资源越来越珍贵,为了充分利用高速公路用地,大多数地方要求高速公路按高架桥的模式建设,地方利用桥下空间配套建设地面道路,结合G92杭甬高速复线宁波段二期地面道路项目对高速桥梁下路基施工给既有高速公路桥梁的安全影响进行充分研究,特别是对于高速互通设置路侧辅墩路段,地面道路路基填筑时在辅墩两侧形成不均衡加载,对辅墩产生水平推挤,对辅墩桩基存在一定安全隐患。通过路基填筑对桥梁桩基影响的充分分析提出了三个处理方案,分别从投资、用地、承台及墩柱位移等方面进行了对比分析,并结合项目实际情况提出了推荐采用的方案,同时对施工期监测提出了具体要求。可为类似的高架结合地面道路的路基填筑施工方案提供参考。

With the development of economy and society,the land resources occupied by traffic projects are becoming more and more precious.In order to make full use of the land used by expressways,most places require expressways to be built according to the mode of viaduct,and local places use the space under the viaduct to build ground roads.Combined with the phase II ground road project in Ningbo section of G92 Hangzhou-Ningbo Expressway complex line,the impact of subgrade construction under the expressway viaduct on the safety of the existing expressway bridge,especially for the section where the roadside auxiliary pier is set for the expressway interchange.The uneven load is formed on both sides of the auxiliary pier during the subgrade filling of the ground road,which results in the horizontal pushing on the auxiliary pier,and there are certain potential safety hazards on the pile foundation of auxiliary pier.Through the full analysis of the impact of subgrade filling on bridge pile foundation,three treatment schemes are put forward,which are compared and analyzed from the aspects of investment,land use,base slab and pier column displacement.And combined with the actual situation of the project,the recommended scheme is put forward,and the specific requirements for monitoring during construction are put forward,which can provide the reference for the similar subgrade filling construction schemes of viaduct combined with ground road.