【摘要】 武汉新河大桥11号桥墩施工作业平台尺寸较小,基坑周边水土压力不均匀且土质条件差,为方便基坑支护和预留桥墩施工空间,比较多种基坑支护设计方案的技术、经济和工期,综合分析对比,因地制宜采用一种外部为双排钢板桩结合桩间填土形成围堰体;中间采用高压旋喷桩加固过渡区形成施工道路;内部采用双排桩结合三道钢管对撑和角撑的桥墩深基坑多级支护体系。通过协同计算模块进行三维计算,借助Plaxis 2D有限元计算分析,得出过渡体系加固区对软土起到了很好的变形控制效果。结合桩体沉降和水平位移监测的结果,证明多级支护体系设计的优越性,减少了支撑的受力,控制了软土的变形,方便了大型机械在滨江软土狭窄地区的施工,为同类工程提供参考。更多还原

【Abstract】 The construction work platform of Wuhan Xinhe Bridge Pier 11 is small in size.The soil pressure and water pressure next to the foundation pit are unevenly distributed and the strength of the soil is low.In order to reserve a certain space for the foundation pit support and bridge pier construction,the technologies of a variety of foundation pit support design schemes are compared.According to local conditions,a double-row steel sheet pile is adopted combined with soil filling between the piles to form a cofferdam externally;the transition zone in the middle is reinforced by high-pressure jet grouting piles to form a construction road;a multi-level support system for deep foundation pits supported by double-row piles and three steel pipes is adopted inside.Through the collaborative calculation module for three-dimensional calculations and Plaxis 2 Dfinite element calculation and analysis,it is found that this transition system can strengthen the soft soil and play agood deformation control effect.Combined with the results of the pile displacement monitoring,the superiority of the multi-level support system is proved.This system can reduce the force of the internal support,reduce the deformation of the soft soil,and solve the construction in the soft soil area of the riverside with heavy equipment.The problem of insufficient space can also provide a reference case for similar projects.更多还原