上海轨道交通市域线下穿桥梁桩基托换施工技术与监测

Underpinning Construction Technology and Monitoring of Underpass Bridge Pile Foundation of Shanghai Rail Transit City Line

依托上海轨道交通市域线机场联络线工程JCXSG-13标南回转匝道托换工程,为确保受力转换过程中桥梁结构安全,结合对既有桥梁结构形式、现场周边环境以及监测数据的分析,详细对桥梁桩基托换施工过程中施工技术、监测内容、监测数据、测点布置进行了研究,对监测结果进行对比分析。施工监测结果表明,所采用桩基托换设计、施工方案可行,桩基托换过程中未发现肉眼可观测的裂缝发生,混凝土梁竖向变形、主纵梁挠度以及钢立柱水平竖向位移基本设在控制值范围内,顶升过程中结构受力稳定、沉降在可控设计范围内,最后给出相关桩基托换设计和施工建议,可为类似工程提供借鉴。

Relying on the South Ramp Underpinning Project of JCXSG-13 Section of Airport Connection Line Project of Shanghai Rail Transit City Line,in order to ensure the safety of bridge structure in the process of stress conversion,combined with the analysis of existing bridge structure,site surrounding environment and monitoring data,the construction technology,monitoring content,monitoring data and measuring point layout in the process of bridge pile foundation underpinning construction are studied in detail,and the monitoring results are compared and analyzed.The results of construction monitoring show that the design and construction scheme of pile foundation underpinning are feasible,no visible cracks have been found in the process of pile foundation underpinning,the vertical deformation of concrete beams,the deflection of main longitudinal beams as well as the horizontal and vertical displacement of steel columns are basically within the control value range,and the structure is stable during the jacking process.Finally,several suggestions on the design and construction of pile foundation underpinning are given,which can provide reference for similar projects.