基于沉降区域轨道交通桥梁徐变监测探讨

Study on Creep Monitoring of Rail Transit Bridges Based on Subsidence Area

近年来在轨道交通建设中普遍采用预应力桥梁,桥墩沉降对桥梁变形造成的影响很小,而桥梁徐变引起的质量事故比较突出,为此桥梁徐变观测也越来越成为桥梁变形监测的重点。通过穿越沉降漏斗区域桥梁徐变变形实例,分析在漏斗区域已知基准点选埋及桥上高精度基点引测方法,应用精密水准观测徐变监测点的沉降量。对桥梁徐变监测,得到徐变监测变形量,通过数据分析,来指导桥梁施工进度。同时,监测数据可进一步验证设计预拱值是否合理,为后续同类桥梁建设积累经验。此外,监测徐变高程系统宜与轨道交通一致,实现数据共享。通过监测验证了监测频率、监测方法、监测点布设等是合理可行的。

In recent years,prestressed bridges have been widely used in rail transit construction.The settlement of Bridge Piers has little effect on the deformation of bridges,while the quality accidents caused by bridge creep are more obvious,therefore,bridge creep observation is becoming more and more important in bridge deformation monitoring.Through the example of bridge creep deformation in the subsidence funnel area,this paper analyzes the method of selecting and burying the known datum points in the funnel area and the method of high-precision datum point leading survey on the bridge,and applies the precise leveling to observe the settlement of the creep monitoring points.Through the bridge creep monitoring,get creep monitoring deformation,through data analysis to guide the progress of bridge construction.At the same time,the monitoring data can further verify whether the design of pre-arch value is reasonable and accumulate experience for the follow-up construction of similar bridges.At the same time,the monitoring system of creep elevation should be consistent with rail transit to realize data sharing.The monitoring results show that the monitoring frequency,monitoring method and monitoring point layout are reasonable and feasible.