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不中断交通下装配式梁桥的挠度监测与性能评估

2020-05-19宋粉丽于品德马赟李华

河南科技 2020年8期

宋粉丽 于品德 马赟 李华

摘 要:桥梁结构挠度是反映结构整体受力性能的关键指标之一,对桥梁结构性能评估具有重要意义。本文以河南省某装配式箱梁桥为例,在不中断交通的情况下,对关键截面的动挠度进行监测,通过监测数据统计了动挠度横向分布并计算了冲击效应,同时与理论状态下挠度数据及冲击效应进行了对比,探讨了不中断交通下桥梁性能评估的方法。

关键词:不中断交通;梁桥;动挠度;监测;性能评估

中图分类号:U446.2文献标识码:A文章编号:1003-5168(2020)08-0106-04

Deflection Monitoring and Performance Evaluation of Assembled Beam Bridges without Interruption of Traffic

SONG Fenli1,2 YU Pinde1,2 MA Yun1,2 LI Hua1,2

(1. Henan Transporation Research Institute Co.,Ltd.,Zhengzhou Henan 450015;2. Highway Bridge Safety Inspection and Reinforcement Technology Transportation Industry Research and Development Center,Zhengzhou Henan 450015)

Abstract: The deflection of bridge structure is one of the key indexes reflecting the overall mechanical performance of the structure, which is of great significance to the performance evaluation of bridge structure. In this paper, taking a fabricated box girder bridge in Henan Province as an example, the dynamic deflection of key sections was monitored without interruption of traffic, the transverse distribution of dynamic deflection was calculated and the impact effect was calculated through the monitoring data, and compared with the deflection data and impact effect under the theoretical state to evaluate the performance of the bridge.

Keywords: uninterrupted traffic;beam bridge;dynamic deflection;monitoring;performance evaluation

桥梁结构挠度是在受力或非均匀温度变化时,梁轴线在垂直于轴线方向的线位移或板壳中面在垂直于中面方向的线位移。影响结构挠度的因素主要分为两类:一是瞬态变化指标,如车辆荷载效应;二是缓慢变化指标,如混凝土的徐变、预应力损伤、构件缺损、环境温度等。桥梁结构的挠度综合反映桥梁结构的整体受力性能,因此挠度是桥梁评估的关键指标之一。桥梁挠度的监测方法很多,可根据监测评估的需要及現场实施条件来确定[1-3]。本文采用非接触式动态挠度监测系统,在不中断交通的情况下,对某重载交通桥梁进行了动挠度监测[4-6],并将监测数据与理论数据进行对比,判别了监测数据的可靠性,利用所测数据对装配式桥梁冲击效应进行评估。

1 挠度监测考虑因素

受监测目的、监测精度要求、仪器设备监测方式和数据采集方式等不同的影响[7],桥梁挠度监测的实现方法较多,实际挠度监测需要考虑的因素如表1所示。……

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