龙江特大桥场地强震动观测系统设计

Design of site strong motion observation system for the Longjiang bridge

主跨1196 m的龙江特大桥是我国第一座位于高烈度地震区的大跨度悬索桥,频繁的地震活动对大桥结构安全构成严重威胁。大桥建设时建立了健康监测系统,其中包含多个结构地震反应观测点,随后布设了场地强震动观测系统,这是对大桥地震响应观测的进一步补充和完善。本文详细介绍场地强震动观测系统的设计方案、系统构成、通信方式等。该系统获取的观测结果,可为龙江大桥在地震作用下结构健康诊断提供依据,为大桥结构地震响应分析提供可靠的地震动输入,有助于了解大桥结构在地震动作用下的反应特征,提高大跨桥梁的抗震设计水平。

The Longjiang bridge with a main span of 1196 m is the first suspension bridge in high seismic intensity region in China.Frequent earthquake activities pose a serious threat to the safety of bridge structures.During the construction of the bridge,a health monitoring system was constructed,which included structure health monitoring points.Then a site strong motion observation system was deployed to optimize the seismic response observation of the bridge.This article mainly introduces the design scheme,system composition,communication methods of the site strong motion observation system.The observation results obtained from this system provide a basis judgment for the structural health of the Longjiang bridge under earthquakes action,and reliable ground motion input for the seismic response analysis of bridge structures.These results also deepen our knowledge of response characteristics under earthquake action and assist in seismic design research of long span bridges.