摘要
2022年1月8日青海门源发生了M s6.9级地震,导致Ⅸ度区的硫磺沟大桥和大梁隧道、祁连山隧道出现严重震害,Ⅵ度区内除了克大高速公路上香卡特大桥发生桥墩挡块开裂、支座移位、横隔板开裂的震害外,其余桥梁几乎没有出现明显震害现象,其中原因值得深入研究。香卡特大桥位于冷龙岭断裂南侧约20 km,是一座16联预应力钢筋混凝土T形特大曲线梁桥。该桥包含简支段、连续段和刚构段,墩梁连接形式多样,且桥墩有墩柱式和壁式2种形式。文中通过有限元分析软件Midas/Civil建立香卡特大桥(右线)模型,利用间隙单元模拟伸缩缝主梁间、挡块与主梁的碰撞效应,通过输入实测和模拟的2组地震动,进行地震反应分析,讨论分析香卡特大桥在此次地震中的震害机理。从得到的结果可以看出:该桥的震害是因为在顺桥向上主梁过大位移导致横隔梁与顺桥向挡块的碰撞,使横隔梁混凝土开裂;在横桥向上,挡块受到主梁碰撞出现破坏的同时致使支座滑动移位,且不同的下部结构形式以及上下部间不同的连接方式使得桥梁在地震作用下表现出了不同的受力特点及震害特征。
An earthquake of M s6.9 occurred in Menyuan,Qinghai Province on January 8,2022,which caused severe earthquake damage to bridges,tunnels and roads above theⅥdegree zone.In theⅥdegree zone,no obvious earthquake damage occurred to other structures except the cracking of pier retaining block,bearing shift and diaphragm cracking of Xiangka super large bridge on the Keda expressway.The reasons are worth studying further.The Xiangka Bridge located on the southern side of the fault is 16 prestressed reinforced concrete T shaped extra-large curved beam bridge.The bridge consists of simply supported section,continuous section and rigid frame section.The pier and beam connection forms are diverse,and the pier has two forms,namely pier column and wall type.In this paper,the finite element analysis software Midas/Civil was used to establish the Xiangka Bridge(right line)model,and the gap element was used to consider the impact effect of expansion joints,retaining blocks and main beams.The seismic response analysis was carried out by intaking two groups of measured and simulated ground motion,and the earthquake damage mechanism of the Xiangka super large bridge in this earthquake was discussed and analyzed.It can be seen from the results that the reason for the earthquake damage of the bridge is that the stiffness of adjacent spans varies greatly.In the direction of the bridge,the concrete of the transverse beam cracks due to the collision caused by the excessive displacement of the main beam.In the transverse direction of the bridge,the retaining block is damaged by the collision of the main beam,and the support shifts at the same time.The different substructure forms and the different connection modes between the upper and lower parts make the bridge show different stress characteristics and earthquake damage characteristics under earthquake action.
作者
黄勇
何静
尹明超
刘炜
蔡丽雯
HUANG Yong;HE Jing;YIN Mingchao;LIU Wei;CAI Liwen(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin 150080,China;Qinghai Earthquake Agency,Xining 810001,China)
出处
《自然灾害学报》
CSCD
北大核心
2023年第1期13-21,共9页
Journal of Natural Disasters
基金
中国地震局工程力学研究所基本科研业务费专项资助项目(2021EEEVL3013)。
关键词
门源地震
香卡特大桥
震害机理
地震反应分析
Menyuan earthquake
Xiangka super large bridge
damage mechanism
seismic response analysis
