寒区冰激桥墩动力模型试验  

Experimental Study of a Model of the Ice-induced Dynamics of Bridge Piers in Cold Regions

作　　者：李忠龙[1] 葛思佳 刘鸿娇 李顺龙 LI Zhong-long;GE Si-jia;LIU Hong-jiao;LI Shun-long(School of Transportation Science and Engineering,Harbin Institute of Technology,Harbin 150090,Heilongjiang,China)

机构地区：[1]哈尔滨工业大学交通科学与工程学院,黑龙江哈尔滨150090

出　　处：《中国公路学报》2024年第9期96-106,共11页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51778194,52278299)。

摘　　要：冰激振动是影响寒冷地区桥梁行车舒适性和安全性的重要因素。以松花江上流冰期典型简支梁桥为研究对象,采用相似理论,建立桥梁的缩尺模型,通过模型试验探究冰排撞击位置和撞击速度对动冰荷载和桥墩结构响应的影响,解译冰激力作用时程特征,揭示冰激振动耦合作用规律。试验结果表明:撞击后的冰排先发生挤压破碎,后发生纵向劈裂,冰排破碎过程中同时存在碎冰的挤出和剥落现象;破冰棱体结构有很好的破冰效果,试验中冰排在7 cm·s^(-1)撞击速度下的冰力值大约是52.63 cm·s^(-1)撞击速度下冰力值的2倍;撞击破冰棱体时的结构响应明显小于撞击圆墩时,在冰排劈裂瞬间横向加速度响应出现并达到峰值,应变和位移响应幅值随冰排速度变化不明显;在冰力加载阶段应变和位移曲线与冰力作用过程吻合较好,可以利用应变和位移响应反演冰力时程,解决了力传感器难以布设的难题。寒区冰激桥墩动力模型试验研究为寒冷地区桥梁的安全评估、结构设计和异常预警提供了数据基础。Ice-induced vibrations significantly affect the comfort and safety of bridges in cold regions.This study considers a typical simply supported girder bridge in the upper Songhua River,exposed to ice.Using a scaled bridge model established using similarity theory,we investigate the impact of an ice row's impact location and impact velocity on dynamic ice loading and the resulting response of the bridge pier structure.We decipher the time-course characteristics of the ice-induced force and determine the law of ice-induced vibration coupling.The test results show that extrusion crushing occurs first after the ice row impacts,followed by longitudinal cleavage.The ice-row crushing process occurs simultaneously with the extrusion of crushed ice and spalling.The ice-breaking prism structure is very efficient:the ice force value of the ice platoon in the test for an impact speed of 7 cm·s^(-1)is approximately twice the value for 52.63 cm·s^(-1).The structural response to impact on the ice-breaking prism is significantly smaller than that to impact on the round pier.The transverse acceleration response peaks at the moment when the ice row splits,and the strain and displacement response amplitudes do not change significantly with the ice-row velocity.The strain and displacement curves at the ice loading stage agree well with the ice force action process.The strain and displacement responses can therefore be utilized to invert the ice force time course,thus providing a solution to the difficult challenge of deploying force sensors.Hence,this modeling study of ice-induced vibrations in bridge piers in cold regions provides a data basis for the safety assessment,structural design,and abnormal warning.

关 键 词：桥梁工程 冰激振动 模型试验 寒区桥梁 冰力荷载 结构响应 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]