泥石流作用下双柱桥墩动力响应研究  

Dynamic response of double column bridge pier subjected to debris flow

作　　者：李聪 邹强[1] 雷雨[1] 蒋虎 周斌 胡镇汝 LI Cong;ZOU Qiang;LEI Yu;JIANG Hu;ZHOU Bin;HU Zhenru(Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Resources,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100000,China;School of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,四川成都610041 [2]中国科学院大学,北京100000 [3]成都理工大学地球科学学院,四川成都610059

出　　处：《人民长江》2022年第12期204-214,共11页Yangtze River

基　　金：国家自然科学基金重大项目(41790432);中国科学院战略性先导科技专项(XDA23090303)。

摘　　要：研究桥墩对泥石流的灾变响应过程对防护工程建设具有重要意义。基于流固耦合理论和有限元接触理论,计算了泥石流冲击桥墩的流场动力过程,探讨了双柱桥墩的承灾破坏特征,总结了泥石流作用下双柱桥墩的响应规律。结果表明:(1)泥石流在冲击双柱桥墩过程中产生了较为显著的圆柱绕流现象,冲击方向的墩前和墩后速度趋近于0,桥墩两侧流速较初始速度显著增加。(2)桥墩冲击压力从接触位置呈三角形向外扩散,前柱对后柱产生的遮蔽效应显著减小了后柱的冲击力。(3)石块冲击处、桥墩基底和系梁连接位置在泥石流及其中石块的冲击作用下容易出现应力集中从而率先发生破坏。(4)浆体冲击导致桥墩只产生细微横向位移,石块的冲击易产生大幅度振动和较大横向位移,极易威胁桥梁上部结构。The research on disaster response process of debris flow to bridge pier is of great significance to the protection work construction.Based on the fluid-structure coupling theory and finite element contact theory,the dynamic process of flow field of debris flow impinging on bridge pier was computed,the disaster bearing and failure characteristics of double column bridge pier were discussed,giving the response law of double column bridge pier subjected to debris flow.The results showed that:(1)The flow around the cylinder was obvious in the process of debris flow impacting the double-column pier.The velocity in front and behind the pier in the impact direction tended to 0,and the velocity on both sides of the pier increased significantly compared with the initial velocity.(2)The impact pressure of the pier diffused outwards in a triangular shape from the contact position,and the shielding effect of the front column on the rear column significantly reduced the impact force on the rear column.(3)The rock impact position,the bridge pier base and the connection position of the tie beam were prone to stress concentration under the action of debris flow and took the lead in failure.(4)The impact of slurry lead to slight transverse displacement of the bridge pier,and the impact of stone was easy to produce large vibration and large transverse displacement,which was easy to threaten the bridge superstructure.

关 键 词：泥石流风险 桥墩 动力响应 流场 有限元分析 

分 类 号：U443.22[建筑科学—桥梁与隧道工程] P642.23[交通运输工程—道路与铁道工程]