摘要
研究目的:随着西部大开发战略的实施,铁路、桥梁等交通基础设施飞速发展。由于西南地区多山和红层广泛分布,受地形地质条件影响,大量山区铁路桥梁基础不可避免地位于滑坡等不良地质体上,同时线路穿越高烈度地震区,因此桥梁-滑坡体系进行抗震分析是非常有必要的。本文首先对桥梁-滑坡体系进行初步的分类和解释,然后通过一系列振动台模型试验,研究桥梁-滑坡平行体系在EL地震波作用下边坡与桥梁的动力响应和失稳特征,再分别对滑坡体的变化特征和加速度响应、桥梁桩基的加速度和应变响应进行分析,结合山侧墩柱附近测点的频谱特性对桥梁-滑坡相互作用进行分析。研究结论:(1)按照滑坡主滑方向和桥梁轴线的位置关系将桥梁-滑坡体系分为两大类型:桥梁横跨滑坡体系、桥梁纵跨滑坡体系,又根据桥梁位置和桥梁跨越滑坡体类型对桥梁-滑坡体系进行了细分;(2)桥梁墩柱上测点的加速度响应随着高程的增加而增强,且河侧墩柱加速度响应强于山侧墩柱;(3)随着地震激励强度的增加,地震波的卓越频率从低频向高频增加,并逐渐向坡体的自振频率靠近,进而使得坡体发生共振破坏,整体呈现协同渐进破坏,但是桥梁-滑坡的相互作用会削弱这一趋势,在桥跨之间土体表现最为明显;(4)本研究成果反映了桥梁横跨滑坡体的相互作用影响机制,可为桥梁横跨滑坡体的抗震设计提供相关试验数据和一定的理论支撑。
Research purposes:With the implementation of western development strategy,railway,bridge and other infrastructure develop rapidly.Due to the mountainous area and wide distribution of red beds in Southwest China,affected by the terrain and geological conditions,a large number of railway bridge foundations in mountainous areas are inevitably located in adverse geological bodies such as landslides,and the lines pass through high intensity earthquake areas.Therefore,it is necessary to carry out seismic analysis of bridge-landslide system.In this paper,the bridge-landslide system is classified and explained.Then,through a series of shaking table model tests,the dynamic response and instability characteristics of the bridge-landslide parallel system under EL seismic wave are studied.The change characteristics and acceleration response of the landslide,as well as the acceleration and strain response of the bridge pile foundation are analyzed,and the bridge-landslide interaction is analyzed through the spectrum characteristics of the measuring points near the pier column.Research conclusions:(1)According to the positional relationship between the main sliding direction of the landslide and the bridge axis,the bridge-landslide system is divided into two types:the bridge-landslide lateral spanning system and the bridge-landslide longitudinal spanning system.The bridge-landslide system is subdivided according to the location of the bridge and the type of landslide mass.(2)The acceleration response of measuring points on bridge piers increases with the increase of elevation,and the acceleration response of river side piers is stronger than that of mountain side piers.(3)With the increase of seismic excitation intensity,the predominant frequency of seismic wave increases from low frequency to high frequency,and gradually approaches to the natural frequency of the slope,thus causing resonance failure of the slope,showing a coordinated progressive failure as a whole.However,the interaction between bridges and landslides will weaken this trend,with the soil between bridge spans being the most pronounced.(4)These research conclusions reflect the interaction mechanism of the bridge across the landslide mass,and can provide relevant experimental data and theoretical support for the seismic design of the bridge across the landslide mass system.
作者
吴红刚
梁彧
赖天文
WU Honggang;LIANG Yu;LAI Tianwen(Northwest Research Institute Co.Ltd of CREC,Lanzhou,Gansu 730070,China;China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan,Hubei 430000,China;Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)
出处
《铁道工程学报》
EI
CSCD
北大核心
2023年第9期54-61,共8页
Journal of Railway Engineering Society
基金
国家重点研发计划(2018YFC1504903)
青海省重点研发与转化计划(科技成果转化专项2022-SF-158)。
关键词
桥梁-滑坡
振动台试验
动力响应
波包
频谱分析
bridge-landslide
shaking table test
dynamic response
wavelet packet
spectrum analysis
作者简介
吴红刚,1983年出生,男,正高级工程师,硕士生导师。
