正交通过滑坡体的桥梁墩基地震动力响应振动台试验研究  

Shaking table test study on seismic dynamic response of bridge pier foundation passing through landslide body orthogonally

作　　者：吴红刚 任建凯 张永谋[2] 雷浩 WU Honggang;REN Jiankai;ZHANG Yongmou;LEI Hao(Northwest Research Institute Co.,Ltd.,of CREC,Lanzhou,Gansu 730070,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)

机构地区：[1]中铁西北科学研究院有限公司,甘肃兰州730070 [2]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《岩石力学与工程学报》2021年第S02期3443-3454,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划资助项目(2018YFC1504901);甘肃省自然科学基金项目(145RJZA068);甘肃省优秀研究生创新之星项目(2021CXZX-632)。

摘　　要：桥梁建设中时常会遇到地震、滑坡等地质灾害问题,鉴于此,本文进行1:100相似比振动台试验模拟桥梁结构正交通过滑坡地区桥墩结构的动力响应特征。在满足相似规律前提下,输入不同加速度幅值的地震波作为基底激励,监测桥墩处加速度、应变和土压力3项动力响应参数。通过对桥墩处的加速度、应变和土压力的动力响应分析,得到如下结论:(1)桥墩处测点应变峰值表现为坡面途径处测点应变峰值最小,并且同一桥墩不同位置在地震波作用下,受到地震波影响大小各不相同,表现为上端振动响应更加剧烈。(2)桥墩处加速度和土压力峰值的大小与加载地震波强度呈正相关。(3)前后桥墩处加速度和应变峰值相关系数都大于0.8,相关性极强,证明在模型试验中桥墩间距的选择符合桥梁设计要求,可以为桥梁工程建设提供参考。(4)桥墩处应变换算得到桥墩在地震波作用下,会有一定的蠕动变形,表现为桥墩顶端变形最大,底端变形最小,在实际工程中,应结合这一特点选择抗震材料的使用。(5)滑带材料滤波作用相比滑体和基岩材料较强,表现为位于滑带中的测点振动响应较弱。Geological hazards such as earthquakes and landslides are often encountered in bridge construction.Therefore,a 1:100 similar ratio shaking table test is carried out to simulate the dynamic response characteristics of pier structure in the area where the bridge structure is passing through the landslide.Under the premise of satisfying the similar law,the seismic waves with different acceleration amplitudes are input as the basement excitation.Additionally,the three dynamic response parameters of acceleration,strain and earth pressure at the bridge piers are monitored.By analyzing the dynamic response of acceleration,strain and earth pressure at the bridge pier,the following conclusions are obtained:(1)The peak strain at the measuring point at the pier shows that the peak strain at the measuring point on the slope path is the smallest.Furthermore,different locations of the same pier are affected by seismic waves,which shows that the vibration response of the upper end is more intense,showing that the vibration response of the upper end is more intense.(2)The magnitudes of acceleration and peak earth pressure at the bridge piers are positively correlated with the intensity of the loaded seismic waves.(3)The correlation coefficients of acceleration and strain peaks at both the front and rear piers are greater than 0.8,with very strong correlation.This indicates that the selection of pier spacing in the model test meets the bridge design requirements and can provide a reference for bridge engineering construction.(4)According to the strainconversion at the pier,the pier will have a certain creep deformation under the action of seismic wave.The top deformation of the pier is the largest and the bottom deformation is the smallest.In practical engineering,the use of seismic materials should be selected in combination with this feature.(5)The filtering effect of the sliding zone material is stronger than that of the sliding body and bedrock material,which is reflected by the weaker vibration response of the measurement po

关 键 词：边坡工程 振动台试验 滑坡 地震 桥墩结构 相关性 动力响应 

分 类 号：P64[天文地球—地质矿产勘探]