爆破振动作用下桥梁桩孔稳定性振动台试验研究  

Shaking Table Test on Borehole Stability of Bridge PileFoundation under Blasting Vibration

作　　者：王建强[1] 巴智坤 杨秋伟 赵卓 朋茜[2,3] WANG Jianqiang;BA Zhikun;YANG Qiuwei;ZHAO Zhuo;PENG Xi(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China;School of Civil and Transportation Engineering,Ningbo University of Technology,Ningbo 315211,China;Engineering Research Center of Industrial Construction in Civil Engineering of Zhejiang Province,Ningbo University of Technology,Ningbo 315211,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001 [2]宁波工程学院建筑与交通工程学院,浙江宁波315211 [3]宁波工程学院浙江省土木工程工业化建造工程技术研究中心,浙江宁波315211

出　　处：《桥梁建设》2024年第3期85-92,共8页Bridge Construction

基　　金：宁波市“科技创新2025”重大专项科技项目(2019B10076)~。

摘　　要：为了解爆破振动对邻近桥梁桩基成孔后桩孔稳定性的影响,以与山体爆破工程计划同时施工的某主跨280 m的斜拉桥为背景,设计、制作土箱和缩尺比1∶40桩孔模型开展振动台试验,研究桩孔孔壁的破坏特征、土体振动速度和动土压力的变化规律。结果表明:土体的振动速度峰值和动土压力峰值均随着爆破强度的增大而增大,在土体产生破坏后,土体的振动速度峰值和动土压力峰值均呈现出非线性增大趋势;爆破强度较小时土体的动土压力峰值曲线为U形,爆破强度较大时桩孔区域土体的动土压力峰值曲线为W形,桩孔中上部区域的动土压力峰值较大;山体爆破振动会使钢护筒底部与土体交界面以下桩孔的中上部区域出现破坏,应对山体爆破施工加强现场监测,桩孔附近的振动速度峰值不宜超过2 cm/s,以保障桩孔的稳定性。This study focuses on the impact of nearby blasting vibration on the stability of completed boreholes of the bridge pile foundation.Based on a cable-stayed bridge that has a main span of 280 m and was constructed alongside the nearby mountain blasting project,a soil box model and a 1∶40 borehole model were designed and prepared for shake table tests,to analyze the failure characteristics of the borehole walls,soil vibration velocity and the dynamic soil pressure.As per the tests,both the peak soil vibration velocity and dynamic soil pressure grew bigger as the blasting impact was gradually intensified,once the soil was damaged,the peak soil vibration velocity and dynamic soil pressure showed the sign of non-linear increase.The variation of peak soil pressure exhibited a"U"trace when the blasting intensity was small,while a"W"trace when the blasting intensity was big,which was concentrated at the central and upper parts of the boreholes.The mountain blasting vibration can result in the damage of the central and upper parts of the borehole below the interface of the bottom of steel casings and soil.The mountain blasting construction must be monitored,peak vibration velocities of the nearby boreholes should not exceed 2 cm/s,so as to ensure the borehole stability.

关 键 词：桥梁桩基 爆破振动 桩孔稳定性 破坏特征 振动速度 动土压力 振动台试验 

分 类 号：U443.1[建筑科学—桥梁与隧道工程] TD235[交通运输工程—道路与铁道工程]