整体桥柔性台身-RC桩-土体系振动台试验  

Shaking Table Test on Flexible Abutment-reinforced Concrete Pile-soil System in an Integral Abutment Bridge

作　　者：黄福云[1,2] 李岚 何凌峰[1,2] 汤程 罗小烨 HUANG Fu-yun;LI Lan;HE Ling-feng;TANG Cheng;LUO Xiao-ye(College of Civil Engineering,Fuzhou University,Fuzhou 350108,Fujian,China;Key Lab of Fujian Province on Prevention Disaster of Civil Engineering,Fuzhou University,Fuzhou 350108,Fujian,China;School of Resource Engineering,Longyan University,Longyan 364012,Fujian,China)

机构地区：[1]福州大学土木工程学院,福建福州350108 [2]福州大学福建省土木工程多灾害防治重点实验室,福建福州350108 [3]龙岩学院资源工程学院,福建龙岩364012

出　　处：《中国公路学报》2025年第2期175-184,共10页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51578161);福建省高校产学合作项目(2024Y4002);福建省交通科技运输示范项目(SF20230202)。

摘　　要：整体桥常通过台底柔性混凝土桩基(RC桩)来适应上部结构的水平变形,但RC桩的抗变形能力较低,地震作用下易开裂且不易维修。因此,通过柔性台身来适应结构的水平变形已成为整体桥新的发展方向,并已应用于实际工程中。为研究整体桥柔性台身-RC桩-土动力相互作用机制、破坏模式以及地震响应特点,以深圳马峦山整体桥为工程背景,进行了整体桥柔性台身-RC桩-土体系振动台试验。试验研究表明:Ⅵ度设防以下地震作用时,柔性台身-RC桩结构未发生开裂,仅台后土体出现少量沉降变形;Ⅷ度设防地震作用时,台身与主梁连接处以及桩基埋深-1.69 m处出现了细微裂缝,但试验结束后这些微裂缝已基本闭合。地震作用下,受台后土的侧向运动的影响,整体桥柔性台身-RC桩-土体系的一阶振型为台身-桩基共同向外凸,这揭示了实际工程中大量薄壁式桥台出现“鼓肚子”破坏的原因。试验还表明,柔性台身-桩基-土体系的最大加速度和最大位移响应均在台底处,而非台顶处或墩顶处。当台底达到峰值位移时,柔性台身-桩基-土体系的变形以一阶振型为主,并少量叠加二阶振型;当台顶达到峰值位移时,则以三阶振型为主;在台顶、底达到峰值位移时,台身均出现了较大的剪切变形,其剪切位移角界于弹性位移角和塑性位移角之间。Integral abutment bridges commonly employ flexible reinforced concrete(RC)piles to mitigate structural lateral deformations.However,RC piles have a limited capacity for horizontal deformation and are susceptible to cracking and are difficult to retrofitting under seismic effects.Therefore,the use of flexible abutments to accommodate structural lateral deformations has emerged as a promising development direction for integral abutment bridges.To investigate the dynamic interaction mechanisms,failure patterns,and seismic response characteristics of an integral bridge with a flexible abutment,a shaking table test was conducted on a flexible abutment-RC pile-soil system using the Maluanshan Integral Abutment Bridge in Shenzhen as anexample. The experimental results reveal that under minor seismic actions, the integral abutmentbridge with a flexible abutment-RC pile structure does not exhibit cracking and only experiencessoil settlement. As the ground motion intensifies, minor cracks appear at the boundary betweenthe abutment top and girder, as well as at a depth of -1. 69 m in the pile foundation. However,these micro-cracks were nearly automatic closed after the seismic motion ceases. During seismicevents, owing to the lateral movement of the soil behind the abutment, the first-order vibrationmode of the flexible abutment-RC pile-soil system involves the outward protrusion of theabutment and pile foundation together. This behavior explains the "bulging" failure observed inseveral thin-walled abutments in the practical engineering. The maximum acceleration anddisplacement responses occur at the bottom of the abutment, rather than at the top of theabutment or pier. When the abutment bottom experiences peak displacement, the deformation ofthe flexible abutment-pile-soil system is dominated by the first-order vibration mode, withcharacteristics of the second-order mode. By contrast, when the abutment top experiences peakdisplacement, the third-order vibration mode is dominant. At both aforementioned instances ofpeak disp

关 键 词：桥梁工程 整体桥 振动台试验 柔性台身 结构-土相互作用 动力特性 

分 类 号：U443.2[建筑科学—桥梁与隧道工程]