高频振动下散粒体-结构界面临界状态强度特征试验研究  

Experimental study on critical state strength characteristics of granular material-structure interface under high-frequency vibration

作　　者：姜海波 付龙龙[1,2] 周顺华 郭培军[3] 叶伟涛[1,2] JIANG Hai-bo;FU Long-long;ZHOU Shun-hua;GUO Pei-jun;YE Wei-tao(Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,China;Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Tongji University,Shanghai 201804,China;Department of Civil Engineering,McMaster University,Hamilton,Canada)

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海201804 [2]同济大学上海市轨道交通结构耐久与系统安全重点实验室,上海201804 [3]麦克马斯特大学土木工程系,加拿大汉密尔顿

出　　处：《岩土力学》2023年第3期810-820,共11页Rock and Soil Mechanics

基　　金：上海市科学技术委员会资助项目(No.21142200400)。

摘　　要：高铁桥梁、路基工程中的桩基础持续承受列车运行引发的振动荷载,当前350 km/h车速下的车致振动已高达近40 Hz。随着车速的进一步提升,可能给桩基础承载性能带来不利影响。桩-土界面是桩和地基土之间力和变形传递的重要媒介,很大程度上决定着桩基础的长期服役性能。但目前对于高频振动荷载下桩-土界面相互作用行为的认识和研究均不足。基于自主研制的可实现土-结构界面高频振动耦合静力剪切的试验装置,研究了散粒体-结构界面在振动下的临界状态强度特征,探讨了振动加速度、法向应力、结构面粗糙度、颗粒形状和振动频率的影响。结果表明:振动会导致界面强度衰减,部分振动条件下的界面强度甚至低于静力条件下的0.5倍;振动下的界面强度随振动加速度、频率的增大而下降,随法向应力的增大而提高。最后,基于摩尔-库仑强度理论,建立了振动下的散粒体-结构界面强度准则。The pile foundation of bridges and subgrades in high-speed railway engineering are frequently suffered from train-induced vibration.The train-induced vibration under a speed of 350 km/h reaches approximately 40 Hz,while a higher speed may do harm to the bearing capacity of the pile foundation.The soil-structure interface plays an important role in force and deformation transformation in pile-soil interaction,largely determining ultimate strength and long-term settlement.However,understanding of the behavior of soil-structure interfaces under high-frequency vibration is still very limited.Using a self-designed interface shear apparatus,which can achieve coupled vibration and high-frequency vibration,the critical state strength of the granular material-structure interface is investigated.The influences of vibration acceleration,frequency,normal stress,particle shape and surface roughness are studied.Test results show that vibrations lower the strength of interfaces.The shear strength under certain vibration conditions is even lower than half of that under static conditions.The weakening degree of interface strength under vibration increases with vibration acceleration and frequency,while decreases with normal stress.Based on Mohr-Coulomb strength theory,the strength criterion of the granular material-structure interface under vibration is built.

关 键 词：散粒体-结构界面 高频振动 剪切强度 振动弱化 振动-静力耦合直剪 

分 类 号：TU435[建筑科学—岩土工程]