激振力作用下桩侧土液化特性及拔桩过程分析  

Analysis of liquefaction characteristics of pile-side soil and pile pulling process under the action of excitation force

作　　者：杨胜文 石旷 杨吉新[2] 凌中水[3] YANG Shengwen;SHI Kuang;YANG Jixin;LING Zhongshui(China First Metallurgical Group Co.,Ltd.,Wuhan 430080,China;School of Transportation,Wuhan University of Technology,Wuhan 430063,China;School of Mechanical and Electrical Engineering,Anqing Vocational and Technical College,Anqing 246003,China)

机构地区：[1]中国一冶集团有限公司,湖北武汉430080 [2]武汉理工大学交通学院,湖北武汉430063 [3]安庆职业技术学院机电工程学院,安徽安庆246003

出　　处：《合肥工业大学学报（自然科学版）》2022年第4期512-519,共8页Journal of Hefei University of Technology：Natural Science

基　　金：中国高校产学研创新基金资助项目(2019ITA01028);安徽省高校自然科学研究资助项目(KJ2019ZD77)。

摘　　要：文章以石首建宁大桥桥下钢管桩为例,利用有限差分软件FLAC3D建立桩-土动力相互作用模型,基于Finn模型分析桩顶激振力作用下桩侧土的液化效应,并对振动拔桩过程进行分析;计算不同上拔力下钢管桩的位移,通过工程实测与数值计算对比验证FLAC3D计算振动锤拔桩过程的准确性。激振过程中桩侧土各测点的超孔隙水压比不断增大,表明桩侧土在逐渐液化,离振源较近的监测点超孔隙水压比最终接近于1并保持稳定;各测点加速度响应分析结果表明,桩侧基本被液化土覆盖,振动锤激振效果较好,可进行振动拔桩施工;桩侧摩阻力的分析验证了桩侧土的液化效应;土液化使得钢管桩基本只受上拔力和自重,因此加载时间相同的条件下,上拔力与位移大致呈线性关系。Taking the steel pipe pile under the Jianning Bridge in Shishou as an example,the finite difference software FLAC3D was used to establish the pile-soil dynamic interaction model.Based on the Finn model,the liquefaction effect of the pile-side soil under the excitation force of the pile top and the vibrating pile pulling process were analyzed.The displacement of the steel pipe pile under different uplift forces was calculated,and the accuracy of the FLAC3D calculation of the pile pulling process with vibratory hammer was verified by comparing the engineering measurement and numerical calculation.During the excitation process,the excess pore water pressure ratio of each measuring point of the pile-side soil continued to increase,indicating that the pile-side soil was gradually liquefied,and the excess pore water pressure ratio of the measuring points closer to the vibration source was finally close to 1 and remained stable.The analysis results of the acceleration response of the measuring points show that the pile side is basically covered by the liquefied soil,the vibration effect of the vibratory hammer is good,and the vibrating pile pulling can be carried out.The analysis of the pile-side friction resistance verifies the liquefaction effect of the pile-side soil.Soil liquefaction makes the steel pipe pile basically only subjected to uplift force and deadweight.Therefore,under the same loading time,the relationship between uplift force and displacement is approximately linear.

关 键 词：桩-土动力相互作用 钢管桩 振动锤 土液化分析 拔桩 

分 类 号：TU473.1[建筑科学—结构工程]