基于CPT的锤击桩贯入分析理论模型  

CPT-based Model for Penetration Simulation of Hammer Installed Piles

作　　者：严凯 庞玉麟 李卫超 杨敏[2] 金易 Yan Kai;Pang Yu-lin;Li Wei-chao;Yang Min;Jin Yi(Shanghai Road and Bridge(Group)Co.,Ltd.,Shanghai 200433;College of Civil Engineering,Tongji University,Shanghai 200092)

机构地区：[1]上海公路桥梁(集团)有限公司,上海200433 [2]同济大学土木工程学院,上海200092

出　　处：《建筑科学》2020年第S01期68-76,共9页Building Science

基　　金：国家自然科学基金(No.41972275,No.41877236)

摘　　要：针对锤击沉桩过程,本文结合原位静力触探试验(Cone Penetration Test,CPT)结果,推导了用于桩基贯入分析的理论模型,编写了Matlab计算程序,并通过现场实测案例对该模型进行了验证。在此基础上,针对建模过程中单元长度、时间增量步长、计算总时间长等参数开展了讨论。研究表明,基于CPT的分析模型可较好地模拟桩基桩贯入过程;在桩的贯入过程中,锤击能不变的条件下,桩顶所受冲击力在第一个波峰不会发生变化,后续波峰随贯入阻力增大出现提前、峰值增大;沉桩时未入土部分的最大压应力不受贯入深度的影响;在建模过程中,桩单元长度的选取建议小于桩径的0.5倍,时间增量步长应小于波在一个单元中传递所需的时间,模拟时间总长应不小于弹性波从桩头到桩底传递所需时间的6倍。To simulate the penetration of hammer installed piles,based on the in-situ Cone Penetration Test(CPT),this study presents a theoretical model and compiled the Matlab code,which is verified against the filed test results.Furtherly,sensitivity study is performed on the element length,time incremental length,total time needed in the simulation.It shows that:this paper presented CPT based model performs well in the simulation of pile penetration installed with hammer;the peak force impacted on the pile head does not change as the increase in pile penetration if the energy transferred from the hammer is constant,however,the following peak force increases and time interval between the peak forces reduces as the penetration length increasing;the stress in pile body above the mudline does not change as the pile penetrating;in the modelling of a hammer installed pile penetration,the length of pile element is suggested to be no more than half of pile diameter,time increments should not be larger than the time needed by wave pass a plie element,the total time for simulation of an impact should be larger than 6 times the time for stress wave traveling from pile head to pile toe.

关 键 词：锤击沉桩 理论模型 静力触探试验 可贯入性 

分 类 号：TU473.1[建筑科学—结构工程]