变阻抗桩非自由端竖向瞬态激振动力响应分析方法及应用  

Dynamic response analysis method for variable impedance pile under vertical transient non-free end excitation and its application

作　　者：吕述晖[1,2,3] 陈章宇 桑登峰 LYU Shu-hui;CHEN Zhang-yu;SANG Deng-feng(CCCC Fourth Harbor Engineering Institute Co.,Ltd.,Guangzhou 510230,China;Key Laboratory of Environment and Safety Technology of Transportation Infrastructure Engineering,CCCC,Guangzhou 510230,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China)

机构地区：[1]中交四航工程研究院有限公司,广东广州510230 [2]中交交通基础工程环保与安全重点实验室,广东广州510230 [3]南方海洋科学与工程广东省实验室(珠海),广东珠海519082

出　　处：《水运工程》2022年第4期161-165,共5页Port & Waterway Engineering

基　　金：国家重点研发计划项目(2017YFC0805303);南方海洋科学与工程广东省实验室(珠海)河口海岸与岛礁工程创新团队建设项目(311020009)。

摘　　要：针对变阻抗桩非自由端竖向瞬态激振时反射波曲线复杂的问题,基于一维黏弹性杆件纵向振动理论和土体平面应变模型,建立简化的桩-土竖向振动数学模型。采用升余弦函数模拟瞬态激振力,通过矩阵运算和积分变换求解得到桩身任意位置动力响应的半解析解,并结合海上带长钢护筒灌注桩的低应变实测数据进行对比分析。结果表明,该方法能够反映混凝土顶面以上钢护筒端部反射信号特征,进一步结合设计、施工参数对类似工况进行模拟,有助于分析变阻抗桩非自由端激振形成的复杂反射波曲线及识别桩身缺陷。In view of the problem that the reflected wave curve is complicated when a variable impedance pile is under vertical transient non-free end excitation,we build a simplified mathematical pile-soil vertical vibration model on the basis of the longitudinal vibration theory of one-dimensional viscoelastic rods and the soil plane strain model.We adopt the raised-cosine function to simulate the transient excitation force,obtain a semi-analytical solution to the dynamic response at an arbitrary position on the pile stem through matrix operation and integral transform,and compare with the measured low-strain data about offshore bored piles with long steel casings.The results show that the proposed method demonstrates the characteristics of the reflected signal at the end of the steel casing above the concrete top.Furthermore,combining the above method with the simulation of similar working conditions under design and construction parameters is conducive to analyzing complicated reflected wave curves produced by non-free end excitation applied to variable impedance piles and identifying the pile stem defects.

关 键 词：变阻抗灌注桩 非自由端激振 反射波曲线 积分变换 半解析解 

分 类 号：TU473[建筑科学—结构工程] U655.55[建筑科学—土工工程]