非对称缺陷对桩顶动力响应的影响及应用研究  

Study on Influence of Asymmetric Defects on Dynamic Response of Pile Top and Its Application

作　　者：王奎华[1,2] 梁一然 吴君涛 赵爽 邱欣晨[1,2] WANG Kuihua;LIANG Yiran;WU Juntao;ZHAO Shuang;QIU Xinchen(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education(Zhejiang University),Hangzhou 310058,China)

机构地区：[1]浙江大学滨海和城市岩土工程研究中心,浙江杭州310058 [2]软弱土与环境土工教育部重点实验室(浙江大学),浙江杭州310058

出　　处：《湖南大学学报（自然科学版）》2023年第7期200-210,共11页Journal of Hunan University:Natural Sciences

基　　金：浙江省自然科学基金重点项目(LXZ22E080001);国家自然科学基金资助项目(52178358)。

摘　　要：针对大直径桩基础桩身缺陷形态非对称分布的情况,采用数值模拟方法,构建三维有限元桩-土模型进行分析,厘清了对称缺陷和非对称缺陷对桩顶动力响应的不同影响规律,并通过模型试验验证了本文数值分析的合理性,最后针对桩-土模型的相关参数进行敏感性分析,探究桩周土、激振脉冲宽度、缺陷形态等因素对非对称缺陷桩桩顶动力响应的影响.结果表明:非对称缺陷使桩顶对称测点的桩顶动力响应曲线呈现双闭环现象,双闭环现象最明显的对称测点位于缺陷截面对称轴上;可采用桩顶中心激振-对称点同步接收模式检测基桩非对称缺陷,为低应变反射波法检测桩身完整性的工程应用提供指导.Aiming at the asymmetric distribution of defects in the pile shaft of large-diameter pile foundation,employing the numerical simulation method,three-dimensional finite element pile-soil models are established for analyzing the dynamic responses of the pile.The different influence laws of symmetrical defects and asymmetric defects on the dynamic responses at the pile top are studied.The rationality of the numerical models is verified by comparing the simulated results with the test ones.In addition,the sensitivity analysis is conducted to study the effects of the parameters,such as soil around the pile and the excitation width and defect shape,on the dynamic responses of asymmetric defect piles.The results show that the dynamic response at the pile top of the symmetrical measuring points presents a double closed-loop phenomenon when asymmetric defects exist.The symmetrical measuring point with the most obvious double closed-loop phenomenon is located on the symmetry axis of the defect section.The mode of central excitation on the pile top and synchronous receiving of the symmetrical points can be used to detect the asymmetric defects of the piles,which can guide the engineering application of the low-strain integrity testing.

关 键 词：桩基础 非对称缺陷桩 桩顶动力响应 数值模拟 低应变检测 

分 类 号：TU473[建筑科学—结构工程]