基于摇摆隔震的桩基础拟静力试验研究

发布时间：2018-07-22 16:00

【摘要】：桩基础摇摆隔震是近年来提出的一种新的桥墩抗震设计方法。本文通过拟静力模型试验和数值分析方法研究这种装置的隔震机理,重点研究桩基础在竖向力和水平力共同作用下桩身应力的分布与变化规律,找出桩身的破坏形式和特点,为此种结构的实际应用奠定基础。主要研究工作如下:(1)通过查阅国内外文献资料,从理论研究、试验方法及实际应用等方面总结基底隔震桥墩和桩土相互作用问题的研究现状。(2)以某客货共线铁路简支梁桥中的重力式桥墩为研究对象,制作3种缩尺比例为1:10的桩基础隔震桥墩模型。模型一为自由摇摆隔震桥墩;模型二为在墩底承台两侧设置限位抗拔钢筋的隔震桥墩;模型三为在墩身内设置预应力防倾覆钢筋的隔震桥墩。并对试验方案、模型制作、加载制度和测试内容等进行介绍。(3)通过拟静力试验,得到3种模型桥墩桩身内纵向主筋的应变值,分析每根桩在竖向及水平往复荷载作用下的桩内主筋应变的分布与变化规律;通过比较3种试验模型的荷载-位移滞回曲线,进一步分析摇摆隔震桥墩桩基础的受力特点及破坏机理。(4)应用规范中的M法对桩基的内力进行求解,分析基于摇摆隔震的桩基础的受力特性,并与试验结果进行对比。(5)应用有限元软件建立群桩基础的分析模型。采用土弹簧模拟土体的弹塑性,对3种模型的桩身应力和弯矩进行分析,并通过与模型试验数据的对比分析,验证有限元分析模型的合理性。
[Abstract]:Rocking isolation of pile foundation is a new seismic design method for bridge pier in recent years. In this paper, the isolation mechanism of the device is studied by pseudostatic model test and numerical analysis, and the distribution and variation of pile stress under the action of vertical force and horizontal force are emphatically studied, and the failure forms and characteristics of pile body are found out. Therefore, the practical application of this kind of structure lays a foundation. The main research work is as follows: (1) through consulting domestic and foreign literature, from the theoretical research, The research status of pile-soil interaction between base isolation pier and pile-soil is summarized in the aspects of test method and practical application. (2) the gravity piers in a passenger and cargo railway simple supported beam bridge are taken as the research object. Three models of isolated pier of pile foundation with 1:10 scale were made. Model 1 is free rocking isolated pier; model 2 is isolation pier with limited uplift steel bar on both sides of pier bottom cap; model 3 is isolated pier with prestressed anti-overturning steel bar installed in pier body. The test scheme, model making, loading system and test contents are introduced. (3) through quasi-static test, the strain values of longitudinal main reinforcement in pile body of three model piers are obtained. The distribution and variation of main reinforcement strain in each pile under vertical and horizontal reciprocating loads are analyzed, and the load-displacement hysteretic curves of three test models are compared. The mechanical characteristics and failure mechanism of rocking isolated bridge pier pile foundation are further analyzed. (4) the internal force of pile foundation is solved by using M method in the code, and the mechanical characteristics of pile foundation based on rocking isolation are analyzed. The results are compared with the test results. (5) the finite element software is used to establish the analysis model of pile group foundation. Soil spring is used to simulate the soil elastoplasticity. The pile stress and bending moment of the three models are analyzed, and the rationality of the finite element analysis model is verified by comparing with the model test data.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55;U443.15

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