结构—桩—水平成层地基系统动力相互作用分析方法研究

发布时间：2017-12-28 16:18

本文关键词：结构—桩—水平成层地基系统动力相互作用分析方法研究　出处：《大连理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着现代工程建设规模的扩大,桩基础在高层结构、港口、核电结构等建筑物中广泛应用。桩基础的动力刚度对这些结构的动力响应有很大影响,因此在地震动力分析中需要考虑桩-土-结构动力相互作用。本文针对层状地基自由场响应和桩基础阻抗函数进行了研究：(1)对于平面体波垂直入射的情形,基于一维波动方程理论解,利用波动在不同分层之间的传播关系,在时域内利用逐步递推方法构造出界面处的上行波和下行波,进而求得土层中任意点处的运动。针对地震波垂直入射的粘弹性地基模型,利用三角级数变换将地震波分解为一系列简谐波动的叠加,运用逐步递推方法求解出在简谐波作用下土层各离散点的运动,最后将所有简谐波动作用下的运动叠加,从而求得在地震波作用下粘弹性地基中任意点处的运动。利用上述方法求解出的自由场响应,运用直接法在有限域内施加粘弹边界也可求解自由场响应。数值算例验证了方法的有效性和适用性。(2)针对成层地基中桩基础的阻抗函数,利用子结构法将成层地基中桩基础阻抗函数的求解分解为成层地基半空间、桩基础和开挖土体三部分阻抗函数的叠加,分别利用混合数值算法和有限元法求解,求解方法高效精确。数值算例验证了方法的准确性。(3)针对大规模的群桩系统,结合粘弹性人工边界条件运用有限元法,按阻抗函数定义在ANSYS中运用谐分析完成对桩基础阻抗函数的求解。方法可以较为全面地考虑地基中存在各种不均匀特性,如孔洞、夹层、非水平成层等情况。(4)运用文中的方法就桩长径比、承台的约束条件、土层的模量对桩-土动力相互作用进行参数分析,并对采用桩基础处理的某核电站地基动刚度进行计算分析。
[Abstract]:With the expansion of the scale of modern engineering construction, pile foundation is widely used in high-rise structures, ports, nuclear power structures and other buildings. The dynamic stiffness of the pile foundation has a great influence on the dynamic response of these structures. Therefore, the dynamic interaction of pile, soil and structure should be considered in the seismic dynamic analysis. This paper studies the free field response of layered soil and pile foundation impedance functions are: (1) the plane wave case, one-dimensional wave equation based on theoretical solution by wave in different layers between the propagation relationship in time domain, the recursive method to construct the upgoing and downgoing waves at the interface. Then at any point in the movement of soil. Based on the viscoelastic foundation model of vertical incident seismic wave, using trigonometric series transform seismic wave is decomposed into the superposition of a series of harmonic wave, the use of soil in simple harmonic wave of each discrete point motion recursive method, the superposition of all motion under the action of harmonic wave, so as to obtain the arbitrary point of viscoelastic in the foundation in the seismic wave motion. The free field response can be solved by using the direct method to apply the viscoelastic boundary in the finite field by using the above method. The numerical example shows the effectiveness and applicability of the method. (2) according to the impedance function in layered soil pile foundation, by substructure method will become the foundation for the superposition layer impedance functions of piles is decomposed into layered half space foundation and pile foundation and soil excavation three part of impedance function, respectively using the hybrid numerical algorithm and finite element method, solving method is efficient and precise. The numerical example verifies the accuracy of the method. (3) for large-scale pile group system, combined with the viscoelastic artificial boundary condition, the finite element method is applied to define the impedance function of pile foundation in harmonic analysis based on the definition of impedance function in ANSYS. The method can consider all kinds of inhomogeneous characteristics in the foundation, such as holes, interbeds and non horizontal formation. (4) parameter analysis of pile soil dynamic interaction is carried out based on pile length diameter ratio, restraint condition of pile cap and modulus of soil layer by using the method in this paper, and the dynamic stiffness of foundation of a nuclear power plant treated by pile foundation is calculated and analyzed.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU435

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