基于改进Vlasov地基模型的柔性悬臂式挡土墙地震动响应分析

发布时间：2018-11-11 09:24

【摘要】：挡土墙作为一种常见的挡土结构,被广泛应用于民用建筑、桥梁工程、公路工程、水利港口工程和铁路工程中。我国地处世界两大地震带—环太平洋地震带和欧亚地震带之间,是个地震多发国家。地震震害调查发现,在较强地震作用下,挡土墙会遭到破坏。因此挡土墙的抗震设计是地震结构工程中非常重要的课题,受到了各国学者的重视。挡土墙抗震设计中计算土压力的常用方法是物部冈部法,但这种方法没有考虑挡土墙与土体之间的相互作用,更多应用在刚性挡土墙抗震设计中。本研究基于改进Vlasov地基模型,对柔性悬臂式挡土墙在墙底固支和墙底铰支两种位移模式下的水平向地震动响应进行了分析。首先,在没有考虑土体中的竖向位移的前提下,对水平向地震作用下的挡土墙-土系统提出一个新的位移模式。其次,根据Hamilton原理,得到自由场位移;进而考虑土-墙相互作用,得到了挡土墙位移和衰减函数的控制方程以及边界条件,这两个控制方程是相互耦合的。再次,通过一个迭代程序来实现解耦。与此同时,与已有方法结果对比,验证本文方法的正确性。最后,对挡土墙-土系统性能以及地震激励下的动响应进行了参数分析。参数分析表明:水平向地震作用下,挡土墙自身刚度、激励频率、挡土墙的约束条件都是影响挡土墙-土动响应的重要因素。本文创新点是:(1)提出一个新的挡土墙-土位移模式;(2)在改进Vlasov地基模型基础上,建立了的挡土墙-土模型,得到了挡土墙水平向谐和荷载下的动响应解析解;(3)针对挡土墙水平向地震动响应,提出有明确力学意义的物理模型,并在Veletsos和Younan模型的基础上,提出了联系一系列弹簧并模拟土体连续性的土膜,其中弹簧刚度和土膜的参数具有详细的表达式。
[Abstract]:As a common retaining structure, retaining wall is widely used in civil construction, bridge engineering, highway engineering, water conservancy and port engineering and railway engineering. China is a earthquake-prone country located between the Pacific Rim seismic belt and Eurasian seismic belt. The earthquake damage investigation found that the retaining wall would be damaged under the strong earthquake. Therefore, seismic design of retaining wall is a very important subject in seismic structure engineering, which has been paid attention by scholars all over the world. In seismic design of retaining wall, the common method of calculating earth pressure is the method of object section, but this method does not take into account the interaction between retaining wall and soil, so it is more widely used in seismic design of rigid retaining wall. Based on the improved Vlasov foundation model, the horizontal ground motion response of flexible cantilever retaining wall is analyzed under two displacement modes of retaining wall bottom clamping and bottom hinge support. Firstly, a new displacement model of retaining wall soil system under horizontal earthquake is proposed without considering the vertical displacement in soil. Secondly, according to the Hamilton principle, the free field displacement is obtained, and the governing equations and boundary conditions of the displacement and attenuation function of the retaining wall are obtained considering the soil-wall interaction. The two governing equations are coupled with each other. Thirdly, decoupling is realized by an iterative procedure. At the same time, the correctness of the proposed method is verified by comparing the results with the existing methods. Finally, the performance of retaining wall-soil system and the dynamic response under earthquake excitation are analyzed. The parameter analysis shows that the stiffness of retaining wall itself, excitation frequency and constraint conditions of retaining wall are important factors that affect the dynamic response of retaining wall under horizontal earthquake. The innovations of this paper are as follows: (1) a new retaining wall-soil displacement model is proposed; (2) based on the improved Vlasov foundation model, the retaining wall-soil model is established, and the analytical solution of the dynamic response of the retaining wall under the horizontal harmonic load is obtained. (3) aiming at the horizontal ground motion response of retaining wall, a physical model with definite mechanical significance is proposed. Based on the Veletsos and Younan models, a series of springs are proposed to simulate the continuity of soil. The spring stiffness and the parameters of the soil film are expressed in detail.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU476.4

【相似文献】