高墩大跨连续刚构桥地震响应下的弹塑性分析

发布时间：2019-05-27 07:09

【摘要】：近年来连续刚构桥在我国获得了大力的发展,特别是在我国西南部的山区中,高墩大跨的预应力混凝土连续刚构桥因其自身的众多优点而得到了广泛的应用。同时西南地区也是地震的多发地带并且大多属于高烈度地区,因此对连续刚构桥进行罕遇地震下的非线性弹塑性地震反应分析,研究其在罕遇地震作用下的弹塑性状态是十分有必要的。本文首先简述了连续刚构桥的发展及其抗震研究的现状,同时对延性抗震的理念进行了简要的介绍,并对桥梁结构在地震响应下的动力分析理论知识和计算方法进行了简单的阐述;其次,以云南省马过河连续刚构桥为工程背景,运用大型通用有限元软件MIDAS CIVIL建立了有限元模型,对其进行了弹性动力时程分析和弹塑性动力时程分析.主要完成了以下几项工作:1、介绍了国内外连续刚构桥的发展与弹塑性抗震分析的研究现状,阐述了我国桥梁抗震设防的基本目标,并对延性抗震的理论进行了简要的介绍。2、介绍了桥梁结构在地震响应下的动力分析基本原理和抗震设计中常用的一些计算方法。3、以云南马过河连续刚构桥为工程实例背景,介绍了运用大型有限元软件MIDAS CIVIL的建模过程,并在考虑桩土作用后进行其自振特性计算。4、分别运用线弹性动力时程分析方法和非线性弹塑性动力时程分析方法在纵桥向和横桥向上对其有限元模型进行对比分析,同时对连续刚构桥桥墩在弹塑性动力时程分析下形成的转角进行研究,确定其塑性铰出现的位置及转角大小,判断连续刚构桥高墩在罕遇地震下的工作状态。5、分别以桥墩系梁的个数和两个桥墩之间的高差为研究对象,对模型在顺桥向和横桥向上进行弹塑性动力时程分析并进行对比,研究其桥墩在罕遇地震作用下的内力、位移和塑性铰延性特性的变化情况,得出对罕遇地震抗震设计最有利的桥墩系梁个数和桥墩高差。
[Abstract]:In recent years, continuous rigid frame bridge has been greatly developed in our country, especially in the mountainous areas of southwest China, the prestressed concrete continuous rigid frame bridge with high pier and long span has been widely used because of its many advantages. At the same time, southwest China is also the prone zone of earthquakes and most of them belong to high intensity areas, so the nonlinear elastic-plastic seismic response of continuous rigid frame bridges under rare earthquakes is analyzed. It is necessary to study its elastic-plastic state under rare earthquakes. In this paper, the development of continuous rigid frame bridge and the present situation of seismic research are briefly described, and the concept of ductile seismic resistance is briefly introduced. The theoretical knowledge and calculation method of dynamic analysis of bridge structure under seismic response are briefly described. Secondly, taking the continuous rigid frame bridge in Yunnan Province as the engineering background, the finite element model is established by using the large-scale general finite element software MIDAS CIVIL, and the elastic dynamic time history analysis and elastic-plastic dynamic time history analysis are carried out. The main tasks are as follows: 1. The development of continuous rigid frame bridges at home and abroad and the research status of elastic-plastic seismic analysis are introduced, and the basic objectives of seismic fortification of bridges in China are expounded. The theory of ductile seismic resistance is briefly introduced. 2, the basic principle of dynamic analysis of bridge structure under seismic response and some commonly used calculation methods in seismic design are introduced. Taking the continuous rigid frame bridge of Ma Yue River in Yunnan Province as an engineering example, this paper introduces the modeling process of using large finite element software MIDAS CIVIL, and calculates its natural vibration characteristics after considering the action of pile and soil. The linear elastic dynamic time history analysis method and the nonlinear elastic plastic dynamic time history analysis method are used to compare and analyze the finite element model of the longitudinal bridge and the transverse bridge respectively. At the same time, the rotation angle formed by elastic-plastic dynamic time history analysis of continuous rigid frame bridge pier is studied, the position and rotation angle of plastic hinge are determined, and the working state of high pier of continuous rigid frame bridge under rare earthquake is judged. Taking the number of piers and the height difference between the two piers as the research objects, the elastic-plastic dynamic time history analysis and comparison of the model in the direction of the bridge and the upward direction of the bridge are carried out, and the internal forces of the piers under the action of rare earthquakes are studied. The number of pier beams and the height difference of piers which are most favorable for seismic design of rare earthquakes are obtained by the variation of displacement and ductile characteristics of plastic hinges.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.23;U442.55

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