【作者】 李佳；

【导师】 夏洪流；

【作者基本信息】 重庆大学 ， 土木工程， 2013， 硕士

【摘要】 砌体结构是典型的脆性结构，在地震作用下，表现出较差的抗震性能，特别是在巨震作用下，砌体结构极易发生倒塌。为了改善砌体结构在巨震作用下的倒塌行为，使地震发生时能够最大限度的保证人们的生命财产安全，有必要对影响砌体结构倒塌行为的因素进行深入研究和分析，并应该提出合理有效的措施改善砌体结构在巨震下的倒塌行为，使之产生相对合理的倒塌模式。本文选取适用于分析砌体结构的有限元软件ANSYS/LS-DYNA，通过设计典型砌体结构算例，选取合理的材料参数及设定材料失效准则，实现了砌体结构在地震作用下的倒塌仿真模拟。本文的主要研究内容及取得成果如下：①本文按照现行设计规范基于多种影响因素建立典型砌体结构模型，对其在小、中、大、巨震下的抗震性能进行研究分析对比，分析结果表明：按照现行规范合理设计的的砌体结构是基本满足“小震不坏，中震可修，大震不倒”的抗震设防要求的，按照规范合理设计的砌体结构必须保证足够的承载力且必须设置合理的抗震构造措施；算例结构在相应巨震下全部发生倒塌，说明现行规范不能控制结构在巨震作用下的抗震行为。②本文所涉及的形状规则、强度和刚度分布均匀的砌体结构算例在巨震作用下发生连续倒塌的破坏模式，其倒塌过程的仿真模拟结果表现为：破坏首先从从门窗洞口等应力集中处开始，随着地震作用的增大，底层破坏加剧直至丧失承载力，底层破坏以后，上部结构随之发生坠落和破坏。③通过对比分析各个影响因素变化的算例模型在巨震下倒塌行为的异同，得出结论：砂浆强度、开洞率、窗间墙与窗下墙刚度比、高宽比、横墙开洞等因素的变化可以影响砌体结构各部位倒塌的时间，构造柱的设置可以增大砌体结构的整体变形能力并延缓结构倒塌的时间，但是两者均不能很好的改善砌体结构易发生连续倒塌的破坏模式。④本文基于以上分析并综合关于砌体结构鲁棒性的研究，提出设置钢筋混凝土避难单元对砌体结构在巨震下的倒塌行为进行改善，并设计对比算例验证了其有效性。更多还原

【Abstract】 Masonry structure is a typical brittle structure with low tensile, bending, andshearing strength. And it shows the worse seismic performance under the earthquakeaction. Especially under the mega earthquake, masonry structure is easily collapsed. Inorder to improve the action of collapse of masonry structure under the megaearthquake, and to guarantee safety and property of people furthest when theearthquake happened, it is necessary to research and analyse the factors thoroughly,which affect the collapse behavior of masonry structure, and put forward reasonableand effective measures which should be improved the collapse behavior of masonrystructure under mega earthquake, and produce relatively reasonable collapse mode.This paper select the finite element software ANSYS/LS-DYNA as the tool toanalyse the masonry structures. Through designing a typical masonry structure,selecting appropriate material parameters and seting the material failure criteria, finallymaking the masonrysimulation of the structure under seismic action. In this paper, themain content and achieve results are as follows:①In accordance with the existing design specifications and based on a variety ofinfluencing factors to establish typical masonry building,Through comparing it’sperformances under its small, medium, large earthquakes,the comparion results showthat: the rational design of masonry structures in accordance with the existing norms isbasically meet the "minor earthquake, earthquake repair, earthquake inverted"requirements for seismic resistance, in accordance with the norms of rational designpuzzlestructure must ensure that sufficient bearing capacity and must be set to improvethe seismic design; example structure all collapses in the huge earthquake, indicatingthat the seismic behavior of existing norms can not control the structure under theaction of mega earthquakes.②Masonry structure with regular shape, uniform distribution of strength andstiffness displays the failure modes of progressive collapse easily under megaearthquake, the simulation result of the collapse process is shown as: first destructionstarts from the windows, doors and other holes where are in the stress concentration,and with the increase of earthquake effect, the ground floor’s damages intensify untillosing bearing capacity. After the ground floor’s destruction, the upper structure’s crashand damage are following. ③By comparing the similarities and differences of collapse behavior of thecontrast calculation model under mega earthquake with various influence factors (suchas mortar strength, ratio of holes, constructional column, etc.), the conclusion isfollowing: changing factors like mortar strength, ratio of holes, stiffness ratio betweenwall and window wall, height-width ratio, opening holes in the cross wall, can affectthe time that each part of the masonry structure collapsed. Setting of constructionalcolumn can increase the overall deformation capacity of masonry structure and delaythe time of structure collapse, but both of them don’t improve the failure modes verywell of progressive collapse in which way masonry structure usually happens.④Based on the above analysis and synthesis of robust masonry structureresearch，This paper put forward that set refuge unit made of reinforced concrete in themasonry structure to improve the collapse behavior of masonry structure under megaearthquake. And through designing a typical comparative structure demonstrated itseffectiveness.更多还原