基于土与结构相互作用—不同地基条件对结构抗震性能的影响研究

发布时间：2018-05-24 13:57

本文选题：土与结构相互作用 + 结构抗震　；参考：《成都理工大学》2015年硕士论文

【摘要】：我国是一地震多发国家,结构抗震性能的研究一直是工程研究的热点、重点,我国目前的抗震规范,主要建立在刚性地基假定之上进行抗震设计。而土与结构相互作用是客观存在的,随着研究的深入,研究人员越来越重视土与结构的相互作用对结构抗震性能的影响,尤其是软弱地基对结构抗震性能的影响,研究表明软弱层一定程度上有利于结构抗震。另一方面,研究人员针对低矮建筑,通过用橡胶-土(废旧轮胎、橡胶颗粒与土或其他物质的混合物)换填低矮建筑的地基土,设置隔震垫层来达到提高低矮建筑抗震性能的目的。然而,由于橡胶土的承载力较小,不足以承载高层建筑物,不能作为高层结构的隔震垫层,因此本文研究了用橡胶-土换填框架结构桩周土后对结构抗震性能的影响。本文依托”遂宁市河东慈音寺棚户区改造联福小区三期F17地块”项目,通过利用ABAQUS有限元分析软件模拟的方式,基于土与结构的相互作用,研究了不同地基假定、不同土层,对结构抗震性能的影响;针对该项目中涉及的高层桩基础框架结构,研究桩周土局部换填橡胶-土后,对结构体系的抗震性能的影响;研究了不同换填深度的橡胶-土,对结构体系地震响应的影响。主要结论如下:(1)刚性地基假定对于柱底剪应力的分析有其局限性,不能将底部受剪应力分为正剪应力区和负剪应力区两部分,与实际情况不相符,且得出的剪应力值偏大,在结构抗震性能研究中有必要考虑土与结构相互作用的影响;(2)考虑土与结构相互作用后,结构体系的频率降低,周期增大,地震响应降低,软弱层(即淤泥质粘土)会进一步降低结构体系的频率,增大周期,降低地震响应;(3)换填橡胶-土后,结构体系的频率降低,周期增大,地震响应降低,随着橡胶-土深度的增加,结构体系的频率随之降低,周期随之增大,地震响应随之降低;(4)在换填的橡胶-土中,对结构抗震性能提高起到主要作用的是结构外围桩的桩周橡胶-土,且是其中的上部分橡胶-土。
[Abstract]:China is an earthquake-prone country, and the research on seismic performance of structures has been a hot topic in engineering research. At present, the seismic code of our country is mainly based on the assumption of rigid foundation to carry out seismic design. The soil-structure interaction exists objectively. With the development of the research, researchers pay more and more attention to the influence of the soil-structure interaction on the seismic performance of the structure, especially the influence of the weak foundation on the seismic performance of the structure. The study shows that the weak layer is beneficial to the earthquake resistance of the structure to some extent. On the other hand, for low-rise buildings, the researchers replaced it with rubber-soil (a mixture of used tyres, rubber particles and soil or other material). The isolation cushion is set to improve the seismic performance of low buildings. However, because the bearing capacity of rubber soil is small, it is not enough to carry high-rise buildings and can not be used as isolation cushion of high-rise structure. Therefore, the influence of rubber soil replacement on seismic behavior of pile surrounding soil of frame structure is studied in this paper. In this paper, based on the project of "rebuilding the third phase F17 plot of Lianfu District in Hedong Ciyin Temple shantytown of Suining City", by using ABAQUS finite element analysis software, based on the interaction between soil and structure, the different foundation assumptions and different soil layers are studied. The influence on the seismic behavior of the structure, the influence of the local replacement of the soil around the pile and the rubber soil on the seismic performance of the structure system is studied for the frame structure of the high-rise pile foundation involved in this project, and the rubber soil with different replacement depth is studied. The effect on seismic response of structural system. The main conclusions are as follows: (1) the analysis of column bottom shear stress based on rigid foundation assumption has its limitations. The bottom shear stress can not be divided into two parts: positive shear stress region and negative shear stress zone. In the study of seismic behavior of structures, it is necessary to consider the influence of soil-structure interaction. (2) considering the soil-structure interaction, the frequency of structural system decreases, the period increases, and the seismic response decreases. The frequency of the structural system will be further reduced, and the period will be increased, and the seismic response will be decreased when the soft layer (I. E. silt clay) is replaced with rubber soil, the frequency of the structural system will decrease, the period will increase, and the seismic response will decrease. With the increase of rubber soil depth, the frequency and cycle of the structure system decrease and the seismic response decreases. It is the rubber soil around the pile and the upper part of the pile that plays an important role in improving the seismic performance of the structure.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU435

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