【作者】 单志伟；

【导师】 李英民；

【作者基本信息】 重庆大学 ， 防灾减灾工程及防护工程， 2008， 硕士

【摘要】 掉层建筑结构指的是同一栋建筑的底界面放置在不同标高的场地基面上,并且最高接地点以下按层高设置楼面的接地结构。该结构形式在竖向与横向均有不规则性,使得其结构性能有别于一般的结构体系。然而目前我国规范对这种结构的抗震设计并未给出详细规定。因此,掉层建筑结构在地震作用下的影响规律值得研究。本文以掉层建筑结构为研究对象,运用SAP2000有限元分析软件对不同接坡方式的掉层建筑结构进行抗震性能的分析:根据不同的接坡方式建立了相应的简化计算模型;研究了掉不同跨数、不同层数的掉层建筑结构的抗震性能的规律;并对比了掉层建筑结构与普通框架结构在进入弹塑性状态下的抗震性能;当陡坎为土层时,对比了考虑土-结相互作用模型与不考虑土层的简化计算模型在水平地震作用下受力性能的差别。研究得到的主要结论有:①在水平地震作用下,不同接坡方式的掉层建筑结构的受力性能是有差别的,这种有差别的楼层主要位于掉层部分及坎上第一层的楼层部分。②当总高度不变时:对于挡土墙与主体结构脱开的结构,其受力性能随着掉层层数的增多而偏不利,当掉层高度为总高度70%左右时为受力最不利的掉层高度;掉层跨数越大,受力性能也越不利;对于挡土墙与主体结构相连的结构,其受力性能比脱开的情况要好。③与普通框架结构相比,掉层建筑结构的薄弱层部位会上移,随着掉层层数的增多,其薄弱层所在的部位越往上。掉层建筑结构的薄弱层一般位于坎上第一层。④由于平面和立面不规则性,掉层建筑结构会产生较大的扭转效应。⑤与考虑土-结相互作用的结果比较,不考虑土层的简化计算模型所得的结果会偏不安全,且影响程度随着土层性质的不同而有差异。更多还原

【Abstract】 Step-terrace structure is a ground structure. It means the structure that the bottom interface is on different venues-surface elevation, and sets floor by storey height at the highest place of the following. The structural form is irregular at transverse and vertical level, distinct from that of ordinary structural system. However, Chinese code didn’t prescribe seismic design of the structural form amply at present. Therefore it is worth researching the influence law of Step-terrace structure against earthquake.In this paper, step-terrace structure for study, analyzing seismic performance of Step-terrace structure with different ways of access ramp in SAP2000. We create a corresponding simplified calculation model depending on the way of access ramp. The paper researches into the law of seismic performance of step-terrace structure through a number of examples on different inter-out and different layers. It compares the seismic performance between step-terrace structure and ordinary frame structure in state of elastic-plastic, and also the differences of mechanical performance of the model taking into consideration soil-structure interaction in horizontal earthquake to not taking into consideration soil simplified calculation.Below are the conclusions:1. In horizontal earthquake,it differs in mechanical performance the step-terrace structure varied accessed ramp. The difference mainly comes from Step-terrace and first floor above the scarp.2. When the structure of the same height: for the structure with the retaining wall separated from main structure, the performance degrades with the increase of Step-terrace scarp and its cross region. When the height of scarp is about seventy percent of the total structure, the mechanical performance reaches its highest vulnerability. In comparison, the mechanical performance with the retaining wall adjoins to main structure stays much better.3. The weak storey of step-terrace structure is higher than the ordinary framework structure. With the increase of the layers below the scarp, the position of the weak layer shift upward. The weak storey of step-terrace structure is usually on the first floor above the scarp.4. Step-terrace structure will have a greater torsion effect for plane and facade of irregularness. 5. Comparing to the results considering soil-structure interaction, it is un-safer for the results of the model that don’t consider soil-structure interaction, and the influence differs with the nature of soil.更多还原