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深厚软弱场地上桩箱基础高层建筑地震反应特性数值模拟

Numerical Simulation on the Characteristics of Earthquake Response of High-rise Building with Pile-box Foundation Built on Deep Soft Deposits

【作者】 张菁莉

【导师】 陈国兴;

【作者基本信息】 南京工业大学 , 岩土工程, 2003, 硕士

【摘要】 土与结构相互作用(SSI)问题长期以来一直是地震工程领域备受关注的一个重大研究课题。对于建在深厚软弱地基上的高层建筑来说,土与上部结构之间必然会存在很强的相互作用。本文的目的在于探讨深厚软弱地基上SSI效应对桩箱基础高层建筑、双塔高层建筑和相邻的双幢高层建筑地震反应的影响。为此,本文将高层建筑—桩箱基础—深厚软弱地基视为一个完整的体系进行了地震反应分析。 首先,以某26层桩箱基础框架—剪力墙高层建筑为例,探讨了深厚软弱地基条件和输入地震动特性对桩箱基础高层建筑地震反应的影响。其成果如下: 1.深厚软弱地基对输入地震波具有明显的放大作用,这种放大效应与地基土的物理力学性质和输入地震动特性有关;并具体探讨了土层放大系数与输入地震动加速度峰值的关系。 2.通过对刚性地基和深厚软弱地基条件下上部结构地震反应的比较,分析了SSI效应对桩箱基础高层建筑地震反应的影响;讨论了在不同的深厚软弱地基条件下,输入地震动特性不同时桩箱基础高层建筑地震反应的特性,指出了SSI效应对上部结构楼层绝对加速度反应和楼层相对位移反应的影响规律。 3.对同一深厚软弱场地条件下同一地震动输入时的相互作用体系进行了二维和三维地震反应对比分析,初步探讨了两种分析方法所得结论的异同。 其次,对深厚软弱地基上带多层地下室的双塔高层建筑的地震反应进行了数值模拟,探讨了SSI效应对双塔高层建筑地震反应的影响规律;并与单塔高层建筑的地震反应进行了对比分析,指出两种不同体系地震反应的差别;另外,还对塔间连体设置位置和方式不同的双塔高层建筑的地震反应进行了探讨,分析结果表明,双塔高层建筑塔间连梁对其地震反应有很大的影响,当输入地震动水平相当于多遇地震和常遇地震时,双塔高层建筑底部或底部和顶部同时设置塔间连体对双塔高层建筑地震反应有显著减震作用。因此,在双塔高层建筑底部或底部和顶部同时设置塔间的连体是比较理想的方式;此外,在双塔高层建筑底部和顶部同时设置连体结构,则其上部楼层的地震反应的减幅特别明显。 最后,对深厚软弱地基上相邻的双幢高层建筑的地震反应进行了探讨,指出SSI效应对双幢高层建筑地震反应的影响规律;并针对双幢高层建筑和单幢高层建筑这两种不同体系,分析了深厚软弱地基上它们之间地震反应的差异。一般地,相邻的双幢高层建筑各楼层的绝对加速度反应要比单幢高层建筑的反应略小一些,而双幢高层建筑中部楼层的绝对加速度反应也可能大于单幢高层建筑的反应。此外,还分析了相邻的双幢高层建筑之间的间距对其地震反应的影响,得到了一些有益的结论。

【Abstract】 The problem of soil-structure interaction (SSI) is always an important research topic paid a great deal of attention to in the field of earthquake engineering over a long period of time. For many structures built on deep soft deposits, strong interaction appears between soils and superstructure. The purpose of this paper is to discuss the influence of SSI effect to pile-box foundation frame and shear wall high-rise building built on deep soil sites, high-rise building with two towers and adjacent double high-rise building. So, in this paper superstructure, pile-box foundation and deep soft soils are considered as a whole system to analyze its earthquake response.First, a 26-storied frame and shear wall high-rise building with pile-box foundation on deep soft deposits is analyzed under input different ground motions. The results show:1. Deep soft sites can amplify the input ground motion, this amplification is related to the characteristic of the soil deposits and the input ground motion. After detailed analysis, the relationships between the amplification coefficient and the maximum acceleration peak value of input ground motion is given.2. Through the comparison of earthquake response of high-rise building built on rigid base and deep soft sites, the influence of SSI effect to frame and shear wall high-rise building with pile-box foundation is analyzed; the earthquake response characteristic of superstructure built on different deep soft sites is discussed for different input ground motions. Some rules of SSI effect to the absolute acceleration peak value and relative displacement of high-rise building floors are drawn out.3. The interaction system is analyzed by two-dimension and three-dimension finite element method, the results are compared with each other.Second, the earthquake response of piles-multistoried basement-high-rise building with two towers is analyzed by numerical simulation, some rules of SSI effect to high-rise building with two towers are drawn out; compared with that of high-rise building with single tower, the difference of the two systems are indicated. Still, this paper discusses the influence of connections between the two towers, the results show that the connections have great effect on the earthquake response of high-rise building with two towers. If the connections are set at the bottom or bottom-top, they can greatly reduce the earthquake response of high-rise building with two towers for input acceleration peak value level equivalent to the most probable earthquake and design basic earthquake. So, the connections set at the bottom or bottom-top of two towers are good manners to reduce the earthquake response of high-rise building with two towers. Still, the connections set at the bottom-top can remarkably reduce the earthquake response of the top floors of high-rise building with two towers.Last, the earthquake response of adjacent double high-rise building built on deep soft sitesis analyzed and the effect of SSI are discussed; In accordance with two different systems of adjacent double and single high-rise buildings, the difference of their earthquake response on deep soft sites is analyzed. The results show that, in general, the absolute acceleration peak value of high-rise building is a little smaller than that of single tower high-rise building, however, the acceleration peak value of the floors in the middle of high-rise building with double tower may be lager than that of single high-rise building. In addition, some valuable conclusions have been obtained by analyzing the influence of the distance between two double high-rise buildings to their earthquake response.

  • 【分类号】TU473.1
  • 【被引频次】2
  • 【下载频次】191
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