【作者】 胡颖平；

【导师】 丁海平；

【作者基本信息】 苏州科技学院 ， 结构工程， 2010， 硕士

【摘要】 现有《建筑抗震设计规范》的时程分析方法基于刚性基础假定,即对结构物进行时程分析时,假定结构物的基础是固定于地球的一个封闭体系,再从封闭体系输入地震波,这忽略了土-结构相互作用。研究表明考虑土-结构相互作用与刚性假定是有差别的,《建筑抗震设计规范》对需考虑土-结构相互作用的结构采用的折减系数方法较粗略。本文提出了一种考虑土与结构相互作用的“等效输入”概念,所谓等效输入就是采用合理的方法获得基础顶面的地震动,认为该地震动已充分考虑了土与结构相互作用,可以作为抗震设计中刚性地基假定下的输入地震动。这样既可以利用传统的刚性地基假设,又考虑了土与结构相互作用。本文主要研究了剪力墙结构对等效输入地震动的影响,从以下方面展开工作:1、提出了采用通用有限元软件ANSYS建立考虑土-结构相互作用计算模型的方案。2、在文献[12]的基础上,探讨了框架结构体系的楼层数和楼层质量对等效输入的影响,结果表明楼层数和楼层质量对等效输入的影响不大。3、采用ANSYS软件建立了考虑土-剪力墙结构相互作用的二维时域动力计算模型,分别考虑了不同土体、上部结构楼层数对等效输入的影响。根据计算结果,上述因素对等效输入的平动影响不大,但对基础的转动影响很大。4、研究了桩基对基础的转动影响:桩基改变了基础的转动角位移,土体越软,影响越明显;桩长在一定范围内变化时基础的转动角位移差别不大。从本文的研究结果看,分析土-结构相互作用的等效输入,应着重研究基础的转动输入。更多还原

【Abstract】 The Time-history analysis method of the existing "Code for Seismic Design of Build-ings" is based on rigid foundation assumption-Structure are fixed in the earth as a closed system when the structures are analyzed with time-history analyzing method, then earth-quake waves were input from the closed system. This overlooked the Soil-Structure Inter-action. Studies have shown difference between considering the Soil-Structure Interaction and the rigid assumption. The method of considering Soil-Structure Interaction in "Code for Seismic Design of Buildings" is too rough. A concept of "equivalent input" considering SSI was put forward in this paper. The "equivalent input" is obtaining the seismic ground motion of foundation’s top with a reasonable approach, and the seismic ground motion was considered it had been completely taken into account SSI, so it can be used as input ground motion under the assumption of rigid foundation in design of earthquake. This method can both make use of the traditional assumption that the rigidity of the foundation, and take into account soil-structure interaction. Effect of shear-wall structure on equivalent input was mainly studied in this paper. Follow work was did from this aspects:1. Program that considering soil - structure interaction model was established by finite element software ANSYS was Proposed.2. Based on the literature [12], number of floors, floor quality of frame structure impact on the equivalent input has been discussed, the results show that the number of floors and floor quality have little effect on the equivalent input.3. 2D Soil Shear wall Structure interaction dynamic model in time domain was estab-lished by ANSYS. The equivalent input’s Impact on Different soil, the number of upper structure was considered separately. According to the results, these factors have little effect on the translation equivalent input, but a great influence on the rotation basis.4. To study the impact of pile on the basic rotation: The pile changed the basic rota-tional displacement-The softer the soil is, the more obvious affect it will be. There is no big difference of the basic rotational displacement when a certain range of the length of the pile was changed.According to the result of this article, in order to analyze the Soil-Structure Interaction equivalent input, we should focus on research the basic rotational input.更多还原