地震动水平—摇摆耦合作用下高柔结构地震效应研究

发布时间：2018-03-16 09:41

本文选题：高柔结构　切入点：摇摆地震动　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：地震动由三个平动分量和三个转动分量共同组成的,在以往的研究中,通常会忽略地震动摇摆分量的地震作用。而实际上,地震动摇摆分量对建筑结构的地震效应会带来显著的影响。特别是对于高柔结构这类高度较高、侧向刚度较低的结构体系,在地震动水平-摇摆耦合作用下时,摇摆地震动不仅会增大高柔结构体系的动力效应,并且由于摇摆转角位移时程的影响,导致高柔结构产生一定的基础倾斜,放大了结构的P-?效应。若忽略摇摆地震动,会造成严重的后果,因此,对高柔结构在多维地震动作用下的地震效应研究是非常必要的。本文将对高柔结构在地震动水平-摇摆耦合作用下的地震效应进行了试验和理论研究,探讨摇摆地震动,特别是摇摆转角位移对高柔结构地震效应的影响。主要研究内容如下:1)基于小波分析获取地震动摇摆分量。基于强震时断层附近地面地震动摇摆分量对单摆式地震仪水平和竖向摆造成的响应差异性,建立基于小波变换和阈值处理获取地震动摇摆分量的新方法。采用该方法获取地震动摇摆分量,并进行振动台试验验证了基于小波分析的地震动摇摆分量获取方法的正确性和精度;2)非线性动力方程推导。推导地震动水平-摇摆耦合作用下高柔结构的非线性动力方程,并将摇摆转角位移产生的非对称P-?效应以一个等效水平侧向力的形式加在动力方程的激励项中;3)高柔结构的振动台试验和理论研究。以某电视塔结构为原型,进行了地震动水平、摇摆和水平-摇摆耦合作用下高柔结构的缩尺模型,并与理论分析结果进行对比,探讨摇摆转角位移产生的地震效应影响。通过振动台试验和理论分析的结果对比表明:1)基于小波分析获取的地震动摇摆分量的残余倾斜位移与实测的基本吻合,且过滤掉摇摆分量的水平分量傅里叶谱的低频部分与竖向分量的较为相似;振动台试验验证了基于小波分析获取地震动摇摆分量方法的正确性,且相较于基于傅里叶分析的方法,结果与实际情况更加吻合,精度实现了大幅提高。2)振动台试验结果与本文推导的动力方程理论分析结果基本吻合,证实了理论分析的正确性;3)由基础转角位移产生的附加P-?效应不仅会增大高柔结构的动力效应,并且会导致高柔结构产生显著的非对称位移效应,从而使得结构的水平位移大幅增加,在实际的抗震设计计算中,应予以重视。
[Abstract]:Ground motion is composed of three translational components and three rotational components. In previous studies, the seismic action of the rocking component of ground motion is usually ignored. The seismic effect of building structure will be affected significantly by the rocking component of ground motion, especially for the high height and low lateral stiffness of the high flexible structure, under the coupling action of horizontal and rocking ground motion, especially for the structural system with high height and low lateral stiffness. Rocking ground motion will not only increase the dynamic effect of the high flexible structure system, but also cause the foundation tilting of the high flexible structure due to the influence of the displacement time history of the rocking angle, and amplify the structure's P--? If the shaking ground motion is ignored, there will be serious consequences, therefore, It is very necessary to study the seismic effect of high flexible structure under the action of multi-dimensional ground motion. In this paper, the seismic effect of the flexible structure under horizontal and rocking coupling of ground motion is studied experimentally and theoretically, and the shaking ground motion is discussed. In particular, the effect of rocking angle displacement on seismic effect of tall and flexible structures. The main research contents are as follows: 1) based on wavelet analysis, the rocking component of ground motion is obtained. Based on the rocking component of ground motion near fault during strong earthquake, the swinging component of ground motion near fault is applied to single pendulum ground. The difference of response caused by horizontal and vertical pendulum of seismograph, A new method based on wavelet transform and threshold processing is established to obtain the rocking component of ground motion, and the method is used to obtain the rocking component of ground motion. The vibration table test verifies the correctness and accuracy of the method for obtaining the rocking component of ground motion based on wavelet analysis. The nonlinear dynamic equation of the flexible structure under horizontal and rocking coupling is derived. And the unsymmetrical P-? The effect is added to the excitation term of the dynamic equation in the form of an equivalent horizontal lateral force. The shaking table test and theoretical study of a flexible structure are carried out. The ground motion level is carried out using a television tower as a prototype. The scale model of the flexible structure under the coupling of rocking and horizontal rocking is compared with the theoretical analysis. The effect of rocking angle displacement on seismic effect is discussed. The results of shaking table test and theoretical analysis show that the residual tilt displacement of the rocking component of ground motion obtained by wavelet analysis is in good agreement with the measured one. The low frequency component of the horizontal component of the rocking component is similar to that of the vertical component, and the method of obtaining the rocking component of the ground motion based on wavelet analysis is verified by the shaking table test. Compared with the method based on Fourier analysis, the results are more consistent with the actual situation, and the precision of shaking table test is greatly improved. 2) the results of shaking table test are in good agreement with the theoretical analysis results of the dynamic equation derived in this paper. It is proved that the theoretical analysis is correct. The effect will not only increase the dynamic effect of the tall flexible structure, but also lead to the significant asymmetric displacement effect of the high flexible structure, which makes the horizontal displacement of the structure increase significantly, which should be paid more attention to in the actual seismic design calculation.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU311.3

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