http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Distribution of Shear Coefficient of Multi-story Buildings Subjected to Near-fault Ground Motions
Wuchuan Pu,Ruijun Liang 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.9
In static seismic design, the strength demands of structural members are decided based on the expected shear force in a seismic event. A reasonable shear force distribution pattern leads to a reasonable configuration of structural parameters and thus makes the structure behave as expected in the design stage. In current seismic codes, the shear force distribution patterns are established based on the elastic response of structures subjected to ordinary far-fault ground motions. Because structural responses induced by pulselike near-fault ground motions are substantially different from the responses induced by far-fault ground motions, shear force patterns specified in current codes are not suitable for the structural design against near-fault ground motions, and a shear force distribution pattern considering the near-fault effect should be established. This study aims to investigate the characteristics of shear coefficients resulting from near-fault ground motions and to provide a new shear force distribution pattern specifically for seismic design against near-fault ground motions. To achieve this goal, dynamic time history analyses are performed on elastic shear models based on 50 near-fault ground motions, and the shear force distributions are analyzed statistically. Findings from the study reveal that the higher modes contribute substantially to the shear coefficient, and the contribution is affected by the pulse period of the ground motion and the structural damping. The shear coefficients for floor levels 2/3 of the way up the height of the structure are significantly larger than code-specified values, if the structure has a limited damping ratio. Based on the numerical results, an empirical formula of the shear coefficient pattern is proposed. In this formula, the effects of damping ratio and period ratio are taken into account, and it can be used to derive shear coefficients more suitable for structures subjected to pulse-like near-fault ground motions.
Estimation of floor response spectra induced by artificial and real earthquake ground motions
Wuchuan Pu,Xi Xua 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.4
A method for estimating the floor response spectra (FRS) of elastic structures under earthquake excitations is proposed. The method is established based on a previously proposed direct estimation method for single degree of freedom systems, which generally overestimates the FRS of a structure, particularly in the resonance period range. A modification factor is introduced to modify the original method; the modification factor is expressed as a function of the period ratio and is determined through regression analysis on time history analysis results. Both real and artificial ground motions are considered in the analysis, and it is found that the modification factors obtained from the real and artificial ground motions are significantly different. This suggests that the effect of ground motion should be considered in the estimation of FRS. The modified FRS estimation method is further applied to a 10-story building structure, and it is verified that the proposed method can lead to a good estimation of FRS of multi-story buildings.