The Influence Of Ground Motion Characteristics On Response Of Structures

The thesis contains two parts: First, the seismic response of structure is discussed under ground motion with same peak acceleration and spectrum of acceleration, and different peak velocity and peak displacement. On the basis of non-linear analysis of 5 high-rise reinforced concrete structures by artificial ground motion with specific parameters, the influence of the peak velocity and peak displacement on the seismic response of structures is discussed. Second, the responses of isolated structures under near-field ground motions are preliminary investigated. The responses of two actual isolated structures are analyzed under a group of near-field ground motions with significant pulse characteristics, in order to explore their relationship.In this thesis, the main research works are as follows:1. Using four groups ground motions with the same peak acceleration and spectrum of acceleration, but with the different peak velocity and peak displacement to analyze the nonlinear seismic response of the five typical high-rise reinforced concrete structures. The influences of the peak velocity and peak displacement of the ground motion on response of the structures are discussed. The results show that for the structure, the peak velocity and the peak displacement have no significant impact on the response in flexible range but have impact in the elastic-plastic stage. Further analysis on 3 of the structures shows that the impact resulting from the peak velocity and peak displacement will be larger with the development of elastic-plastic. That peak displacement has large impact to long-period structures especially but the peak velocity has little to it.2. Through the seismic response analysis on two actual isolated structures, compared the impacts to the isolated structure under near-field ground motion with the impacts under ordinary ground motion. The results show that isolated structures keep apparent isolating performance in the ordinary ground motions, but the seismic responses under near-field ground motions are far bigger than that under ordinary ground motions. The yield of the isolated layer has happened with fairly bigger displacement in small earthquakes under near-field ground motions. The value of PGV/PGA and the duration of velocity impulse of near-field ground motion have significant effect to the isolated structures. The displacements of isolated layers of the two actual isolated structures exceed displacement limit under part of the near-field ground motions. Therefore, the design of isolated structures should be strengthened and effective measures should be taken to protect structures in the areas where may happen near-field ground motion.Finally, summarize the ideas in the thesis, and discuss the problems in the studies. Consequently, forecast the further study.