A Study On The Statistic Characteristic Of Local Deformation In Displacement-Based Design

At the present time, many researchers pay more attention to displacement-based design which is a tendency of seismic design. Current displacement-based design methods often emphasize the control of global deformation of building (such as peak topmost displacement, peak interstorey drifts), and use these value to the seismic design. Whereas, How to control the local deformation of elements and make the deformation satisfy the requirements of design need more researches.The analysis for a representative reinforced concrete public frame in 8 region which is designed according to Chinese Codes in this paper, emphasize the local deformation of elements from the point of view of displacement-based design. All results of structural analysis in the paper are calculated by a new structural analysis procedure OpenSees.The fist part of this paper is making a statistic analysis of local deformation and other deformation of the building under many numbers of rare earthquake ground motions. The statistic results such as distribution of probability and characteristic value from the statistic analysis would be the foundation and criterion for the latter comparison and estimation.The second part of this paper is estimating the effect of"3+1"method (three natural earthquake waves and one synthetic earthquake waves) which is used to select earthquake waves in seismic design. The main conclusions are as following: the mean value of"3+1"are almost at the great probability range, and denote the most possible deformation of building under the random earthquake. Whereas, for a number of local deformation, the mean value of"3+1"are less than the mean value of results of dynamic analysis for many numbers of earthquake ground motions slightly.The third part of this paper concerns pushover analysis in displacement-based design, and estimate the effect of different lateral load pattern and structural target displacement in pushover analysis. The main conclusions are as following: when we take the pattern of SRSS of modes at every step(pattern C in the paper) and mean+standard value of dynamic analysis results as target displacement, the deformation of structure and element of pushover results are proximate to the statistic result of dynamic analysis for many numbers of earthquake ground motions.