Papers by Keyword: Artificial Accelerogram

Abstract: This paper presents the method of establishing artificial accelerogram for analysis and calculation of structures in accordance with seismic characteristics and earthquake risk in one specific construction areas in Vietnam. The artificial accelerogram allow to analyze nonlinear or linear dynamic behavior of the structures in time series in accordance with Vietnam National Standards for Design of structures for earthquake resistances (TCVN 9386: 2012) and seismic parameters specified in Vietnam Building Code on Natural Physical and Climatic Data for Construction (QCVN 02:2009-BXD). The accelerograms are also used as input parameters for shaking table tests by Vietnam's most modern sharking table at the Vietnam Institute for Building Science and Technology.

Abstract: Currently, theoretical and experimental studies on the overall behavior of semi-precast reinforced concrete high-rise buildings subjected to the earthquake are limited. These studies have mostly focused on the behavior of either joints or frames. To study the overall behavior of a structure under an earthquake, one of the best methods is to do the seismic shaking table test. This paper presents the results of an experimental study on the overall behavior of a semi-precast reinforced concrete multi-story building, which uses new design and construction technology, by using the seismic shaking table test method. These buildings are constructing in series in Vietnam. This research carried out both the linear and nonlinear behavior of the structure until the stage of near collapse. The study consists of three main steps: designing the simulating model; establishing a process to generate artificial accelerograms which are in accordance with the seismic characteristics in Vietnam; testing the 12-story semi-precast model to verify theoretical predictions.

Abstract: The acceleration record of an earthquake ground motion is a nonstationary process with both amplitude and frequency content varying in time. The paper presents a general procedure for the analysis and simulation of strong earthquake ground motions based on parametric ARMA models. Structural design spectra are based on smoothed linear response spectra obtained from different events scaled by their peak values. Such an approach does not incorporate other characteristics of the excitation represented by measured data. This study investigate the use of non-stationary models which can be considered characteristic and representative of specific historical earthquakes. An earthquake record is regarded as a sample realization from a population of such samples, which could have been generated by the stochastic process characterized by an Autoregressive Moving Average (ARMA) model. This model is capable of reproducing the nonstationary amplitude as well as the frequency content of the earthquake ground accelerations. The moving time-window technique is applied to synthesize the near field earthquakes, Boumerdes-1, Boumerdes -2, and Boumerdes -3 2003 recorded on dense soils in Algeria. This model, is based on a low-order, time-invariant ARMA process excited by Gaussian white noise and amplitude modulated using a simple envelope function to account for the non-stationary characteristics. This simple model gives a reasonable fit to the observed ground motion. It is shown that the selected ARMA (2,1) model and the algorithm used for generating the accelerograms are able to preserve the features of the real earthquake records with different frequency content. In this evaluation, the linear and non linear responses of a given soil layer have been adopted. This study suggests the ability to characterize the earthquake by a minimum number of parameters.