Papers by Keyword: Earthquake

Abstract: It is found from the earthquake statistics in recent decades that the vertical seismic oscillation of near field was strong. And even the recorded peak value of vertical seismic oscillation was far more than the peak value of horizontal seismic oscillation in some sites. In order to study the characteristics of vertical and horizontal seismic oscillation acceleration acted on the slope. Calculate the slope earthquake dynamic response characteristics under the horizontal and vertical seismic acceleration by the FLAC3D numerical analysis method. Compared the acceleration, velocity and the displacement amplification coefficient under two kinds of excitation. Analyzed the influence on seismic stability by the acceleration of different direction.

Abstract: Due to the earthquake of Yushu in April 14, 2010, Airport Road landslide No.3 deformed cracking, resulting in lower stability of slope, triggering landslides and other diseases. Selecting the section 2-2 (mileage K823 + 809) of Airport Road landslide No.3 as the calculation section, we use the ABAQUS finite element program to establish landslide numerical mode. The slip mass of landslide was simulated by the elastic-plastic damage constitutive model, and the bedrock was analyzed as Mohr - Coulomb constitutive model. Landslide No3 is analyzed for example, and showed that earthquake triggering mechanism elastplastic damage constitutive model can describe the landslide very well.

Abstract: The penetration cracks in sluice concrete structure have more disadvantage influence on the structure integrity. On the condition of earthquake, it may cause structure collapse. For a typical sluice structure found penetration crack in construction, the finite element model is created and the structure dynamic computation is applied with response spectrum method. The calculation results show if the reinforced steel bar cross the crack is not rusted and destroyed, the tension stress in the sluice and the general safety factor against sliding will meet the corresponding standard. As for the existing cracks, seepage prevention is suggested to avoid steel bar against rust.

Abstract: With the aim of planning preventive measures of seismic protection, estimation of possible damages on building constructions plays an important role. In order to predict the category of damage , a data base was formed out of the data from reports submitted by the commission of the Faculty of Technical Sciences in Novi Sad. The paper presents the research on the influence of the number and structure of input data and the comparative results of prediction of damage category on building constructions for two models of ANN (ANN-1 and ANN-2)

Abstract: Establish the finite element calculation (solid-liquid coupling) model of uranium ion exchanging tower with ANSYS. Time-procedure analyze the pillar of uranium ion exchanging tower with seismic waves. The wave form is EI Centro seismic with M=8.0, and the time interval is 0.02 seconds, lasts 30s.It is suitable for Class 1 site soil. Simulate the stress of two important welding position of uranium ion exchanging tower under the effect of the seismic wave. Compare the simulating results with the calculating results of Anti-seismic for Petrochemical Equipment to show that model simulating is similar to that of manual. Simulating analysis has proved that the maximum stress of two welding positions of the uranium ion exchanging tower is under the ultimate strength of tower welding, so the application of uranium ion exchanging tower in seismic zone meets the requirement of anti-seismic property. And this research provides the information of main risk positions for future entity analysis.

Abstract: Progressive collapse is defined as the collapse of the whole building due to local weak stories or weak zones. In this paper, collapse should theoretically be avoided for any building under any earthquake, it is necessary to study the collapse behavior of buildings to acquire a better understanding of the collapse mechanism and to find efficient methods to prevent it. The collapse process highly depends on the feature of the whole structural system, so numerical simulation becomes a major method to study it. Based on the finite element method, by selecting the appropriate cell death and cell contact algorithm criterion can better simulate the structure collapsed in an earthquake under the continuity of the whole process of destruction, to help understand the causes and mechanism of structural damage. The real buildings are analyzed to study the failure mechanism of the structure. The models proposed are reasonable to study the seismic collapse mechanism of high-rise buildings.

Abstract: Earthquake is common but one of the major natural disasters that cause heavy casualties in the world. In China, half of the deaths caused by natural disasters were brought by earthquakes since 1950. Undertaking effective relief operations when an earthquake strikes is important not only for life saving but also for the sustainable development of the affected area. Estimation of seismic mortality is an important part of relief operation. Based on the analysis of existing seismic mortality estimation models, the paper compares three empirical models of estimating the deaths caused by four earthquakes in China, discovers large errors in the models, and proposes that the models should be improved to meet the needs of emergency rescue. The paper also discusses factors that affect model precision and makes some suggestions on how to improve these empirical models.

Abstract: To explore the practical rail-bridge seismic design methods, dynamic response analysis model of the train-rail-bridge system under seismic loads was established, and the widely used simply supported track-bridge in rail transport was taken for the study. By inputting different intensity and frequency artificial seismic waves to the train-rail-bridge system, the whole history of the vehicles running through the bridge is simulated and the dynamic responses of the bridge and the vehicles are calculated. The influence of train type, seismic intensity and spectral characteristics of the earthquake were analyzed. Taking Japanese traffic safety evaluation indexes including derailment coefficient, wheel offload rate and lateral wheel-rail force as evaluation criteria, the allowed lateral bridge displacement limits and acceleration limits that ensuring train running safety under earthquake were obtained, and the bridge vibration limit curve was drawn. Using Lagrange interpolation method, the mathematical expression of the curve was worked out, which can provide a reference to rail-bridge aseismic design.

Abstract: Establishment of earthquake elusion and dispersion layout is an effective way to reduce seismic damage.This paper takes Weifang street in Shanghai as a case to study the planning of evaculation during earthquake.Firstly,we divided the demonstration zone into six evacuation units,introduced calculation steps and statisticed the effective areas of seismic refuge , width of routes for evacuation.Secondly,the population to be evacuated were counted according to the results of Earthquake-resistant capacity of urban residence.Finally,we made a comprehensive evaluation on the ability of evacuation when demonstration zone sustained the earthquake of 6,7,8 degrees.The results show that demonstration zone can meet evacuation requirements.However,there are still some weaknesses in local partition.We pointed out weak links and gave reasonable suggestions on the planning of sites and routes for evacuation.

Abstract: Through collecting real liquefaction in-situ data available worldwide, the correlations of influencing characteristics parameters such as PGA, water table depth, buried depth of sandy layer, SPT counts and shear wave velocity with respect to liquefaction were analyzed by means of Pearson correlation method. The correlative performance of the characteristic parameters with liquefaction was comparatively analyzed under conditions of varying buried depths, water tables and seismic intensities. The real correlations of the characteristic parameters with liquefaction were obtained corresponding to real dynamic loading, real buried condition and in-situ testing data. The analytical results show that water table, buried depth of sandy layer, SPT and shear wave velocity keep negative correlations with respect to liquefaction while correlation of PGA with liquefaction was positive. The correlations of buried depth of sandy layer, SPT were remarkable while the correlations of water table, shear wave velocity were weak. The correlation coefficient of SPT was the largest, followed by buried depth of sandy layer, PGA and water table; and the correlation coefficient of shear wave velocity was the smallest. The results presented herein can be used for updating the liquefaction evaluation methods in the codes.