Papers by Author: Bai Tao Sun

Abstract: The natural frequency of model was analyzed by finite element software in the first and the result was consistent with the experience formula. Then, time history of ground motion was inputted. The seismic capacity of the structure was analyzed by parameters as structural damage, seismic shear and acceleration. Structural damage in seismic “three levels” and the results of seismic appraisal were consistent. The injury site structure put forward strengthening measure of circle beam and structural column. Scientific basis and technical support for seismic strengthening were provided for Tianjin Western-style dwellings.

Abstract: The brick-timber structures have a long history and are still used widely in Chinese rural area at present. A large amount of structures were damaged in Wenchuan earthquake occurred on May 12, 2008, and the brick-timber structures in different intensity regions were investigated in detail. Based on the investigate data of Wenchuan earthquake and other previous seismic data, the typical damage of brick-timber structures are summarized and the earthquake resistant design methods and research status are discussed, the earthquake resistant capability of brick-timber structure are also analyzed. Combined with current country codes, the constructional measures for earthquake resistance and construction technology of brick-timber structures are studied. Finally, some reasonable suggestions on the seismic strengthening and reconstruction of this kind of structure after disaster have been given.

Abstract: The Wenchuan earthquake occurred on May 12, 2008 (Beijing Time) caused great casualty and economic losses, a large number of masonry buildings were damaged in various degrees in this earthquake. The masonry residential buildings are widely used in China, and the study on them is significant. Although the masonry residential building discussed in this paper which was located in the highly intensity region was damaged severely, it hasnt collapsed and has very typical earthquake damage. The story comprehensive seismic capacity indexes are developed to anti-collapse capacity index which are used to calculate anti-collapse capacity of the building, and the results are also used for comparative analysis with the results calculated by means of structure vulnerability analysis. The earthquake resistant capacity of masonry residential buildings are discussed and analyzed. Finally, some reasonable suggestions on the seismic strengthening and reconstruction of this kind of building after disaster have been given.

Abstract: In this paper, the dynamic responses of an arch dam in the case of normal water level and operating low water level were simulated by using additional mass model and incompressible finite element model for reservoir respectively. The results showed that the reservoir models have a great impact on dynamic response of arch dams. The maximum principle tensile stress using incompressible finite element model of fluid is less than that using additional mass model. With the depth of the reservoir water increasing, the hydrodynamic pressure acting ton the dam surface caused by earthquake force increased and the dynamic responses of dam also increased.

Abstract: The Wenchuan earthquake occurred on May 12, 2008 (Beijing Time) caused great economical loss and large amount of buildings were destroyed. Many of single-story reinforced concrete industrial buildings in Hanwang town located in the highly seismic region were damaged, and the damaging phenomenons are very typical. According to the damage survey and analysis of typical seismic damage for the single-story reinforced concrete industrial buildings located in Hanwang town, the damage distribution and failure characters of these buildings are summarized in this paper. The single-story reinforced concrete industrial buildings which were designed according to current seismic design code have better earthquake resistant behavior than those old single-story reinforced concrete industrial buildings and the damaging phenomenon show some new features. Finally, combining current seismic design code of our country and the earthquake damage lessons, some reasonable suggestions on the work of seismic strengthening and earthquake resistant design of the single-story reinforced concrete industrial buildings have been given.

Abstract: In this paper, the typical seismic damage of earthquake fortification and non-earthquake fortification masonry buildings are analyzed and the causes are illustrated, which are based on a large number of earthquake disaster survey data of Ms8.0 Wenchuan earthquake, Ms6.4 Baotou earthquake and Ms7.8 Tangshan earthquake and so on. According to the damage statistics data of several past earthquakes of China in recent years, the difference of damaging phenomenon and rate of earthquake damage of earthquake fortification and non-earthquake fortification masonry buildings in highly and lowly seismic regions are discussed and analyzed. Finally, based on the analysis conclusions, how to improve the seismic capacity of masonry buildings are discussed combining current seismic design code of China and some reasonable suggestions on the post-disaster reconstruction of masonry buildings have been given.

Abstract: Based on the nearly 5,000 building samples investigated on site, damage characteristics of different types of building structures which located in different intensities regions are described and the reasons are analyzed in this paper. Three kinds of structural damage characteristics have been summarized as follows: 1) fortified masonry structures and unfortified ones; 2) masonry buildings with bottom frame; 3) reinforced concrete frame structures. The damage ratio of these three kinds of buildings in different intensities is obtained and the vulnerability has been compared. It provides the reference for those people who work for earthquake engineering to know the earthquake damage of different types of structures with fortified or unfortified. Also it provides important reference for revising seismic design code.

Abstract: In this paper, we study the problems of scattering of out-of-plane line source load by half-space shallow-embedded circular lining structure and a crack in the field of linearly elastic dynamic mechanics. This is an essential solution to the displacement field for the elastic space possessing shallow-embedded circular lining structure and a crack while bearing out-of-plane harmonic line source load at arbitrary point. The wave function of scattering of shallow-embedded circular lining structure impacted by incident steady SH-wave is constructed based on the symmetry of SH-wave scattering and the method of multi-polar coordinates system. Then a crack is made out using the method of “crack-division”. Thus expressions of displacement and stress are established when shallow-embedded circular lining structure and a crack are both in existent. Finally, with two different dimensionless parameters, numerical results of scattering of out-of-plane line source load by half-space shallow-embedded circular lining structure and a crack are obtained and numerical examples are provided to show the influence of wave number ratio, shear modulus ratio, thickness ratio and the ratio of distance between the center of the different cavity and ground surface and the radius of the circular lining structure upon the dynamic stress concentration factor(DSCF) and dynamic stress intensity factor(DSIF) at crack tip.

Abstract: On 12 May 2008, a magnitude 8.0 earthquake happened in Wenchuan, Sichuan province, China .It was the most serious earthquake in china since 1949, causing very huge casualties and engineering damages to the buildings. In the earthquake, a reinforced concrete frame structure of Beichuan Hotel in Beichuan County collapsed completely because of the unsuitable arrangement of column network, and the engineering damage was characteristic. In the paper, the properties of material nonlinearity were considered ,the nonlinear analysis model of reinforced concrete frame structure was established, the time history analysis and nonlinear static analysis were used during inelastic stage, the main cause of structural destruction was obtained, the influence of the arrangement of column network on the structure was discussed.Therefore ,the results can provide valuable reference for the seismic design of reinforced concrete frame structure.

Abstract: In this paper, the vulnerability of the multi-storey reinforced concrete is classified and analyzed according to three control factors: construction age, story and uses. And the different categories vulnerability matrices of multi-story reinforced concrete are obtained from the monomer sample buildings which are already evaluated. The proportion of construction area of different categories can be attained from buildings census statistics. Then the vulnerability matrix of concrete building group in study region can be established by sum-product of construction area ratio of each vulnerability class in study region and each class vulnerability matrix. Finally, the vulnerability matrix of reinforced concrete structure of Xi'an Yanliang District was obtained using this approach. After comparing with the traditional earthquake damage prediction method, it is shown that this method is feasible, simple idea and high reliable and can be used for rapid assessment of post earthquake.