Advanced Materials Research Vols. 671-674

Abstract: The dynamics model was established for the simple elastic support Beam structure and derived the natural frequency equations of simple elastic support beam. Then some special frequency equations for certain supporting conditions have been analysis via the above equation. The results show that vertical elastic support constraint and torsional elastic constraint have more influence to the natural frequency of beam.

Abstract: Elastio-plastic dynamic analyses of 5 reinforced concrete frame-core wall structures with different structural characteristics were carried out under several sets of ground motions. The earthquake total input energy of the structure under ground motion, and the regularity of the total input energy between hysteretic energy and damping energy were discussed; the distribution of hysteretic energy among shear wall, coupling beams and frames were studied, as well as the distribution of hysteretic energy along different stories. The results show that the hysteretic energy is increased with the peak ground acceleration. The earthquake records with different spectrum characteristics have a great influence on hysteretic energy. Although the total hysteretic energy among different structural members are steady, the distribution of hysteretic energy among shear wall, coupling beams and frames may vary significantly. It is found that the bottom portion of shear walls and coupling beams in middle floors are the predominant energy dissipated area.

Abstract: Steel frame - shear wall structure of the teaching building has been by the software PKPM respectively in the design basic acceleration of ground motion of 7~9 degrees, include story drift, component stress, overturning moment and the amount of steel. Comparative analysis shows that the main factors affect the stress ratio is related to the sectional dimension, and has little to do with the intensity. By calculating the overturning moment, it proved that in 9 degree 0.4g and 8 degree 0.3g, the frame with shear wall structure combined with a relatively close. The structure not only meeting the earthquake disaster prevention requirements of the teaching building in highly seismic region, but also the structure has good economic applicability.

Abstract: The research on elastic-plastic dynamic response analysis of the high-rise building with transfer storey is carried out under different earthquake record inputs.The displacement time- history response of the top floor and the transfer storey, also the displacement envelope diagram and interlayer drift angle envelope diagram are obtained.Theoretical reference for the design of the weak layer is provided.

Abstract: It is important for tall building to infer seismic hazard analysis. Recently, researchers paid great efforts to study the seismic hazard analysis using the method of probabilistic seismic hazard analysis (PSHA), and PSHA has been proved to be sound and popular. The PSHA method is not new. However, the use of PSHA in China is not extensive. The purpose of this paper is to explore the use of ground motion distribution analysis about one typical tall building Taipei-101. Based on the earthquake catalog around Taiwan with more than 50,000 events over 100-years of recording, the author takes Taipei-101’s geographic coordination as object to do ground motion distribution analysis. The research shows that ground motion is affected significantly by service year, and the chi-square test applied in testing Annual ground motion distribution better than K-S test, In addition, Bernoulli distribution is verified reasonable in evaluating the entire service year ground motion distribution.

Abstract: The seismic damage investigation on 488 buildings in Anchang County during Wenchuan earthquake was performed and the investigation data were analyzed, especially for the school buildings. The results indicate that the seismic damages of buildings with seismic design are obviously lower than those of buildings without seismic design, and the damages of the Type-A buildings are most severe, those of the Type-B buildings are second while those of the Type-C buildings are the slightest. Moreover, the damages of Type-B and Type-C school buildings are a little higher than the average level of Type-B and C buildings in Anchang County.

Abstract: Two different retrofitting concepts, including anti-seismic (pier strengthening) and seismic isolation (replacing with isolation bearing) were applied to bridge seismic strengthening. Influence factors of post-retrofitting performance in bridge were determined by the following parameters: pier stiffness and isolation bearing stiffness. By finite element analysis of controlling one parameter, the post-retrofitting performance was evaluated and compared with respect to the strategy with another variable parameter and vice versa. Meanwhile, comparative analysis was concerned by economic factors: bridge importance, labor cost, material cost and transportation, construction period, etc. Quantified parameter and the “performance/cost” which was a popular index in engineering economy were applied to find the best point (it was an optimal retrofitting strategy point). It also served as a project case of using this methodology to testify the rationality and provided a practical reference for expert and scholar in the field of bridge seismic retrofit.

Abstract: Monte-Carlo was applied to generate random traffic flow after frequent, moderate and rare earthquake respectively based on sample of vehicle investigation in“907”Zhaotong, Yiliang earthquake (2012), Yunnan province, considering vehicle parameters, such as types, driving, distance, ratio in earthquake-relief campaign. Vehicle load effect was analyzed for different spans of Simply Supported Beam Bridge, then characteristic value of lane loading which ruled by 《General Code Designs of Highway Bridges and Culverts(JTG D60-04)》(China) was revised. Research can not only provide standard for rapid estimate and repair of bridge after earthquake, but also give theoretical basis for revising anti-seismic codes or guidelines in China.

Abstract: Near-fault ground motions are more complex than the common far field, and it can significantly change the response characteristics of the structure. The records of Taiwan chi-chi earthquake associating with velocity pulse are selected, and the seismic accelerate response spectrum of different site are studied in deep. On the basis of time-history analysis, the seismic responses of a long-span CFST (concrete-filled steel tubular) arch bridge are discussed. Weakness section of the CFST arch rib are also indicated, providing a valuable reference for aseismic design.

Abstract: The insufficient consideration of seismic risk caused hidden danger for structural safety in many areas. A promising retrofit method for these structures is base isolation. In order to evaluate the effectiveness of this approach, a hypothetical RC frame based on actual situation is designed to be retrofitted using base isolation. Then, seismic fragilities for both un-retrofitted and isolated frames are analyzed, utilizing the results obtained from nonlinear finite-element analysis. The ground motion of the analysis contains 22 earthquake motions, and the results of considering mainshock-aftershock and those of considering only mainshock are compared. The study proves the well designed base isolation can reduce the seismic fragility of the RC frame effectively, and the exclusive consideration of mainshock will underestimate the seismic hazards for structures.