Advanced Materials Research Vols. 163-167

Abstract: A reinforced concrete column with inside concrete filled steel tube (RC-CFT) has many advantages over reinforced concrete (RC) column, such as higher compression, shear and moment capacity, higher ductility. So this kind of composite column has been used as frame column in buildings. In this paper, the composite columns are used as piers of a continuous bridge to improve the seismic performance. Using nonlinear time-history analysis method and fiber element model, considering elasto-plastic nonlinearity, the nonlinear relationships between lateral load and horizontal displacement of RC-CFT pier and RC pier are calculated, and the seismic behaviors of continuous bridges with the two types of piers are analyzed. Based on the comparison of the results, it is found that the ductility of RC-CFT pier is much larger than RC pier. Under the same intensity earthquakes, the damage of RC-CFT pier is less than the RC pier, and RC-CFT pier is more safe and easy to be repaired after earthquake.

Abstract: A new modified model for assessing the effects of SSI on base-isolated structures is presented from the case of conventional structures. The equations of motion of the equivalent fixed-base 2-DOF system are formulated in frequency domain. Based on this, rigorous and closed-form formulations for fundamental period and composite damping are derived. Finally, analysis of parameters based on frequency independent coefficients in detail is conducted. The analytical model and method presented can serve to assess the effects of SSI in the design of base-isolated structures including high-rise structures. Significant differences between the system with and without radiation damping and the flexibility of supporting soil have been observed in this study. For the results of the analysis, overall SSI effects have been identified as elongation of fundamental period of the system and decreased composite damping, especially for the high-rise and slender isolated structures.

Abstract: The shape and seismic behavior of concrete-faced rockfill dams under designed seismic load are usually studied by shaking table test, dynamic centrifuge model test and finite element dynamic analysis. Particle flow code (PFC) simulation is analyzed based on the shaking table test, which overcomes the deficiency of macro-continuity assumption in continuum mechanics and can demonstrate the failure characters of dam under dynamic loading action intuitively and vividly. The law obtained from numerical simulation is almost consistent with the one obtained from the shaking table test. The simulation results indicate that the failure characters of concrete-faced rockfill dam are particle sliding on the dam surface and that the concrete face can efficiently reduce the slide displacement and dam top settlement.

Abstract: Seismic damage prediction of multistory brick buildings is a multi-factor nonlinear complex problems, this paper analyzed the deficiencies of the traditional methods for predicting the seismic damage, so a prediction model of multistory brick buildings based on RBF Neural Network model is established, RBF network structure elements and parameters are studied and obtained. With examples the research proved that the prediction results are similar to the actual seismic damage to multistory brick buildings by the RBP neural network model, the analytic method and process discussed in this paper can also be applied to seismic damage prediction of brick buildings of urban earthquake disaster prevention planning.

Abstract: The seismic response of the asymmetric structure isolated by the friction sliding bearings is carried out. The eccentricity and the torsional stiffness of superstructure are taken into account. The eccentricity and the torsional stiffness of the superstructure have less effect on the horizontal response of the base-isolated structure, but these have significant impact on the displacement at the corner of the superstructure and the rotational response of the structure.

Abstract: Plate-cone reticulated shell is a new type of space structure with good mechanical behavior and technical economy. In this paper, the wind-induced vibration response characteristics of plate-cone reticulated shell are studied. By using the wave superposition method, the fluctuation wind loads are simulated. By using the large general structural analysis software ANSYS, wind dynamic vibration time domain analysis of plate-cone reticulated shell are carried out. After comparing the wind dynamic vibration results of the model with different material, some important conclusions for plate-cone reticulated shell are obtained for practical design.

Abstract: To study the seismic behavior under conventional earthquakes, according to a case of Shifang Telecom Building (STB) under 5.12 earthquake, this paper makes the computation of internal force and deformation of structure; then compares the seismic behavior of two different models with spectrum analysis and time-history analysis. The conclusion shows that STB can approximately meet requirements for fortification against seismic impact under conventional earthquakes; the steel tower on top can amplify the seismic effect indeed and the weakness of numerical simulation tallies with the reality.

Abstract: The earthquake resistant behavior of buildings with steel tower on top is different from ordinary buildings. In order to investigate the deformations, internal force and damage of structure under rare earthquake, based on a case of Shifang Telecom Building (STB) under 5.12 earthquake, the static elasto-plastic analysis is carried out. This paper compares the seismic behavior of structure under different loading cases, and studies the weakness and plastic hinge of the building. The result shows the structure can meet the requirements of non-collapse under rare earthquake, the top steel tower can amplify the seismic effect, and numerical simulation tallies with the reality.

Abstract: This paper present a new seismic isolation device which assembled sliding friction, energy dissipation and limit, then clarified the work performance and the optimization of its design ideas. The author utilized FEM analysis software ANSYS to establish a parametric model, taking the working condition of single-ring and stress concentration distribution under the yield state as the research object, the shape of the energy loop was optimum designed, and the hysteresis energy consumption performance of seismic isolation bearings was analyzed before and after optimizing. It can be received that energy consumption performance of the seismic isolation bearings improved 32.7% after optimizing. A 6 layer frame structure FEM model was built, at this basis, the seismic responses of fixed structure and sliding seismic isolation structure of foundations were compared. The results indicated that the seismic responses of sliding structures decreased significantly.

Abstract: Recent development in analytical models on earthquake-induced pounding between adjacent bridge decks are introduced. The bridge damage induced by seismic pounding in recent 30 years strong earthquakes are reviewed, various analytical models used to simulate impact effect between bridge decks are presented, which include impact-restitution approach and contact-element approach. The contact-element approach include the linear spring element model, Kelvin-Voigt element model, Hertz model, Hertz-damp model and updated Hertz-damp model. The areas required to further investigate are proposed.