Advanced Materials Research Vols. 243-249

Abstract: At present, the effect of tower-line coupling is neglected in seismic vibration control with TMD for transmission tower-line system. However, for large crossing transmission tower-line system(LCTL), the neglect can affect the performance of TMD. In this study, a typical FEM model of LCTL is established. The effect of tower-line coupling on dynamic character of LCTL is analyzed. Then, the performance of TMD considering the tower-line coupling is compared with TMD neglecting the tower-line coupling. It is concluded that tower-line coupling affect the performance of TMD significantly for LCTL.

Abstract: The macroseismic intensity is a subjective indicator of ground motion intensity. Convex analysis method and China Probabilistic Seismic Hazard Analysis methodology are combined to derive peak acceleration for Ningbo city, China. The peak acceleration interval obtained by using the convex set theory-based seismic hazard analysis methodology is compared with that calculated by using China Probabilistic Seismic Hazard Analysis methodology. The sensitivity analysis indicates that the interval of peak acceleration is most sensitive to the annual occurrence rate. Furthermore, the correlation of uncertain variables cannot be neglected for peak acceleration prediction.

Abstract: The uncertainties of earthquake currently were not considered with the various lateral load patterns of pushover. The convex set theory, which requires much less information, is employed to model the uncertainties of the seismic influence coefficient maximum and the characteristic period of response spectrum. Then the convex analysis method is integrated into the fundamental equation of pushover, and the analytic relationship of lateral seismic load and top displacement of buildings is derived. The results of numerical example shows that the new lateral load pattern of pushover proposed in this research may effective simulate the uncertainties of strong ground motion.

Abstract: The spectral displacement and the damage state medians were assumed as deterministic parameters in HAZUS-Advanced Engineering Building Module (AEBM). As the historical material and experimental data were insufficient to establish an exactly probability density function model of uncertain variable, the damage assessment results by probabilistic model derived from many assumptions and simplification were unreliable. The uncertainties of the spectral displacement and damage state medians were modeled by the Envelope Bound Convex Model. Furthermore, a bound fragility analysis methodology is derived by integrating HAZUS-AEBM module with the convex set theory. The fragility of a hotel in southern China are calculated and compared to the damage derived by HAZUS-AEBM method, and the results of fragility analysis are more sensitive to the spectral displacement and the damage state medians.

Abstract: In order to study the influence of the action of coupling earthquake to sliding base-isolation structure and improve its effect of vibration reduction by means of optimizing its major parameters. The theory of sliding base-isolation structure under the action of coupling earthquake is studied. A dynamic differential equation is developed. Seismic response analysis of 6-storey sliding base-isolation structure is processed, the results by exemplification show that the peak values of relative acceleration, relative displacement and inter-storey shear force of sliding base-isolation structure increase in different degree under the action of coupling earthquake. The increments increase with the action of earthquake in vertical direction increasing. In view of that SGA has such frequent shortcomings as premature convergence, oscillation and over-randomization in iterative process, a new genetic operator named transgenic operator had been developed for the purpose of improving SGA. Moreover, FBSA is proposed and combined with IGA. The parameters optimization model for the sliding base-isolation structure is set up. The various earthquake responses of sliding base-isolation structure get better control after it is optimized with IHGA. The results by exemplification show that IHGA is an efficient optimal method for parameters and layout optimization of sliding base-isolation structure.

Abstract: This paper illustrates the basic principles of "concept design" in seismic design of tall buildings, and presents the application of conceptual design in a specific shear wall structural design. Two different structural layout schemes of this structure are compared using a finite element analysis program.

Abstract: The strain-rate effects of reinforced concrete beams are studied in this paper. Considering the strain-rate effects of structural material, dynamic responses of reinforced concrete beams subjected to monotonic loading and cyclic loading at different loading rates that might be experienced during earthquakes are simulated using the nonlinear finite element program ABAQUS. The influences of loading rate on loading capability and failure mode of reinforced concrete beams are investigated. The results show that as the loading rate increases, the loading capability increases, the increment is associated with the shear span ratio and loading mode. The increment at cyclic loading is smaller than that at monotonic loading; as the shear span ratio changes, the failure mode changes, the increment changes; the failure mode has nothing to do with the loading rate.

Abstract: Scattering of SH-wave by a semi-cylindrical hill above a subsurface elastic cylindrical inclusion in half-space is studied by complex variable function. Firstly, the whole solution domain is divided into two parts, and the solutions that satisfied the boundary conditions are constructed in two parts respectively. Then according to the “conjunction” condition of junction interface and the boundary condition around the subsurface elastic cylindrical inclusion, a set of infinite algebraic equations about the problem can be obtained. Finally the computational results of surface displacement were provided and discussed.

Abstract: Seismic performance of the steel-concrete mixed structure is studied compared with concrete structure by Sap2000, including modal analysis, response spectrum analysis and time-history analysis. Also, a simplified calculation model of the steel-concrete mixed structure is established, and some formulae are derived from the model including the natural frequency, top displacement, shear of both the core tube and the frame on the basis of finite element method of bar system. Those formulae can be used to explain and approximately count the seismic response of steel-concrete mixed structure.

Abstract: For resolving the practical problem about bridge structures, according to the seismic damage regularity and the structural characteristics, the capacity design method of bridge structure was introduced. In order to account synthetically for the influence factors and convert the inelastic seismic design method into the pseudo-static method, which is easily accepted by engineers, the strength reduction factor was commonly used in seismic design of structures. Based on the principles of the inelastic spectrum established by using the relationship between the strength reduction factor R and ductility factor μ, the seismic demand spectra were obtained from the design spectrum of the Highway Engineering Seismic Design Code (JTJ 004-89). This will be beneficial to the earthquake-resistant capacity design in practical bridge structures.