摘要:

AbstractThe rigid body motions of the bridge deck, along with the impact between the bridge deck and the abutments, were the source of extensive damage on skew highway bridges during the 1971 San Fernando earthquake. In this paper, a model for the rigid body motions of skew bridges is presented and analysed. The focus of the model is the appropriate representation of the impact between the bridge deck and the abutments and the explanation of the inducement of in‐plane rotational vibrations of the bridge deck as the result of this impact. A simplified model is briefly described first, and the kinematic mechanism of the problem is explained. Then, the analysis of a more detailed and realistic model follows. This model is applied on a short skew bridge located in Riverside, California. The response of this bridge to several earthquake shakings revealed that the planar rigid body rotations of the deck are induced primarily as a result of the skewness of the deck and the impact between the deck and the abutment

ISSN:0098-8847    

DOI:10.1002/eqe.4290150802

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractPrevious achievements using the dynamic non‐linear analysis of an interaction system are reviewed briefly, after which a three dimensional (3D) model of the stress redistribution of soil based on the Mohr–Coulomb failure law is presented to evaluate the unbalanced tensor at every iteration in the load transfer method. A 3D, full non‐linear analysis was used to examine the validity and accuracy of results obtained by 2D analysis by combining the model of redistributed stresses proposed here with the joint element model.Based on the numerical solution reported here, we concluded that both the 3D and 2D models of stress redistribution work well and reflect the yielding pattern of soil during excitation, but the former is more realistic. The failure area in the structural zone obtained by 3D analysis is slightly larger but similar to that obtained by 2D analysis. The ratio of maximum strain to yield strain and non‐linear time ratio, βs, for the soil elements in the structural zone are also a little larger. In contrast, the maximum separation values for the joint elements are much smaller and the separation pattern for thex‐side wall interface is the reverse of that found by 2D analysis. These values, however, affect only responses in the short period range and the regions close to the interface. In general, the tendencies shown by 2D analysis for the effects of non‐linear behaviour on structural responses are confirmed for the parameters

ISSN:0098-8847    

DOI:10.1002/eqe.4290150803

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA simplified method of analysis of base‐isolated structures supported on flexible soil is presented, in which the soil–base‐isolated‐structure system is represented by a SDOF oscillator supported on rigid soil. A parametric study illustrates the application and accuracy of the method. The results obtained lead to the conclusion that the simplified procedure that is presented is sufficiently accurate for purposes of preliminary design of base‐isolated structures, and for studies to determine the feasibility of using base

ISSN:0098-8847    

DOI:10.1002/eqe.4290150804

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA method to generate artificial time‐histories from given floor response spectra is presented in this paper. The original method proposed by Levy and Wilkinson1is modified. New iterative equations are developed, based on extensive computational experimentation, to speed up and stabilize the convergence process. The present approach, when applied to spectra with peaks in the high frequency range (40 to 100 Hz) along with seismic peaks, converges very closely to the target spectra within eight iterations regardless of damping values. The original computer program for synthetic time‐history generation was developed on the UNIVAC 1100 series computer. This program was converted to work on the IBM PC. The PC based program ‘MICRO‐SEIM’ saves the response spectra generated at each iteration and the final synthetic time‐history on the PC diskette. The post processing program reads those saved data from the diskette and plots the spectra and t

ISSN:0098-8847    

DOI:10.1002/eqe.4290150805

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractReinforced concrete members subjected to cyclic inelastic deformation may exhibit both stiffness and strength degradation, depending on the maximum amplitude and the number of cycles experienced by the member. Many of the currently available models do not simulate the cycle‐dependent stiffness loss often observed during the experiments. An analytical model based on a damage parameter which is a function of the cumulative cyclic inelastic deformation is proposed. A small‐scale reinforced concrete beam–column joint was constructed and subjected to cyclic loading to calibrate the damage parameter. The model is able to approximate the complete hysteretic response and is simple to implement. The sensitivity of the analytical model was examined by comparing the model with several experimental re

ISSN:0098-8847    

DOI:10.1002/eqe.4290150806

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractFor a proper response spectrum analysis of a secondary system with multiple supports, the seismic inputs are required to be defined in terms of the auto and cross floor response spectra. If no feed‐back or interaction effect from the secondary system to its supporting primary structure is suspected, these inputs can be developed by a direct analysis of the supporting structure alone. However, sometimes the effect of the interaction on the secondary system response can be quite significant. Herein, a method is developed to incorporate the feed‐back effect, through proper modification of the interaction‐free floor spectrum inputs. The interaction coefficients are used to effect such modifications in different floor spectral quantities. A procedure for the calculation of the interaction coefficients is proposed. The modified floor spectra when used as inputs to the secondary system do introduce the interaction effect in the secondary system response. A successful application of this method is demonstrated by numerical examples of secondary systems with three different secondary‐to‐primary system ma

ISSN:0098-8847    

DOI:10.1002/eqe.4290150807

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractUsing reciprocal theorems for dynamic and static boundary value problems, boundary integral equations are presented for wave propagation in elastic, isotropic media and compressible, inviscid fluids in the time domain as well as in the frequency domain. For the analysis of fluid–soil and fluid–structure systems, suitable coupling conditions are prescribed along the interfaces. The numerical treatment of the boundary integral equations consists of a point collocation and of a discretization of the boundary, in which constant and linear approximation functions are assumed. Step‐by‐step integration is applied to the time‐dependent equations, where again the states are taken to be linear and constant over each time interval.These boundary element procedures are used to analyse the response of dams due to horizontal and vertical ground motions considering dam–water interaction and absorption of hydrodynamic pressure waves at the reservoir bottom or at the far end into the soil medium. Both the frequency response and the impulse generated transient response are i

ISSN:0098-8847    

DOI:10.1002/eqe.4290150808

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290150809

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290150810

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290150811

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY