摘要:

AbstractA strong‐motion accelerograph array in Santiago, Chile has been installed. One of the sites is located on rock and the other six sites are on soil ground with different surface geology, so that local site effects on ground motions can be studied. As a preliminary evaluation of the site effects, the spectral ratios of weak‐motion records at soil sites with respect to the rock site are calculated. The spectral ratios show that the amplification of ground motions with respect to the rock site is approximately 1.25 on dense gravel deposits, 2.5 on stiff pumice ground and 3.5 on soft silt gro

ISSN:0098-8847    

DOI:10.1002/eqe.4290200502

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe paper deals with the non‐linear dynamic analysis of concentrically braced pinned frames under earthquake conditions. A model is first presented for the behaviour of bars subjected to cyclic axial force, which takes into account the overall and local buckling phenomena, section shape, residual stresses, material behaviour and damage accumulation due to low‐cycle fatigue and fracture. Dynamic analyses of bracing systems are then described: these have been performed, on the basis of the axially loaded bar model, within the framework of a simplified procedure for the determination of optimal design factors. The results obtained are first reported for the case of one‐storey systems; an example of the behaviour of a four‐storey system is given

ISSN:0098-8847    

DOI:10.1002/eqe.4290200503

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe horizontal earthquake induced hydrodynamic pressure acting on the surface of axisymmetric offshore and coastal structures is explored. A semi‐analytical and semi‐numerical approach based on the use of a complete and non‐singular set of Trefftz functions is developed. Using this method, one can model accurately the compressibility of the sea water and gravity waves on the water surface. The proposed method shows a relatively simple and efficient approach. This is because the number of degrees of freedom in the matrix equation depends only on the number of selected Trefftz functions and because the discretization of the fluid domain into boundary elements is restricted to the structural surface only. This method is also easy to apply in engineering analysis of hydrodynamic pressure induced by an actual earthquake acceleration. Numerical examples are presented to illustrate the results obtained from this method. Several special interesting topics, such as the effects of the water compressibility, the gravity waves on the water surface and the geometrical shape of the structural surface, are also disc

ISSN:0098-8847    

DOI:10.1002/eqe.4290200504

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper is concerned with the dynamic response of a system of flexible strip foundations resting in smooth contact with a homogeneous isotropic viscoelastic half space. An arbitrary number of foundations with different flexibilities and geometries subjected to time‐harmonic distributed loadings are considered in the formulation. The response of each strip foundation is governed by the classical plate theory and its transverse deflection is represented by an admissible function containing a set of generalized co‐ordinates. A coupled variational‐Green's function scheme is employed to establish the equations of motion of the strip foundation system. The numerical stability and convergence of the solution scheme are established. The influence of the foundation flexibility, distance between adjacent foundations and frequency of motion on the response of the foundation system is investigated in the numerical

ISSN:0098-8847    

DOI:10.1002/eqe.4290200505

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes an analysis of damage costs to house and farm property in the Ms= 6.6 Edgecumbe, New Zealand earthquake of 2 March 1987. The study investigated damage ratios for dwellings, their contents and domestic motor vehicles. The damage costs were converted to damage ratios by dividing them by the total value of the relevant property in the intensity zones concerned. The mean values and statistical distributions of these damage ratios were then found, the lognormal distribution fitting very well.The mean damage ratio for house buildings at MM intensity IX was 0.080 and the mean damage ratios were generally smaller than previous studies had shown. The mean damage ratios were similar for buildings and contents from MM6 to MM9, but there was no correlation between building and contents damage on an individual basis.

ISSN:0098-8847    

DOI:10.1002/eqe.4290200506

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper uses an incremental mode‐superposition procedure to compute the inelastic dynamic response of multi‐degree‐of‐freedom systems. A damping matrix proportional to the instantaneous properties is used throughout the analysis. The non‐linear response of several shear type plane and space frames with elastic‐plastic and bilinear column properties subjected to ground excitation was computed by both the incremental mode‐superposition and the direct integration of the coupled equations of motion. When all modes are considered, the responses computed by the incremental mode‐superposition are identical to those from the direct integration. Fewer modes can also be used to compute the response with reasonable accuracy by performing the modal truncation for each time increment.The study shows that incorporating instantaneous damping in non‐linear dynamic analysis is relatively simple and requires less computational time than the d

ISSN:0098-8847    

DOI:10.1002/eqe.4290200507

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe objective of this paper is to develop a unified earthquake‐resistant design method for moment‐resisting steel frames, including the design earthquake via a dynamic ARMA model.Important features of this design method are: (i) to make it possible to incorporate inherent uncertain features of design earthquakes into the design process itself through the dynamic ARMA model, (ii) to provide a simplified design formula for a preliminary design of moment‐resisting steel frames based upon the concept of stiffness‐oriented design and (iii) to facilitate the formulation of a new probabilistic multi‐objective optimal design problem aimed at finding the design with the minimum level of designer's dissatisfaction. In this optimal design problem, constraints and objectives are handled in a unified manner after a feasible design is obtained.A design example is presented to demonstrate the validity of this unified design method and to examine the convergence of response statistics. Finally, the generality and practicality of this design method are

ISSN:0098-8847    

DOI:10.1002/eqe.4290200508

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290200509

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290200501

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY