摘要:

AbstractStatistical analyses on a catalogue of instrumental data for earthquakes in northeastern Italy since 1900 are presented. The different types of magnitude, which are the main parameters under study, have been evaluated so as to be as homogeneous as possible. Comparisons of the different magnitude values show linear dependence, at least in the medium magnitude range represented by the available data set. Correlations between the magnitude most significant for this region and chosen macroseismic data indicate a methodology for assessing the macroseismic magnitude of historical earthquakes which seems to be stable.

ISSN:0098-8847    

DOI:10.1002/eqe.4290221202

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper presents a probabilistic approach to the estimation of lateral strengths required to provide an adequate control of inelastic deformations in structures during severe earthquake ground motions. In contrast to a deterministic approach, the approach presented herein accounts explicitly for the variability of the response of non‐linear systems due to the inherent uncertainties in the intensity and characteristics of the input excitation by considering the probability distribution of maximum inelastic strength demands. This study is based on the computation of non‐linear strength demands of single‐degree‐of‐freedom (SDOF) systems experiencing different levels of inelastic deformation when subjected to 124 recorded earthquake ground motions. Using empirical cumulative distribution functions site‐dependent probabilistic non‐linear spectra were computed for six probabilities of exceedance of different levels of inelastic deformation. It is concluded that the lateral strength required to control displacement ductility demands is significantly affected by the maximum tolerable inelastic deformation, the system's period of vibration, the local site conditions and the level of risk in exceeding the maximum tolerable

ISSN:0098-8847    

DOI:10.1002/eqe.4290221203

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA simple and general technique to obtain a six‐component earthquake input motion of a rigid foundation using three‐linear‐components earthquake record is presented. Using the multicomponent input, the maximum structural response to an arbitrarily oriented earthquake is derived. The method is applied to determine the response spectrum for a two‐d.o.f. laterally and torsionally coupled linear system. The effects of foundation geometry, structural properties and apparent wave velocity on the structural response are investigated. It is found that increasing the foundation size reduces the peak values of the input motion; this reduction is more pronounced for a square foundation than for a circu

ISSN:0098-8847    

DOI:10.1002/eqe.4290221204

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe seismic response of a dam is strongly influenced by its interaction with the water reservoir and the foundation. The hydrodynamic forces in the reservoir are in turn affected by radiation of waves towards infinity, wave absorption at the reservoir bottom, and cross‐coupling between the foundation below the dam and the reservoir bottom. The fluid–foundation interaction effect, i.e. the wave absorption along the reservoir bottom, can be accounted for by using either an approximate one‐dimensional (1D) wave propagation model or a rigorous analysis of interaction between the flexible soil along the base and the water. The rigorous approach requires enormous computational effort because of (a) cross‐coupling between the foundation of the dam and the soil below the reservoir and (b) frequency dependence of the boundary condition along the fluid‐foundation interface. The analysis can be simplified by ignoring the cross‐coupling and by using the approximate 1D wave propagation model. The effects of each of these two simplifications on the accuracy and computational efficiency of the procedure used for the seismic response analysis of a dam are examined. Analytical results are presented for the complex frequency‐response functions as well as the time histories of the response of Pine Flat dam to Taft and E1 Centro g

ISSN:0098-8847    

DOI:10.1002/eqe.4290221205

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA structure incorporating the mechanism of sliding, as used in seismic isolation, along with the mechanism of uplift, but at a different elevation, is proposed to study the possible beneficial effects on the response of the structure, as compared to allowing partial base uplift only. A two‐mass model of system uplift and sliding is established. The equations of motion for both the phase of full contact and the phase of base uplift are derived. The criteria governing the transformation of these two phases are given. Both the time history and the response spectrum results show that the structure with both uplift and sliding mechanisms is superior to that with only the uplift mechanism. Not only is the response of the structure lessened, but also the amount of uplift is greatly reduced because of the added sliding mechanis

ISSN:0098-8847    

DOI:10.1002/eqe.4290221206

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290221207

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290221208

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290221201

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY