摘要:

AbstractIt is pointed out that the number of modes which should be included in a mode superposition dynamic response analysis depends on both the frequency content and the distribution of the loading. If the loading frequency is low the effect of the higher modes can be approximated by a static analysis. A technique is described for calculating this static contribution from the higher modes; the total response is then represented by the sum of the lower mode dynamic response and the higher mode static effects. The effectiveness of the procedure is demonstrated by a numerical example.

ISSN:0098-8847    

DOI:10.1002/eqe.4290070502

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe International Workshop on Strong‐motion Earthquake Instrument Arrays was held during 2‐5 May 1978 in Honolulu, Hawaii. The goal of the workshop was to develop a workable plan for the possible future deployment of dense strong‐motion arrays with primary emphasis on ground motion studies. Topics considered by the workshop included: favourable array locations, the design of arrays for source mechanism and wave propagation studies, the design of arrays for local effects studies, array construction and operation, and implementation. This paper gives a summary of the recommendations and conclusions of the wor

ISSN:0098-8847    

DOI:10.1002/eqe.4290070503

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA number of problems relating to characteristics of harmonic phase angles contained in earthquake ground motions are discussed, which have been mostly overlooked in the past in contrast with the importance placed on harmonic amplitudes. Particularly, the significance of the concept of phase differences in certain properties of earthquake ground motions is emphasized. A few applications of this new concept to earthquake engineering problems are illustrated as well.

ISSN:0098-8847    

DOI:10.1002/eqe.4290070504

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA method for calculating the two‐dimensional scattering of incident SH waves by canyons of arbitrary shape is presented. The problem is formulated in terms of a Fredholm integral equation of the first kind with the integration path outside the boundary. Point‐source discretization and a least‐squares scheme are used. Numerical results are compared with the known analytic solution for a semi‐cylindrical canyon. Spatial variations of surface amplitudes are computed for triangular and half‐cycle sinusoidal canyon

ISSN:0098-8847    

DOI:10.1002/eqe.4290070505

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractSeismic response of underground pipelines is investigat́ed theoretically considering dynamic soil‐pipe interaction. A lumped mass model of the pipe is employed with the soil reactions derived from static and dynamic continuum theories. The soil is supposed to be homogeneous or composed of two different media separated by a vertical boundary. Axial and bending stresses in the pipe due to travelling waves are examined.An extensive parametric study indicates that the axial stresses in the pipe are much higher than bending stresses. In a homogeneous medium, soil‐pipe interaction reduces the stresses in the pipe compared to those calculated ignoring interaction. In a soil composed of two different media, the pipe stresses are highest close to the boundary and can exceed those predicted neglecting interac

ISSN:0098-8847    

DOI:10.1002/eqe.4290070506

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThis paper is concerned with the free vibrations of a restricted class of multi‐storey shear buildings in which inertial coupling exists between the torsional and the two sway vibrations. The restrictions imposed are that (a) the shear centres of all storeys lie on a vertical straight line, (b) the principal axes of shear are in the same directions in all storeys, (c) the centres of mass of all floors lie on another vertical straight line, (d) the radius of gyration about the shear centre of every floor mass is the same and (e) the ratios of the two shear stiffnesses to the torsional stiffness do not vary from storey to storey.In consequence of the last restriction it is proved that the 3nnatural frequencies, normal modes and generalized masses, wherenis the number of storeys, are expressible very simply in terms of products of the three natural frequencies, normal modes and generalized masses of the single‐storey, three‐dimensional building formed by removing everything above the first floor, with thennatural frequencies, normal modes and generalized masses of a certainn‐storey, two‐dimensional shear frame.In the special case of auniformbuilding, a simple closed form solution, valid for any number of storeys,

ISSN:0098-8847    

DOI:10.1002/eqe.4290070507

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractAlthough the Santa Barbara earthquake was only a moderate seismic event, it was the most destructive earthquake in the United States in 1978 causing more than $7 million damage and at least 65 injuries. Reported Richter magnitudes ranged from 5–1 to 5–7, but estimates based on strong motion records yielded about 5–8. Due to the geologic features of the earthquake, the intensity of strong shaking was geographically asymmetrical, being much larger in the Goleta area north and west of the epicentre. Peak ground accelerations of 0–40gwere recorded near Goleta, while 0–23gwas recorded closer to the epicentre in Santa Barbara. The duration of strongest shaking was only about 2–3 s. The earthquake caused light cracking of shear walls in multi‐storey reinforced concrete structures, as well as damage to highway overcrossings, many mobile homes and to rooftop mechanical equipment. Presented in this paper are the results of preliminary investigations of the engineering features of th

ISSN:0098-8847    

DOI:10.1002/eqe.4290070508

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290070509

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290070501

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY