摘要:

AbstractA response spectrum method for dynamic analysis of linear structures subjected to multicomponent seismic input is developed. The method is based on elementary concepts of stationary random vibration and assumes the existence of a set of principal directions along which components of ground motion are uncorrelated. Modal combination rules in terms of ground response spectra are developed for the mean and standard deviation of peak responses and for rootmean‐square responses. These rules account for correlations between modal responses of the structure, as well as correlations between the input components. When the position of principal directions is unknown, two alternative rules are proposed: one uses the direction which is most critical for the response quantity of interest, and the other considers the direction as a random variable. The proposed method is simple for practical implementation and gives more accurate results than other existing method

ISSN:0098-8847    

DOI:10.1002/eqe.4290130103

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe linear response of an idealized concrete gravity dam monolith to harmonic horizontal or vertical ground motion is presented for a range of the important system parameters that characterize the properties of the dam, foundation rock, impounded water and reservoir bottom materials. Based on these frequency response functions, the effects of alluvium and sediments at the reservoir bottom on the response of the dam, including its interaction with the impounded water and foundation rock, are investigated. It is shown that the partial absorption of hydrodynamic pressure waves by the reservoir bottom materials has an important effect on the dynamic response of concrete gravity dams.

ISSN:0098-8847    

DOI:10.1002/eqe.4290130104

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractIt is shown that two of the damping ratios of certain systems composed of a building and a small attachment in resonance are given by the average of the damping ratios of the two independent components. Based on this fact and the fact that the seismic response of a building can always be reduced by increasing its damping, it is demonstrated that the attachment of a small heavily‐damped system in resonance can increase the damping of a building and reduce thus its response to earthquake excitations. Numerical solutions are presented to confirm the demonstration, and recommendations are given to calculate the parameters of such system

ISSN:0098-8847    

DOI:10.1002/eqe.4290130105

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe usual assessment of performance of Newmark's method for direct integration in structural dynamics is by reference to amplitude and period error of a single mode of vibration. As an alternative the local and global truncation errors due to the time discretization are introduced. Methods of obtaining norms of the error sequences are presented. The results of numerical experiments confirm the anticipated error order and show how the error formula varies with β. The effect of the presence of physical damping on the error order and formula is also examined

ISSN:0098-8847    

DOI:10.1002/eqe.4290130106

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractA boundary element formulation for the dynamic analysis of axially and laterally loaded single piles and pile groups is presented. The piles are represented by compressible beam‐column elements and the soil as a hysteretic elastic half‐space. The governing equations of motion for the pile domain have been solved exactly for distributed periodic loading intensities. These solutions are then coupled with a numerical solution for the motion of the soil domain by satisfying equilibrium and compatibility at the pile‐soil interface. The results obtained from the analysis compare favourably with those from alternative analyses, e.g. finite element, but at greatly reduced computational

ISSN:0098-8847    

DOI:10.1002/eqe.4290130107

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractBecause earthquake intensity has strong fuzziness, it may be considered as a fuzzy subset of an intensity reference set. The methods of single‐stage and two‐stage multifactorial evaluation that are presented herein can be used to evaluate this intensity. The human responses and experiences that are often employed to rate earthquake intensity can be expressed concretely in mathematical form through the use of these methods. In addition, by using related membership levels in the fuzzy vector of intensity, a method has been developed to determine the values of the parameters used in structural aseismic des

ISSN:0098-8847    

DOI:10.1002/eqe.4290130108

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractSome lifelines, such as gas and oil transmission lines and water and sewer pipelines, have been damaged in recent earthquakes. The damages of these lifelines may cause major, catastrophic disruption of essential services for human needs. Large abrupt differential ground movements that result from an active fault present one of the most severe effects of an earthquake on a buried pipeline system.Although simplified analysis procedures for buried pipelines across strike‐slip fault zones that cause tensile failure of the pipeline have been proposed, the results are not accurate enough because of several assumptions involved, such as the omission of flexural rigidity of the pipe, simplification of soil resistant characteristics, etc. Note that the omission of flexural rigidity cannot satisfy equilibrium conditions for pipelines across a ‘reverse’ strike‐slip fault that causes compressions in the pipeline.This paper presents a refined analysis procedure for buried pipelines that is applicable to both strike‐slip and reverse strikeslip faults after modifying some of the assumptions used previously. Based on the analytical results, this paper also discusses the design criteria for buried pipelines which are subjected to various fault movements. Parametric responses of buried pipeline for various fault movements, angles of crossing, buried depths and pipe diameters are

ISSN:0098-8847    

DOI:10.1002/eqe.4290130109

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractAccelerograms from the Imperial Valley have been integrated and baseline corrected by a simple procedure which keeps track of the signal that is removed at long periods. Specifically, acceleration is integrated once to obtain velocity, a linear baseline is subtracted from velocity, the velocity is integrated to displacement, and low order terms of a trigonometric expansion of displacement are subtracted. It is observed that even though this procedure is not suitable for routine processing, one obtains displacement traces which usually resemble the results obtained by standard methods. It is also observed that amplitudes of the trigonometric series expansions are consistent with a simple earthquake source theory for frequencies greater than 1/12 Hz, suggesting that the records are dominated by signal at those frequencies.

ISSN:0098-8847    

DOI:10.1002/eqe.4290130110

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractIn this investigation, the feasibility of earthquake simulation in centrifuge soil experiments is studied. The strong detrimental effect of standing waves for such an endeavour is clearly shown. A modest degree of success toward producing a model earthquake is reported via two devices—a certain kind of physically tuned internal excitor and an effective absorbent material at the wall

ISSN:0098-8847    

DOI:10.1002/eqe.4290130111

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290130112

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY