摘要:

AbstractIn recognition of the life‐threatening dangers posed by many thousands of buildings completed prior to the requirement for provision of any specific earthquake resistance, in 1981 the City of Los Angeles adopted a seismic safety ordinance requiring the upgrading of these buildings to predetermined engineering standards. Various methods of modifying such structures, which are characteristically of unreinforced multi‐storey masonry bearing wall configuration with interior wood framing, are summarized in this paper. In addition to presenting typical structural details, some of the socio‐economic and financial aspects of the earthquake hazard mitigation programme are disc

ISSN:0098-8847    

DOI:10.1002/eqe.4290120202

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractTransient flexural vibrations of an elastic column supported by an elastic half‐space are investigated analytically under the condition that an arbitrarily shaped free‐field lateral acceleration is given as an input. Applying the Timoshenko theory to the column and making use of Laplace transformations with respect to time and numerical inverse Laplace transformations, the time histories of the column free end acceleration are presented. Numerical results obtained from the Timoshenko theory are compared with those of a previous paper1(applying the Bernoulli‐Euler theory to the column), and the effects of column slenderness and foundation stiffness on the transient flexural vibrations of the column are clar

ISSN:0098-8847    

DOI:10.1002/eqe.4290120203

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe steady‐state solution for two parallel under ground tunnels of circular cross‐section subjected to incident plane harmonic SH‐waves is obtained in closed form, by using the method of wave function expansion. The image technique is employed to account for the reflection of waves at the ground surface. Numerical studies are carried out to determine the influence of spacing between the tunnels on the shear stresses in concrete and steel li

ISSN:0098-8847    

DOI:10.1002/eqe.4290120204

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA linear multistorey structure with a seismic base isolation system consisting of rubber bearings and frictional elements is considered. The non‐linear equations of motion are derived for the first mode vibration and the stochastic response to a white noise ground acceleration is determined. Based on this response, suitable objective functions are defined and the optimum design of the isolation system is performed. It is shown that a small amount offriction increases the effectiveness of the system compared with the same system but without frictional element

ISSN:0098-8847    

DOI:10.1002/eqe.4290120205

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractPrecast concrete panels form attractive facades for steel frame buildings and are generally regarded as non‐structural by structural engineers. However, panels have been found to add lateral stiffness until their capacity or that of their connections is exceeded. Consequently, the computed dynamic response based on a model of the structural framing alone may be quite different from that experienced by the actual structure.As a case study, the influence of precast concrete panels on lateral and torsional stiffness of a 25‐storey building was investigated. The effect of cladding on dynamic properties and linear seismic response was explored by varying panel stiffness. Cladding stiffness was added to the bare frame model until analytical frequency values matched vibration test results. Then, using the cladding stiffness values obtained, an accidental eccentricity between centres of mass and rigidity at each floor level was imposed and linear seismic response computed. Torsional response effects were increased substantially. Finally, a modified cladding panel connection was developed based on previously‐reported studies for panelized construction. The influence of the proposed connection on overall structural response was determined for different ground motion i

ISSN:0098-8847    

DOI:10.1002/eqe.4290120206

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractAn analytical representation of the bilinear hysteretic characteristic is presented. Using this representation, the response of a single‐degree‐of‐freedom bilinear hysteretic system subjected to non‐stationary random excitation is examined by equivalent linearization. An ordinary differential equation is derived for the covariance matrix of the response. Numerical examples are presented and the accuracy of the approach is demonstrated. Extension of the approach to a wider class of hysteretic systems is di

ISSN:0098-8847    

DOI:10.1002/eqe.4290120207

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe work presented in this paper investigates the effect of the foundation flexibility on the coupled lateral‐torsional response of single‐storey buildings excited by translational ground motion. The eccentricity between the centre of mass and the centre of resistance is considered to be the only cause of coupling of the lateral and torsional response of the building.The study is confined to the steady‐state response of rigidly supported and flexibly supported torsionally coupled buildings subjected to harmonic free‐field ground displacement perpendicular to the direction of the eccentricity. In the case of the flexibly supported building the foundation medium is assumed to be an elastic homogeneous isotropic half‐space.The effect of the controlling parameters on lateral‐torsional coupling is investigated. It is concluded that for a particular range of values of these parameters (representing most cases of actual buildings) their effect on the coupling of lateral and torsional response is not qualitatively affected by increases in the flexibility of the founda

ISSN:0098-8847    

DOI:10.1002/eqe.4290120208

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effects of transient foundation uplift on the earthquake response of flexible structures are investigated. The structural idealization chosen in this study is relatively simple but it incorporates the most important features of foundation uplift. In its fixed base condition the structure itself is idealized as a single‐degree‐of‐freedom system attached to a rigid foundation mat which is flexibly supported. The flexibility and damping of the supporting soil are represented by a Winkler foundation with spring‐damper elements distributed over the entire width of the foundation. Based on the response spectra presented for several sets of system parameters, the effects of foundation‐mat uplift on the maximum response of structures are identified. The influence of earthquake intensity, structural slenderness ratio, ratio of foundation mass to structural mass, foundation flexibility andp‐δ effects on the response of uplifting structures is also

ISSN:0098-8847    

DOI:10.1002/eqe.4290120209

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290120211

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290120212

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY