Transient waves generated by a vertical flexible wavemaker plate with a general ramp function

The propagation of transient waves in a homogeneous, isotropic, linearly elastic half space excited by a traveling normal point load is investigated. The load is suddenly applied and then it moves rectilinearly at a constant speed along the free surface. The displacements are derived for the interior of the half space and for all load speeds. Wave-front expansions are obtained from the exact solution, in addition to results pertaining to the steady-state displacement field. The limit case of zero load speed is considered, yielding new results for Lamb’s point load problem.

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Transient waves in an infinite thick plate on elastic foundation subjected to concentrated moving loads.

Doboku Gakkai Ronbunshu ◽

10.2208/jscej.1996.543_71 ◽

1996 ◽

pp. 71-81

Author(s):

Kiyoshi Ishikawa ◽

Teruhiko Yoda ◽

Masaharu Hirashima

Keyword(s):

Elastic Foundation ◽

Thick Plate ◽

Moving Loads ◽

Transient Waves ◽

Plate On Elastic Foundation

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Elastic displacements in the near-field of a propagating fault

Bulletin of the Seismological Society of America ◽

10.1785/bssa0590020865 ◽

1969 ◽

Vol 59 (2) ◽

pp. 865-908

Author(s):

N. A. Haskell

Keyword(s):

Fault Plane ◽

Near Field ◽

Strong Motion ◽

Dislocation Motion ◽

Displacement Discontinuity ◽

Wave Form ◽

Strong Motion Station ◽

Ramp Function ◽

Wave Forms ◽

Parkfield Earthquake

abstract Displacement, particle velocity, and acceleration wave forms in the near field of a propagating fault have been computed by numerical integration of the Green's function integrals for an infinite medium. The displacement discontinuity (dislocation) on the fault plane is assumed to have the form of a unilaterally propagating finite ramp function in time. The calculated wave forms in the vicinity of the fault plane are quite similar to those observed at the strong motion station nearest the fault plane at the Parkfield earthquake. The comparison suggests that the propagating ramp time function is roughly representative of the main features of the dislocation motion on the fault plane, but that the actual motion has somewhat more high frequency complexity. Calculated amplitudes indicate that the average final dislocation on the fault at the Parkfield earthquake was more than an order of magnitude greater than the offsets observed on the visible surface trace. Computer generated wave form plots are presented for a variety of locations with respect to the fault plane and for two different assumptions on the relation between fault length and ramp function duration.

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