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Shear vibration of vertically inhomogeneous earth dams
Author(s) -
Gazetas George
Publication year - 1982
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.1610060208
Subject(s) - crest , vibration , geology , shear (geology) , modal , cube (algebra) , homogeneous , structural engineering , geometry , mathematics , physics , materials science , engineering , acoustics , petrology , combinatorics , polymer chemistry , quantum mechanics
Closed‐form solution to the problem of free vibrations of vertically inhomogeneous earth dams, modelled as truncated‐wedge‐shaped shear beams, has been obtained by implementing an inverse procedure in which the determination of the function descrbing the inhomogeneity constitutes part of the problem. The resulting cube‐root variation of the shear‐wave velocity with distance from the crest compares very favourably with measurements in two Japanese dams. The results of the method are presented in theform of natural periods, modal shapes and average seismic coefficients for a number of truncation ratios. Compared with an ‘equivalent’ homogeneous dam, the inhomogeneous experiences sharper amplification of modal displacements and greater averge seismic, coefficients near the crest and has natural periods which are closer to each other. This behaviour is in better agreement with the observed response of a 37m‐high dam during five earthquake motions.