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Ambient vibration test of an anchorage of South Bisan‐seto suspension bridge
Author(s) -
Higashihara Hiromichi,
Moriya Tamotsu,
Tajima Jiro
Publication year - 1987
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/eqe.4290150603
Subject(s) - vibration , structural engineering , natural frequency , geotechnical engineering , suspension (topology) , geology , elasticity (physics) , bridge (graph theory) , young's modulus , seismology , inertial frame of reference , engineering , acoustics , physics , materials science , mathematics , composite material , medicine , homotopy , pure mathematics , quantum mechanics
Dynamical properties of an anchorage of South Bisan‐seto Suspension Bridge are determined by means of in situ measurement of the ambient vibrations. This anchorage, being located in the sea, is tall and slender; its natural frequencies are expected to be low. On the other hand, the elasticity of the ground estimated from the conventional geological data is highly dispersed. It even suggests the possibility of resonance between the towers and this anchorage. It is therefore necessary to know its natural frequencies precisely. Seismic motions and microtremors are acquired and used properly. The observation is repeated every year during the period of construction of the anchorage so that its inertial properties change significantly. First modes of the longitudinal and the transversal vibrations of the anchorage are identified and their frequencies determined. The elasticity modulus estimated from these natural frequencies is about five times as large as that of the geological survey while it is consistent with that obtained from the velocity of the elastic waves of the ground.