Civil Engineering Association

A study of the measurement, prediction and characterisation of
the dynamic behaviour of tall buildings is presented. Initially
a review of the history of tall buildings and the study of their
dynamic behaviour is presented. The characterisation of tall
buildings by conventional means and by the use of spectral
functions is considered.
The results of tests on twelve tall buildings and one quarter-scale
model are presented. The response of twelve of these structures
to wind excitation has been monitored, and, for the purpose of
calibration, all but one of the buildings has been excited
artificially by the use of eccentric mass vibrators. The handling
of deterministic and random data is considered and some new
techniques for their reduction are presented.
The introduction of a new vibrator system has allowed the study of
the dynamic characteristics of tall buildings with a greater
precision than has previously been possible. The new precision
has suggested reasons for the confusion which previously existed
in the assessment of dynamic characteristics of tall buildings,
and a new rationale for the prediction of natural frequencies and
damping ratios is presented.
Finally, currently popular methods for the prediction of the
response of tall buildings to wind excitation are considered and
comparisons have suggested several areas where research is
urgently needed.