Analysis of Two and Three-Dimensional R.C.C. Frames
Md. Atikur Rahman Talukder
strong earthquake vibrations, Reinforced Concrete (R. C. C.) structures have
often behaved unsatisfactorily in recent earthquakes in USA, Japan, Taiwan,
Turkey, India and many other countries. Results of two-dimensional linear
dynamic analyses of R. C. C. structures have shown that the ‘equivalent’
static forces predicted by the existing building codes are often much smaller
than the dynamic forces. Two-dimensional nonlinear dynamic analyses have shown
that the static forces may not be adequate for a safe design against severe
earthquakes. Therefore, this work is conducted with a view towards extending the
studies to nonlinear three-dimensional analysis. The linear three-dimensional
analysis of R. C. C. frames performed in this study is a step in that direction.
ground motion data from the Kobe earthquake (Japan, 1995) and the Northridge
earthquake (USA, 1994) are used to conduct structural dynamic analyses.
dynamic analyses are conducted on 2, 5 and 10 storied buildings with
‘adequate’ structural dimensions from static point of view. The results
indicate that the maximum shear forces in the ‘critical’ beams and columns
of these buildings predicted by the 2-dimensional and 3-dimensional analyses are
often quite different and may be significant from design point of view. Also the
shear forces predicted by the static analyses are found to be much smaller than
the earthquake-induced forces in all the cases studied here.