r - The Hong Kong Polytechnic University

In order to check the loss assessment results, a series of dynamic time-history analysis are carried out by a
nonlinear fiber program “SeismoStruct”. Four 2D reinforced concrete frames with two bays are built in fiber
element, 5-storey (H T =15m, T y =1.5s), 8-storey (H T =24m, T y =2.4s), 10-storey (H T =30m, T y =3.0s) and 12-storey
(H T =36m, T y =3.6s) respectively. Geometry parameters of the model frames are used the same with that in Table
1. Since fiber elements model only flexural response. Shear strength and shear deformation are generally not
modeled. Column-beam joints and foundation joints are modeled by elastic non-fiber spring elements in order to
take the joint rotation and shear deformation into account. The analysis outcomes are shown in Figure 6 and the
maximum equivalent displacement is calculated as Equation (16)
Δ
eq
=
n
∑
i=
1
2
i i
m Δ
n
∑
i=
1
m Δ
where m i is the mass at the height H i associated with maximum displacement Δ i during the time-history analysis.
i
i
(16)
Displacement (cm)
25
20
15
10
PGA=0.25g
Ta=0.15s
Tb=0.5s
Tc=2.5s
T=3.13s
H=31.3m
Capacity Displacement
5 T=0.91s
H=9.1m Demand Displacement
0
0 1 2 3 4 5 6
Period (seconds)
Figure 5 Beam-sway RC frame yield capacity and demand curves
Displacement (m)
0.27
max disp. of a single wave
0.24
Average Displacement
0.21
Demand Displacement
0.18
Capacity displacement
0.15
0.12
0.09
0.06
0.03
5-storey RC frame
PGA=0.25g
0.00
0 2 4 6 8 10 12 14 16 18 20
Serial number of artificially wave
Displacement (m)
0.27 8-storey RC frame
0.24
PGA=0.25g
0.21
0.18
0.15
0.12
Max disp. of a single wave
0.09
Average Displacement
0.06
Demand Displacement
0.03
Capacity Displacement
0.00
0 2 4 6 8 10 12 14 16 18 20
Serial number of artificially waves
Displacement (m)
0.27
10-storey RC frame
0.24
PGA=0.25g
0.21
0.18
0.15
0.12
Max disp. of a single wave
0.09
Average displacement
0.06
Demand displacement
0.03
Capacity displacement
0.00
0 2 4 6 8 10 12 14 16 18 20
Serial number of artificially waves
Displacement (m)
0.27
0.24
0.21
0.18
0.15
12-storey RC frame
PGA=0.25g
0.12
Max disp. of a single wave
0.09
Average displacement
0.06
Demand displacement
0.03
Capacity displacement
0.00
0 2 4 6 8 10 12 14 16 18 20
Serial number of artificially waves
Figure 6 Maximum equivalent displacement of time-history analysis
According to the result of the DBELA, the 5-storey and 8-storey reinforced concrete frames have been failed in
the yield limit state, which agrees well with the result of dynamic time-history analysis. All the maximum
-305-