Based on the above statements, six prototype models are defined as (IIC-10th), (IFBC-10th), (IIC-All), (IFBC-All), (IIC), and IFBC. Configurations of all the models are explained in the following:
(vi) Model IFBC stands for a structure with an inner fixed base core only, which has no outer frames.
From Table 9, we can see that in terms of collapse capacity, the IFBC model when compared to those with embedded outer stiff frames (e.g., IFBC-All) displayed a marked reduction of 16.42% and 94.40% in spectral acceleration and interstory drift ratio, respectively.
Generally, flatter curves (e.g., IFBC-10th, IFBC-All, and IIC-All) exhibit a longer elastic range, whereas when the slope of the yielding curves continually increase (e.g., IIC-10th, IIC, and IFBC), elastic range becomes short and maximum yielding capacity is reached early.
From this figure, it is evident that the IIC structure has significantly lower collapse probability compared to that of IFBC-10th, IIC-10th, IFBC-All, IFBC, or IIC-All.
For brevity, only the first three modes of vibration for the model inner fixed base core (IFBC) is tabulated in Tables 11 and 12.
Figure 9(b) and Table 14 show that IIC-10th has slightly better performance in reducing the seismic responses of building in comparison to models IFBC-10th, IFBC-All, IIC-All, and IFBC.
However, SBI system and specifically model IIC-10th reduce both the acceleration and base shear in comparison to the IFBC-10th, IFBC-All, IIC-All, and IFBC with comparably similar displacements.
In contrast to models IFBC-10th, IFBC-All, IIC-All, and IFBC, model IIC-10th has both acceleration and base shear reduced.