The maximum displacement of 49 mm measured from the GPS receiver on the top of the test model is
used for calculation of deformed shapes. Deformed shapes based on the modal parameters in Figure 10
and the maximum displacement of 49 mm from the GPS receiver are compared in Figure 8. Due to the
error between the initial displacement of 50 mm and the displacement of 49 mm from GPS, besides
numerical errors in SSI method, differences in magnitudes of lateral displacement at every story level
are easily found.For clear comparison of deformed shapes obtained from three different methods, Figure 11 shows
deformed shapes at discrete time interval of 0.2 s for the cycle (from 0.55 s to 1.75 s) in Figure 8. It
displays that the deformed shapes based on 2D laser scanner are slightly better than those from the
numerical method with GPS. The differences in magnitudes of lateral displacements at 2nd and 1st
floor levels are relatively greater than those at 3rd floor level. Even though there are many issues to be
considered for improvement in precision of measurement, the deformed shape measurement model
based on a 2D laser scanner can be a promising alternative for high-rise buildings where installation of
laser displacement sensors is impossible