2. Generalised Force Method (GFM): [5 marks] Given an already constructed 4-storey hospital building (Important Class IV

Post by **answerhappygod** » Thu May 26, 2022 12:06 pm

2. Generalised Force Method (GFM): [5 marks] Given an already
constructed 4-storey hospital building (Important Class IV) with a
building height (H) of 12.8 m and a total mass of 400 t, situated
at the same site in Johor in Question 1. The building was designed
by others without much consideration of lateral load, you as the
consulting engineer are required by the client to evaluate the
seismic performance of the building in terms of its dynamic
property.
a) Based on the ground type selected in Question 1(f), compute
and plot the RSA of Model B according to the Malaysia EC8 NA (2017)
for the hospital building, with a PGA of 0.07g.
b) Estimate the natural period according to the EC8 empirical
equation T = 0.05H^0.75.
c) Find the corresponding RSA value based on Question 2(b) and
calculate the base shear.
d) A structural analysis was carried out, and the deflection
results are shown in Table 2. Recalculate the exact structural
period using the GFM.

: 2 Generalised Force Method Gfm 5 Marks Given An Already Constructed 4 Storey Hospital Building Important Class Iv 1 (104.29 KiB) Viewed 17 times

Table 2: Lateral displacement results of the 4-storey hospital building. Floor Storey accumulated height, Lateral deflection, di no. Hi (mm) (mm) 4 12.8 65 3 9.6 50 2 6.4 32 1 3.2 23 base 0 0 e) Calculate the effective deflection of the building. f) Calculate the effective mass of the building. g) Calculate the effective stiffness of the building. h) Calculate the effective natural period of the building. i) Find the corresponding RSA value on Question 2(h) and calculate the revised base shear, assuming the effective mass factor (4) is 0.85. j) Comment on the new base shear obtained using GFM. k) Compare your answers in 2(i) with program MY2 on quakeadice.org with the consideration of the first three mode of vibration. 1) What is the limitation of the simplest GFM method and how to circumvent the limitations?