Abstract:
One of the most widely used structural systems in Indonesia is the reinforced
concrete portal structure with brick walls. Generally, the infill walls are only
considered as a load transferred to the structure, so the effect of the strength and
stiffness of the infill walls on the structure is not taken into account. This contradicts
reality, where infill walls can change the behavior of a structure. This study aims
to determine how much the strength and stiffness of the infill walls affect a structure.
The building structure is modeled as a 2-dimensional portal consisting of an open
portal model and an infilled portal. First, a linear analysis is performed on both
models and then followed by a nonlinear analysis to obtain its performance. The
results of this analysis show that the infill walls make a significant contribution to
affecting the strength and stiffness of a structure. This is indicated by the structural
model with Using infill walls has a capacity against shear force of 808.338 kN with
a target displacement of 93 mm. This value is 9.74% greater than the capacity of
an open portal, which can only accommodate a shear force of 822.275 kN with a
target displacement of 103 mm. For structural performance at maximum lateral
force = 4,838.865 kN at step 4 with a displacement of = 0.00114 m, after being
analyzed using the ATC-40 method, a drift ratio of = 0.000025 was obtained. This
drift value falls into the Immediate Occupancy category, so the structural
performance level is Immediate Occupancy. The installation of brick walls has a
significant impact on the dynamic characteristics, strength, stiffness, and seismic
response of the building. The axial force in columns increases and the bending
moment decreases due to the brick wall acting as a structural element.
