ABSTRACT

Nonlinear Seismic Analysis of Piloti-Type
RC Residential Building

Lee, Hye In
School of Civil, Environmental and Architectural Engineering
Graduate School of Korea University
Advised by Prof. Lee, Han Seon

This paper was present the results of analytical simulation of shake-table response against the 1:5 scale piloti type RC residential building by using the PERFORM-3D program and according to the analytical model figure out not only the amount of displacement caused by the Rocking phenomena but also internal force distribution which were not discovered by experiment. In addition, we compared the distorted model and the true replica model to see how the gravity load affects the structure under a lateral load and compared the seismic response of an analytical model depending on the stiffness of the load cell.
When we compared the experimental result with the analytical result, we were able to learn the following. (1) The global behavior including natural period, base shear, roof drift, and overturning moment were simulated by an earthquake with a recurrence period of 50 years and the design earthquake. However, for a maximum scale earthquake, the maximum response was underestimated. (2) both the torsional moment and the torsional rotation were wholly underestimated. (3) the vertical displacement of the foundation was well simulated. (4) both the out-of-plane of slab for the elevator hall section and living room were fairly well simulated but the out-of-plane of coupled beam for the bathroom was not simulated well. (4) flexural deformation of the wall was simulated well, but shear deformation of the wall was not.
According to the analytical model analysis result (1) the base shears both in X and Y directions were mostly supported by the core part, while the 2nd story shear was considerably supported by the outer wall in both directions. (2) the axial force acting on the column was used to resist the overturning moment on the piloti story. On the 2nd story, most of the overturning moment was also resisted by the axial force acting on the exterior wall in both ends. (3) though the X direction displacement was not greatly affected by the rocking phenomena, the Y direction displacement was mostly caused by the rocking phenomena.
When we compared the distorted model and the true replica model, (1) both models were almost similar in most of the behavior including base shear, roof drift, and stiffness and strength reduction. However, the more strong earthquake, the longer the natural period of the distorted model. (2) When we compared the column P-M curves of the true replica model and the distorted model through Pushover analysis, we could not see a difference in the yield point.
According to the seismic response comparison results based on the load cell stiffness (1) the natural period was shortended both in X and Y directions. (2) the seismic response in the X direction showed a little change, while the change was significantly in the Y direction. (3) the response period of the torsional moment was reduced by more than one half while the size more than doubled.