Structural Performance Assessment of Single-Story RC Precast Structures Subjected to Pulse-Type Ground Motions


Altunışık A. C. , Sunca F.

International IDU Engineering Symposium – IES’20 , İzmir, Turkey, 5 - 13 December 2020, vol.1, no.1, pp.1-10

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • City: İzmir
  • Country: Turkey
  • Page Numbers: pp.1-10

Abstract

Industrial development has accelerated throughout the world since the early 1900s. Within this period, many industrial buildings have constructed with precast structural elements produced in the factory environment. Precast structures, which greatly contribute to industrial and economic development, are one of the important civil engineering structures. Due to the advantages provided by prefabricated buildings in various perspectives such as usage and quality, the majority of industrial buildings in our country consist of one-story RC precast structures. In past earthquakes, it has been observed that the existing prefabricated structures suffered critical damages due to weakness such as weak junction points, insufficient diaphragm behavior, insufficient strength, and rigidity. These situations raise the idea of comprehensively investigating the seismic performances of prefabricated structures.

 

Various methods are used to evaluate the seismic performance of the structures. The time history analysis method is widely used by researchers and designers. In this method, the use of various ground motion records and a detailed structure model allows the results to contain smaller errors compared to other calculation methods. However, the seismic responses of the structures are very sensitive to the properties of the selected ground motion records. Therefore, appropriate ground motion records should be selected for reliable analysis results.

 

When the ground motion records in a region are examined, it can be seen that there are differences between the near-fault ground motion and far-fault ground motion. Near-fault ground motions contain large velocity signals and apply great energy to the structures in the region at the earthquake. This energy can lead to serious damage to structures. On the other hand, the fault mechanism affects the characteristics of the near-fault ground motion, and the ground motion records may include large-period and high-amplitude pulse effects. These effects can dramatically increase damage levels in structures. It has been determined by the researchers that the effects of near-fault ground motion in 1971 San Fernando, 1994 Northridge, 1995 Kobe, 1999 Kocaeli and Düzce earthquakes increase the damage levels in the structures. Therefore, these effects should be considered in the design and analysis of the structures.

 

In this study, the seismic performance of a single-story reinforced concrete prefabricated structures exposed to near-fault ground motions is evaluated. The finite element model of the selected prefabricated structure is constituted by using the SAP2000 program and the nonlinear time history analyses are performed. The near-fault ground motion sets with and without pulse effect are used in the analyses. In the selection of pulse-like ground motions, the acceleration records with the ratio of the pulse period to the first natural period greater than 1 are used. Thus, ground motions with large pulse period are taken into account in the analysis. The plastic rotations and internal forces of precast columns, peak displacements, and base shear forces are used as comparison parameters. Analysis results show that near-fault and pulse-type ground motion effects should be considered in the design and analysis of precast structures.