Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing
The present study proposes a new seismic retrofitting method using a concrete-filled tube modular frame (CFT-MF) system, a novel technique to overcome and improve the limitations of existing seismic strengthening methods. This CFT-MF seismic retrofitting method makes the most of the advantages of bo...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-05-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/11/11/4898 |
| _version_ | 1827691412211105792 |
|---|---|
| author | Jin-Seon Kim Ju-Seong Jung Dong-Keun Jung Eui-Yong Kim Kang-Seok Lee |
| author_facet | Jin-Seon Kim Ju-Seong Jung Dong-Keun Jung Eui-Yong Kim Kang-Seok Lee |
| author_sort | Jin-Seon Kim |
| collection | DOAJ |
| description | The present study proposes a new seismic retrofitting method using a concrete-filled tube modular frame (CFT-MF) system, a novel technique to overcome and improve the limitations of existing seismic strengthening methods. This CFT-MF seismic retrofitting method makes the most of the advantages of both concrete and steel pipes, thereby significantly improving constructability and increasing integration between the existing structure and the reinforcement joints. This method falls into the category of typical seismic retrofitting methods that focus on increasing strength, in which the required amount of seismic reinforcement can be easily estimated. Therefore, the method provides an easy solution to improving the strength of existing reinforced concrete (RC) structures with non-seismic details that are prone to shear failure. In the present study, a full-size two-story test frame modeled from existing domestic RC structures with non-seismic details was subjected to pseudo-dynamic testing. As a result, the effect of the CFT-MF system, when applied to existing RC structures, was examined and verified, especially as to its seismic retrofitting performance, i.e., restoring force characteristics, stiffness reinforcement, and seismic response control. In addition, based on the pseudo-dynamic testing results, a restoring force characteristics model was proposed to implement non-linear dynamic analysis of a structure retrofitted with the CFT-MF system (i.e., the test frame). Finally, based on the proposed restoring force characteristics, non-linear dynamic analysis was conducted, and the results were compared with those obtained by the pseudo-dynamic tests. The results showed that the RC frame (building) with no retrofitting measures applied underwent shear failure at a seismic intensity of 200 cm/s<sup>2</sup>, the threshold applied in seismic design in Korea. In contrast, in the frame (building) retrofitted with the CFT-MF system, only minor earthquake damage was observed, and even when the maximum seismic intensity (300 cm/s<sup>2</sup>) that may occur in Korean was applied, small-scale damage was observed. These results confirmed the validity of the seismic retrofitting method based on the CFT-MF system developed in the present study. The non-linear dynamic analysis and the pseudo-dynamic test showed similar results, with an average deviation of 10% or less in seismic response load and displacement. |
| first_indexed | 2024-03-10T11:01:21Z |
| format | Article |
| id | doaj.art-428ddd28a0d14b198a99123dee7c795a |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T11:01:21Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-428ddd28a0d14b198a99123dee7c795a2023-11-21T21:29:55ZengMDPI AGApplied Sciences2076-34172021-05-011111489810.3390/app11114898Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic TestingJin-Seon Kim0Ju-Seong Jung1Dong-Keun Jung2Eui-Yong Kim3Kang-Seok Lee4Department of Architectural Engineering, Hanyang University, Seoul 04763, KoreaInnovative Durable Building and Infrastructure Research Center, Hanyang University, Ansan 15588, KoreaDepartment of Smart City Engineering, Hanyang University, Ansan 15588, KoreaARISU Engineering Ltd., Seoul 05404, KoreaDepartment of Architectural Engineering & Smart City Engineering, Hanyang University, Ansan 15588, KoreaThe present study proposes a new seismic retrofitting method using a concrete-filled tube modular frame (CFT-MF) system, a novel technique to overcome and improve the limitations of existing seismic strengthening methods. This CFT-MF seismic retrofitting method makes the most of the advantages of both concrete and steel pipes, thereby significantly improving constructability and increasing integration between the existing structure and the reinforcement joints. This method falls into the category of typical seismic retrofitting methods that focus on increasing strength, in which the required amount of seismic reinforcement can be easily estimated. Therefore, the method provides an easy solution to improving the strength of existing reinforced concrete (RC) structures with non-seismic details that are prone to shear failure. In the present study, a full-size two-story test frame modeled from existing domestic RC structures with non-seismic details was subjected to pseudo-dynamic testing. As a result, the effect of the CFT-MF system, when applied to existing RC structures, was examined and verified, especially as to its seismic retrofitting performance, i.e., restoring force characteristics, stiffness reinforcement, and seismic response control. In addition, based on the pseudo-dynamic testing results, a restoring force characteristics model was proposed to implement non-linear dynamic analysis of a structure retrofitted with the CFT-MF system (i.e., the test frame). Finally, based on the proposed restoring force characteristics, non-linear dynamic analysis was conducted, and the results were compared with those obtained by the pseudo-dynamic tests. The results showed that the RC frame (building) with no retrofitting measures applied underwent shear failure at a seismic intensity of 200 cm/s<sup>2</sup>, the threshold applied in seismic design in Korea. In contrast, in the frame (building) retrofitted with the CFT-MF system, only minor earthquake damage was observed, and even when the maximum seismic intensity (300 cm/s<sup>2</sup>) that may occur in Korean was applied, small-scale damage was observed. These results confirmed the validity of the seismic retrofitting method based on the CFT-MF system developed in the present study. The non-linear dynamic analysis and the pseudo-dynamic test showed similar results, with an average deviation of 10% or less in seismic response load and displacement.https://www.mdpi.com/2076-3417/11/11/4898reinforced concreteseismic strengtheningconcrete-filled tubeseismic capacitypseudo-dynamic testingnon-linear dynamic analysis |
| spellingShingle | Jin-Seon Kim Ju-Seong Jung Dong-Keun Jung Eui-Yong Kim Kang-Seok Lee Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing Applied Sciences reinforced concrete seismic strengthening concrete-filled tube seismic capacity pseudo-dynamic testing non-linear dynamic analysis |
| title | Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing |
| title_full | Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing |
| title_fullStr | Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing |
| title_full_unstemmed | Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing |
| title_short | Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing |
| title_sort | seismic strengthening effects of full size reinforced concrete frame retrofitted with novel concrete filled tube modular frame by pseudo dynamic testing |
| topic | reinforced concrete seismic strengthening concrete-filled tube seismic capacity pseudo-dynamic testing non-linear dynamic analysis |
| url | https://www.mdpi.com/2076-3417/11/11/4898 |
| work_keys_str_mv | AT jinseonkim seismicstrengtheningeffectsoffullsizereinforcedconcreteframeretrofittedwithnovelconcretefilledtubemodularframebypseudodynamictesting AT juseongjung seismicstrengtheningeffectsoffullsizereinforcedconcreteframeretrofittedwithnovelconcretefilledtubemodularframebypseudodynamictesting AT dongkeunjung seismicstrengtheningeffectsoffullsizereinforcedconcreteframeretrofittedwithnovelconcretefilledtubemodularframebypseudodynamictesting AT euiyongkim seismicstrengtheningeffectsoffullsizereinforcedconcreteframeretrofittedwithnovelconcretefilledtubemodularframebypseudodynamictesting AT kangseoklee seismicstrengtheningeffectsoffullsizereinforcedconcreteframeretrofittedwithnovelconcretefilledtubemodularframebypseudodynamictesting |