Seismic Analysis and Design of Structural Lightweight Concrete High Rise Building with and Without Retrofitting
Mirza Mahaboob Baig1, C Mahalingam2, T.G.N.C Vamsi Krishna3, Atif Zakaria4
1Mirza Mahaboob Baig, Department of UG (Civil Engineering), JNTUK Post Graduation (Structural Engineering) VFSTR University, Vadlamudi, Guntur, (Andhra Pradesh), India.
2C. Mahalingam Tamilnadu, Department of (Structural Engineering) CIT UG Anna University, Chennai. Asst. Professor VFSTR University, Vadlamudi, Guntur, (Andhra Pradesh), India.
3T.G.N.C. Vamsi Krishna, Department of UG (Civil Engineering) JNTUK Post Graduation (Structural Engineering) VFSTR University, Vadlamudi, Guntur, (Andhra Pradesh), India.
4Atif Zakaria, Department of UG (Civil Engineering) Post Graduation (Structural Engineering) VFSTR University, Vadlamudi, Guntur, (Andhra Pradesh), India.
Manuscript received on 02 June 2019 | Revised Manuscript received on 10 June 2019 | Manuscript published on 30 June 2019 | PP: 3157-3161 | Volume-8 Issue-8, June 2019 | Retrieval Number: H7314068819/19©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Natural frequency of a structure depends upon mass and stiffness of the structure, structural lightweight concrete (SLWC) doesn’t shows good response in high seismic zones and critical soil conditions due to its lesser modulus of elasticity when compared to normal weight concrete but gives an economical design results which reduces the construction cost, the responses of structure like story drifts and stiffness of the structure can be enhanced by global retrofitting technique i.e. by providing the bracings at the critical locations of the structure. The maximum storey stiffness of the retrofitted structural lightweight concrete building was found to be three times the unretrofitted structural lightweight concrete building; the maximum bending moment value for an slwc braced structure is nearly 160 kN-m less than the unbraced structure. Results showed that storey drift of retrofitted slwc building is less than 0.4% of storey height. After non-linear dynamic analysis, it is found that pseudo-spectral acceleration for a braced slwc building is 1.65×103 mm/sec2 whereas for an unbraced slwc building is 9×103 mm/sec2 . The maximum cross-sectional size of the beam and column for a braced building is 30% and 20% less than the unbraced building, the maximum reinforcement ratio of unbraced to braced in beams and columns is 1.24 and 0.67 respectively. Due to the lesser modulus of elasticity for structural lightweight concrete (SLWC) the structure made with this has less stiffness when compared to normal weight concrete building, if we can enhance the elastic modulus of slwc then the structure made with slwc will show the best performance during an earthquake.
Keyword: Storey drifts, Storey stiffness, Overturning moment, Bracings, Natural frequency, time period and pseudo spectral acceleration.
Scope of the Article: Design and Performance of Green Building.