Seismic collapse risk of reinforced concrete tall buildings in Istanbul

Author(s):  
Omer Odabasi ◽  
Mohsen Kohrangi ◽  
Paolo Bazzurro
2021 ◽  
pp. 875529302098196
Author(s):  
Siamak Sattar ◽  
Anne Hulsey ◽  
Garrett Hagen ◽  
Farzad Naeim ◽  
Steven McCabe

Performance-based seismic design (PBSD) has been recognized as a framework for designing new buildings in the United States in recent years. Various guidelines and standards have been developed to codify and document the implementation of PBSD, including “ Seismic Evaluation and Retrofit of Existing Buildings” (ASCE 41-17), the Tall Buildings Initiative’s Guidelines for Performance-Based Seismic Design of Tall Buildings (TBI Guidelines), and the Los Angeles Tall Buildings Structural Design Council’s An Alternative Procedure for Seismic Analysis and Design of Tall Buildings Located in the Los Angeles Region (LATBSDC Procedure). The main goal of these documents is to regularize the implementation of PBSD for practicing engineers. These documents were developed independently with experts from varying backgrounds and organizations and consequently have differences in several degrees from basic intent to the details of the implementation. As the main objective of PBSD is to ensure a specified building performance, these documents would be expected to provide similar recommendations for achieving a given performance objective for new buildings. This article provides a detailed comparison among each document’s implementation of PBSD for reinforced concrete buildings, with the goal of highlighting the differences among these documents and identifying provisions in which the designed building may achieve varied performance depending on the chosen standard/guideline. This comparison can help committees developing these documents to be aware of their differences, investigate the sources of their divergence, and bring these documents closer to common ground in future cycles.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Zhe Wang ◽  
Liang Cao ◽  
Filippo Ubertini ◽  
Simon Laflamme

The tuned liquid multiple column damper (TLMCD) is a variation of the tuned liquid column damper (TLCD) that includes multiple vertical columns. A new damping system that embeds TLMCDs within reinforced concrete shear wall systems, termed tuned liquid wall damper (TLWD), is proposed, augmenting the traditional structural component with energy dissipation capabilities. The objective of this study is to assess energy mitigation and strength trade-offs in designing TLWDs and demonstrating the promise of TLWD systems in tall buildings through vertically distributed applications. This is done by investigating the performance of the proposed TLWD through the finite element model (FEM) of a simplified representation of a 42-story building equipped with the multifunctional component. A strength model for the TLWD is developed to empower faster performance evaluation on more complex models. Results from the FEM are used to validate the strength model and show that the model could be used conservatively in assessing strength performance. Design considerations are discussed based on the simplified representation. In particular, to improve mitigation performance while maintaining strength, it is found that a single-layer arrangement of the vertical columns is preferred, while distributing the inertia among a higher number of smaller columns. The proposed TLWD is numerically evaluated on a more realistic system consisting of a multi-degrees-of-freedom representation of the 42-story building under stochastic wind excitation. Simulation results demonstrate that the TLWD, used in a vertically distributed configuration through the building, could be used to mitigate vibrations, outperforming a traditional TLCD system with geometric constraints under 20 design wind realization. Results from the numerical simulations also confirmed the design considerations established through the simplified representation.


2019 ◽  
Vol 9 (22) ◽  
pp. 4913 ◽  
Author(s):  
Han-Soo Kim ◽  
Yi-Tao Huang ◽  
Hui-Jing Jin

Outrigger systems have been used to control the lateral displacement of tall buildings. Reinforced concrete (R.C.) outrigger walls with openings can be used to replace conventional steel outrigger trusses. In this paper, a structural model for an R.C. outrigger wall with multiple openings was proposed, and the effects of the multiple openings on the stiffness and strength of the outrigger walls were evaluated. The equivalent bending stiffness of the outrigger wall was derived to predict the lateral displacement at the top of tall buildings and internal shear force developed in the wall. The openings for the passageway in the wall were designed by the strut-and-tie model. The stiffness and strength of the outrigger wall with multiple openings was analyzed by the nonlinear finite element analysis. Taking into consideration the degradation in stiffness and strength, the ratio of the opening area to the outrigger wall area is recommended to be less than 20%. The degradation of stiffness due to openings does not affect the structural performance of the outrigger system when the outrigger has already large stiffness as the case of reinforced concrete outrigger walls.


2018 ◽  
Vol 12 (03) ◽  
pp. 1850008 ◽  
Author(s):  
Satish Bhagat ◽  
Anil C. Wijeyewickrema

In this paper, the seismic collapse probability of base-isolated reinforced concrete buildings considering pounding with a moat wall and financial loss estimation is studied. For this purpose, three-dimensional finite element models of a code-compliant 10-story base-isolated shear wall-frame (BI-SWF) building and a 10-story base-isolated moment resisting frame (BI-MRF) building are used. Results indicate that the BI-MRF building has a greater probability of collapse compared to that of the BI-SWF building, the probability of collapse in 50 years for the BI-MRF building is 1.3 times greater than that of the BI-SWF building for both no pounding and pounding cases. The probability of collapse increases when pounding is considered, which results in a smaller value of the collapse margin ratio compared to no pounding case for both the buildings. The financial losses resulting from damage to the BI-MRF and BI-SWF buildings under design earthquake (DE) and risk-targeted maximum considered earthquake (MCER) levels are calculated for the no pounding case, since there was no pounding under DE-level and very few instances of pounding under MCER-level. Calculation of financial losses due to damage to structural and nonstructural components, service equipment and downtime shows that the BI-SWF building results in larger repair costs and downtime cost compared to the BI-MRF building.


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