Performance-based Seismic Design Using REDSET: A Novel Reliability Evaluation Approach | Chapter 6 | Science and Technology: Developments and Applications Vol. 3

Considering the economic impacts of recent major earthquakes all over the world, the Performance-Based Seismic Design (PBSD) concept is now under development, replacing the life safety concept, to be incorporated in the next generation of design guidelines. Although PBSD is a risk-based concept, no such acceptable concept is currently available. To fill this knowledge gap, the authors and their team recently proposed a concept known as the Reliability Evaluation of Dynamic Systems Excited in the Time Domain (REDSET). The implementation of PBSD using REDSET is demonstrated in this chapter. The structures are represented by finite elements and the seismic loading is applied in the time domain incorporating all major sources of nonlinearity and uncertainty in the design variables. The Limit Performance Functions (LPFs) are implicit for this class of problems. To retain simplicity, they are made explicit using the response surface concept and the First-Order Reliability Method (FORM) is used to extract the reliability evaluation. The basic Monte Carlo Simulation (MCS) method is used to verify REDSET. The authors then developed required serviceability LPFs correlating them with performance levels of Collapse Prevention (CP), Life Safety (LS), and Immediate Occupancy (IO), as suggested in PBSD. The capabilities of REDSET to implement PBSD are demonstrated with the help of examples. Uncertainties in the design earthquake time history are incorporated using multiple time histories as suggested in design guidelines. The information on the reliability estimated using REDSET correlates well with different levels of performance. The study clearly indicates that reliable information can be obtained using only a few hundred instead of millions of deterministic nonlinear finite element analyses. The authors believe that REDSET can be used to advance the development of the PBSD philosophy further.

 

Author (s) Details

 

J. Ramon Gaxiola-Camacho
Department of Civil Engineering, Autonomous University of Sinaloa, Culiacan, Sinaloa, México.

Achintya Haldar
Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, Arizona, USA and Indian Institute of Technology (IIT) – Delhi, India.

 

Aaron Gutierrez-Lopez
Department of Civil Engineering, Autonomous University of Sinaloa, Culiacan, Sinaloa, México.

 

Please see the book here:- https://doi.org/10.9734/bpi/stda/v3/4039

Reliability Evaluation of Structures Excited by Earthquakes in Time Domain Using a Novel Concept | Chapter 3 | Science and Technology: Developments and Applications Vol. 3

A novel reliability evaluation method for structures excited by the seismic loading applied in the time domain is presented. Major sources of nonlinearity and uncertainty are incorporated into the algorithm. Structures are represented by finite elements. To demonstrate that the algorithm will work in different computational platforms, the stress-based finite element is used. Connections are more realistically considered partially restrained (PR) with different rigidities. Multiple site-specific design earthquake acceleration time histories are numerically generated using information on the seismic activities of the region using the broadband platform (BBP) available at the Southern California Earthquake Center (SCEC). The reliability of structures is estimated by exciting them with real and artificially generated earthquake time histories. The accuracy of the method is verified using Monte Carlo Simulation. With the help of examples, it is demonstrated that the proposed reliability concept is efficient and accurate. The procedure can extract the reliability information with the help of a few hundred deterministic analyses instead of millions needed for simulation and users can use any computer available to them. Post-Northridge PR beam-to-column connections are superior to the pre-Northridge FR connections. Structural reliabilities are estimated for the overall lateral deflection and inter-story drift limit states. Inter-story drifts are more critical than the overall lateral deflections. The Performance-Based Seismic Design (PBSD) guidelines are briefly discussed. The reliability method fills a knowledge gap and helps to implement the PBSD concept. Currently, the authors call the method REDSET (Reliability Evaluation of Dynamic Systems Excited in Time Domain). REDSET appears to be an exciting development replacing the classical random vibration concept and providing an alternative to the simulation approach.

 

Author (s) Details

 

J. Ramon Gaxiola-Camacho
Department of Civil Engineering, Autonomous University of Sinaloa, Culiacan, Sinaloa, México.

 

Achintya Haldar
Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, Arizona, USA and Indian Institute of Technology (IIT) – Delhi, India

 

Aaron Gutierrez-Lopez
Department of Civil Engineering, Autonomous University of Sinaloa, Culiacan, Sinaloa, México.

 

Please see the book here:- https://doi.org/10.9734/bpi/stda/v3/4011