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RC Book: Design of Reinforced Concrete Buildings for Seismic performance
PANOPTIS: Decision support system for increasing the resilience of transportation infrastructure
iDesign: Enabling Seismic Design Decision-Making under Uncertainty

RC Book—Design of Reinforced Concrete Buildings for Seismic performance
Title Design of Reinforced Concrete Buildings for Seismic performance:
Practical, deterministic and probabilistic approaches
Authors M.Aschheim, Santa Clara University, CA
E.Hernandez-Montes, University of Granada, Spain
D.Vamvatsikos, NTU Athens
Publisher CRC Press, 2019
Book Cover The costs of inadequate earthquake engineering are huge, especially for reinforced concrete buildings. This book presents the principles of earthquake-resistant structural engineering, and uses the latest tools and techniques to give practical design guidance to address single or multiple seismic performance levels.

It presents an elegant, simple and theoretically coherent design framework. Required strength is determined on the basis of an estimated yield displacement and desired limits of system ductility and drift demands. A simple deterministic approach is presented along with its elaboration into a probabilistic treatment that allows for design to limit annual probabilities of failure. The design method allows the seismic force resisting system to be designed on the basis of elastic analysis results, while nonlinear analysis is used for performance verification. Detailing requirements of ACI 318 and Eurocode 8 are presented. Students will benefit from the coverage of seismology, structural dynamics, reinforced concrete, and capacity design approaches, which allows the book to be used as a foundation text in earthquake engineering.
Websites Online resources: Examples, source code, records & tools
Manuscsript: The actual book from the publisher

 

PANOPTIS—Enabling development of a decision support system for increasing the resilience of transportation infrastructure based on combined use of terrestrial and airborne sensors and advanced modelling tools
Project Funding European Commission - Innovation and Networks Executive Agency
Horizon 2020, Mobility for Growth
H2020-MG-2017-Two-Stages
Collaborators Airbus Defence and Space SAS
National Technical University of Athens
ACCIONA Construcción SA
Egnatia Odos AE
Future Intelligence Ltd
Universiteit Twente
French Institute of Science and Technology for Transport, Development and Networks
Finnish Meteorological Institute
Aristotle University of Thessaloniki
Sofistik Hellas AE
C4Controls Ltd
Hydrometeorological Innovative Solutions
Confederation of Organisations in Road Transport Enforcement
Time period Jun 2018 - Nov 2021

www.panoptis.eu

The purpose of the PANOPTIS project is to improve the resiliency (ability to adapt) of the road infrastructures and ensuring reliable network availability under unfavourable conditions, such as extreme weather, landslides, and earthquakes. The project's main goal is to combine down-scale climate change scenarios (applied to road infrastructure) with structural and geotechnical simulation tools, and with actual data from sensors (terrestrial and airborne) so as to provide the operators with an integrated tool able to support more effective management of their infrastructures at planning, maintenance and operation level. The following technologies will be implemented in the PANOPTIS tool:

  • Reliable quantification of climatic, hydrological and atmospheric stressors
  • Multi-Hazard vulnerability modules and assessment toolkit
  • Development of a forecasting module to provide high-resolution tailored weather and precipitation forecasts
  • Improved prediction of structural and geotechnical safety risk through the use of Geotechnical and Structural Simulation Tool (SGSA)
  • Improved multi-temporal, multi-sensor observations with robust spectral analysis, computer vision and Machine Learning (ML) damage diagnostic for diverse Road Infrastructures (RI).
  • Detailed and wide area transport asset mapping, integrating state-of-the-art mobile mapping and making use of Unmanned Aerial Vehicles (UAV) technology
  • Design of a Holistic Resilience Assessment Platform (HRAP)
  • Design of a Common Operational Picture (COP) including a Decision Support System (DSS), an enhanced visualization interface and an Incident Management System (IMS)
The PANOPTIS integrated platform (and its sub-modules) will be implemented in two motorway sections in the Greek and Spanish primary road network.

Relevant publications
  1. Bakalis K., Vamvatsikos D., Grant D.N., Mistry A. (2019). Downtime assessment of base-isolated liquid storage tanks. Proceedings of the SECED 2019 Conference, Greenwich, UK.
  2. Chatzidaki A., Vamvatsikos D. (2019). Mixed probabilistic seismic demand models for fragility assessment. Proceedings of the SECED 2019 Conference, Greenwich, UK.
  3. Vamvatsikos D. (2019). Decision support for road infrastructure resilience: the PANOPTIS perspective. Proceedings of the SECED 2019 Conference, Greenwich, UK.
  4. Kazantzi A.K., Vamvatsikos D. (2019). Prescriptive approaches in performance-based design? A case-study on base isolation. Proceedings of the 13th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP13, Seoul, South Korea.
  5. Spillatura A., Vamvatsikos D., Bazzurro P., Kohrangi M. (2019). Issues in harmonization of seismic performance via risk targeted spectra. Proceedings of the 13th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP13, Seoul, South Korea.

 

iDesign—Enabling Seismic Design Decision-Making under Uncertainty
Project Funding EU Research Executive Agency
Marie Curie Actions, Continuing Integration Grant
FP7-PEOPLE-2011-CIG
Collaborators D. Vamvatsikos, NTU Athens
A.K. Kazantzi, NTU Athens
M. Fragiadakis, NTU Athens
D. Giannopoulos, NTU Athens
M. Aschheim, Santa Clara University, USA
Time period Sep 2011 - Aug 2015

Figure 1: An efficient algorithm based on Latin Hypercube Sampling is employed to estimate the dispersion due to model parameter uncertainty in the seismic capacity of a 9-story steel moment-resisting frame. Using 160 (right) versus 10 (left) realizations of the uncertain model significantly tightens the estimates around the correct answer (red line).

Figure 2: We seek to design a 4-story steel frame building for a high-seismicity site. The hazard surface (left) shows the frequency of different levels of seismic excitation (spectral acceleration) being exceeded at the site for potential (currently unknown) vibration periods of the building. The Yield Frequency Spectra (right) help the engineer find the appropriate period and strength of the structure, shown in the lower right corner, by selecting the closest curve that lies below the specified performance objectives. These are the red X symbols, each representing a maximum allowable frequency of a given global ductility (or damage) occurring in the building.

The primary objective is the development of a simple yet accurate method for performance-based design of structures in seismic areas. In essence, we seek to revolutionize the standard process that every professional structural engineer undertakes to design a structure subject to seismic forces. The reason is that recent earthquakes have shown that buildings reflecting current design approaches may reduce the rate of fatalities, but often result to staggering monetary losses and disruption of functionality. Thus, earthquakes can still financially cripple entire cities, or even countries.

To holistically quantify such effects, the concept of “seismic performance” is employed. This characterizes the behavior of a given structure under seismic loads. Ideally this is based on the use of metrics that are of immediate use to engineers, e.g., story forces and deformations, but also to stakeholders, such as monetary losses, human casualties and time-to-repair (or replace). At a simpler level, one may quantify damage by using simpler engineering metrics such as global ductility or maximum interstory drift. “Performance-based” earthquake engineering is concerned with tackling the dual problems of assessment and design. Assessment is the direct process of estimating the performance of a given (existing) structure. Design is the inverse problem, whereby a (new or rehabilitated) structure, its members and properties are sought to assure a desired performance under a given seismic hazard. As typically befitting such dualities, the direct path of assessment is by far the simpler of the two. Designing a structure to achieve a desired level of performance is an indirect process that is currently solvable only through arduous iterations: It is simply not applicable in practice. To make things worse, the considerable uncertainty inherent in earthquakes (i.e., when, where, how intense) and structures (what has been constructed versus what was designed on paper, what are the material properties, issues of corrosion, aging etc.) make this problem even more difficult.

To offer a practicable path for performance-based design, three important innovations have been introduced. First, a computationally efficient approach is proposed for rapidly establishing the effect of model uncertainties on the seismic performance (Figure 1). This allows the quantification of the consequences of uncertainties and their inclusion in subsequent analyses. Second, a simplified, yet accurate formula is offered for evaluating the seismic performance in terms of the mean annual frequency of damage occurring in the building. Thus, intuition is gained on the structural parameters that influence the seismic behavior of the building, while an analytical estimation of the building performance becomes possible. Finally, the concept of Yield Frequency Spectra (Figure 2) is developed, whereby an engineer can directly determine the required strength and stiffness of the structure given the seismic hazard at the building site and the owner's requirements on how frequently it sustains low or high levels of damage. Both analytical approximations and accurate numerical solutions are available, encoded in open-source software that can estimate Yield Frequency Spectra within seconds to provide a reliable design basis for any building and any user requirements.

Relevant publications
  1. Kazantzi A.K., Vamvatsikos D.(2016). Intensity measure selection for vulnerability studies of building classes. Earthquake Engineerning and Structural Dynamics, (accepted).
    [official] [free]
  2. Kazantzi A.K., Vamvatsikos D., Lignos D.G. (2014). Seismic performance of a steel moment-resisting frame subject to strength and ductility uncertainty. Engineering Structures, 78: 69-77.
    [official] [free]
  3. Vamvatsikos D. (2014). Seismic Performance Uncertainty Estimation via IDA with Progressive Accelerogram-wise Latin Hypercube Sampling. ASCE Journal of Structural Engineering, 140(8), A4014015.
    [official] [free]
  4. Vamvatsikos D. (2014). Accurate application and second-order improvement of the SAC/FEMA probabilistic formats for seismic performance assessment. ASCE Journal of Structural Engineering, 140(2), 04013058.
    [official] [free]
  5. Vamvatsikos D. (2013). Derivation of new SAC/FEMA performance evaluation solutions with second-order hazard approximation. Earthquake Engineerning and Structural Dynamics, 42(8): 1171-1188.
    [official] [free]
  6. Giannopoulos D.G., Vamvatsikos D. (2015). Influence of rotated ground motion components on the response distribution of inelastic oscillators. Proceedings of the COMPDYN2015 Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, Crete, Greece.
  7. Kazantzi A.K., Vamvatsikos D. (2015). A next generation scalar intensity measure for analytical vulnerability studies. Proceedings of the COMPDYN2015 Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, Crete, Greece.
  8. Vamvatsikos D. (2015). A view of seismic robustness based on uncertainty. Proceedings of the 12th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP12, Vancouver, Canada.
  9. Vamvatsikos D., Katsanos E.I., Aschheim M.A. (2015). A case study in performance-based design using yield frequency spectra. Proceedings of the SECED 2015 Conference, Cambridge, UK.
  10. Vamvatsikos D., Aschheim M.A. (2014). Direct performance-based seismic design of structures using Yield Frequency Spectra. Proceedings of the 10th U.S. National Conference on Earthquake Engineering, Anchorage, AK, USA.
  11. Vamvatsikos D., Aschheim M.A., Kazantzi A.K. (2014). Direct performance-based seismic design: Avant-garde and code-compatible approaches. Proceedings of the 9th European Conference on Structural Dynamics (EURODYN 2014), Porto, Portugal.
  12. Giaralis A., Vamvatsikos D. (2014). Local wavelet-based spectral "epsilon" modification of ground motions in support of incremental dynamic analysis. Proceedings of the 2nd International Conference on Vulnerability and Risk Analysis and Management (ICVRAM2014), Liverpool, UK.
  13. Vamvatsikos D., Aschheim M.A. (2014). A code-compatible application of yield frequency spectra for direct performance-based design. Proceedings of the 2nd European Conference on Earthquake Engineering and Seismology (2ECEES), Istanbul, Turkey.
  14. Vamvatsikos D., Aschheim M.A., Kazantzi A.K. (2013). Direct performance-based seismic design using yield frequency spectra. Proceedings of the Vienna Congress on Recent Advances in Earthquake Engineering and Structural Dynamics (VEESD 2013), Vienna, Austria.
  15. Kazantzi A.K., Vamvatsikos D., Lignos D.G. (2013). Model parameter uncertainty effects on the seismic performance of a 4-story steel moment-resisting frame. Proceedings of the 10th International Conference on Structural Safety and Reliability (ICOSSAR), New York.
  16. Vamvatsikos D. (2012). Accurate application and higher-order solutions of the SAC/FEMA probabilistic format for performance assessment. Proceedings of the 15th World Conference on Earthquake Engineering, Lisbon, Portugal.
  17. Kazantzi A.K., Vamvatsikos D. (2012). A study on the correlation between dissipated hysteretic energy and seismic performance. Proceedings of the 15th World Conference on Earthquake Engineering, Lisbon, Portugal.

 

Last updated:
01/Nov/2015
Photo Copyright © Chris Kotsiopoulos
earthquakes, steel, dynamics & probability

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