As part of Entuitive’s commitment to technical excellence, we often partner with academia to help push the AEC industry forward.
Last month, our own Agha Hasan, Principal, presented a talk entitled “Practical Non-linear Seismic Design of Tall Buildings” to a research group at Toronto Metropolitan University consisting of professors and doctoral students.
The presentation encompassed the practical aspects of the nonlinear seismic design of a real-life tall building designed at Entuitive. Emphasis was placed on the performance-based design of the building to circumvent prescriptive code limitations relating to structural irregularities. This allowed the team to design architecturally preferred lobby spaces and drive structural material economies.
Below, we discuss the advantages of performance-based seismic design (PBSD) and go behind the curtain to learn how these principals can be extended to performance-based wind design.
Beyond the Code: Performance-Based Seismic Design
Code-specified prescriptive procedures are intended to protect life during the most severe earthquakes, and limit property damage and loss during more frequent, moderate earthquakes. However, prescriptive codes, such as those found in the National Building Code of Canada, seek to accomplish this goal through indirect means, for example by limiting structural configurations through mandatory requirements relating to structural irregularities.
PBSD, on the other hand, provides several advantages over conventional design methods, allowing us to go beyond the code. These include:
Consideration of multi-level seismic hazards, with an emphasis on the transparency of performance objectives.
Guaranteed building performance through control of inelastic deformation and satisfaction of strength and ductility.
Transparent performance criteria driving seismic design.
Compliance with multi-level seismic hazard levels to meet prescribed performance objectives. This leads to the structure being reliably resilient against all future earthquakes that may exceed the expected code level.
Economies in structural cost relating to lateral systems. Lateral system savings for buildings in high seismic zones may be on the order of 30-40%.
Performance-Based Wind Design: A Collaboration with TMU
Entuitive is currently working with Toronto Metropolitan University on a research project to develop a methodology leading to the practical application of performance-based wind design for buildings. The project is sponsored by NSERC (Natural Science and Research Council of Canada) and OIC (Ontario Innovation Centre), with Entuitive being the industry partner.
The research aims to utilize the ductility built into the structural system for seismic design concurrently for wind-resisting structural mechanisms, thereby incorporating economies by reducing the wind load factors. This would help to override the current design practice of incorporating structural inelastic capacity for seismic while ignoring it for wind design. The aim is to develop a protocol for structures to remain elastic for the service wind level but dissipate energy for high recurrence wind effects inelastically.
Decades of Experience in Seismic Engineering
With decades of experience in seismic engineering, Entuitive has delivered building structures around the world, with economical designs and ease of construction equally for reinforced and prestressed concrete, structural steel, masonry, and timber structures.
Our specialized performance-based seismic design group leverages modern techniques and advanced software to design structures that provide multiple safety levels against seismic hazards. Our work includes a 250-metre residential tower in Istanbul, one of the most severe earthquake zones in the world.
To learn more, reach out to Agha Hasan.