ENEQ640-20A (C) Any Time Start 2020

Displacement-based Design of Low Damage Structures

15 points

Details:
Start/End Date: The start and end dates are specific to each student. For further information please contact one of the following (as appropriate):
  • For Masters theses please contact the relevant College Office.
  • For Doctoral degrees (PhD) please contact the Postgraduate Office.
  • For other types of anytime start courses (i.e. generally courses worth 60 points or less) please contact the Course Coordinator.
Withdrawal Dates
The withdrawal dates for this course (both with and without fee refund) will be confirmed once a) the course start date and b) course length is confirmed. Students are advised to consult the department for further information.

Description

Alternative design philosophies and solutions for the seismic design of low-damage structures. Analysis and design criteria for buildings. Introduction to base-isolation, viscous dampers, PRESSS-Technology and the hybrid (rocking-dissipative) system concept. Introduction to and application of Displacement Based Design (DBD). Simplified modelling techniques using lumped plasticity approach. Connection between floor-diaphragm and lateral resisting systems. Capacity Design: Issues and solutions. Examples of on- site applications worldwide in low-, medium- or high-seismic areas. Constructability aspects, sequence and detailing.

Background and Motivation
Earthquake Engineering is facing an extraordinary challenging era, the ultimate target being set at increasingly higher levels by the demanding expectation of our modern society: to provide low-cost, more widely affordable, still architecturally appealing, high-seismic-performance structures capable of sustaining a design level earthquake with limited or negligible damage, minimum disruption of business (downtime) or, in more general terms, controllable socio-economical losses.

These compelling requirements of cost-effectiveness and high-performance are leading to a major effort towards the development of damage-control design approaches and technologies.

The 22nd Feb 2011 Christchurch earthquake has further highlighted the mismatch between the expectations of building occupants and owners over the reality of engineered buildings’ seismic performance. Ductile plastic hinges, designed to concentrate the damage in discrete location and thus prevent the collapse of a buildings, have proven to lead, under a major seismic event, to a severe level of damage, often resulting into several months of downtime and loss of occupancy of the building if not to the need for demolition.

Scope
In this course, building on the lessons learnt from the Canterbury Earthquake Sequence 2010-2011 and the needs and opportunity for the Christchurch Rebuild as well as for the overall country’s next generation of more resilient structures and infrastructures, an overview of recent developments on innovative damage-resisting (or low-damage) solutions for precast concrete buildings based on dry jointed ductile connections, typically referred to as PRESSS-Technology (PREcast Seismic Structural Systems) will be given.

The combination of unbonded post-tensioning techniques and of additional sources of internal or external dissipaters leads to self-centering and dissipative systems, capable of undergoing major earthquake with minor damage when compared with traditional solutions.

Main aspects related to the conceptual behaviour and design criteria will be discussed based on extensive experimental testing and numerical analysis. Examples of the several on site-applications in New Zealand and overseas will be given, as a confirmation of the rapid and increasingly wide acceptance of such construction technique within different construction markets and realities.

At the end of the course, the students are expected to gain familiarity with the conceptual behaviour, the design criteria and step-by-step procedure as well as modeling aspects of these systems. Updates on current trends in major international seismic code provisions will be provided along with real examples of on-site applications as a further confirmation of the advantages associated to easy constructability, speed of erection, off-site quality control and safety on construction-site.

Pre-requisites

Subject to approval of the Head of Department or
Programme Director

Restrictions

ENCI615

Timetable 2020

Students must attend one activity from each section.

Lecture A
Activity Day Time Location Weeks
01 Tuesday 09:00 - 17:00 E12 3 Feb - 9 Feb
Lecture B
Activity Day Time Location Weeks
01 Wednesday 09:00 - 17:00 E12 3 Feb - 9 Feb
Lecture C
Activity Day Time Location Weeks
01 Monday 09:00 - 17:00 E12 10 Feb - 16 Feb
Lecture D
Activity Day Time Location Weeks
01 Tuesday 09:00 - 17:00 E12 10 Feb - 16 Feb

Timetable Note

The course will be delivered in two blocks, lasting two consecutive days each to facilitate the attendance of practicing engineers as well as out-of-town students.

Block 1:
Tuesday 4th February - 9:00am-4:00pm (E12)
Wednesday 5th February - 9:00am-4:00pm (E12)

Block 2:
Monday 10th February - 9:00am-4:00pm (E12)
Tuesday 11th February - 9:00am-4:00pm (E12)

Topics covered:
- Reality Check and new challenges in Performance-Based Design in the aftermath of the Canterbury earthquakes sequence. Moving towards the next generation of damage-resisting structures.
- Alternative design philosophies and solutions for the seismic design of precast concrete structures. Emulation of cast-in situ concrete. Introduction to jointed ductile connections, PRESSS-Technology and the hybrid system concept. Research & Development on low-damage structural system (skeleton) and non-structural components (envelope).
- Introduction to Displacement Based Design. Review of limitation of current Force-Based (FBD) approaches. Closed-Form solution for non-iterative FBD.
- Example of DBD for SDOF and MDOF frame and wall systems.
- Analysis and design criteria for post-tensioned rocking/dissipative frames and single or coupled walls.
- Simplified analytical/numerical modeling techniques using lumped plasticity approach. From section and connection moment-rotation to overall structural system modeling.
- Connection between floors and lateral resisting systems. Displacement incompatibility issues and suggested design solutions. Non-Tearing floor solutions.
- Examples of on-site applications worldwide of PRESSS-technology in low-, medium- or high-seismic areas.
- Loss modeling and Cost-benefit analysis of low-damage structures vs. traditional solution Evaluation of Expected annual Losses.

Course Coordinator

Stefano Pampanin

Assessment

Assessment Due Date Percentage 
Project report 50%
Final exam 50%


As part of the assignment/project requirements, students will be assigned the task to design and analyze the seismic response of a multi-storey building consisting of post-tensioned & dissipative frames and/or shear walls.

The design will follow either a Force-Based Design (FBD) (traditional and/or closed-form “retrofitted’ solution) and a Displacement Based Design.

Lumped plasticity models will be created using commercially available software such as Ruaumoko, SAP2000, ETABS, OpenSees at discretion of the students.

Pushover and time-history analyses will be carried out using a suite of far field and near field events, including few recently recorded ground motions in the Christchurch CBD during the 2010-2011 events. The numerical analyses will be used to confirm the design assumptions and compare the performance of these solutions with more traditional counterpart options.

The main findings of the project will be presented in the form of a project report (worth 50%).
A final written exam (worth 50%) will take place at the end of the course.

Textbooks / Resources

- NZCS, 2010 “PRESSS Design Handbook” (Editor: S. Pampanin), New Zealand Concrete Society, Wellington, New Zealand, pp.283
- Priestley, M.J.N., Calvi, G.M., Kowalski, M.J., 2007, Displacement-Based Seismic Design of Structures, IUSS PRESS, Pavia, pp. 721
- Additional reading on the topics covered in class will be provided in electronic form and uploaded on the repository Learn. More specific reading and literature search might be necessary as part of the project work

Indicative Fees

Domestic fee $1,102.00

* Fees include New Zealand GST and do not include any programme level discount or additional course related expenses.

Minimum enrolments

This course will not be offered if fewer than 5 people apply to enrol.

For further information see Civil and Natural Resources Engineering.

All ENEQ640 Occurrences

  • ENEQ640-20A (C) Any Time Start 2020