The 2016 IDEERS Seismic Design World Conference and Competition: A Report by New Zealand Postgraduate Team from the University of Auckland

Developed by the University of Bristol, Introducing and Demonstrating Earthquake Engineering Research in Schools (IDEERS) is a shaking table competition with an aim to communicate the challenge and excitement of earthquake engineering research to young people. Each participating team is required to construct a small-scale model of a building that can withstand the simulated earthquakes generated by a shaking table. Since 2001, this programme has attracted hundreds of Taiwanese and international students each year in Taiwan. The competition challenges students to design and build the most efficient model of a multi-storey building to withstand simulated earthquakes on a shaking table. This competition not only introduces the concept of engineering to secondary school students but it also develops and promotes interest in earthquake engineering for university students including undergraduate and postgraduate students. It has been increasingly successful since its inception, attracting more participants with each event

Proposed simplified approach for the seismic analysis of multi-storey moment resisting framed buildings incorporating friction sliders

An innovative, simplified, and accurate model is proposed and developed to enable simplified yet realistic time history analysis of multi-storey buildings with moment resisting connections using friction energy dissipaters in the commonly used structural analysis and design program, SAP2000. The analyses are rapid to undertake, thereby enabling detailed study of the influence of many building system effects on the overall response. This paper presents the outcome of dynamic analysis of a complete 13-storey moment resisting steel building with Sliding Hinge Joints as the beam-column connections, considering the influential self-centring factors such as MRF and gravity columns continuity as well as column base and diaphragm flexibilities. The building is one of the Te-Puni towers, which are structural steel apartment buildings with steel-concrete composite floors, designed according to the low damage design philosophy, built inWellington, New Zealand in 2008 and which have already been subjected to two significant earthquakes. The key objectives of the research have been to take the design of the 13-storey building and convert that into the proposed simplified model required for time history seismic analysis, to undertake analysis under scaled El-Centro earthquake record, investigate the peak inter-storey drift and the residual drift of the building, and determine the influence of column base rotational stiffness, floor slab out of horizontal plane displacement, type of friction damper, and MRF and gravity column continuity. It is concluded that the response of the building is stable and predictable, as expected, and that the post-earthquake state of the building, particularly from the self-centring point of view, is well within the limits for maintaining operational continuity following an ULS level design earthquake

Proposed Simplified Approach for the Seismic Analysis of Multi-Storey Moment Resisting Framed Buildings Incorporating Friction Sliders

An innovative, simplified, and accurate model is proposed and developed to enable simplified yet realistic time history analysis of multi-storey buildings with moment resisting connections using friction energy dissipaters in the commonly used structural analysis and design program, SAP2000. The analyses are rapid to undertake, thereby enabling detailed study of the influence of many building system effects on the overall response. This paper presents the outcome of dynamic analysis of a complete 13-storey moment resisting steel building with Sliding Hinge Joints as the beam-column connections, considering the influential self-centring factors such as MRF and gravity columns continuity as well as column base and diaphragm flexibilities. The building is one of the Te-Puni towers, which are structural steel apartment buildings with steel-concrete composite floors, designed according to the low damage design philosophy, built in Wellington, New Zealand in 2008 and which have already been subjected to two significant earthquakes. The key objectives of the research have been to take the design of the 13-storey building and convert that into the proposed simplified model required for time history seismic analysis, to undertake analysis under scaled El-Centro earthquake record, investigate the peak inter-storey drift and the residual drift of the building, and determine the influence of column base rotational stiffness, floor slab out of horizontal plane displacement, type of friction damper, and MRF and gravity column continuity. It is concluded that the response of the building is stable and predictable, as expected, and that the post-earthquake state of the building, particularly from the self-centring point of view, is well within the limits for maintaining operational continuity following an ULS level design earthquake

Self-Centering Capability of the Seismic Friction Dampers: A Conceptual Study on the Static and Dynamic Self-Centering Requirments for the Sinple Degree of Freedom

The aim of this research is to determine the effects of wind-down, frequency, seismic weight, spring stiffness, and spring precompression on the self-centering capability of the Asymmetric Friction Connection, and hence the Sliding Hinge Joint. Numerical time-history direct integration non-linear dynamic analysis of 1,024 single degree-of-freedom (SDOF) models representing single-storey systems was completed using SAP2000. Results of this study showed that for the majority of cases with wind-down and the presence of springs, the amount of residual drift experienced was reduced. Springs with a degree of precompression had a significant influence on the self-centering capability of each system, lowering residual drift to within the acceptable threshold of 0.14% for most cases

Short- and long- term loss of preloading in slotted bolted connections

One recent solution to reduce the building repairing costs, in case of exceptional or destructive seismic events, is represented by the Sliding Hinge Joint (SHJ), initially proposed by the research group of the University of Auckland in 2005. This connection typology, using slotted bolted connections in beam-to-column joints of Moment Resisting Steel Frames (MRFs), ensures a large energy dissipation capacity with negligible damage. The slip resistance of the SHJ is usually provided by Asymmetrical or Symmetrical Friction Connections (AFCs or SFCs), whose response depends on the friction coefficient of the shims and on the bolt preloading. Since the bolt forces directly affect the resistance, the control of preloading during the life-time of the connection represents a key issue for the proper functioning of the device. Within this framework, considering the lack of previous experimental works specifically devoted to the long-term response of SHJs, this paper presents the results of an experimental activity on subassemblies of friction dampers, assessing the loss of preload under service loading conditions, examining the possibility to limit the loss through different conical washer layouts (Belleville disk springs). Short-, mid- and long-term tests have been carried out in a joint experimental program carried out at the Universities of Liege and Salerno. The experimental results have been exploited to calibrate an analytical model able to predict the loss of preload over time, accounting for the influence of the external loads. The adoption of pre-set disk springs, reducing the stiffness of 1/10, shows a substantial reduction of the loss

The China-NZ ROBUST Friction Building Shaking Table Testing Overview

Shaking table testing of a full-scale three storey resilient and reparable complete composite steel framed building system is being conducted. The building incorporates a number of interchangeable seismic resisting systems of New Zealand and Chinese origin. The building has a steel frame and cold formed steel-concrete composite deck. Energy is dissipated by means of friction connections. These connections are arranged in a number of structural configurations. Typical building non-skeletal elements (NSEs) are also included. Testing is performed on the Jiading Campus shaking table at Tongji University, Shanghai, China. This RObust BUilding SysTem (ROBUST) project is a collaborative China-New Zealand project sponsored by the International Joint Research Laboratory of Earthquake Engineering (ILEE), Tongji University, and a number of agencies and universities within New Zealand including the BRANZ, Comflor, Earthquake Commission, HERA, QuakeCoRE, QuakeCentre, University of Auckland, and the University of Canterbury. This paper provides a general overview of the project describing a number of issues encountered in the planning of this programme including issues related to international collaboration, the test plan, and technical issues

ROBUST friction building shaking table testing overview

Shaking table testing of a full-scale three storey resilient and reparable complete composite steel framed building system is being conducted. The building incorporates a number of interchangeable seismic resisting systems of New Zealand and Chinese origin. The building has a steel frame and cold formed steel-concrete composite deck. Energy is dissipated by means of friction connections. These connections are arranged in a number of structural configurations. Typical building nonskeletal elements (NSEs) are also included. Testing is performed on the Jiading Campus shaking table at Tongji University, Shanghai, China. This RObust BUilding SysTem (ROBUST) project is a collaborative China-New Zealand project sponsored by the International Joint Research Laboratory of Earthquake Engineering (ILEE), Tongji University, and a number of agencies and universities within New Zealand including BRANZ, Comflor, Earthquake Commission, HERA, QuakeCoRE, QuakeCentre, University of Auckland, and the University of Canterbury. This paper provides a general overview of the project describing a number of issues encountered in the planning of this programme including issues related to international collaboration, the test plan, and technical issues

Numerical studies on the seismic response of a three-storey low-damage steel framed structure incorporating seismic friction connections

A 9 m high, near full scale three-storey configurable steel frame composite floor building incorporating friction-based connections is to be tested using two linked bi-directional shake tables at the International joint research Laboratory of Earthquake Engineering (ILEE) facilities, Shanghai, China, as part of the RObust BUilding SysTem (ROBUST) project. A total of nine structural configurations are designed and detailed. To have a better understanding of the expected system behaviour, as well as effects of other structural and non-structural elements (NSEs) on the overall system response, experimental testing at component level has been conducted prior to the shake table testing. This paper presents an introduction to the ROBUST project, followed by a numerical study on one of the nine configurations of the structure, having Moment Resisting Steel Frame (MRSF) in the longitudinal direction and Concentrically Braced Frame (CBF) in the transverse direction. Hysteretic properties employed in the numerical models are validated against component test results. The predictions of the building's seismic response under selected base excitations are presented indicating the likely low damage performance of the structure