Alfredo Ang Lecture

Prof. Yan-Gang Zhao

Department of Architecture, Kanagawa University, Yokohama, Japan

Structural Reliability Assessment with Uncertain Distribution Parameters

It has been recognized that the uncertainty of distribution parameters has a significant effect on the structural reliability analysis results. In this paper, an efficient and accurate method is proposed to estimate the predictive failure probability including the uncertainty of distribution parameters. This method obtains the predictive failure probability by integrating in the probability space of the conditional reliability index. A three-parameter lognormal distribution is suggested to approach the distribution of the conditional reliability index, in which the first-three central moments of the conditional reliability index are estimated from the point-estimate method combined with the bivariate dimension-reduction method. On basis of this, the analytical solutions for the quantiles and probability distribution of the conditional failure probability are derived and investigated. It is found that the proposed method uses only one calculation process to obtain the predictive failure probability and the quantiles of conditional failure probability, which saves the calculation time using two calculation processes in previous methods, it is easy to provide a complete picture of structural reliability evaluation results under distribution parameter uncertainty efficiently in a wide range of applications.

Keynote Lectures

Prof. Jim Hall FREng

Professor of Climate and Environmental Risk, School of Geography and the Environment, University of Oxford, UK

Analysis of climate risks to infrastructure at national and global scales

Recently available global datasets and increasing computational capabilities are providing the possibility to analyse infrastructure networks and systems at very large scales. This is motivated by the need to understand the potential systemic risks from climatic extremes, which can cause wide-spread disruption to infrastructure networks, and to prioritise plans and investments to adapt infrastructure systems to a changing climate. This talk will provide an overview of the methodologies adopted for climate risk analysis to infrastructure systems and will describe recent large-scale applications in Africa, the Caribbean and South-East Asia. It will sketch out the journey towards global-scale analysis of transport, energy, water and telecommunications networks.

Prof. Mark G. Stewart

Director of the Centre for Built Infrastructure Resilience, University of Technology Sydney, Australia

Chasing Ghosts: Terrorism Risks to infrastructure

A key motivation for much research on protective structures is terrorism or insurgency attacks as witnessed by the Oklahoma city bombing, 7/7 attacks in London and other bombings worldwide. Risk is the integration of threat, vulnerability and consequences, but threat is often based on worse-case thinking about the capability of terrorists to successfully plan and execute large scale bombings. The presentation initially looks at the nature of the terrorist adversary by exploring their capabilities and motivation, technical skills, and target selection. An improved understanding of the threat allows decision-makers to more effectively deploy resources to counter such threats, which includes appropriate design and assessment of civilian and military protective structures.
The presentation will then show how a probabilistic understanding of blast loads and structural resistance can be used to estimate reliability-based load factors and probability of blast damage. This allows risk reductions to be calculated for blast protective measures. A cost-benefit assessment is illustrated by considering the effectiveness of bollards to increase stand-off from a VBIED and hence reduce the risk of progressive collapse. The presentation will describe infrastructure resilience to terrorist attacks, and discuss the nature of resilience and its impact on society under these threats.

Prof. Hongwei Huang

Department of Geotechnical Engineering and International Joint Research Center for Resilient Infrastructure, Tongji University, Shanghai, China

Resilience of Assembled Shield Tunnel Linings: from Test to Modeling and Measures

Shield tunnel is extensively employed for underground infrastructures, such as metro tunnel systems. In the operation of such a complex critical infrastructure, the vulnerability and the recovery of the segmental linings subjected to unexpected disruptions are badly concerned by the engineers and owners. These two aspects compose the basic concept of system resilience, which is receiving increasing attention these years. The notion of resilience has prompted the formulation of a new philosophy in the design and assessment of the metro network, against external shocks, such as natural and man-made disasters. However, the study on the system resilience for tunnels remains at the stage of conceptualization so far. In this presentation, the reason for the structural resilience in terms of the deformed shapes is revealed by the full-scaled loading test on the segmental joint. The assembly of different structural components might be the reason that enables the integrated lining ring to have the resilience ability to deform forward and backward from extreme loading and unloading scenarios. Based on these physical test results, a resilience model in terms of the deformational performance is put forward with the emphasis on the general response of the lining deformation. This could be regarded as the systematical responses of the multiple components of an integrated lining ring, which consists of several concrete segments connected by the joints with connecting bolts and seal gasket. One countermeasure, i.e., grouting on the soils at two sides of the tunnels, is then discussed with the emphasis on the deformational performance of the resilience. Based on a case study on the Shanghai shield tunnel, the grouting resulted in a 30% reduction in horizontal convergence. However, less than 5% of the grouted volume contributed to the horizontal movement of the tunnel cross sections. Later, tunnel longitudinal uneven settlement caused by ground or closer engineering disturbance can also be recovered by grouting. In addition to the deformational performance, the performance in terms of the bearing capacity is furtherly analyzed given the strength enhancement by steel plate reinforcement. The resilience of the strength of the tunnel lining in a similar philosophy from a component of joint to a system of integrated rings is discussed at the end of this lecture.

Prof. Xiaobo Qu

Chair Professor of Intelligent Transportation, Tsinghua University, China

From Transportation Engineering to Intelligent Transportation Systems: Evolution, Trends and Applications

In this talk, the speaker will revisit the revolution from traditional transportation engineering to intelligent transportation systems, which is triggered by rapid development of vehicular, tele-communications, data collection and processing technologies. Then three trends will be discussed: high-resolution big data (due to the paradigm change in data collection and processing), emerging mobility modes and their integration with existing systems (e.g. connected and automated vehicles, modular buses, flying cars, boring), and systems of multiple systems (e.g. interactions with electricity grid, tele-communications systems). These three trends will play important roles in the planning, design, operations and control of our next generation transportation systems. A series of applications of these three trends will be introduced, and their benefit in relieving congestion reduction will be presented. This revolution needs collective multi-disciplinary efforts from transport engineering, vehicle engineering, industrial engineering and operations research, electrical engineering, social science as well as other relevant sectors.

Dr. Mohammad Pourgol-Mohammad

Associate professor (Adj.), Mechanical Engineering Department, University of Maryland, USA

Approaches and Trends in Reliability Qualification Techniques in Semiconductor Industry

Electronics dominated complex engineering systems consistent of interconnected and diverse hardware, and software in dynamic conditions, physical processes, and environments. There are vast advancements in the semiconductor industries like 5G, and 3-Nano technologies, requiring thorough reliability and life evaluation at the various levels of wafers, components, and system. Specific Electronics features and challenges are unique failure mechanisms, high density of populated components, and high sensitivity to high frequency ranges, noises as well as environments variations. There are significant advancements and still immense challenges in electronics systems (alone or in conjunction with Elecrtomechanical entities) reliability evaluation. This presentation will overview the analytical, simulation-based, and experimental advancements in electronics industry reliability analysis. The tools and approaches will be explained, and the trends will be discussed. This will include the classical FMEA, HALT/HASS testing, part stress and parts counts. Recent approaches are based on physics of failure, prognostics health management (PHM), and dynamic reliability evaluation.
Significant advances in sensing and computing have led to an explosion of system health data and development of PHM algorithms designed to monitor component reliability. This speech will discuss an integrated sensory measurement-based health prognostic and degradation prediction system consisting of a method for measuring, gathering, and processing environmental and operation information and collating it into useful health metrics that are available for monitoring remotely through standardized data aggregation systems. The focus will be here to estimate the fatigue, corrosion, wear and creep remaining useful life (RUL) of structures, Systems and Components (SSCs). The PoF models are represented through mathematical or deep learning, that predict degradation and likelihood of failure of SSCs using offline and sensor-based online vibration data along the working and environmental condition data and information (USPatented). Several Case studies will be presented.