Bøger udgivet af International Association for Bridge and Structura

Failures of structures occur in all parts of the world as the result of design errors, construction defects, abuse or misuse, ageing and deterioration of the structure, lack of maintenance, as well as environmental effects such as wind, flood, snow, earthquake and, of course, human errors. They can result in catastrophic human costs as well as heavy financial losses to all involved, including local economic growth deceleration, expensive delays and repairs, as well as other repercussions, such as legal actions to responsible parties.'Welcome' effects of these unfortunate events include a better understanding of the origins and causes of structural failures, their corresponding lessons learnt, and a more effective mitigation of their occurrence through changes in codes, standards, guidelines, and practice.In several countries the investigation process of the causes of failures, responsibilities, and resolution of the consequent claims have created an active, demanding, and specialised field of professional practice - often referred to as Forensic Structural Engineering - with well-defined technical and legal procedures.This bulletin is the result of the work lead by the Task Group 5.1 'Forensic Structural Engineering'. It provides understanding of the origins, causes, and consequences of failures, their forensic investigations, and the lessons learnt from them. The aim of the bulletin is not only to describe different examples but, mainly, to use emblematic case studies to show procedures that can be used when dealing with structural failures. In addition to obtaining a deeper insight into the technical causes for structural failure, the reader would be duly informed about the different countries' legal issues related to the investigation process.The bulletin is aimed at young, mid-career and experienced structural engineers who want to acquire a better understanding of failure mechanisms towards improving their design, inspection, construction, administrative, and other project-related practices to avoid pitfalls that may lead to failures. It also aims at those wanting to acquire a working knowledge of the challenging professional practice of forensic structural engineering.

On January 15, 2018 at 11:49, the west pylon of the cable-stayed Chirajara Bridge collapsed during construction of the bridge girder. The collapse led to the total destruction of the pylon, together with the erected span of the bridge girder. Authorities reported nine fatalities resulting from the collapse.In this case study, the findings of the detailed investigation into the failure mechanism of the bridge are reported. In addition, selected drawings used for construction, geotechnical aspects, and deficiencies in the bridge design are presented, together with observations made during site visits and interviews with relevant parties.

The seismic resilience of new and existing structures is a key priority for the protection of human lives and the reduction of economic losses in earthquake-prone areas. The modern seismic codes have focused on the upgrade of the structural performance of the new and existing structures. However, in many cases, it is preferable to mitigate the effects of earthquakes by reducing the induced loads in the structures using seismic isolation and response control devices. The limited expertise in the selection and design of the appropriate system for new and existing structures is the main challenge for the extensive use of seismic isolation and response control systems in practice.This document aims to provide a practical guide by presenting a collection of the most commonly used seismic isolation and response control systems and a critical evaluation of the main characteristics of these systems. Comparisons of the key parameters of the design processes for new buildings with seismic isolation are presented, while the application of seismic isolation systems and response control systems for the retrofitting of existing structures is also examined, followed by various case studies from Greece, Japan, Mexico, New Zealand, and Turkey.