Distributed Fibre Optic Strain Sensing For Monitoring Civil Infrastructure

This book aims to consolidate academic knowledge on distributed optical fibre sensing into a practical guide in order to demonstrate the capabilities of fibre optic strain sensing, the opportunities it can offer to the construction industry, and how it can be implemented to monitor geotechnical infrastructures.

Structural health monitoring (SHM) can be characterized as the integration of sensing and intelligence to enable the potential damage to be monitored, analyzed, localized, and predicted in real time and in a nondestructive manner. Over the past two decades, extensive research has demonstrated that fiber-optic sensors (FOSs) are well suited for SHM sensing requirements in infrastructure systems. In this book, a brief overview of SHM and the application of FOS are presented. The book focuses on advanced techniques that utilize fiber-optic long-gauge sensing and overcome the limitations of traditional sensing and fulfill the requirements of infrastructure systems. The long-gauge FOSs have the merit of revealing both micro- and macrolevel information. Subsequently, a new approach, areawise distributed monitoring, is thoroughly discussed and its superior performance in SHM demonstrated. Finally, the application of areawise distributed monitoring, combined with the aforementioned long-gauge sensing technique, is presented for groups and networks of complex infrastructure systems.

Structural health monitoring is an extremely important methodology in evaluating the ‘health’ of a structure by assessing the level of deterioration and remaining service life of civil infrastructure systems. This book reviews key developments in research, technologies and applications in this area of civil engineering. It discusses ways of obtaining and analysing data, sensor technologies and methods of sensing changes in structural performance characteristics. It also discusses data transmission and the application of both individual technologies and entire systems to bridges and buildings. With its distinguished editors and international team of contributors, Structural health monitoring of civil infrastructure systems is a valuable reference for students in civil and structural engineering programs as well as those studying sensors, data analysis and transmission at universities. It will also be an important source for practicing civil engineers and designers, engineers and researchers developing sensors, network systems and methods of data transmission and analysis, policy makers, inspectors and those responsible for the safety and service life of civil infrastructure. Reviews key developments in research, technologies and applications Discusses systems used to obtain and analyse data and sensor technologies Assesses methods of sensing changes in structural performance

Sensors are used for civil infrastructure performance assessment and health monitoring, and have evolved significantly through developments in materials and methodologies. Sensor Technologies for Civil Infrastructure Volume I provides an overview of sensor hardware and its use in data collection. The first chapters provide an introduction to sensing for structural performance assessment and health monitoring, and an overview of commonly used sensors and their data acquisition systems. Further chapters address different types of sensor including piezoelectric transducers, fiber optic sensors, acoustic emission sensors, and electromagnetic sensors, and the use of these sensors for assessing and monitoring civil infrastructures. Developments in technologies applied to civil infrastructure performance assessment are also discussed, including radar technology, micro-electro-mechanical systems (MEMS) and nanotechnology. Sensor Technologies for Civil Infrastructure provides a standard reference for structural and civil engineers, electronics engineers, and academics with an interest in the field. Describes sensing hardware and data collection, covering a variety of sensors Examines fiber optic systems, acoustic emission, piezoelectric sensors, electromagnetic sensors, ultrasonic methods, and radar and millimeter wave technology Covers strain gauges, micro-electro-mechanical systems (MEMS), multifunctional materials and nanotechnology for sensing, and vision-based sensing and lasers

Over the past two decades, extensive research has been conducted on the application of fiber-optic sensors (FOSs) in structural health monitoring (SHM). In Volume 1 of this book a long-gauge sensing technique for incorporating a proposed areawise sensing, developed by the authors, was introduced. High precision and good durability of the long-gauge sensors were also demonstrated via technical improvements that further enable the applications of optical fiber sensors and carbon fiber sensors. In Volume 2, based on the merits of the long-gauge sensors, the methods that have been developed for processing areawise distributed monitoring data for structural identification are introduced. A discussion follows on how those methods are capable of performing a rich recognition of local and global structural parameters including structural deflections, dynamic characteristics, damages, and loads. Also presented is a three-level method of structural performance evaluation that utilizes monitoring data and identified results.

The use of sensors based on fibre optic technology allows a broad range of applications in the fields of structural and geotechnical monitoring, which can effectively improve the maintenance of infrastructures and the safety of communities. Thanks to its valuable features, such as distributed monitoring, the easiness and endurance of cabling, long term stability, reliable responses in both static and dynamic regimes and fibre optic technology, innovative and efficient solutions to quite difficult monitoring problems have already been provided. The increasing worldwide attention to infrastructures and communities with resilience capabilities against natural disasters has opened up new and challenging perspectives of applications to the use of fibre optic technology for structural and geotechnical monitoring. This book collects contributions in the development and application of monitoring solutions, based on fibre optic technology for structural and geotechnical engineering works and issues. In the book preface, the content of the contributions is reviewed, pointing out the relevance of the work, with respect to the advance and spreading of fibre optic technology for monitoring applications. All contributions provide a comprehensive discussion and report a rich bibliography on the current trends and issues relative to the theme of the work presented.

The use of fibre optic sensors in structural health monitoring has rapidly accelerated in recent years. By embedding fibre optic sensors in structures (e.g. buildings, bridges and pipelines) it is possible to obtain real time data on structural changes such as stress or strain. Engineers use monitoring data to detect deviations from a structure’s original design performance in order to optimise the operation, repair and maintenance of a structure over time. Fibre Optic Methods for Structural Health Monitoring is organised as a step-by-step guide to implementing a monitoring system and includes examples of common structures and their most-frequently monitored parameters. This book: presents a universal method for static structural health monitoring, using a technique with proven effectiveness in hundreds of applications worldwide; discusses a variety of different structures including buildings, bridges, dams, tunnels and pipelines; features case studies which describe common problems and offer solutions to those problems; provides advice on establishing mechanical parameters to monitor (including deformations, rotations and displacements) and on placing sensors to achieve monitoring objectives; identifies methods for interpreting data according to construction material and shows how to apply numerical concepts and formulae to data in order to inform decision making. Fibre Optic Methods for Structural Health Monitoring is an invaluable reference for practising engineers in the fields of civil, structural and geotechnical engineering. It will also be of interest to academics and undergraduate/graduate students studying civil and structural engineering.