AUTOMATED SCOUR DETECTION ARRAYS USING BIO-INSPIRED MAGNETOSTRICTIVE FLOW SENSORS

Scour is the most common cause of catastrophic bridge failures worldwide. Approximately over 60% of bridge failures reported in the United States from 1966 to 2005 are scour related. To ensure the continued safe operation of bridges, monitoring bridge scour is of paramount importance. Most monitoring regimes that are widely used are based on expensive underwater instrumentation. This research focuses on scour detection using automated remote flow detection arrays based on bio-inspired flow sensors. This study employs an array of bio inspired flow sensors that are inexpensive and robust versions of buried-rod scour sensor arrays, coupled with low-power wireless sensor network utilizing civil-engineering domain wireless sensing units to detect scour around bridge piers and abutments. Sensors within the network that report dynamic flow signals are considered to be waterborne or located above the sediment and sensors reporting static signals are characterized as buried or as being located in sediment. The a priori information of sensor depth will help to establish the sediment level in real time. An automated data interrogation system collects data, processes the raw sensor data using in-network data interrogation methods, then and communicates the results to the on-site base station. The relative directness of this data interrogation adds to the robustness of the system. The main purpose of the scour detection system is to provide remote scour information to bridge owners in a format that is easy to comprehend as an aid in decision making. In this project, only processed results, not raw data, are transmitted to the user. The system under study utilizes a cellular data link to relay simplified data to the bridge owner to aid in decision making. A robust program of validation has been conducted to define the limits of the approach in the laboratory and the results of the laboratory validation experiments have been presented in this thesis. This thesis also illustrates the ongoing initial field installation of scour monitoring system on local bridges with some scour concern

Review of Methodologies to Assess Bridge Safety During and After Floods

This report summarizes a review of technologies used to monitor bridge scour with an emphasis on techniques appropriate for testing during and immediately after design flood conditions. The goal of this study is to identify potential technologies and strategies for Illinois Department of Transportation that may be used to enhance the reliability of bridge safety monitoring during floods from local to state levels. The research team conducted a literature review of technologies that have been explored by state departments of transportation (DOTs) and national agencies as well as state-of-the-art technologies that have not been extensively employed by DOTs. This review included informational interviews with representatives from DOTs and relevant industry organizations. Recommendations include considering (1) acquisition of tethered kneeboard or surf ski-mounted single-beam sonars for rapid deployment by local agencies, (2) acquisition of remote-controlled vessels mounted with single-beam and side-scan sonars for statewide deployment, (3) development of large-scale particle image velocimetry systems using remote-controlled drones for stream velocity and direction measurement during floods, (4) physical modeling to develop Illinois-specific hydrodynamic loading coefficients for Illinois bridges during flood conditions, and (5) development of holistic risk-based bridge assessment tools that incorporate structural, geotechnical, hydraulic, and scour measurements to provide rapid feedback for bridge closure decisions.IDOT-R27-SP50Ope

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms

The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications

A vibration-based bridge scour monitoring technique

Historically, the most common cause of bridge failure has been “scour” – the gradual erosion of soil around bridge foundations due to rapid water flow. A reliable technique to monitor scour could potentially guide timely repair and, in turn, mitigate the risk of future scour-induced bridge failure. Currently, there are various, mostly underwater, techniques employed by bridge managers to monitor scour, ranging from diving inspections to autonomous underwater vehicles; however, none have gained wide acceptance. A particular disadvantage of underwater monitoring techniques is that the equipment underwater is relatively difficult to install and prone to damage from fast-flowing water and debris. One possible solution might be to use a vibration-based method to monitor scour indirectly, using changes in dynamic modal parameters (e.g. the natural frequency of vibration) captured by sensors mounted on the bridge deck or piers above the water level. There has been extensive research into the use of vibration-based monitoring methods to identify other causes of failure, such as cracking and deterioration in bridge superstructures; however, this has proven to be ineffective in practice, as the expected sensitivities in modal parameters were only single-digit percentages and therefore insufficient to overcome environmental/operational sensitivity. In contrast to superstructure damage, scour is a special damage case, which changes a boundary condition of the bridge in the form of an increase in effective pier height as a result of the lowering of the ground level and therefore, significant changes in modal parameters can be expected. Recently, this concept has been studied primarily using numerical modelling simulations of a hypothetical integral bridge with piled foundations. Only one modal parameter – natural frequency – was investigated in most of these studies and it was predicted to change by up to double-digit percentages due to scour. Although such a high change could potentially overcome environmental and operational sensitivities, a critical problem is that this has been difficult to observe in practice with experiments on either real field bridges or small-scale soil-structure models. Another problem is that there is little knowledge of the applicability of this technique to different types of bridges and forms of scour. This research proposes a vibration-based technique based on a combination of three vibration parameters (spectral density, mode shape and natural frequency), which were studied using first-of-a-kind experiments and numerical modelling simulations on various types of bridges and forms of scour. A field trial was carried out on a bridge with pre-existing scour, which was monitored for ambient vibrations throughout a repair process involving controlled scour backfilling, i.e., “scour in reverse”. The effect of this scour backfilling was captured by measuring changes in two of these parameters, mode shape and spectral density, derived from the ambient vibrations. The mode shapes, in particular, showed the potential to localise the presence of scour to a specific pier. The most commonly measured vibration parameter of natural frequency was also observed from ambient vibrations, but this did not capture the effects of backfilling due to high measurement uncertainties. In order to study all three of these vibration parameters in a controlled environment, a centrifuge model testing programme was developed. These tests considered small-scale models representing three full-scale bridges with different bridge deck and foundation configurations (i.e. integral/ simply supported decks and shallow/deep foundations) and two forms of scour (i.e. local/global). The observed results of these small-scale centrifuge models were used to calibrate numerical models of full-scale bridges representative of these centrifuge models. Numerical simulation techniques were also developed to simulate the experimentally observed effects of local and global scour. These centrifuge experiments and the associated numerical modelling found that vibration-based methods have broad applicability for bridges, although only some parameters showed sufficient sensitivity to be viable as a monitoring technique in certain types of bridges. For example, the centrifuge bridge models with a shallow foundation did not show a significant change in natural frequency or mode shapes, but they did show a significant change in modal spectral density. This research therefore concludes that a vibration-based scour monitoring technique, examining the combined effect of natural frequency, mode shape and spectral density parameters, has significant potential to measure and even localise the change of scour depths at bridge foundations.Gates-Cambridge Scholarship (Bill and Melinda Gates Foundation grant reference number OPP1144) Laing O’Rourke Centre for Construction Engineering and Technology Cambridge Centre for Smart Infrastructure and Construction (Innovate UK Grant reference number 920035 and EPSRC Grant no EP/N021614/1

D5.1 SHM digital twin requirements for residential, industrial buildings and bridges

This deliverable presents a report of the needs for structural control on buildings (initial imperfections, deflections at service, stability, rheology) and on bridges (vibrations, modal shapes, deflections, stresses) based on state-of-the-art image-based and sensor-based techniques. To this end, the deliverable identifies and describes strategies that encompass state-of-the-art instrumentation and control for infrastructures (SHM technologies).Objectius de Desenvolupament Sostenible::8 - Treball Decent i Creixement EconòmicObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPreprin