Panagiotis Michalis

BRIDGE SMS: Intelligent bridge maintenance and management system

An intelligent system for bridge inspection and management requires a knowledge and appreciation of structural engineering, geotechnics, hydraulics, hydrology, materials and transport management. This study introduces BRIDGE SMS, an EU/FP7 project, which couples state-of-the art scientific knowledge in hydrology, river and structural engineering with industrial knowledge in infrastructure management and web-based bridge management. This involves the application of monitoring systems for the assessment and management of the structural and hydraulic vulnerability of infrastructure assets over waterways in an effort to develop an open-source cloud-based intelligent Decision Support System. BRIDGE SMS aims to deliver procedures for complete bridge inspections, through scour and structural inspections, and to develop a reliable decision support tool which would efficiently manage bridge failure risks in a cost-effective way.

Electromagnetic sensors for monitoring of scour and deposition processes at bridges and offshore wind turbines

Recent increases in precipitation have resulted in severe and frequent flooding incidents. This has put hydraulic structures at high risk of failure due to scour, with severe consequences to public safety and significant economic losses. Foundation scour is the leading cause of bridge failures and one of the main climate change impacts to highway and railway infrastructure. Scour action is also being considered as a major risk for offshore wind farm developments as it leads to excessive excavation of the surrounding seabed.

Deformations of Pournari I dam (Greece) based on long-term geodetic monitoring data

A big number of large earth fill dams worldwide are expected to exceed their design lifespan until 2020. This number is becoming larger when taking into account predictions that dam infrastructure is not expected to withstand future natural disasters, with severe consequences to public safety and significant economic losses. Systematic monitoring and analysis is an important tool that enables the evaluation of the on-going performance of a dam, the validation of laboratory models and the assessment of different engineering designs. Currently, relationships describing the long-term evolution of dam deformations are based on only a few studies and mainly focused on the magnitude of crest settlements and the downstream horizontal deflections of the dam. This study presents the post-construction analysis of the behaviour of one of the largest earth fill dams in Greece, based on long-term monitoring data. The 29 year long dataset consisted of geodetic measurements of vertical and horizontal deformations from the crest and the body of the dam, reservoir level fluctuations, in addition to rainfall records of the dam area. Our analysis shows that the settlement of the crest remains within normal limits while the rate of deformations was stabilised almost seven years after the completion of the dam, which is longer than the period suggested by previous studies. The impoundment of the reservoir had a significant effect on the horizontal deflections of the body of the dam: an upwards and upstream movement in part of the downstream shoulder was detected. We compare our results with those obtained from the analysis of one of the highest earth fill dams in Europe, the Kremasta dam. We suggest that this pattern, though rarely mentioned in the international literature, is neither uncommon nor abnormal (when the horizontal deflections are still within safety limits) and is related to changes in the water pressure within the dam along with the on-going consolidation of the dam clay core.

Real-time monitoring of scour and sedimentation evolution with a new developed prototype sensor

Scour action is one of the main climate change impacts to civil infrastructure due to more frequent and severe flooding incidents. It is the leading cause of bridge failures worldwide and it is expected to occur at most of the hydraulic structures during their service life. Scour process also leads to excessive excavation of the surrounding seabed and is being considered a major risk for offshore wind farm developments. This research project presents a new type of electromagnetic sensor for monitoring underwater bed level variations around bridges and offshore wind turbine foundations. The capability of the prototype sensor to detect scour and deposited sediment was evaluated using scour simulations and real time flume experiments. The performance of the newly developed sensor under different environmental conditions is also reported in this study. The obtained results indicate that the sensing technique is highly dependent on the scour depth and sedimentation processes. Future research entails the field application of the prototype sensor to scour-critical structures.