Innovative Techniques for Bridge Assessment

This presentation was held at the 2020 NAFEMS UK Conference "Inspiring Innovation through Engineering Simulation". The conference covered topics ranging from traditional FEA and CFD, to new and emerging areas including artificial intelligence, machine learning and EDA.

Resource Abstract

The topic of bridge assessment has taken particular relevance on the later part of the 20th Century when the advancements in the knowledge of reinforced concrete behaviour made the structural engineering community aware of the fact reinforced concrete and pre-stressed structures designed and built in the 1960's were unlikely to last the 100 years they had been designed to. The United Kingdom, with most of its motorway network having been built during the 1960s, is a typical example of this.

This paper focus on the inspection, structural assessment and load monitoring that Mott Macdonald's A3M (Advanced Analysis for Asset Management) team was commissioned to undertake on this rather unique reinforced concrete arch bridge with a total span of circa 50m, built in 1968. This arch bridge, located in an area of outstanding natural beauty in South Wales and presently owned and managed by a Water Company.

The first part of the paper explores the numerical analysis techniques employed, such as 3D model build and the live strain monitoring of a 96T moving crane that was undertaken using a system of wireless strain gauges is covered in detail. Alongside this, the approach and development of an in-house finite element package, developed by one of the authors, to visualise and validate results from a commercial package is discussed.

The second part of the paper focus on the aspects related to the static and dynamic modelling of the structural behaviour of the bridge using the finite element method. Some of the techniques developed by the authors to establish comparisons between the experimental and numerical results are explored, with an approach to calibrating complex 3D models with experimental acceleration data recorded using smartphones located in key areas of dynamic response.

The paper finishes with a summary of the fundamental conclusions of the use of acceleration and strain data and their use as validation tools in understanding more about historic structure's condition and response to modern day loading.