Environmental Engineering Reference
In-Depth Information
A Measured Step Towards
Performance-Based Visual Inspection
of Flood Defence Assets
6
GAVIN LONG AND MICHAEL J. MAWDESLEY
Background
inspection is prone to inaccuracy as it can only
assess the surface details of an asset; changes to
interior structure and condition are not easily
identifiable until they lead to changes to the sur-
face of the asset. Visual inspection of flood defence
assets in most of the UK has been carried out by
the Environment Agency (EA) since its inception
in 1996.
In the UK the Environment Agency (EA) is
tasked with the management of a large flood
defence infrastructure of approximately 70,000
assets with a total length of over 35,000 km
(Halcrow, 2004). These assets are periodically
inspected by qualified staff and assigned a con-
dition grading based on their visual condition.
The current method of inspection is effective
for assessing the visual condition of an asset but
is thought to produce an inadequate assessment
in terms of
Aims and Objectives
likely asset performance under
The work described here was undertaken
under the auspices of the Flood Risk Manage-
ment Research Consortium (FRMRC) and
funded by the Engineering and Physical Sciences
Research Council (EPSRC), the Department of
Food and Rural Affairs (Defra) and the EA. Its
primary aim was to produce a revised method-
ology for the visual inspection of flood defence
assets, to the proof of concept level, which
represented an advance towards performance-
based assessment.
A more detailed list of objectives is:
1
To achieve ameasured step forward in the visual
inspection of flood defence assets.
2
To introduce a scientific methodology into the
process wherever possible.
3
To highlight areas where the scientific method-
ology is lacking.
4
To provide a vision of howthe inspection should
be done in the future.
loading.
Asset monitoring and inspection is a primary
input to any asset management system. Without
assessments of condition and likely performance
of the assets within an infrastructure system
it is impossible to provide effective decision-
making regarding the management of such sys-
tems. Accuracy and recency of inspection data
are key determinants in the success of any asset
management system.
Visual inspection is the simplest form of non-
destructive testing as it does not require any spe-
cialist equipment. It is a widely used technique for
monitoring assets. Itmust be noted that any visual
