Now more than ever, the management of ageing infrastructures has become an important issue. Indeed, it is becoming increasingly clear that maintenance is now the main focus of high stake infrastructure managers - all the more since the high cost of complete refurbishment is often prohibitive.

In light of this, the aim of infrastructure managers is to ensure operation of their ageing structures under the best conditions of safety, service and costs, while also maintaining their asset value.

In addition to continual monitoring which gives information on the overall condition of the structure and enables the early detection of potential warning signs (cracks, humidity, rust…), as well as compulsory monitoring procedures, a specific monitoring of particular parameters can help to reach these goals.

What should I monitor on my structures in order to reach my goals of performance ?

In order to ensure the relevance of a monitoring plan, and to focus this plan on the most significant areas, OXAND recommends a risk analysis.

This approach ensures an economic control of risks of civil engineering infrastructures, by concentrating the necessary means on the components with the highest risk for the overall integrity of the structure.

Indeed, since not all flaws have an impact on security, serviceability, or other issues related to the structure, their systematic characterisation is not only pointless but may also force the owner to undertake a complete refurbishment which is obviously very expensive, and most of which will be of very little benefit.

Advantages for the owner :

Guarantee of the monitoring plan’s relevance, defined according to predefined functional objectives and the advantages of which are quantified in terms of reduction of risks of civil engineering infrastructures, or reduction of uncertainties relating to risk level.

Illustration of a possible evolution of the risk mapping of a civil engineering structure after uncertainties reduction

Guarantee of reaching ambitious goals due to an appropriate monitoring and treatment of data.

Examples of client objectives :

Increase the operation and service period of a portfolio of structures while ensuring their service condition ;

Anticipate detection of a failure in order to allow for planned preventative interventions, thus avoiding a reactive remedial response.

Illustration of the monitoring device for concrete and steel sheet pipes validated and developed industrially by OXAND for a portfolio of seaside nuclear power stations. Commercialisation of Oxand’s international Patent « Intelligent Monitoring ».

How should the monitoring data be used ?

Give a maximum value to existing data !

There is usually much available existing data about a civil engineering structure (design and construction files, studies, history…), and processing this data with a risk management approach provides the necessary information to establish a monitoring plan in order to obtain missing data.

Even with little data, it is possible to performe at an initial estimation, and in particular to obtain a clear idea of what information is missing which could reduce uncertainties.

Create an operating system, generating the necessary information for the owner of a civil engineering portfolio to decide what actions are needed and how to plan them. More

Advantages for the owner :

Quick overview of the situation, whereas an approach which starts by acquiring and processing data results in a much longer delay before arriving at an initial conclusion

Value given to existing data

Specification and planning of interventions

What investments are needed for a risk management of civil engineering structures portfolio ?

The necessary investment is for a low-budget study as opposed to a much more expensive maintenance budget. In addition, the direct benefits of a risk management approach for optimising monitoring and maintenance can reach as much as 20 to 100 times the cost of the study itself.