Maintenance of complex underground tunnels

1. Responsibility of each operator

2. Commitment of each operator in the context of the overall maintenance strategy

3. Coordination between the Operators

4. Sharing of best practices

Maintenance in complex tunnels is a holistic and interrelated issue where a contribution of one sector must be proactively complemented by the contribution of other sectors. The purpose of maintenance in underground and complex tunnel structures is to improve the serviceability of the infrastructure and to reduce operational costs. When maintenance is performed at the right time of the tunnel life cycle it optimises the available equipment, minimises the risk of accidents and largely contributes to public safety. Tunnel operators, particularly those involved in the maintenance of large underground and interconnected infrastructures are reminded of the need to optimise their maintenance strategies and to enhance public confidence in the use of these infrastructures by making them safer, efficient and continuously available for use.

The strategic components related to maintenance in tunnel networks may be divided into four categories:

• The responsibility of each operator,
• The commitment of each operator in the context of an overall maintenance strategy,
• Coordination between the operators,
• Best practices to be shared.

1. Responsibility of each operator

Each operator is responsible for the safety level of its infrastructure, which contributes to the overall level of safety of the entire complex. Each operator is responsible for informing the lead operator of its maintenance demands and the demands of the others. A global maintenance coordination plan should be established among all operators and adjusted to the individual operators. Focus should be on global benefits and minimizing the time of restricted tunnel operations is essential.

At same time, each operator has responsibilities that may be impacted by actions of other operators. The Lead Operator of the underground tunnel infrastructure is responsible for the overall co-ordination and communication process.  

2. Commitment of each operator in the context of the overall maintenance strategy

Each operator is responsible for managing and maintaining its own equipment. Each operator must establish the list of equipment under its responsibility and share it with the other operators.

Some equipment could be considered as strategic equipment, necessitating collective responsibilities. The list of this strategic equipment must be established, discussed and shared. It has also to be clearly defined who is in charge of what.

It is crucial to acknowledge that the collective efforts of operators will trigger combined responsibilities for all participants in the process.

3. Coordination between the Operators

The coordination process in the context of the underground interconnected complex tunnels entails the following:

a) Organizational Behaviour

There is a need to develop group work which is only achievable if the organisational behaviour is aligned to the needs of the infrastructure (refer to Operation of complex tunnels).

b) Maintenance of one has implications on the others

• Where interfaces are unavoidable, it is important that each operator fully respects its obligations in a timely manner. This may have a direct impact on the road tunnel users and on the overall quality of service being offered to the public.
• Interfaces entail teamwork, proactiveness and compromise. No improvement works should be undertaken if they lead to complicated situations for other tunnel operators. 

4. Sharing of best practices

Best practices in tunnel maintenance will also require a coherent effort from the key players and stakeholders. This can be achieved by defining a set of principles and procedures set out in the operator’s procedure manual generally known as the inventory manual. Tunnel operators are encouraged to be acquainted with all key components of the inventory manual which are applicable to their functions and have been developed by PIARC over many years.