Summary

Underground facilities, such as tunnels, maintenance holes and handholes, deteriorating continuously with time. For example, cracks and water leakages occur and these phenomena degrade the safety and serviceability of the underground facilities. If the deterioration is neglected, large-scale repair and reinforcement measures may be required, which will increase future costs. Therefore, it is highly recommended that periodic inspection and timely maintenance are performed.

Safety management of telecommunication infrastructure facilities is described in general in ITU-T Recommendation L.330, but the detailed technologies and countermeasures for each facility are left for other Recommendations.

Recommendation ITU-T L.340 describes the inspection procedures, technologies and countermeasures for the maintenance of underground facilities as defined in Recommendation ITU-T L.330.