Inspection Protocol for Permanent Support Structure of Road and Railway tunnels

tunnels, as an inevitable and necessary technical structure in transportation, usually incurs considerable cost. With the passage of time, this structure, and its related parts and equipment, such as its Support Structure, will gradually deteriorate. Inspection is the prelude to trying to maintain the desired condition and improve the performance of the structure during the useful life of the tunnel and will result in providing a solution for timely maintenance and repair. In this way, in addition to increasing the safety and efficiency of the tunnel, its damage and excessive damage will be prevented and significant savings will be made in the costs of major repairs or construction and reuse of the tunnel.Experience shows that the main part of maintenance costs is determined by the decisions made during the design and construction stages of the tunnel project. It is most important to consider the requirements of operation and maintenance of the tunnel during its planning and design.