DIDACTIC UNIT 1: MAINTENANCE REQUIREMENTS AND REGULATIONS 1. General aspects 2. Inspection and mantenance process 3. Sample regulations DIDACTIC UNIT 2: TYPES OF TUNNELS AND UNDERGROUND STRUCTURES 1. Introduction 2. The objective of underground structures 3. Classification of underground structures 4. Template cross-section of a tunnel 5. Construction systems 6. References DIDACTIC UNIT 3: ANALYSIS OF PATHOLOGIES 1. Introduction 2. Definitions 3. Evaluation of the condition of the tunnel 4. Analysis of the causes 5. Pathologies 6. References DIDACTIC UNIT 4: TUNNEL INSPECTION 1. Introduction 2. Possible types of inspections. Dividing the tunnel into modules 3. Visual inspection 4. Non-destructive inspection 5. Destructive inspection 6. Inspection analysis 7. Actions to be carried out after the inspection 8. References DIDACTIC UNIT 5: REPAIRS AND AUSCULTATION 1. Introduction 2. Measures to be taken in the event of water inflow and its manifestations 3. Structural measures in the linings of mined tunnels 4. Measures to be taken in cut-and-cover tunnels 5. Repair of false tunnels 6. Auscultation of tunnels in service 7. References DIDACTIC UNIT 6: ANALYSIS OF SPECIFIC CASES OF THE INSPECTION AND REHABILITATION OF TUNNELS AND UNDERGROUND STRUCTURES 1. Introduction 2. Condition of the lining of old railway tunnels 3. Enlarging the section of an old tunnel 4. Tunnels in expansive and karstified terrain 5. Urban metro tunnels 6. Repair of a pre-cast structure 7. References