Portal de Periódicos da CAPES

Development of inner lining for deteriorating reinforced lining of mountain tunnels

2016; Volume: 2; Issue: 3 Linguagem: Inglês

10.3208/jgssp.vps-03

2188-8027

Yoshinori Nagayama, Masahiro Kondo,

Geotechnical Engineering and Underground Structures

Long-term stability of mountain tunnels is disrupted by natural causes such as ground pressure and earthquakes. In some cases, their serviceability is disturbed by deterioration of lining concrete. There are 280.5 kilometers of tunnels in Sanyo Shinkansen. Among them, 16.8 kilometers are reinforced concrete structures. Rock pockets and cold joints are main causes of loose parts of lining concrete. They are mainly defects at the time of construction, and once they are removed, further deterioration is limited. However, the cause of loose parts of reinforced lining is carbonation combined with deficiency in the depth of cover of rebars, and carbonation continues into the future. In order to ensure long-term performance of tunnels with reinforced lining, the authors have developed a new technology of inner lining. Members of the new lining were tested in laboratory, and confirmed they will withstand grouting pressure, wind pressure caused by train operation, and weight of loose parts of concrete. Mock tunnel was constructed and test executions were carried out to verify execution time before actual construction.