Repairing Damaged Tunnel Lining with Small-Size Cavity in Surrounding Rocks.

This paper presents a case study of local repair to damaged concrete lining in an operational tunnel, in which a local repairing countermeasure is proposed and adopted in practical implementation. The countermeasure consisted of grouting cavities with cement slurry and installing a ribbed ring reinforcement in the damaged part of the concrete lining. The field investigation and numerical analysis demonstrate the concrete lining damage is primarily induced by the field-observed construction deficiency of small-size cavities around surrounding rocks. The implemented treatment work demonstrates that the employed countermeasure is capable of local repair of the damaged concrete lining induced by the aforementioned construction deficiency of small-size cavities around surrounding rocks, which can provide the design basis for similar treatment work. [ABSTRACT FROM AUTHOR]