LINING STRUCTURE FOR TUNNEL INNER WALL AND CONSTRUCTION METHOD THEREFOR

PURPOSE:To effectively prevent a water leakage into a secondary lining by forming a specific porous water permeable layer and a specific waterproofing film layer between primary and secondary lining concrete layers. CONSTITUTION:A water permeable material capable of forming a water permeable layer 4 having compressive strength equal to or more than 1kg/cm and a water permeable factor equal to or more than 5X10cm/sec. is sprayed to the surface of a tunnel wall where primary lining concrete 3 is sprayed. Then, an aqueous waterproof material capable of forming an aqueous waterproof layer 4 having bond strength equal to or more than 0.1kg/cm for the water permeable layer 4 and a water permeable factor equal to or less than 1X10cm/ sec. is sprayed. Then, secondary lining concrete 5 is additionally placed. In order to form the water permeable layer 4, an inorganic composition expandable at normal temperature is, for example, used to form the prescribed foamed porous water permeable layer 4. Then, aqueous waterproof paint made of the first and second liquids is concurrently sprayed to the surface of the layer 4, thereby forming the waterproof layer 4. According to this construction, water gushing from the natural ground can be well sealed.