Road tunnel trough structure - has drainage system in and below caps at expansion joint strips

摘要

The trough or approach structure for a tunnel is of concrete or with grooved supporting walls for a road surface. It comprises a soleplate supporting this surface and on which sealing material is laid, with caps at the sides of the laminated surface of bituminous material or concrete etc.. Expansion joints at regular intervals accommodate seam strips. A drainage system is provided in and below the caps at these strips (18). This can slope downwards to the next water drain, and can be formed by one or more spiral tubes (21). ADVANTAGE - Prevents damage to road surface by water penetration.