Ground water seal for tunnel concrete lining panels has inner seal bridging gap heat welded to outer seal

摘要

Following the excavation of a tunnel the walls are lined with sections of concrete which are joined at seams behind which seals are applied. The gap between adjacent concrete lining blocks is covered by a first plastic seal (12) placed on the outer face of the concrete lining. The first plastic seal is in contact with a second plastic seal (17) which is esp. wider than the first. The outer margins (18) of the second plastic seal overlap a further seal (17). The outer seal and inner seal are heat welded (28).