RESEARCH ON SEGMENTS COMBINED WITH SECONDARY LINING FOR SEWERAGE SHIELD TUNNELS

Abstract

The authors have developed "Segments combined with Secondary Lining for Sewerage Shield Tunneling Works". The segments are manufactured with a corrosion protection layer of 50-mm thick non-reinforced concrete at the inner side, which aims at reduction of construction period and costs by omitting the secondary lining construction process. In this research, load carrying performances of the segment under possible loading cases including the thrust force of shield jacks were measured and compared with segments without secondary lining. In addition, durability of the corrosion protection layer was confirmed by the exposure tests to hydrogen sulfide gas. A new type of joints which can make smooth inside surface has developed for additional cost reduction and the performances of the joint were verified. Guideline for design and construction is provided for the practical use of the segments.