Mechanical splice of grid carbon fibre-reinforced polymer reinforcement and steel plate

摘要

A new shield-cuttable tunnel wall system has been developed. This system enables a shield tunnelling machine to break in or break out by directly cutting the launch or arrival part of the concrete wall of a vertical shaft with its cutter bits without performing prior ground improvement works and manual demolition. When this system is applied to a column-type diaphragm wall, H-shaped steel piles used as the reinforcement in the wall should be replaced by bit-cuttable mixed-in-place mortar piles reinforced with carbon fibre reinforced polymer (CFRP). In order to connect the grid CFRP reinforcement and the flange of H-shaped steel, a specially designed mechanical splice has been developed. Tension tests of the mechanical splices were carried out to investigate their mechanical behaviour. The mechanical splice was applied to the newest subway tunnel in Tokyo.