The tunnel construction method null which constructs in the seabed or the riverbed

摘要

PROBLEM TO BE SOLVED: To shorten term of works and reduce costs on constructing a road or a railroad across a strait or a riverbed. SOLUTION: On constructing a road or a railroad across a strait or a river 50, a plurality of grouped piles are driven into the sea bottom or the riverbed 14, and a box-shaped container is supported with each of the grouped piles with the upper ends of the piles included. Then, concrete is cast into the container and an underwater foundation 20 is constructed with the piles made integral with the container. A plurality of underwater foundations 20 are installed at intervals at a construction site. A plurality of tunnel cases 22, each constituting a part of a tunnel 42 in its longitudinal direction, are produced at a production yard on the ground with both ends of each of the cases closed with temporary partition walls. Then, the tunnel cases 22 are towed to the construction site and sunk into the water to bridge over the adjoining underwater foundations 20, being drawn one by one toward the tunnel cases already installed, and are connected with one another with flexible couplings. After that, water in the joints is removed and after the temporary partition walls are removed, the tunnel 42 is finished with various kinds of works for fitting-up the inside executed.