| 摘要 |
PROBLEM TO BE SOLVED: To provide an effective and appropriate branch junction part construction method for easily constructing a branch junction part at low cost. SOLUTION: A plurality of roof shield tunnels 4 are constructed being arranged at predetermined spaces in a construction predetermined location of the branch junction part to be constructed at the side of a main tunnel 1, and a soil improving body 5 is formed on the outside by a freezing method or a chemical solution injection method to construct a shield roof preliminary construction 6 with these roof shield tunnels 4 and soil improving body 5. The construction predetermined location of the branch junction part is surrounded by the shield roof preliminary construction and the main tunnel, and the main tunnel 1 is excavated to be widened to the side to construct the branch junction part. COPYRIGHT: (C)2009,JPO&INPIT |
