CULVERT CONSTRUCTION TYPE TUNNELING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for constructing a high-strength tunnel with no structural defect while aiming at rationality, stability, and safety of works in a culvert construction type tunneling method. SOLUTION: In the culvert construction process, an inner space substantial layer 6, a culvert circumferential wall 7, and an earthen cover layer 8 outside the culvert are formed of a relatively low-strength improved soil D3, a relatively high-strength improved soil D4, and non-improved soil on the ground G respectively. In the inner excavation process, the inner space substantial layer 6 is removed and a culvert inner space part 9 is formed inside the culvert circumferential wall 7.