| 摘要 |
PROBLEM TO BE SOLVED: To enable an escape door 9, which is longitudinally longer than an escape hatch 8 formed by being notched in a watchman passage 4 of a tunnel 1, to be easily removed to the side of a roadway 2.SOLUTION: An escape door 9 includes door bodies 11 and 12 which are shorter than a longitudinal length of an escape hatch 8, and auxiliary door bodies 11b and 12b which are detachably attached to the door bodies 11 and 12 and which become longer than the longitudinal length of the escape hatch when they are attached to the door bodies 11 and 12. The auxiliary door bodies 11b and 12b are detached so that the door bodies 11 and 12 can be removed from the escape hatch 8 to the side of a roadway 2.SELECTED DRAWING: Figure 3 |
