Differential settlement, etc. measures for box culvert

摘要

PROBLEM TO BE SOLVED: To enhance the moldability, mold releasing ability by using a flexible coupling member and by composing the box-culvert without dividing it into two segments. SOLUTION: A box-culvert is made of precast concrete formed into a cylindrical shape for building an underground structure such as a culvert or an under path. A flexible coupling member 4 having a predetermined width is embedded in the annular cross-section in parallel with either and/or both of the inner and outer surfaces of the box culvert, and an annular breakable part 3 is formed into the cylindrical section, substantially along the center line of the flexible coupling mamber 4. With this arrangement, stress is concentrated in a part between the breakable part 3 and the inner and outer surface so as to break the culvert upon unequal sinking.