MANHOLE SECTION JOINT STRUCTURE FOR UNDERGROUND BURIED CABLE PROTECTIVE TUBE AND PIPE JOINT STRUCTURE FOR PROTECTIVE TUBES

摘要

PROBLEM TO BE SOLVED: To provide a joint structure giving little damage to a cable even at the large lateral deflection and ground settlement. SOLUTION: A manhole socket short tube 12 is provided on a manhole wall 1, and the spigot 14 of a protective pipe P is inserted into the short tube 12 to the middle. A sponge rubber 18 is provided at the tip via a stopper rubber 13, and a water stop packing 17 is provided on the opening side. A joint structure between the protective pipes P has a similar mechanism. Pushing force is suppressed by the squeezing of the sponge rubber 18, and pulling force is suppressed by the resistance force of the water stop packing 17 to prevent the breakage of a joint section. If a lug is provided in the front of the spigot 14 to be locked on the water stop packing 17, a release can be effectively prevented. The inclination of the axis is absorbed by the squeezing of the packing 17, and a gap for it is secured between the inner face of a socket and the outer face of the spigot 14.