The occasion where it constructs shaft such as the manhole to the sealant null earth using for the joint structure and its joint

摘要

PROBLEM TO BE SOLVED: To secure proper workability of fitting of a seal material into a groove of a joint and sufficient water sealability.;SOLUTION: In a connecting structure of a cylindrical casing, the grooves 11 and 12 around the whole circumferences of joint end surfaces of a plurality of cylindrical concrete casings 2 and 3 are formed, and a sealant 13 is charged into the whole circumference of the grooves. The groove is formed in an isosceles-trapezoidal vertical section. When the sealant is charged into the groove, it is compressed by self-weight of the casing (Fig. a). In this case, since a vertical section of the sealant is formed in an oblong shape line-symmetric with respect to a width-direction central axis, side surfaces (both side walls 13a and 13a) of the sealant surely seal an interface between abutting end surfaces of the cylindrical casings 2 and 3 by surely swelling to the outside, when the sealant 13 is pressed from above and crushed downward by a cavity 14. When water pressure on the outside of the vertical shaft is low, water is sealed with a compressive force of the sealant 13 itself (Fig. c). When the water pressure becomes higher, the sealant is pressed (moved) against the one side surface of the groove, so as to seal the water (Fig. d). This pressing force becomes stronger together with an increase in water pressure, so as to enhance a water sealing effect.;COPYRIGHT: (C)2011,JPO&INPIT