JPS61202584U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a sectional view of casings connected by the joint structure of the casings according to the present invention, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is an enlarged sectional view of the joint structure, and Fig. 4 is the same side view, Figures 5 and 6 are explanatory diagrams of the conventional propulsion method, Figure 7 is a cross-sectional view of the casings connected by the conventional joint structure, and Figure 8 is the line shown in Figure 7. FIG. 1: Casing, 2: Underground, 3: First annular step, 3a: Downward protruding edge, 4: Second annular step,
4a: upwardly projecting edge, 5: high-tensile bolt, 6: nut, 7: first rectangular recess, 8: second rectangular recess, 9: bolt insertion hole.

Claims (1)

[Scope of utility model registration request] In a casing joint structure for connecting a plurality of casings vertically buried in the ground, a first annular step having a downwardly protruding edge is provided at the lower end of the upper casing, and the first annular step is located at the lower part of the casing. A second annular step is provided at the upper end of the casing, the second annular step having an upwardly projecting edge that fits with the downwardly projecting edge of the first annular step; A plurality of first rectangular recesses that are open are formed in the circumferential direction, and a second rectangular recess that is opened inward is formed at a position corresponding to the first rectangular recess on the inner peripheral surface of the upper end portion of the casing located at the lower part. A casing joint structure in which a recess is formed, and a bolt insertion hole through which a bolt for fastening the casing is inserted is vertically formed between the first rectangular recess and the second rectangular recess.