JPS6243037Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an air vent pipe used in tunnel construction using the shield method to prevent air from accumulating in the concrete placement space and creating cavities when concrete is placed on the inner surface of the segment. Regarding.

Conventionally, when constructing a tunnel, after a horizontal hole is excavated, segments are assembled in the hole into a cylindrical shape, and the inner surface of the segment tube is lined with concrete.

When pouring this concrete, movable segments are placed inside the segment tube, with approximately 10 m of the segment tube as one section, and concrete is poured from one end into the cavity between the center frame wall and the segment tube.

However, as shown in FIG. 7, each segment of the segment tube has ring ribs 11 and 11a protruding from each other for joining the adjacent segments 1 and 1a, so when concrete 3 is poured, the upper part of the segment tube 10 There is a problem in that air accumulates between the ring ribs 11 and 11a, which prevents the filling of concrete and creates cavities 2 even after the concrete hardens.

For this reason, in the past, pipes were installed in each upper segment before pouring concrete so that through holes 31 were formed in the concrete layer, and after the concrete had solidified, foamed cement was injected through the holes 31 to fill the cavities. However, the work took a lot of effort.

(Technical Problem) The purpose of this invention is to fill the upper space between the segment and the formwork with concrete without forming a cavity when constructing a tunnel.

(Structure) The present invention has a straddle part with a length corresponding to the length plus the thickness of the abutting ring ribs of adjacent segments, and arms at both ends of the straddle part that extend substantially orthogonally to the straddle part and in substantially the same direction. An air vent pipe was formed by bending a single pipe, and had a hook part formed at the tip of each arm part and hooked to a fastener passing through the ring rib.

(Function) Fit the air vent pipe across the abutting ring ribs of adjacent segments, and hook the hooks at both ends of the pipe onto the ends of the fasteners protruding from the ring ribs. As a result, adjacent segments are communicated with air vent pipes, and when concrete is injected between the segments and the frame wall, the air inside the segments flows downstream through the pipes due to the filled concrete, and flows into the segments. There are no air pockets and therefore no cavities between the concrete layer and the segments.

(Special effects) The air vent pipe can be easily installed by hooking the end of the pipe onto a fastener, eliminating the need for filling cavities by pouring foamed concrete after pouring concrete, improving construction efficiency. much improved.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 shows a state in which a cylinder 10 is assembled by segments 1, and since each segment 1 is connected in two directions, the tunnel longitudinal direction and the circumferential direction, the longitudinal direction of an arc-shaped skin plate 12 is known. It is formed with a ring rib 11 protruding from the edge thereof and end plates 13, 13 protruding from the edges in the circumferential direction, and reinforcing ribs 14, 14 protruding between the ring ribs 11, 11.

The segments 1 are assembled out of phase with respect to the longitudinal direction of the tunnel, and the ring ribs 11, 11a of the axially adjacent segments 1, 1a that abut each other are connected to the fasteners 4 using bolts 41 and nuts 42 as shown in FIG. The end plates 13, 13 of the circumferentially adjacent segments 1, 1a abut against each other are fixed with fasteners 4 similar to those described above.

The air vent pipe 5 of the present invention is attached to the upper inner surface of the segment tube 10.

The air vent pipe 5 has an outer diameter of about 9 mm, a wall thickness of about 1 mm,
It is formed by bending a metal pipe with a length of about 85 cm, and the ring ribs 1 of adjacent segments 1 and 1a
Straight straddle portion 51 with a length including the thickness of 1 and 11a
The arm portions 52, 52 are extended from both ends in substantially the same direction and perpendicular to the straddle portion 51 to form a U-shape.
a hook portion 53 that is caught on the fastener 4 passing through the
53 is formed.

The length of the arm portions 52, 52 corresponds to the length from the tip edge of the ring rib 11 to the fastener 4, and in the embodiment, the arm portions 52, 52 are slightly inclined in the direction in which the tip sides approach each other. , the distance between the tips of the arm portions 52, 52 is slightly narrower than the thickness W of the ring ribs 11, 11a. Further, in the case of the embodiment, both hanging parts 53, 53 connect the tips of the arm parts 52, 52 to the arm part 52 and the straddling part 51.
and are bent in opposite directions to each other.

However, the air vent pipe 5 is connected to its both arms 52,
The ends of the fastener 4 are fitted into the abutting ring ribs 11, 11a of the adjacent segments 1, 1a while slightly expanding the 52 outwardly, and further rotated by twisting the arms 52, 52, so that the ends of the fastener 4 protrude from the ring ribs 11, 11a. Hook the hooking parts 53, 53 from opposite directions.

As in the embodiment, the thickness W of the ring ribs 11, 11a of the segments 1, 1a is
By fitting the arms 52, 52 into the segments 1, 1a while expanding the arms 52, 52, the elastic return of the pipe causes the arms 52, 52 to fit into the segments 1, 1a.
1a, and the hooks 53, 53 hook onto the ends of the fastener 4 from opposite directions. Once fastener 4
After setting the arm piece 5 of the air vent pipe 5.
2, 52 in the opposite direction and segment 1, 1a.
The air vent pipe 5 will not fall off unless a strong force is applied to pull it away from the air vent pipe 5.

When concrete is injected from one end side of the annular space formed between the frame wall 6 of the center (not shown) and the segments 1, 1a, as the concrete liquid level rises, each segment 1, Air is filled between the ring ribs 11, 11a of 1a and the end plates 13, 13.

However, the adjacent segments 1 and 1a are connected by an air vent pipe 5, and when the segments are filled with concrete, air is pushed out to the downstream segment by the air vent pipe 5.
This is repeated sequentially on the downstream side due to the concrete flow, so the concrete is
fills the area and does not create a cavity.

This is possible if the air vent pipe 5 is buried in concrete and the concrete is solidified.

[Brief explanation of the drawing]

Figure 1 is a front view of the segment frame, Figure 2 is a slope view of the air vent pipe, Figure 3 is a front view of the air vent pipe, Figure 4 is a vertical sectional view of the segment frame along the tunnel axis, and Figure 5 is FIG. 6 is an enlarged view of the installed state of the air vent pipe, and FIG. 7 is an explanatory diagram of a conventional example. 1, 1a... Segment, 5... Air vent pipe, 51... Straddling part, 52... Arm part, 53... Hanging part.

Claims (1)

[Claims for Utility Model Registration] Formed by bending a single pipe, the length corresponds to the sum of the thickness of the abutting ring ribs 11, 11a of the segments 1, 1a adjacent in the axial direction of the tunnel. At both ends of the straddling part 51, arm parts 52, 52 extend substantially perpendicularly to the straddling part and in the same direction, forming a substantially U-shape, and at the ends of the arm parts 52, 52 there are fasteners penetrating the ring ribs 11, 11a. An air vent pipe in which hanging portions 53, 53 hooked on the air vent pipe 4 are bent. The air vent pipe for tunnel construction according to claim 1, wherein the hanging portions 53, 53 at both ends are bent in opposite directions. The arm portions 52, 52 are slightly inclined in a direction in which their tips approach each other.Claim 1 of Utility Model Registration
The air vent pipe for tunnel construction according to item 1 or 2.