JPS63107697A - Lining method of shield tunnel - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for lining a shield tunnel, and more specifically, it relates to a method for lining a shield tunnel, and more specifically, concrete is applied to the inner surface of the tunnel as the shield machine advances, without using ready-made lining segments. The invention relates to a method of pouring and thereby forming a lining wall.

(Conventional technology) Specifically, the lining method using cast-in-place concrete is carried out using the following method. That is, after propelling the shield machine, a plurality of formworks are assembled in a ring shape inside the tail part, concrete is poured between the formwork and the tail part, and this concrete is poured while the shield machine is propelled. It is pressed against the inner surface of the tunnel behind the tail section via the gable ring to form a primary lining wall that is in close contact with the ground.

After the concrete hardens and the formwork is removed, -
Shoring is assembled in a ring shape on the inner surface of the lining wall, and this shoring supports the primary lining wall and counteracts the earth pressure of the ground.

(Problems to be Solved by the Invention) However, the conventional method described above cannot keep up with the demolding of the formwork because it takes time to assemble the shoring. As the distance between the walls and the walls became larger, the primary lining wall that corresponded to that distance was influenced by the Tonosho.
There was a problem that it became unstable.

This invention was made in order to solve the problems of the conventional method as described above, and it is possible to immediately maintain the primary lining wall in a stable state after demolding the formwork, and moreover, the entire process is simplified. It is an object of the present invention to provide a shield tunnel lining method that can shorten the construction time and speed up the construction.

(Means for solving problems) This invention method solves the above problems.

Before assembling the formwork, a shoring is removably installed in advance, and an anchor member is attached to this shoring so that it can protrude toward the ground, and the anchor member is attached to the lining material before the lining material hardens. This is characterized in that the shoring and anchor members are left on the primary lining wall surface when the formwork is removed from the mold after the lining material has hardened.

(Example) In FIG. 1, only the tail part 1 of the shield machine is shown,
A plurality of propulsion jacks 2 are disposed inside the tail portion 1 and a plurality of concrete suppression jacks 3 are arranged on the outside thereof, and a rod end of the concrete pressing jack 3 is provided between the tail portion 1 and the formwork 4. A gable frame ring 5 is attached to close the frame.

The formwork 4 is divided into a plurality of segments in the circumferential direction of the tunnel, and after the shield machine is propelled, the rod of the propulsion jack 2 is retracted and the formwork 4 is assembled into a ring shape inside the tail part 1. Concrete is forced and placed between the formwork 4 and the tail part 1 from a supply port (not shown) provided in the gable ring 5, and a reaction force is obtained from the formworks 4 connected to each other in the axial direction of the tunnel. The shield machine is propelled by the propulsion jack 2, and the primary lining wall 6 is sequentially formed as the shield machine is propelled. At this time, the poured concrete is pressed through the gable frame ring 5 by the concrete suppressing jack 3 to bring the concrete into close contact with the ground 7.

The above procedure is the same as the conventional method, and in the present invention, the shoring 8 is removably attached to the outer peripheral surface of the formwork 4 before it is assembled. That is, as shown in detail in FIGS. 2 and 3, the formwork 4 is a box having inner and outer circumferential plates 9, 10 in the radial direction of the tunnel and side plates 11. An opening 12 is provided.

In this embodiment, H-shaped steel is used as the support 8, and like the formwork 4, the support 8 is divided into a plurality of segments in the circumferential direction of the tunnel, and has openings 12 in the formwork 4.
It has been housed after.

A hole 25 is provided in one flange portion 8a of the shoring 8, and a hole 26 is provided in the other flange portion 8b, and the formwork 4
A hole 27 is provided in the inner circumferential plate 9 of.

An anchor bolt 24 passes through these holes 25, 26, 27, and nuts 14a, 14 are inserted into this anchor bolt 24.
b is screwed on, so that the shoring 8 can be attached to and detached from the formwork 4. The other flange portion 8b of the shoring 8 has its outer circumferential surface aligned with the outer circumferential surface of the outer circumferential plate lO, and the opening 12
is closed, and the tip of the anchor bolt 24 is aligned with the outer peripheral surface of the flange portion 8b. When assembling the formwork 4, the supporting structures 8 adjacent to each other in the circumferential direction are
Connected by 3.

Note that a minute gap is created between the edge of the opening 12 and the flange portion 8b, and this gap is filled with a sealing material 15 such as a rag. A hole 16 is provided in the web portion 8c of the shoring 8, and a rod 18 having a threaded portion 17 at the tip and rear end is passed through this hole 16 laterally, and the threaded portion 17 is inserted into the side plate 11.
It is screwed on.

This rod 18 has the function of reinforcing the formwork 4 and transmitting stress during propulsion of the shield machine.

With the propulsion of the shield machine, the gable ring 5 slides along the outer peripheral plate 10 of the formwork 4, but after the gable ring 5 passes the attachment position of the anchor bolt 24, the poured concrete hardens. First, nuts 14a and 14b are loosened to allow anchor bolt 24 to protrude into the poured concrete (as shown by the chain line in FIG. 3). Note that the nut 14b can be operated through an operation opening (not shown) provided in the formwork 4.

After the concrete of the primary lining wall 6 has hardened, the formwork 4 is removed from the mold. At this time, the rod 18 is pulled out and the nuts 14a are removed, so that only the formwork 4 is separated from the primary lining wall 6. As a result, the shoring 8 and the anchor bolts 24 are left on the primary lining wall 6, and the primary lining wall 6 is supported by the shoring 8, which is integrated with the primary lining wall 6 via the anchor bolts 24. , maintained in a stable state.

At the rear of the formwork 4 for primary lining, axial reinforcing bars 19 and circumferential reinforcing bars 20 are placed inside the -method lining wall 6, and end frames 21 are placed inside these reinforcing bars 19 and 20. A formwork 22 for secondary lining is placed, and concrete is poured between the formwork 22 and the primary lining wall 6 to form a secondary lining wall.

The formwork can have various shapes, but by making it a box with the opening 12 as described above and storing the support 8 inside the box, the gable ring 5 can slide along the formwork. Since it is movable, the gable ring S can be pressed against the end face of the lining wall 6 at all times, and escape of groundwater from the ground 7 can be prevented. The shoring 8 and the formwork 4 are not limited to being removably fixed by the anchor bolts 24 as described above, but may be provided with separate bolts for attachment. Moreover, instead of the rod 18, a plurality of ribs for transmitting stress may be integrally molded on the formwork 4.

(Effects of the Invention) As described above, according to the present invention, a shoring is removably attached to the formwork before it is assembled, and an anchor member is attached to the shoring so that it can protrude toward the ground. , the anchor members are made to protrude into the lining material before the lining material hardens, and when the formwork is removed, the shoring and anchor members are left on the primary lining wall surface, so that the formwork is removed simultaneously. The primary lining wall can be kept in a stable state by the shoring, and the conventional assembly process for the shoring alone is omitted, so the overall process can be shortened and construction can be done more quickly.

Further, since the shoring and the primary lining wall are integrated with each other via the anchor members, the cross section of the shoring can be reduced. Furthermore, through this anchor member and shoring -
Since the secondary lining walls are integrated, it is possible to consider both lining walls as a composite wall, so that the lining cross-section can be made smaller, and thereby the excavation cross-section can also be made smaller.

[Brief explanation of the drawing]

FIG. 1 is an axial cross-sectional view of a tunnel showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG.
The figure is an enlarged sectional view of the formwork. 1...Tail part 2...Propulsion jack 3.
... Concrete suppression jack 4 ... Formwork 6 ... - Law lining wall 8 ...
・Shoring 9...Inner circumferential plate 10...Outer circumferential plate
11...Side plate 12...Opening
18...Rod 24...Anchor bolt Fig. 2

Claims (1)

[Claims] 1. Assemble a plurality of formworks in a ring shape inside the tail section of the shielding machine, place lining material between the formwork and the tail section, and apply the primary covering to the inner surface of the tunnel as the shielding machine moves forward. In the method of forming a construction wall, a shoring is removably attached to the formwork before assembly, an anchor member is attached to the shoring so that it can protrude toward the ground, and the lining material is hardened. The anchor member is made to protrude into the lining material before, and when the formwork is removed from the mold after the lining material has hardened,
A method for lining a shield tunnel, characterized in that the shoring and anchor members are left on the primary lining wall surface.