JPH01271600A - Concrete placing for cast-in-place concrete lining construction - Google Patents

Abstract

PURPOSE:To densely fill concrete and improve the quality by arranging a soft sheet on the inside face of a tail plate before arranging reinforcing bars in the circularly formed concrete placing space. CONSTITUTION:An inner framework 6 is assembled in a tunnel hole drilled by a shield drilling machine, a circular concrete placing space is formed between the tail plate 2 of the drilling machine and the front face of the existing con crete 1. A soft sheet 3 made of resin is arranged on the inside face of the tail plate 2, then reinforcing bars 7 are arranged in the concrete placing space, and concrete 13 is filled by pressure. The collapse of the natural ground, the infiltration of underground water or earth lumps into the concrete 13, the infiltra tion of mortar contained in the concrete 13 into the natural ground can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a concrete pressure filling method for a concrete lining portion in a cast-in-place concrete lining method.

(Conventional technology) Conventionally, this type of cast-in-place concrete lining construction method
It was done as follows.

(i) In addition to placing reinforcing bars in the lining concrete section in front of the existing lining concrete (a) in the tunnel hole excavated by the shield excavator, a steel inner formwork (
Assemble C) and connect the valve (□□□) and concrete supply pipe (5) to the concrete supply port (f) attached to the press ring plate (e) of the internal formwork or concrete press-fitting jab (d). (See Figure 2A) (i:)
A concrete press-fitting jack mounted on the shield excavator is extended to the end side of the annular space (J) formed between the tail plate (i) of the shield excavator and the inner formwork, and the concrete press-fitting jack mounted on the shield excavator is extended. Set the press ring plate.

(iii) Then, open the valve connected to the concrete supply port of the inner formwork or the press ring plate of the concrete press-fitting jab, and feed concrete (k) into the annular space using a bird. (See Figure 2B) (1■
) After the supply of concrete into the annular space is completed, the pulp is closed, the tail plate 1 and the moving jack (n) mounted on the shield excavator are retracted to move the tail plate forward, and the Simultaneously with the forward movement of the tail plate, the concrete press-fitting jack is extended and the press ring of the concrete press-fitting jack presses and fills the void created by the movement of the tail plate I with concrete.

At the same time as the pressurized filling of concrete is completed, the movement of the tail plate is stopped, but at this time, the rear part of the tail plate is left in the concrete to ensure water-tightness, so that the concrete develops sufficient strength. Remain in that state until you get it. (See Figure 2C) (v) After the strength of the pressurized concrete has been developed, the concrete supply pipe is removed, and the concrete press-fitting jack is moved back to remove the press ring plate of the concrete press-fitting jack. Thereafter, the shield excavator resumes excavation while extending the propulsion jack (E) mounted on the shield excavator using the inner formwork as a reaction force. (Refer to Figure 2D) (■1) After completing the required excavation, perform the steps (i) to (
While repeating step V), the inside of the tunnel hole is lined with concrete to construct a tunnel.

(See Figure 2E) (Y, a to be solved by the invention) However, this type of conventional construction method has the following problems.

(i) When pressurizing and filling concrete into the formwork assembled in the tunnel hole and the annular space formed between the tail plate and the front surface of the existing concrete lining, move the tail plate 1 forward. However, it is unlikely that other mountains exposed at this time will collapse.

(11) Furthermore, as the tail plate moves forward, there is a risk that underground water and soil clods may mix into the unhardened concrete.

(iii) When constructing a curved section or correcting meandering between the ground excavation surface and the outer surface of the shield excavator, it is necessary to shift the axis of the shield excavator from the existing excavation line. Although a small gap is formed for ease of use, concrete tends to enter this gap when pressurized and filled with concrete.

(1v) Furthermore, during pressurized filling of concrete, mortar in the concrete often penetrates into other piles through the excavated surface.

The present invention has been proposed in view of the problems of the prior art described above, and its purpose is to soften the inner surface of the tail plate before placing reinforcing bars in the concrete lining. By arranging the sheet, it prevents the collapse of the ground, the infiltration of groundwater and soil clods into the concrete, and even the infiltration of mortar into other piles in the concrete during pressurized concrete filling of the concrete lining. The object of the present invention is to provide a concrete construction method for cast-in-place concrete lining construction method.

(Means for Solving the Problems) In order to achieve the above object, the concrete construction method in the cast-in-place concrete 5-inning method according to the present invention is as follows:
A soft sheet is arranged on the inner surface of the tail plate of the shield excavator, and a soft sheet is formed between the tail plate, the inner formwork assembled in the tunnel hole, and the front surface of the existing lining concrete. Pressurize the concrete in the annular space,
It is to be filled.

(Function) According to the present invention, since a soft sheet is placed on the inner surface of the tail plate before reinforcing bars for the lining concrete part are arranged in the annular space, when filling concrete with pressure, , the surface of the concrete that has not hardened yet is completely covered with a soft sheet, and therefore groundwater and soil clods do not mix into the concrete as in the past.
Concrete does not enter the gap between the outer surface of the shield excavator and the ground excavation surface, and the mortar in the concrete does not penetrate into other piles.Furthermore, because the sheet is a soft material, the tail plate can be moved forward. The concrete covered with the soft sheet is completely pressurized and filled into the gap between the concrete and the ground excavation surface, which is in close contact with the ground excavation surface.

(Example) The present invention will be described below with reference to the illustrated embodiments.

The shield excavator's tail plate (
A newly installed resin soft sheet (3) that covers the inner surface of the
) is glued to the front end of the soft resin sheet (3) that covers the outside of the existing concrete lining (1) (see Figure 1A). (3a) in the figure shows both the soft sheets (3) Adhesive part, (4
) is the gap formed between the cross-cutting surface (5) and the tail plate (2), and (6) is the inner formwork.

Next, the inner formwork (6) is assembled by arranging reinforcing bars (7) in the concrete lining construction space, and the valve (8) and concrete supply pipe are connected to the concrete supply port (6a) of the inner formwork (6). (9) (see Figure 1B) Next, connect the concrete regular jack 0■ mounted on the shield excavator.
Stretch out the same jack O■ Bren ring plate (1
1) is set on the gable side of the concrete lining construction space, and the tip of the soft sheet (3) is attached to the bran ring plate (II) via a soft material block 0 attached to the reinforcing bar (7).
and the tail plate (2). Then the valve (
Open 8) and supply 0■ of concrete into the inner formwork (6). (See Figure 1C) Thus concrete 03)
After completing the supply of
) while moving it to the face side, extend the concrete regular jack 00) and remove the concrete Q3 that has not solidified yet.
) is pressurized, and the gap created between the tail plate (2) and the other excavated surface (5) is filled with concrete to the right size as shown by the arrow, and the concrete 03) is pressurized.
Waits for the development of strength. (See Figure 1D) Meanwhile, remove the valve (8) and concrete supply pipe (9).

After the strength of the concrete 0■ has been sufficiently developed, the shield excavator resumes excavation while extending the propulsion jacks θ mounted on the shield excavator.
(See FIG. 1E) The above steps are then repeated.

(Effects of the Invention) According to the present invention, as described above, between the inner formwork assembled in the tunnel hole excavated by the shield excavator, the tail plate of the excavator, and the front surface of the existing lining concrete, When pressurizing and filling concrete into the annular space formed in the tail plate, a soft sheet is placed on the inner surface of the tail plate, and the surface of the concrete that has not yet solidified is completely covered with the sheet. Since the concrete is filled under pressure, the concrete is filled densely and without waste into the gap between the excavated surface of another mountain and the surface created by the forward movement of the tail plate.
Furthermore, when the tail plate is moved forward, groundwater and soil clods are not mixed into the unhardened concrete, which improves the quality of the concrete.

Furthermore, according to the present invention, since concrete does not enter the gap between the outer surface of the shield excavator and the excavation surface of another mountain, it is difficult to change the direction of the shield excavator or excavate when constructing a curved section or correcting meandering. There is no problem during this process, and since the mortar in the concrete that has not yet solidified does not penetrate into the ground, there is no risk that the excavated pile will solidify and cause problems to the excavation.

[Brief explanation of the drawing]

Figures 1A to 1E are vertical sectional side views showing steps of an embodiment of the concrete construction method in the cast-in-place concrete lining method according to the present invention, and Figures 1A to 2E are longitudinal side views showing steps of an embodiment of the concrete construction method in the cast-in-place concrete lining method according to the present invention. It is a longitudinal side view showing a process. (1) - Existing concrete lining (2) - Tail plate (3) - Soft sheet (6) - Inner formwork surface... - Concrete G51 - Propulsion jack agent Patent attorney Shige Okamoto 2 other people

Claims (1)

[Claims] (1) an inner formwork assembled in a tunnel hole excavated by a shield excavator, and a tail plate of the excavator;
Concrete is pressurized and filled into the annular space formed between the front surfaces of the existing concrete lining, and the shield excavator is moved by a propulsion jack mounted on the shield excavator by taking a reaction force against the inner formwork. A concrete construction method in the cast-in-place concrete lining method in which the cast-in-place concrete lining method is promoted, characterized in that a soft sheet is disposed on the inner surface of the tail plate, and concrete is pressurized and filled into the annular space.