JPH01131796A - Cut off method of shield tail section in cast-in-place concrete lining construction method - Google Patents

Abstract

PURPOSE: To prevent water from leaking by arranging a hollow hard water cut-off ring on the inner circumferential part of a tail plate, and after hardening of concrete pressure-filled in an annular space, pressing-in pressure fluid in the hollow part of the water cut-off ring to expand it. CONSTITUTION: A hollow hard ring 12 formed out of rubber or the like is fitted to the inner circumferential face in the vicinity of the rear end of a tail plate 11 so as to be flush with the face, and the hollow part 12a of the ring 12 is connected to a pressure pipe 13. Next in an excavated tunnel hole A, reinforcements of a concrete part and an annular inner form 16 made of steel are assembled, concrete 17 is filled in between the frame 16, the plate 11, and the front face of an existing concrete, and the concrete 17 is pressurized by a concrete press jack 18. After hardening the concrete 17, pressure fluid is fed to the hollow part 12a, and the ring 12 is expanded to be pressure fitted to the concrete 17. Consequently, water can be surely prevented from leaking.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for water-stopping a shield tail portion in a cast-in-place concrete lining method.

(Prior Art) Figures 4 to 9 show the steps of the conventional cast-in-place concrete lining method, in which reinforcing bars of the concrete lining (
1), assemble the steel inner formwork (2), and attach the concrete supply pipe (3) to the inner formwork (2) (see Figure 4). ) valve (4
) is opened, and the annular space formed between the shield tail plate (5), the inner formwork (2), and the front surface (6) of the existing lining concrete is filled with concrete (7).
(See Figure 5) Next, close the valve (4) of the concrete supply pipe (3), extend the concrete press jack (8) mounted on the shield excavator, and remove the rusling plate (9) at the tip of the jack. is inserted into the annular space to pressurize the poured concrete (7), and at the same time, a propulsion jack (not shown) mounted on the shield excavator,
The shield tail plate (5) is advanced by taking the reaction force against the inner formwork (2) (see Figure 6). Then, when the concrete (7) hardens, the concrete press jack (
8) to the face side, pull out the press ring plate (9) from the annular space, remove the concrete supply pipe (3) and pulp (4) (see Figure 7), and remove the concrete lining thus constructed. In front of section (6), the reinforcing bars (1) for the next concrete lining section are arranged, and the inner formwork (2
) (see Figure 8), then attach the concrete supply pipe (3) with pulp (4) to the inner formwork (2), and extend the concrete press jack (8) to press the tip. The ring plate (9) is attached to the inner formwork (2).
and the shield tail plate (5) (see FIG. 9) and repeat the above steps to construct a tunnel with a cast-in-place concrete lining.

(Problems to be Solved by the Invention) The cast-in-place concrete lining construction method involves filling concrete under pressure between the pile and the inner formwork.
This construction method constructs the primary lining without generating tail voids, but when groundwater pressure acts, water leaks from the gap between the tail plate of the shield excavator and the poured lining concrete.

At this time, relying only on the adhesion strength between the tail plate and the poured concrete to prevent water leakage, as in the past, is insufficient in view of the shaking of the shield excavator.

(Means for Solving the Problems) The present invention has been proposed to solve these problems, and includes an inner formwork and a tail plate assembled in a tunnel hole excavated by a shield excavator. At the same time, concrete is pressurized and filled into the annular space formed between the front surfaces of the existing concrete lining, and a propulsion jack mounted on a shield excavator takes the reaction force from the inner formwork to excavate the same excavation. In the cast-in-place concrete lining construction method in which a cutting machine is propelled, a hollow hard water stop ring is arranged on the inner periphery of the tail plate, and after the concrete filled under pressure in the annular space has hardened, the water stop ring is The present invention relates to a method for stopping water at a shield tail portion in a cast-in-place concrete lining construction method, which is characterized by injecting pressurized fluid into a hollow portion to expand the water stop ring and press it against the concrete.

(Function) As described above, in the present invention, a hollow hard water stop ring is provided on the inner circumference of the tail plate of a shield excavator, so that the tail plate, the inner formwork, and the existing concrete lining are connected to each other. After the concrete pressurized and filled into the annular space at the front hardens, pressurized fluid is injected into the hollow part of the water stop ring to expand the water stop ring and press it to the lining concrete part. , to prevent water leakage between the shield tail plate and the poured concrete.

Next, when pouring the next lining concrete, the pressure inside the hollow part of the water stop ring is reduced to return the water stop ring to its original state, and when the concrete is pressurized and filled in the annular space, the concrete is This is to prevent flow from being obstructed.

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

(11) is a tail plate of a shield excavator, in which a hollow hard water stop ring (12) made of rubber or the like is provided on the inner circumferential surface near the rear end, and the inner circumferential surface of the ring (12) is attached to the tail plate ( The hollow part (12a) of the ring (12) is mounted so as to be flush with the inner peripheral surface of the ring (11)
One end of the pressure pipe (13) is connected to the pressure pipe (13).
3) The other end is connected to a pressure fluid supply source (not shown) installed inside the shield excavator.

In the illustrated embodiment, the water stop ring (12) has four annular parts (Ila
), and the presser ring plate (I4) and fixed pole) (
15).

Since the illustrated embodiment is constructed as described above, the concrete lining is reinforced in the tunnel hole (A) excavated by the shield excavator, and the annular steel inner formwork (16) is installed. After assembly, the annular space formed between the inner formwork (16), the tail plate (11), and the front of the existing lining concrete section was filled with concrete (17), and mounted on a shield excavator. The press ring plate (19) at the tip of the concrete press jack (18) is inserted into the annular space, and poured concrete (17) is pressurized and filled until the poured concrete (17) hardens. The press ring plate (19) ensures watertightness.

Note that when pressurizing and filling the concrete (17), the pressure inside the hollow part (12a) of the water stop ring (12) is reduced;
The water stop ring (12) should not protrude inside the tail plate (11) when pouring concrete.
(17) Avoid impeding the fluidity of the product.

After the concrete (17) has hardened, the pressure pipe (1) is inserted into the hollow part (12a) of the water stop ring (12).
3) by supplying pressure fluid such as pressurized air or pressurized water to inflate the water stop ring (12) and press it against the poured concrete (17) to stop water. (See figure) This prevents water from leaking between the tail plate (11) and the poured concrete (17) even when groundwater pressure P is applied.

(Effects of the Invention) According to the present invention, as described above, a hollow hard water stop ring is disposed on the inner peripheral surface of the tail plate of a shield excavator, and the tail plate, the inner formwork, and the front surface of the existing lining concrete part are provided. After the concrete is pressurized and filled into the annular space formed between the water stop ring and the water stop ring, the water stop ring is expanded by injecting pressurized fluid into the hollow part of the water stop ring. It is crimped onto concrete to reliably stop water between the tail plate and the concrete, and to reliably prevent water from leaking between the tail plate and the lining concrete even when underground water pressure is applied.

In addition, by releasing the pressure applied by the pressurized fluid to the hollow part of the water stop ring and returning the water stop ring to its original state, the flow of the concrete during pressurized filling is not inhibited, and the concrete is This is to ensure that the pouring process is carried out smoothly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing an implementation status of an embodiment of the method for stopping water in the shield tail part in the cast-in-place concrete lining method according to the present invention, FIGS. 2 and 3 are partially enlarged views thereof, and FIG. The figure shows the state of the hollow hard penetrating water stop ring before pressurization, and FIG. 3 shows the state of the same water stop ring during pressurization. 4 to 9 are vertical side views showing the steps of the conventional cast-in-place concrete lining method. (11)...Tail plate (12)...Hollow hard water stop ring (13)...Pressure pipe (16)...Inner formwork (17)...Concrete agent Patent attorney Shige Okamoto Two people outside the text Figure 1 ρ Figure 2

Claims (1)

[Claims] Concrete is pressurized and filled into the annular space formed between the inner formwork assembled in the tunnel hole dug by the shield excavator, the tail plate, and the front surface of the existing lining concrete, and the inner formwork is filled with concrete. In the cast-in-place concrete lining construction method, in which the shield excavator is propelled by a propulsion jack mounted on the shield excavator, a hollow hard water stop ring is arranged on the inner periphery of the tail plate. , a place characterized in that after the concrete filled under pressure in the annular space has hardened, pressurized fluid is injected into the hollow part of the water stop ring to expand the water stop ring and press it to the concrete. Water stoppage method for the shield tail part in poured concrete lining construction method.