JPH0546436B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tunnel construction method using a cast-in-place concrete lining method.

(Prior art) The method of constructing a tunnel using the cast-in-place concrete lining method is to construct a tunnel between the inner formwork assembled in the tunnel hole excavated by a shield excavator, the shield tail, and the front surface of the existing concrete lining. After placing lining concrete in the annular space formed, the concrete to be placed is pressurized by a concrete press jack installed on the shield excavator, and the concrete is pressurized by a concrete press jack installed on the shield excavator. The ring girder at the tip of the jack takes a reaction force against the inner formwork to propel the shield excavator, assembles the reinforcing bars and inner formwork for the next lining concrete construction, and pours the lining concrete. Then, the above steps are repeated to construct concrete.

(Problems to be Solved by the Invention) In the concrete construction method using the cast-in-place concrete lining method, when a muddy shield excavator is used, it is difficult to support the buckling pressure received from the front surface of the face when assembling reinforcing bars for the lining concrete. The problem is the method.

In conventional shield drilling machines, this buckling pressure is counteracted by replacing the propulsion jack with the existing segment to bear pressure, but in the cast-in-place concrete lining method, an annular ring girder is used at the tip. This replacement work is difficult because the propulsion jacks provided are operated.

In addition, when performing curved construction or meandering correction, it is extremely difficult to control the pressure using the annular ring girder, and the forced movement of the jacks can cause distortion in the inner frame and cause damage to the excavation machine itself. I may make it.

(Means for Solving the Problems) The present invention was proposed to solve these problems, and includes an inner formwork assembled in a tunnel hole excavated by a shield excavator,
After pouring lining concrete into the annular space formed between the shield tail, the shield tail, and the front surface of the existing lining concrete, the poured concrete is processed using a concrete press jack installed on the shield excavator. In the tunnel construction method, the shield excavator is propelled by pressing the shield excavator, and a ring girder at the tip of a propulsion jack mounted on the shield excavator takes a reaction force against the inner formwork to propel the shield excavator. A tip spreader of a telescoping jack for backing pressure support mounted on the shield excavator is disposed in a space between adjacent split ring girders which are divided in the circumferential direction, so as to be movable in and out. After pouring and curing the concrete, the telescopic jack is extended and the end of the jack is pressed against the inner formwork to support the buckling pressure applied to the shield excavator from the face surface, and in this state, the split ring carder is This relates to a tunnel construction method characterized in that the concrete press jack is retreated toward the face side together with the concrete press jack.

(Function) According to the present invention, as described above, the inner formwork is assembled in the tunnel hole excavated by the shield excavator, and the inner formwork, the shield tail, and the front surface of the existing lining concrete are assembled. After pouring concrete lining into the annular space formed and curing it, the telescopic jack for supporting the buckling pressure mounted on the shield excavator is extended, and the tip spreader is moved circumferentially at the tip of the propulsion jack. The tip spreader of the telescopic jack is advanced from the space between adjacent split ring girders, and by pressing the inner formwork, it supports the buckling pressure from the front face of the face, and in this state, the split ring The girder is returned to the face side together with the concrete press jack, and the reinforcing of the lining concrete next to the above-mentioned lining concrete is arranged and the inner formwork is assembled.At this time, once the inner formwork is installed, the propulsion jack is When activated, the inner formwork is pressed by the split ring girder at its tip, the backing pressure is redirected and supported, the telescopic jack is returned to the face side, and the above process is repeated to construct the tunnel.

(Embodiments) The present invention will be described below with reference to illustrated embodiments.
1 is a shield excavator, 2 is a skin plate, and the shield excavator is a concrete press jack 3
and a propulsion jack 4 are mounted.

A circular ring girder 5 is mounted on the tip of the propulsion jack 4, and the ring girder has an S-shaped cross section in which an outer casing-shaped part opening on the tail side and an inner periphery casing-shaped part opening on the face side are connected. It is formed into a plurality of parts in the circumferential direction, and brackets 5a are disposed opposite to the inner peripheral case-shaped parts of adjacent split ring girders 5.
Both brackets 5a and adjacent split ring girder 5
A jack box 7 at the tip of a buckling pressure supporting telescopic jack 6 mounted on the shield excavator 1 is retractably disposed in the gap formed between the opposing parts. In the figure, 8 is a spreader of a telescopic jack attached to the tip of the same jack box 7, and 9 is a spreader attached to the tip of each split ring girder 5.

Further, a divided concrete press ring 10 divided in the circumferential direction is attached to the tip of the concrete press jack 3, and is configured to slide within the outer peripheral housing mold portion of each divided ring girder 5.

Then, in the tunnel hole A dug by the shield excavator 1, the reinforcing bars B of the lining concrete part are
At the same time, assemble the inner formwork C, and insert the lining concrete D between the inner form C, the shield tail of the shield excavator, and the front of the existing lining concrete.
After pouring and curing the poured concrete, the telescopic jack 6 is extended and its tip spreader 8 is advanced from between the adjacent split ring girders 5 to press the inner formwork C. Therefore, the buckling pressure applied to the shield excavator 1 is supported from the front side of the face, and in this state, the propulsion jack 4 returns the split ring girder 5 to the face side, and the concrete press jack 3 is also moved together with the spreader 10 to the face side. Return to

Next, the reinforcing bars B of the next concrete lining part adjacent to the front surface of the concrete lining part, the inverted part of the inner formwork C, the spring part, and the crown part are assembled in this order. At this time, as soon as the inner formwork C is installed, the propulsion jack 4 is operated to press the spreader 9 mounted on the split ring girder 5 against the inner formwork C, and the backing pressure is replaced and supported.
is retracted, and the spreader 8 is retracted into the space between the adjacent disassembling ring girders 5.

Next, concrete is poured between the inner formwork C, the shield tail of the shield excavator 1, and the front surface of the existing lining concrete section, and then the poured concrete is poured through the tip spreader 10 by the concrete press jack 3. The shield excavator 1 is moved forward by operating the propulsion jack 4 while applying pressure and filling the tail void.

Build the tunnel by repeating the above steps.

The tip spreaders 9 and 8 of the split ring girder 5 and the telescoping jack 6 are rotatably mounted via ball joints, etc., so that the propulsion jack 4 and the telescoping jack 6 are in contact with the inner formwork C. This is to ensure that force is always applied evenly and to prevent excessive force from being applied to the existing concrete lining of the inner formwork C.

(Effects of the Invention) According to the present invention, as described above, when constructing a tunnel using the cast-in-place concrete lining method, the ring girder of the propulsion jack is divided in the circumferential direction, and the space between the adjacent divided ring girders is In between, the tip spreader of the telescopic jack for buckling pressure support, which is installed on the shield excavation machine and is independent of the propulsion jack and concrete press jack, is installed so that it can move in and out. When assembling the formwork, the backling pressure applied to the shield excavator from the front face of the face is supported by the inner formwork of the existing concrete lining section via the tip spreader of the telescopic jack, so that tunnel construction can be carried out safely.

Furthermore, since the ring girder is divided and each propulsion jack is independent, it is easy to control, and therefore curve construction and meandering correction can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing the implementation status of one embodiment of the tunnel construction method according to the present invention, and FIGS. 2, 3, and 4 are respectively shown in the direction of the arrows in FIG. Figure 5 is a slope view of the split ring girder section, Figure 6 is a slope view of the tip of the telescopic jack, Figure 7 is a slope view of the tip of the concrete press jack, and Figure 8 is a slope view of the tip of the concrete press jack. The figure is a perspective view showing adjacent parts of the split ring girder, FIG. 9 is a longitudinal sectional side view showing the buckling pressure supporting telescopic jack and the ring girder in a steady state, and FIG. 10 is a longitudinal sectional side view showing the propulsion state. 1... Shield excavation machine, 3... Concrete press jack, 4... Propulsion jack, 5... Divided ring girder, 6... Telescopic jack for backing pressure support, 8... Spreader of the telescopic jack,
9...Split ring girder splitter, A...tunnel hole, B...reinforcing bar, C...inner formwork.

Claims (1)

[Claims] 1 After pouring lining concrete into the annular space formed between the inner formwork assembled in the tunnel hole dug by the shield excavator, the shield tail, and the front of the existing lining concrete. , Pressurize the poured concrete with a concrete press jack installed on the shield excavator, and apply a reaction force to the inner formwork with a ring girder at the tip of a propulsion jack installed on the shield excavator. In the tunnel construction method for propelling the shield excavator, the ring girder is divided in the circumferential direction, and the ring girder is mounted on the shield excavator between adjacent divided ring girders. A spretzer at the tip of a telescoping jack for supporting backing pressure is arranged so as to be movable in and out, and after the lining concrete is poured and cured, the telescoping jack is extended and the spretzer at the end of the jack is pressed against the inner formwork to form the face. A method for constructing a tunnel, characterized in that the buckling pressure applied to the shield excavator is supported from the surface, and in this state, the split ring girder is retreated toward the face side together with the concrete press jack.