JP2711287B2 - Tunnel lining structure and lining method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tunnel lining structure and a lining method, and more particularly to a tunnel lining structure and a lining method suitable for a shield tunnel.

[Conventional technology]

As is well known, a segment lining method is generally used in a tunnel lining method, especially in a shield tunnel. In the segment lining method, as shown in FIG. 21, as the shield machine excavates, arc-shaped segments 30 made of concrete or steel are assembled in a ring shape, and the rings have already been constructed in a cylindrical shape. The tubular body 31 is extended while being connected to the segment. In this segment lining method, in order to secure higher waterproofness (or in some cases for the purpose of interior decoration), a secondary lining 32 is further provided inside the tubular body 31.

[Problems to be solved by the invention]

However, the above segment lining method has disadvantages such as disadvantageous in terms of cost reduction because the lining thickness is large and the excavation diameter is large, and a cast-in lining method (cast in place) is a lining method that can eliminate these adverse effects. Concrete lining method).

As shown in FIGS. 22 and 23, after forming a formwork (not shown) at a predetermined position facing the excavation wall surface of the tunnel, a reinforcing bar 33 (shown only in FIG. 23) is provided in the formwork. ) Is arranged, and concrete 34 is poured to cover the wall surface of the excavation hole with reinforced concrete 35.

However, even this cast-in-place lining method has an inconvenience that the assembly of the reinforcing steel bar 33 in the mine is complicated and workability is poor.

In addition, both the segment lining method and the cast-in-place lining method cannot often have a sufficient function with respect to water leakage from the ground, and may cause inconvenience depending on the application (for example, electric power conduit or sewage). Tunnel etc.).

The present invention has been made in view of the above circumstances, and by reducing the thickness of the lining, it is possible to effectively utilize the cross section of the tunnel. It is an object of the present invention to provide a tunnel lining structure and a lining method that can completely prevent the tunnel lining.

[Means for solving the problem]

The tunnel lining structure according to claim 1 of the present invention is provided with a cylindrical outer steel shell provided along a wall surface of a drilled hole, and provided inside the outer steel shell concentrically with the outer steel shell. And an inner steel shell constituting an inner wall surface of the lining, and concrete cast between the outer steel shell and the inner steel shell.

In addition, the tunnel lining method according to claim 2 of the present invention is characterized in that the first strip steel plate having an arc shape with a predetermined width is connected in the length direction of the strip steel plate itself in the drill hole, thereby forming the wall surface of the drill hole. Forming an outer ring body along with the step of forming an outer steel shell by connecting the outer ring bodies in the width direction; and forming a second strip steel sheet having a smaller radius of curvature than the first strip steel sheet. Forming the inner ring body concentrically with the outer ring by connecting in the longitudinal direction of the strip steel plate itself,
A step of forming an inner steel shell by connecting the inner ring bodies in the width direction, a step of placing concrete between the outer steel shell and the inner steel shell, and a required strength is developed in the concrete And then excavating the shield machine using the face face side end surface of the concrete as a reaction force surface.

[Action]

By filling the steel shell with concrete, the required bending stiffness and shear stiffness can be ensured, and a material with high load-bearing capacity can be obtained. The length can be reduced to about 1/2.

In addition, a structure in which concrete is filled between steel shells formed in a double cylindrical shape exhibits extremely high water stopping performance.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a tunnel lining structure according to the present invention together with a shield machine 10 and the like. In the figure, reference symbol G denotes a ground on which a tunnel is constructed, 1 denotes a digging hole formed by the shield machine 10, and 2 denotes a lining body provided along the wall surface 1a of the digging hole 1.

The lining body 2 has a cylindrical outer steel shell 3 provided along the wall surface 1a as shown in FIGS. 2 and 3 and a concentric center of the outer steel shell 3 inside the outer steel shell 3. An inner steel shell 5 which is provided in a lining and forms a lining inner wall surface, and a concrete 7 cast between the outer steel shell 3 and the inner steel shell 5.

In the case of the present embodiment, the outer steel shell 3 is formed by connecting ring bodies (outer ring bodies) 4, 4,... Having a predetermined width in the width direction, for example, as shown in FIG. . Each of the ring bodies 4, 4,... Is formed by connecting strip steel plates (first strip steel plates) 4a, 4a,. Similarly, the inner steel shell 5 has a ring body (inner ring body) 6, 6, formed by connecting arc-shaped strip steel plates (second strip steel plates) 6a, 6a,. Are connected in the width direction. As a matter of course, the second steel strip 6a has a smaller radius of curvature than the first steel strip 4a. The connection between the first steel strips 4a (the second steel strips 6a) and the connection between the outer ring bodies 4 (the inner ring bodies 6) are made by welding.

The welding means in this case may be butt welding as shown in FIG. 4 or, as shown in FIG. 5, for example, a connection portion between the ring bodies 4 (6) is slightly wrapped, and the wrap portion is formed. It is also possible to fill the ends with fillet welds.

According to the tunnel lining structure having the above configuration, the double closed cylinder of the outer steel shell 3 and the inner steel shell 5 completely blocks groundwater and the like, and completely prevents water leakage from the ground into the tunnel. Thus, maintenance costs such as pumping water leakage can be reduced. In addition, since there is no reinforcing bar inside the concrete 7, the cost related to the reinforcing bar work is eliminated, and the structure in which the concrete is filled between the double steel shells has high bending rigidity and shear rigidity. While ensuring extremely high load-bearing capacity.

FIG. 19 and FIG. 20 show the load-bearing capacity and dimensions of the lining according to the present invention.

The condition is that the allowable compressive stress of concrete is 100kgf
/ cm ² , Allowable tensile stress of rebar is 2000kgf / cm ² , Cover of rebar is 4cm (= d '), Allowable tensile stress of steel shell is 1400kgf
/ As cm ^2, bending moment Ma is calculated thickness of the relationship between the thickness and reinforcement ratio or steel shell lining member required when working.

From these graphs, for example, a standard rebar ratio of 1%
(= 0.01), the allowable bending moment Ma = 5tf-m / m
In this case, the thickness of the reinforced concrete lining is about 1.9 cm. If the lining thickness is to be reduced, the spacing between the reinforcing bars is limited by the aggregate size and the reinforcing bar diameter of the concrete.

On the other hand, in the case of a steel shell concrete lining, a lining thickness of 19 cm and a steel shell plate thickness of 0.2 cm, while maintaining the same allowable bending moment, with a lining thickness of 5 cm
It is possible to replace it with a 1cm thick steel shell. This is possible because there are no obstacles to concrete casting in the steel shell.

The effect of reducing the lining thickness increases as the acting bending moment increases, which allows the outer diameter of the excavation to be reduced, thereby greatly reducing the amount of excavated soil and significantly reducing costs. Becomes

As described above, in the lining structure according to the present invention, a large load-bearing capacity can be obtained with an extremely small cross section, so
Can be reduced in diameter, and the cost can be greatly reduced.

Next, a method of constructing the lining body 2, that is, a lining method according to claim 2 of the present invention will be described.

FIG. 1 shows a state in which the excavation hole 1 is lining with the excavation of the shield machine 10. In the figure, reference numeral 11 denotes a propulsion jack of the shield machine 10, and reference numeral 12 denotes an erector for transporting the steel strip 4a (6a). FIG. 1 shows a state in which the lining has already been partially completed by the lining method.
For convenience of explanation, the description will be made from the middle step of the lining as shown in the figure.

First, the shield machine 10 is excavated for a predetermined stroke as shown in FIG. At this time, the reaction force of the propulsion jack 11 is applied to the end surface 2a of the completed lining body 2. Symbols in the figure
Reference numeral 13 denotes a frame ring interposed between the propulsion jack 11 and the pressing portion, which is divided into a plurality in the circumferential direction. Reference numeral 14 denotes an internal support for supporting the lining body 2,
The concrete 7 cast between the inner and outer steel shells 3 and 5 is provided corresponding to a portion where the final strength is not developed due to complete hardening (see FIG. 1).

When the shield machine 10 is excavated, the propulsion jack 11 is contracted as shown in FIG. 7 and the outer steel shell 3 and the inner steel shell 5 are assembled so as to be continuous with the already completed lining 2. When assembling these two steel shells 3 and 5, the outer steel shell 3 is assembled first.

Here, FIG. 11 shows an erector 12 for assembling the steel shells 3,5. In the figure, reference numeral 15 denotes a rotating ring, 16 denotes a turning motor, 17 denotes a gripping mechanism attached to the rotating ring 15, 18 denotes a lifting jack, and 19 denotes a gripping device. The erector 12 has basically the same structure as an erector conventionally generally used for a concrete segment, but the gripping device 19 includes a thin strip steel plate 4a.
It has a mechanism that can grip (6a). FIG. 12 shows the gripping device 19 in detail, and reference numeral 20 denotes an erector arm provided at the tip of the lifting jack 18. The erector arm 20 is provided with attitude control jacks 21, 21,...
A holding frame 22 for directly holding the steel strip 4a (6a) is attached to the tip of the rod 21a via a pin 23. The holding frame 22 is provided with a mounting device 24 such as an electromagnet or a vacuum suction disk.

That is, in order to assemble the outer steel shell 3, first, as shown in FIG. 13 to FIG. 3 by welding to form a ring shape (form outer ring body 4). Thus, the outer steel shell 3 is newly extended by the width of the outer ring body 4. When the outer ring body 4 is formed in this manner, the inner ring body 6 is assembled inside the outer ring body 4 in the same manner as shown in FIGS. At this time, as shown in FIG. 7, by providing the end frame ring 13 inside the previously assembled outer ring body 4, the roundness of the outer ring body 4 is maintained. Good to put.

Here, in the present embodiment, as described above, for example, when the outer ring body 4 is formed, it is performed by connecting the first strip steel plate 4a constituting the outer ring body 4 to the already formed outer steel shell 3. The extension of the outer steel shell 3 is completed simultaneously with the completion of the outer ring body 4. The same applies to the inner ring body 6.

When the outer ring body 4 and the inner ring body 6 are formed as described above, as shown in FIG. 8, the inner support 14 is installed inside the newly assembled inner ring body 6. This internal support 14 is used by rearranging the one installed at the rearmost side (opposite face side) in FIG. The internal support 14 has an effect of keeping the inner ring body 6 in a perfect circle and an effect of preventing the buckling of the propulsion jack 11 of the shield machine 10 which is not excavated. In order to prevent buckling of the propulsion jack 11, a required compression force is applied by a jack (not shown) in the ring direction of the internal support 14 to further assist the support 14 and the inner ring 6 After temporarily fixing with
The propulsion jack 11 may be pressed against the internal support 14.

When the internal support 14 is installed as described above, the concrete 7 (or mortar) is poured between the inner and outer ring bodies 4 and 6 as shown in FIGS.

Then, when the required strength is developed in the cast concrete 7, the shield machine 10 is excavated by applying a reaction force to the concrete 7 and extending the propulsion jack 11.

Thereafter, by repeating the above steps, the lining 2
May be sequentially extended and constructed with the excavation of the shield machine 10.

According to the above construction method, in addition to being able to reliably and efficiently create the lining structure of the tunnel, the lining accompanying the excavation of the shield machine 10 is performed similarly to the segment lining. Can be shortened, and a lining structure having the above-described excellent functions can be realized at low cost.

The formation or welding of the inner and outer ring bodies 4, 6 in the excavation hole 1 can be fully or semi-automated by, for example, attaching an automatic welding machine to the erector arm 20. The efficiency of the lining work is further improved.

〔The invention's effect〕

As described above, according to the tunnel lining structure according to claim 1 of the present invention, groundwater and the like are completely blocked by the double closed cylindrical body of the outer steel shell and the inner steel shell, and Leakage from the ground can be completely prevented, thereby reducing maintenance costs such as pumping up leakage. In addition, since there is no reinforcing bar inside the concrete, the cost of rebar work is eliminated, and the structure filled with concrete between the double steel shells has high bending rigidity and shear rigidity. It is possible to secure a very high load bearing capacity.

Further, according to the tunnel lining method according to claim 2,
Needless to say, the above lining structure can be surely created.
As in the case of the segment lining, the lining according to the excavation of the shield machine is performed, so that the construction period can be made more efficient, and the tunnel lining structure according to claim 1 having excellent functions can be realized at low cost. It has excellent effects.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a longitudinal sectional view showing a tunnel under lining together with a shield machine, etc., FIG. 2 is a partial side view of a lining body, FIG. 4 and 5 are perspective views showing a ring body, and FIGS. 6 to 10 show a lining method according to an embodiment in the order of steps. The lining body is shown together with a propulsion jack of a shield machine and the like. Partial cross-sectional view, FIG. 11 is an elevation view showing an erector for performing the lining method according to one embodiment, FIG. 12 is a perspective view showing an enlarged part of the erector, FIG. 13 to FIG. The figure shows the method of forming the outer steel shell (outer ring body) and the inner steel shell (inner ring body) in the order of steps.
FIG. 19 is a graph showing the relationship of the required section moment to the allowable bending moment for the lining according to the present invention, and FIG. 20 is a graph showing the relationship of the required section moment to the allowable bending moment in the reinforced concrete lining. The graphs shown in FIGS. 21 to 23 illustrate the prior art.
FIG. 21 is a front sectional view showing a tunnel lining structure, FIG. 22 is a front sectional view showing the tunnel lining structure, and FIG. 23 is a partial side sectional view thereof. 1 ... excavation hole, 1a ... wall surface, 3 ... outer steel shell, 4 ... outer ring body, 4a ... first strip steel plate, 5 ... inner steel shell, 6 ... inner ring body, 6a ... … Second steel strip, 7 …… concrete,
10 ... Shield machine.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoji Higashi 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Akihiro Honda 2-6-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Corporation (72) Inventor Shigeru Goto 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Corporation (56) References JP-A-62-273399 (JP, A) JP-A-62-220697 ( JP, A) JP-A-62-153498 (JP, A)

Claims (2)

(57) [Claims] 1. A cylindrical outer steel shell provided along a wall surface of an excavation hole, and an inner steel formed concentrically with the outer steel shell inside the outer steel shell to form a lining inner wall surface. A tunnel lining structure comprising a shell and concrete cast between the outer steel shell and the inner steel shell. 2. A step of forming an outer ring body along a wall surface of the excavation hole by connecting a first strip steel plate having an arc shape with a predetermined width in the excavation hole in a longitudinal direction of the strip steel plate itself. Forming an outer steel shell by connecting the outer ring bodies in the width direction, and connecting a second steel strip having a smaller radius of curvature than the first steel strip in the longitudinal direction of the steel strip itself. Forming the inner ring body concentrically with the outer ring, forming the inner steel shell by connecting the inner ring bodies in the width direction, and between the outer steel shell and the inner steel shell. A step of casting concrete into the concrete, and a step of excavating a shield machine with the face face side end face of the concrete as a reaction surface after the required strength is developed in the concrete. Method.