Concrete casting method and concrete casting cradle for composite segment

Abstract

To provide a concrete casting method and a concrete casting cradle for a composite segment, which can improve fillability in casting concrete and eliminate the surface-finishing work for the inner-space side surface of the segment.SOLUTION: A steel shell 1 is constituted, in an approximate arc shape along a natural ground of a tunnel in a side view, of: girders 2, 2 arranged in a circumferential direction of the tunnel; joint plates 3, 3 arranged between ends of the girders 2, 2; and a skin plate 5 arranged on the natural ground side of a frame body 4 constituted of the girders 2, 2 and the joint plates 3, 3. The infilled concrete 8 is cast into the steel shell 1 having an opening inner space side through the steps of: (1) placing the steel shell 1 on a recessed curved surface mold 16 that is formed in an approximate arc sectional shape corresponding to the approximate arc shape in the side view of the steel shell 1 and is inclined in the circumference direction of the tunnel: and (2) pouring the infilled concrete 8 into the steel shell 1 from a side of the joint plate 3 positioned above the recessed curved surface mold 16.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for placing concrete of a synthetic segment used as a lining material for a shield tunnel and a table for placing concrete, and in particular, it can enhance the fillability when placing the filling concrete into a steel shell constituting the synthetic segment, and can omit the surface finishing of the inner space side (inner surface side) of the segment.

Background Art

[0002] The lining of a shield tunnel (hereinafter referred to as "tunnel") is generally constructed by assembling divided lining materials called segments in the tunnel and fastening them with joints. In particular, for the lining of a tunnel that requires particularly high strength, a synthetic segment, which is a composite structural material of steel and concrete, is used.

[0003] As this type of synthetic segment, a synthetic segment composed of a steel shell and filling concrete filled in the steel shell is known.

[0004] The steel shell is formed into a rectangular frame shape that is long in the circumferential direction of the tunnel from a pair of main girders (side plates) respectively arranged in the circumferential direction and axial direction of the tunnel and a pair of joint plates, and is formed into a substantially arc shape in side view along the ground of the tunnel from a skin plate arranged on the ground side (outer surface side) of the frame body. In particular, the skin plate is arranged on the ground side (outer surface side) of the frame body, or on both sides of the ground side and the inner space side (inner surface side). The former is called a five-sided steel shell synthetic segment, and the latter is called a six-sided steel shell synthetic segment.

[0005] Also, for example, in the synthetic segment disclosed in Patent Document 1, a plurality of vertical ribs are arranged between the main girders, a plurality of divels (studs, etc.) project from the inner surface of the skin plate, and further, reinforcing bars may be arranged in the filling concrete.

[0006] In addition, when manufacturing the former five-sided steel shell composite segment, in order to place the filling concrete inside the steel shell, with the steel shell formed in a substantially arc shape in side view, in a state where the skin plate is on the lower side (the tunnel inner surface side is on the upper side), after placing the concrete in the space (inside the steel shell) surrounded by the skin plate, the main girder, and the end plate, finishing work such as troweling is performed on this concrete placement surface (concrete surface). In particular, when insert members such as insert nuts are to be attached to the inner surface of the segment, they are pre-attached so that their positions do not shift.

[0007] As another placement method, there is also a method of providing a placement opening for placing concrete on the skin plate, placing the filling concrete into the steel shell through the placement opening, and after placing the filling concrete, welding and closing the placement opening with a closing plate made of an iron plate or the like.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Disclosure of the Invention

Problems to be Solved by the Invention

[0009] However, since a plurality of vertical ribs and the like are arranged inside the steel shell, there is a problem that the filling property of the filling concrete is greatly impaired.

[0010] In addition, after placing the filling concrete, since it is necessary to perform finishing work such as troweling on the concrete placement surface (concrete surface), there is also a problem that both the cost and the labor increase.

[0011] Furthermore, in the method of placing the filling concrete from the placing opening of the latter skin plate, there is a risk of causing a strength reduction due to the provision of the placing opening in the skin plate. In addition, since the closing plate is a non-structural member, there are problems that it not only becomes a factor in increasing the steel weight but also requires extra labor for installation.

[0012] The present invention has been made to solve the above problems, and in particular, it is possible to enhance the fillability when placing the filling concrete inside the steel shell constituting the synthetic segment, and it is an object of the present invention to provide a method for placing concrete of a synthetic segment and a concrete placing table that can omit the surface finishing on the inner space side (inner surface side) of the segment.

Means for Solving the Problems

[0013] The present invention is a method for placing concrete of a synthetic segment composed of a pair of main girders arranged in the circumferential direction of a shield tunnel, a pair of joint plates respectively arranged between the ends of the main girders, and a skin plate arranged on the ground side of the frame formed by the main girders and the joint plates, which is formed in a substantially arc shape in side view along the ground of the shield tunnel and has an opening on the inner space side, and the filling concrete placed inside the steel shell, and is characterized by including the following steps.

[0014] (1) A step of placing the steel shell along the circumferential direction of the shield tunnel on a convex curved surface shape mold part formed in a substantially arc shape in cross section in the circumferential direction of the shield tunnel corresponding to the substantially arc shape in side view of the steel shell and formed to be inclined in the circumferential direction of the shield tunnel.

[0015] (2) A step of placing the filling concrete into the steel shell from the side of the joint plate located above the convex curved surface shape mold part.

[0016] The filling concrete can be placed extremely efficiently by preventing scattering of the filling concrete and the like by placing it through a concrete placing hopper from a placing opening provided in the joint plate.

[0017] When an insert member such as an insert nut is to be attached to the inner hollow side of the synthetic segment, the insert member may be temporarily attached to the bottom of the convex curved surface-shaped mold part in a detachable manner in advance.

[0018] In addition, the concrete placing method and the placing table of the present invention can be used in principle without being particularly affected by the structure of the steel shell as long as the steel shell is a five-sided steel shell synthetic segment with an open inner hollow side (inner surface side).

Advantages of the Invention

[0019] According to the present invention, the inner hollow side (inner surface side) of the filling concrete placed in the steel shell is surface-finished by the convex curved surface-shaped mold part formed in a substantially arc shape in the circumferential direction of the tunnel corresponding to the substantially arc shape in the side view of the steel shell, so that the separate surface finishing of the inner hollow side can be omitted.

[0020] In addition, since the convex curved surface-shaped mold part is inclined in the circumferential direction of the tunnel, by placing the filling concrete into the steel shell from the joint plate side located on the upper end side of the steel shell set on the convex curved surface-shaped mold part, the filling property of the filling concrete is not impaired by a plurality of vertical ribs in the steel shell, and the filling concrete can be filled to every corner in the steel shell.

[0021] Furthermore, when an insert member is to be attached to the inner hollow side (inner surface side) of the synthetic segment, by temporarily attaching the insert member to the bottom of the convex surface-shaped mold part in advance, it can be integrated with the segment when placing the filling concrete, and the positioning and fixing of the insert member can be easily performed on the convex curved surface-shaped mold part.

[0022] In addition, by providing a concrete placing port in the joint plate and placing through the placing hopper from the concrete placing port, the filling concrete can be surely filled into the steel shell.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0024] FIGS. 1-4 illustrate an example of a five-sided steel shell composite segment composed of a steel shell and the filling concrete placed inside the steel shell.

[0025] The steel shell 1 includes a frame body 4 formed in a rectangular frame shape that is long in the tunnel circumferential direction, which is composed of a pair of main girders (side plates) 2, 2 arranged in the tunnel circumferential direction and the axial direction respectively, and a pair of joint plates 3, 3 arranged between both ends in the tunnel circumferential direction of the main girders 2, 2. The steel shell 1 also includes a skin plate 5 arranged on the ground side of the frame body 4, and is formed in a substantially arc shape in side view that is long in the tunnel circumferential direction along the tunnel ground. In particular, the inner space side of the frame body 4 has no skin plate and is open to the inner space side over the entire frame body 4.

[0026] In addition, a plurality of shape retention members 6,... are arranged along the axial direction of the tunnel between the main girders 2, 2, and a pair of reinforcing flanges (hereinafter referred to as "inner flanges") 7, 7 are respectively attached continuously in the circumferential direction of the tunnel to the inner surfaces (opposing surfaces) of the main girders 2, 2.

[0027] The joint plates 3, 3 are respectively welded to both ends in the circumferential direction of the tunnel of the main girders 2, 2, and the skin plate 5 is welded to the base side of the frame body 4, that is, the edge portions on the base side of the pair of main girders 2, 2 and the joint plates 3, 3.

[0028] In addition, the main girder plate 2 and the joint plate 3 are formed of a steel plate or a section steel. In particular, the main girders 2, 2 are formed in a substantially arc shape in side view that is continuous in the circumferential direction of the tunnel along the ground of the tunnel.

[0029] The shape retention members 6,... are formed of section steels such as angle materials (angle steels) or channel steels, and are arranged to be spaced apart from each other in the diameter direction of the tunnel between the main girders 2, 2. That is, they are arranged on the base side and the inner space side between the main girders 2, 2 (for example, arranged in two upper and lower stages in the height direction of the main girders 2, 2), and are arranged at intervals in the circumferential direction of the tunnel.

[0030] In addition, both ends of each shape retention member 6,... are welded to the inner surfaces of the main girders 2, 2 (for example, the upper and lower edge portions of the inner surfaces). In particular, the shape retention members 6,... arranged on the base side of the tunnel are welded to the inner surfaces of the main girders 2, 2 and the inner surfaces of the skin plate 5, and each shape retention member 6,... arranged on the inner space side of the tunnel is welded to the inner surfaces of the main girders 2, 2 and the side surfaces of the inner flanges 7, 7.

[0031] As a result, the former shape retention members 6,... originally arranged in that row have the function of displacement prevention 9,... (described later) that exerts the effect of preventing displacement of the in-filled concrete 8 in the steel shell 1, so the displacement prevention 9 arranged in that row can be omitted, and the amount of steel used can be reduced. In addition, the latter shape retention members 6,... can be expected to have the function of maintaining the shape of the steel shell 1 and preventing deformation of the steel shell 1.

[0032] Furthermore, since the shape-retaining members 6, … are arranged to be spaced apart from each other in the diameter direction of the tunnel, the fillability during the placement of the backfill concrete 8 can be ensured.

[0033] The inner flanges 7, 7 are formed to be continuously substantially arc-shaped in the circumferential direction of the tunnel along the arc shape of the main girders 2, 2 in side view, and are welded to the inner surfaces of the main girders 2, 2. Note that the inner flanges 7, 7 are formed of a steel plate, a section steel, or the like.

[0034] The anti-shift members 9, … are stud dowels, headed studs, perforated steel plate dowels, section steel dowels, etc., and a large number of them are arranged at predetermined intervals in the circumferential and axial directions of the tunnel on the entire inner surface of the skin plate 5, and are welded to the inner surface of the skin plate 5.

[0035] These shape-retaining members 6, …, inner flanges 7, 7 and anti-shift members 9, … are completely embedded in the backfill concrete 8 and integrated with the backfill concrete 8, thereby forming a composite structure in the entire circumferential and axial directions of the tunnel. Also, it functions as a composite structure not only for the sectional force in the circumferential direction of the tunnel but also for the sectional force in the axial direction of the tunnel.

[0036] Note that the covering concrete 10 is filled to a certain thickness in the surface layer portion of the backfill concrete 8, and anti-peeling bars 11 for preventing the peeling of the backfill concrete 8 are arranged in the covering concrete 10.

[0037] Reference numeral 12 denotes a segment joint for joining adjacent composite segments in the circumferential direction of the tunnel, and the segment joint 12 is attached to the joint plate 3.

[0038] Also, reference numeral 13 denotes a ring joint for joining adjacent segment rings in the axial direction of the tunnel, and the ring joint 13 is attached to the main girder 2. Further, reference numeral 14 denotes a concrete placement port for placing the backfill concrete 8 into the steel shell 1, and the concrete placement port 14 is provided in the joint plate 3.

[0039] Figs. 5 and 6 illustrate a concrete placing table used for placing the filling concrete into the steel shell during the fabrication of the five-sided steel shell composite segment described in Figs. 1-4.

[0040] The concrete placing table 15 is provided with a convex curved surface shaped portion 16 on which the steel shell 1 is placed. The convex curved surface shaped portion 16 is formed in a substantially arc shape in cross section in the circumferential direction of the tunnel corresponding to the substantially arc shape in the side view of the steel shell 1, and its bottom portion 16a is formed smoothly over the entire surface.

[0041] Thereby, the inner hollow side surface of the filling concrete 8 placed in the steel shell 1 is formed smoothly.

[0042] Also, it is inclined in the circumferential direction of the tunnel (hereinafter referred to as "the longitudinal direction of the steel shell 1"), and a steel shell receiving portion 17 for holding the placed steel shell 1 so as not to fall is formed at the lower end side portion in the inclined direction. Further, guide portions 18, 18 for guiding the steel shell 1 are formed on both sides in the tunnel axis direction (hereinafter referred to as "the width direction of the steel shell 1"), that is, outside both sides of the steel shell 1, namely, outside the main girders 2, 2.

[0043] The steel shell receiving portion 17 is installed so that its position can be arbitrarily changed in the longitudinal direction of the steel shell 1, and the guide portions 18, 18 are installed so that their positions can be arbitrarily changed in the width direction of the steel shell 1.

[0044] Thereby, the length and width in the circumferential direction of the tunnel of the convex curved surface shaped portion 16 can be freely changed according to the length and width of the steel shell 1. Also, by firmly fixing the steel shell 1 with the steel shell receiving portion 17 and the guide portions 18, 18 on both sides, deformation of the steel shell 1 during the placement of the filling concrete can be prevented.

[0045] Also, the inclination of the convex curved surface shaped portion 16 can be arbitrarily changed according to the fluidity of the filling concrete 8. For example, when the fluidity during the placement of the filling concrete 8 is small, the filling property of the filling concrete can be enhanced by increasing the inclination as necessary.

[0046] In addition, the joint plate 3 located at the lower end side of the steel shell 1 placed on the convex curved surface shape portion 16 abuts against the steel shell receiving portion 17, so that the steel shell 1 does not fall.

[0047] Reference numeral 19 denotes a concrete pouring hopper used when pouring the filler concrete 8 into the steel shell 1. The pouring hopper 19 is detachably attached to the concrete pouring port 14 provided in the joint plate 3 located at the upper end side of the steel shell 1 placed on the convex curved surface shaped mold portion 16.

[0048] In this configuration, a method for pouring the filling concrete will now be described. (1) First, the steel shell 1 is set on the convex curved mold portion 16 of the concrete pouring platform 15. Then, the positions of the steel shell receiving portion 17 and the left and right guide portions 18, 18 are adjusted to fix the steel shell 1. Also, the inclination of the convex curved mold portion 16 is adjusted according to the fluidity of the filling concrete 8. Furthermore, insert members (not shown) are placed on the inner side of the composite segment to be manufactured. When the insert member (omitted) is attached, the insert member is temporarily and detachably attached to the bottom portion 16a of the convex curved surface mold portion 16 by plugging or bolting or the like.

[0049] (2) Next, a concrete pouring hopper 19 is attached to the concrete pouring port 14 provided in the joint plate 3 located at the upper end side of the steel shell 1, and the filler concrete 8 is poured into the steel shell 1 through the hopper 19. If necessary, the attached vibrator (not shown) is operated to compact and cure the concrete. [Industrial Applicability]

[0050] The present invention can improve the filling properties when pouring filler concrete into the steel shell that constitutes the composite segment, and can omit surface finishing of the hollow side (inner surface) of the segment. [Explanation of symbols]

[0051] 1 Steel shell 2 Main girder 3 Joint plate 4 Frame body 5 Skin plate 6 Shape retaining member 7 Inner flange 8 Filled concrete 9 Displacement prevention 10 Covered concrete 11 Anti-peeling reinforcement 12 Segment joint 13 Ring joint 14 Concrete placing port 15 Concrete placing stand 16 Convex curved surface shaped part 17 Steel shell receiving part 18 Steel shell guide part 19 Concrete placing hopper

Claims

1. A method for placing concrete of a composite segment, comprising a pair of main girders arranged in the circumferential direction of a shield tunnel, a pair of joint plates respectively arranged between the ends of the main girders, and a skin plate arranged on the ground side of the frame formed by the main girders and the joint plates, the method being characterized in that it includes the following steps: A steel shell is formed along the ground of the shield tunnel in a substantially arc shape in side view and has an opening on the inner cavity side, and a method for placing concrete of a composite segment composed of the infill concrete placed in the steel shell. (1) A step of placing the steel shell along the circumferential direction of the shield tunnel on a convex curved surface-shaped mold part formed in a substantially arc shape in cross-section in the circumferential direction of the shield tunnel corresponding to the substantially arc shape in side view of the steel shell and formed to be inclined in the circumferential direction of the shield tunnel. (2) A step of placing the infill concrete into the steel shell from the side of the joint plate located above the convex curved surface-shaped mold part.

2. The method for placing concrete of a composite segment according to Claim 1, characterized in that it includes a step of temporarily attaching a detachable insert member to the convex curved surface-shaped mold part.

3. The method for placing concrete of a composite segment according to Claim 1 or 2, characterized in that the infill concrete is placed through a concrete placing hopper provided at a concrete placing opening provided on the joint plate.

4. A table for placing concrete of a composite segment, comprising a pair of main girders arranged in the circumferential direction of a shield tunnel, a pair of joint plates respectively arranged between the ends of the main girders, and a skin plate arranged on the ground side of the frame formed by the main girders and the joint plates, the table being characterized in that a steel shell is formed along the ground of the shield tunnel in a substantially arc shape in side view and has an opening on the inner cavity side, and the table for placing concrete of a composite segment composed of the infill concrete placed in the steel shell, is formed in a substantially arc shape in cross-section in the circumferential direction of the shield tunnel corresponding to the substantially arc shape in side view of the steel shell, is formed to be inclined in the circumferential direction of the shield tunnel, and is provided with a convex curved surface-shaped mold part on which the steel shell is placed and a concrete placing hopper for placing the infill concrete into the steel shell.

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