JP4261428B2 - Tunnel floor slab structure and tunnel floor slab construction method - Google Patents

Description

  The present invention relates to a structure of a tunnel floor slab constructed inside a tunnel in which a lower part of a cylindrical shield tunnel or the like is formed in an arc shape, and a construction method thereof.

  A floor slab is provided at the lower part of the tunnel 1 for the purpose of forming a flat bottom surface to form a road surface or dividing the tunnel 1 vertically (see FIGS. 5 and 6).

  Among such tunnels 1, a shield tunnel forms a cylindrical tunnel 1 inner wall surface by arranging a plurality of arc segments on a cylindrical excavation surface excavated by a shield excavator.

  Conventionally, a method as shown in FIG. 5 is known as a method for constructing a floor slab inside the tunnel 1 formed in such a cylindrical shape (see, for example, Patent Document 1). In this method, a temporary sleeper 3 is bridged on the inner wall surface of the tunnel 1 in a direction orthogonal to the tunnel axis direction, and a rail 4 is laid thereon.

  And the material required in order to construct | concrete the concrete floor slab 2 is conveyed to a work site using the conveyance vehicle which drive | works on the rail 4. FIG. At the work site, the concrete floor slab 2 is constructed by placing concrete after assembling the reinforcing bars.

  Further, in this method, the sleepers 3 and the rails 4 are removed after the placed concrete has hardened.

  Moreover, as shown in FIG. 6, a method of constructing a tunnel floor slab by laying a precast floor slab 6 made of reinforced concrete manufactured in a factory is also known (see, for example, Patent Documents 2 and 3).

Thus, in the method of laying the precast floor slab 6, first, the cradle 5 that extends in the tunnel axial direction (tunnel 1 extending direction) is constructed on the inner wall surface of the tunnel 1. Then, precast floor slabs 6 are laid out on two rows of pedestals 5 and 5 constructed in parallel.
Japanese Patent Laid-Open No. 7-18990 (FIGS. 1 and 2) JP 2003-278495 A (FIGS. 1, 3, 4, 0002 to 0003 paragraphs) JP 2002-89195 A (FIGS. 1 and 3)

  However, in the conventional method for constructing a tunnel floor slab in which concrete is directly placed at the above-mentioned site, the concrete waits for the concrete to move to the next operation, so the waiting time is long and the construction period is prolonged.

  Moreover, since the work which removes the sleepers 3 and the rails 4 must be performed after constructing the concrete floor slab 2, the number of work steps increases.

  Further, in the conventional tunnel floor slab construction method in which the precast floor slab 6 is supported by the cradle 5 extended in the tunnel axial direction, the concrete is hardened because the cradle 5 is constructed by placing concrete on site. Thus, the concrete slab 6 cannot be placed until a predetermined strength is reached, and a waiting time for the work can be achieved.

  Further, since the precast floor slab 6 is supported on two sides by the cradles 5 and 5, the floor slab tends to be thick in order to reduce the amount of deflection. As the floor slab becomes thicker, the weight increases, and the cradle 5 that supports the precast floor slab 6 becomes larger and the cost increases.

  Therefore, an object of the present invention is to provide a tunnel floor slab structure and a tunnel floor slab construction method that can be easily constructed in a short period of time.

  In order to achieve the above object, a first aspect of the present invention is directed to a tunnel floor slab constructed inside a tunnel having a lower portion formed in an arc shape, a beam member bridged in a chord shape between tunnel inner walls, and the beam The tunnel having a fixing means for fixing a member to the inner wall surface of the tunnel, and a floor slab member placed on the beam member installed at intervals in the tunnel axis direction and facing the end surfaces of the beam member It is characterized by being molded according to the shape of the inner wall surface.

  Further, in the present invention, the beam member has a convex shape in which a cross section cut in a direction along the tunnel axis is formed by a central protrusion and shelf portions on both sides thereof, The tunnel floor slab structure according to claim 1, wherein when the floor slab member is placed on a shelf, an upper surface of the floor slab member and an upper surface of the protrusion are flush with each other.

  Moreover, what is described in Claim 3 has the structure of the tunnel floor slab of Claim 1 or Claim 2 shape | molded according to the shape of the said inner wall surface of the tunnel which faces the end face of the said floor slab member. It is said.

  Further, according to a fourth aspect of the present invention, the fixing means includes a substantially L-shaped metal fitting formed integrally with a bottom surface fixed to the inner wall surface of the tunnel and a standing surface fixed to the beam member, The tunnel floor slab structure according to any one of claims 1 to 3, wherein the hole through which the fastening material provided on the standing surface is inserted is a long hole.

  According to a fifth aspect of the present invention, there is provided a tunnel floor slab construction method for constructing a floor slab inside a tunnel whose lower part is formed in an arcuate shape. It is bridged between the inner wall surfaces of the tunnel in a string shape, and after positioning the beam member, it is fixed to the inner wall surface of the tunnel by fixing means, and between the beam member and the beam member laid in the same manner at intervals in the tunnel axis direction. The floor slab member is bridged and the floor slab member is fixed to the beam member.

  According to a sixth aspect of the present invention, there is provided a method in which a hole for fixing a fastening material in advance is provided at a predetermined position of each of the tunnel wall surface member, the beam member, and the floor slab member that forms the inner wall surface of the tunnel. The construction method of the tunnel floor slab described in Item 5 is characterized.

  According to the first aspect of the present invention configured as described above, the end face of the beam member is formed in conformity with the shape of the inner wall surface of the tunnel facing, and is supported only by being placed on the tunnel wall surface.

  Then, the beam member temporarily placed on the tunnel wall surface is aligned, and the floor slab member may be placed thereon.

  For this reason, the beam member can be easily aligned, and a tunnel floor slab structure can be obtained simply by assembling members manufactured in advance at a factory or the like, so that the construction period at the site can be shortened.

  According to a second aspect of the present invention, a flush floor surface is formed by fitting the floor slab member between the projections of the plurality of beam members installed.

  For this reason, the floor slab member can be easily installed without positioning such as surveying, and a flush floor can be formed by installing the floor slab member.

  Furthermore, since the said protrusion part prevents that the said floor slab member moves along a tunnel axial direction, it also has an effect as a slip prevention.

  Moreover, what is described in Claim 3 is shape | molded according to the shape of the tunnel inner wall surface which the end surface of the said floor slab member also opposes.

  For this reason, the floor slab member is supported on four sides by the beam member and the inner wall surface of the tunnel, and the amount of deflection is reduced compared to the two-side support, so the thickness of the floor slab can be reduced. .

  Further, according to a fourth aspect of the present invention, a long hole is provided in the standing surface of a substantially L-shaped metal fitting used for fixing the beam member.

  For this reason, even if the segment forming the inner wall surface of the tunnel is inclined and attached due to construction errors, the beam member can be easily fixed at an accurate position by adjusting within the long hole.

  Further, in the invention described in claim 5, the beam member formed with the end face adapted to the shape of the inner wall surface of the tunnel is bridged between the inner wall surfaces of the tunnel, and the beam member is aligned and then fixed to the inner wall surface of the tunnel. To do.

  Then, a tunnel floor slab is constructed by bridging the floor slab member between the plurality of beam members installed at intervals in the tunnel axis direction.

  For this reason, construction of the beam member, alignment, and installation work of the floor slab member can be performed in a short time without waiting time.

  Further, in the method described in claim 6, holes for fixing the fastening material used for joining the members are provided in advance at predetermined positions of the members.

  For this reason, since each member can be arrange | positioned rapidly according to the said hole, a tunnel floor slab can be constructed | assembled in a short period of time.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The same or equivalent parts as those in the conventional example will be described with the same reference numerals.

  FIG. 1 shows a perspective view of main members constituting the structure of a tunnel floor slab according to the present embodiment.

  Such a structure of the tunnel floor slab of the present embodiment is constructed inside the tunnel 1 having a lower portion formed in an arc shape. As shown in FIG. 2, the shield tunnel as the tunnel 1 forms a cylindrical tunnel 1 inner wall surface by combining a plurality of arc-shaped segments 13 made of concrete or steel.

  The structure of the tunnel floor slab of the present embodiment includes a beam member 10 that spans between the inner wall surfaces of the tunnel 1, a fixing means that fixes the beam member 10 to the inner wall surface of the tunnel 1, and a plurality of bridge members that are spaced apart in the tunnel axial direction. And the floor slab member 11 placed on the beam members 10.

  The beam member 10 is a beam member that hangs in a string between two points on the inner wall surface of the tunnel 1 formed by assembling the segments 13 into an arc shape (see FIG. 3). The beam member 10 is manufactured from reinforced concrete or prestressed concrete at a factory or a manufacturing yard.

  And both end surfaces 10e and 10e of the beam member 10 are shape | molded according to the shape of the inner wall face of the tunnel 1 which opposes when constructed. For example, since the segment 13 is formed into an arc having a curvature determined by the size of the tunnel 1, the end faces 10 e and 10 e of the beam member 10 are formed into a curved shape that matches the arc.

  Moreover, the cross section which becomes a direction along a tunnel axis | shaft at the time of construction of the beam member 10 is formed in convex shape. For example, the central portion of the beam member 10 is formed as a wall-shaped protrusion 10a extending in the longitudinal direction.

  And the shelf parts 10b and 10b which form the upper surface lower than the upper surface of the projection part 10a are provided in the both sides of the projection part 10a. The height difference between the upper surface of the protrusion 10 a and the upper surface of the shelf 10 b is the same as the thickness of the floor slab member 11.

  Thus, when shape | molding the beam member 10 in convex shape, since the rigidity by a shape increases, the inside can be made hollow and weight-reduced.

  Further, holes (beam side hole 10c, shelf side hole 10d) for fixing the fastening material are provided in advance at predetermined positions of the beam member 10. The hole is formed by placing concrete (insert) for securing the hole when the beam member 10 is manufactured and then placing concrete. Alternatively, the beam member 10 may be formed by drilling after the beam member 10 is made of concrete or the like.

  As a hole for fixing the fastening material, for example, a beam-side hole 10c extending in the tunnel axis direction is provided on the side surface of the shelf 10b in the vicinity of the end face 10e. This beam side hole 10c is a hole for joining with a fixing means. A shelf side hole 10d extending in the vertical direction is provided on the top surface of the shelf 10b. The shelf-side hole 10d is a hole for fixing the floor slab member 11.

  The beam member 10 is fixed to the inner wall surface of the tunnel 1 through fixing means. Since both end faces 10e, 10e of the beam member 10 are formed in accordance with the shape of the inner wall surface of the tunnel 1 facing each other, the load acting on the beam member 10 is mainly transmitted to the inner wall surface of the tunnel 1 as a supporting pressure.

  If the load is always loaded with a good balance between the left and right, the beam member 10 may be simply bridged on the inner wall surface of the tunnel 1, but the installed beam is displaced only by the frictional resistance between them, such as when the load is concentrated on one side. Therefore, the beam member 10 is fixed to the inner wall surface of the tunnel 1 by the fixing means.

  As the fixing means, for example, a combination of the L-shaped metal fitting 12 and a rod-shaped fastening material can be used (see FIG. 1). The L-shaped metal fitting 12 has a bottom surface 12b and a standing surface 12a substantially orthogonal thereto. Bolts, pins, etc. can be used as the rod-shaped fastening material.

  Here, a hole for fixing to the segment 13 with a bolt 14 is provided in the bottom surface 12 b of the L-shaped metal fitting 12. The bottom surface 12b may be a flat surface, but may be formed into a curved surface in accordance with the shape of the inner wall surface of the tunnel 1.

  And the elongate surface 12a of the L-shaped metal fitting 12 is provided with a long hole 12c into which a bolt 15 used for fixing the beam member 10 is inserted. The long hole 12 c is a hole that is long in the width direction of the L-shaped bracket 12.

  The segment 13 on which the beam member 10 is placed is installed in accordance with the excavation shape of the tunnel 1, and thus is not necessarily arranged at a predetermined accurate position.

  For this reason, the beam side hole 10c may not be arranged in an accurate positional relationship with respect to the position of the wall side hole 13a provided in the segment 13 in advance (see the lower left in FIG. 1). On the other hand, if the hole provided in the standing surface 12a into which the bolt 15 is inserted is the long hole 12c, the construction error can be absorbed.

  Here, the long hole 12c refers to a hole that is long with respect to another direction in which one direction is orthogonal, such as a shape in which a semicircle is connected to both sides of a square, an ellipse, or a rectangle.

  The floor slab member 11 is a floor slab member that is placed on the two beam members 10 and 10 that are installed at intervals in the tunnel axis direction. The floor slab member 11 is manufactured from reinforced concrete or prestressed concrete at a factory or a manufacturing yard.

  And it is preferable to shape | mold the both end surfaces 11b and 11b of the floor slab member 11 in a circular-arc-shaped curved surface according to the shape of the inner wall surface of the tunnel 1 which faces when it mounts (refer FIG. 4).

  As shown in FIG. 1, the floor slab member 11 is provided with a floor slab side hole 11 a penetrating in the plate thickness direction in a portion placed on the shelf 10 b. The bolt 16 as the fastening material inserted into the floor slab side hole 11a is inserted into the shelf side hole 10d. As a result, the floor slab member 11 and the beam member 10 are coupled.

  Both side ends in the tunnel axis direction of the floor slab member 11 configured as described above are placed on the shelf portions 10 b and 10 b and supported by the beam members 10 and 10.

  In addition, when the end faces 11 b and 11 b facing the inner wall surface of the tunnel 1 of the floor slab member 11 are formed according to the inner wall surface of the tunnel 1, the floor slab member 11 is also supported by the inner wall surface of the tunnel 1.

  Next, the construction method of the tunnel floor slab will be described, and the operation of this embodiment will be described.

  First, as shown in FIG. 2, the arc-shaped segment 13 is installed on the excavation surface excavated by the shield excavator. Although only the lower half portion of the tunnel 1 is shown in FIG. 2, the segment 13 is also arranged in the upper half portion of the tunnel 1 so that the inner wall surface of the cylindrical tunnel 1 is formed.

  The joint between the segments 13 and 13 in the tunnel circumferential direction is preferably staggered so as not to be continuous in the tunnel axis direction. Further, a wall side hole 13a extending in the wall thickness direction for inserting the bolt 14 is provided in advance at a predetermined position of the segment 13 to which the L-shaped metal fitting 12 is attached later.

  Then, the L-shaped metal fitting 12 is fixed at the position where the wall side hole 13 is provided. FIG. 3 is a perspective view in which the L-shaped bracket 12 is fixed at a predetermined position.

  The fixed position of the L-shaped metal fitting 12 is a position where the end faces 10e, 10e of the beam member 10 are arranged. For example, the L-shaped brackets 12 and 12 are attached so that the tunnel 1 digging direction side surface of the beam member 10 is in contact with the standing surfaces 12 a and 12 a of the L-shaped brackets 12 and 12.

  Then, the beam member 10 carried in from the tunnel 1 wellhead side is pressed against the standing surfaces 12a and 12a, and the beam member 10 is bridged between the inner wall surfaces of the tunnel 1 in a string shape (see FIG. 4).

  Next, the beam member 10 temporarily supported by the inner wall surface of the tunnel 1 is positioned in a horizontal state. By this positioning, the beam side hole 10c provided in advance on the side surface of the beam member 10 appears within the range of the long hole 12c provided in the standing surface 12a. Therefore, the bolt 15 is inserted into the exposed beam side hole 10c from the L-shaped bracket 12 side, and the L-shaped bracket 12 and the beam member 10 are coupled.

  Here, the segment 13 may be arranged at a position including a construction error from an accurate position where it should originally be arranged. It is difficult to absorb construction errors that occur during installation of the segment 13 with a hole that is slightly larger than the diameter of the bolt 15.

  Therefore, if the long hole 12c as shown in the present embodiment is provided in the standing surface 12a of the L-shaped bracket 12, the beam member 10 can be arranged at an accurate position and joined to the L-shaped bracket 12. .

  Separately from the beam member 10 installed as described above, the beam member 10 in which the floor slab member 11 is placed on the shelf 10b on one side is already installed on the tunnel 1 well entrance side (see FIG. 2).

  The spacing between the beam members 10 and 10 is such that almost no gap is generated between the projection 10a and the floor slab member 11 when the floor slab member 11 is bridged between the shelves 10b and 10b. .

  Thus, if the size of the opening formed by the projections 10a, 10a of the beam members 10, 10 and the inner wall surface of the tunnel 1 is equal to the size of the floor slab member 11, the floor slab member 11 is not required to be surveyed. Can be placed at an accurate position.

  Further, since the floor slab member 11 is installed between the projections 10a and 10a, errors do not accumulate compared to the case where the floor slab member 11 is continuously installed.

  FIG. 4 is a cross-sectional view showing a process of placing the floor slab member 11 on the beam member 10 fixed to the inner wall surface of the tunnel 1 by the L-shaped metal fittings 12 and 12. After the floor slab member 11 is placed on the shelves 10b and 10b, the bolt 16 is inserted into the floor slab side hole 11a and the shelf side hole 10d to fix the floor slab member 11 to the beam members 10 and 10.

  When the floor slab member 11 is placed on the beam member 10 in this way, the side ends of the floor slab member 11 in the tunnel axis direction are supported by the beam members 10 and 10.

  At the same time, the end faces 11 b and 11 b of the floor slab member 11 facing the inner wall surface of the tunnel 1 are supported by the inner wall surface of the tunnel 1. For this reason, the floor slab member 11 is supported by four sides.

  If the floor slab member 11 can be supported by the four sides, the thickness of the floor slab can be reduced as compared with the case where the floor slab member 11 is supported by two sides, which is economical. In addition, since the flush floor surface is formed by the upper surface of the floor slab member 11 and the upper surface of the protruding portion 10a, it is not necessary to separately fill the step.

  Furthermore, since the size of the floor slab member 11 can be reduced by the width of the protruding portion 10a, it is possible to easily carry in or change the direction inside the tunnel 1.

  Even if a large force in the tunnel axis direction is applied to the floor slab member 11 due to an earthquake or the like, the floor slab member 11 will not be displaced if the movement can be restricted by the protrusion 10a.

  According to the construction method of a tunnel floor slab as described above, a tunnel floor slab can be constructed only by installing a member manufactured in advance and fixing with a fastening material. For this reason, it is possible to construct a tunnel floor slab in a short period of time without generating work waiting time such as it is impossible to move to the next step until the strength of concrete is developed.

  In addition, since the tunnel floor slab can be constructed sequentially according to the tunnel 1 excavation, and can be used immediately for carrying in materials after construction, work efficiency is improved.

  Moreover, since the end surface of the beam member 10 is formed in accordance with the shape of the inner wall surface of the tunnel 1, the beam member 10 can be supported only by being placed on the inner wall surface of the tunnel 1. For this reason, once beam member 10 is temporarily placed, positioning can be performed.

  Further, the overload acting on the beam member 10 can be transmitted to the inner wall surface of the tunnel 1 as a supporting pressure of the surface. For this reason, compared with the case where it is supported only by the shear resistance of the inner wall surface of the tunnel 1 such as a stud joint, or when only the corner of the beam member is in local contact with the inner wall surface of the tunnel 1, Concentrated stress is not generated.

  Although the best embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are possible. Are included in the present invention.

  For example, the tunnel 1 is not limited to a shield tunnel constructed in a cylindrical shape, and may be a tunnel having a lower portion formed in an arc shape by a combination of a curved surface and a polygon.

  Moreover, the beam member 10 or the floor slab member 11 is not limited to concrete, and can be manufactured by combining steel plates, H-shaped steel materials, and the like.

  Further, when the width of the floor slab member 11 is widened, the floor slab member 11 may be divided into a plurality of members in a direction perpendicular to the tunnel axis, and the bridge members 11 and 10 may be bridged and fixed. .

  Moreover, in the said embodiment, although the floor slab member 11 was mounted in the shelf part 10b of the beam member 10, using the beam member (not shown) whose cross section of a tunnel axial direction is a square, the beam member 10 is attached. The floor slab member 11 may be installed so as to cover it.

  Furthermore, in the above embodiment, the beam member 10 is fixed to the inner wall surface of the tunnel 1 via the L-shaped metal fitting 12, but a hole that appears on the end surface 10e of the beam member 10 is provided, and a fastening material such as a pin is used. The beam member 10 may be directly fixed to the inner wall surface of the tunnel 1.

  Further, the hole provided for fixing the fastening material to the segment 13, the beam member 10 or the floor slab member 11 may not be provided in advance at the time of manufacture but may be provided when the fastening material is driven at the installation site.

  Furthermore, the fixing means for fixing the beam member 10 to the inner wall surface of the tunnel 1 may not be a combination of a metal fitting and a fastening material, but may be an adhesive such as epoxy resin or non-shrink mortar.

It is a disassembled perspective view explaining the whole structure of the structure of the tunnel floor slab of the best embodiment of this invention. It is a perspective view explaining the process of arrange | positioning a segment among the processes of the construction method of the tunnel floor slab of the best embodiment of this invention. It is a perspective view explaining the process of arrange | positioning a beam member among the processes of the construction method of the tunnel floor slab of the best embodiment of this invention. It is sectional drawing explaining the process of arrange | positioning a floor slab member among the processes of the construction method of the tunnel floor slab of the best embodiment of this invention. It is sectional drawing explaining the structure of the tunnel floor slab constructed by placing concrete of the prior art on-site. It is a perspective view explaining the structure of the tunnel floor slab constructed using the precast floor slab of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel 10 Beam member 10a Protrusion part 10b Shelf part 10c Beam side hole 10d Shelf side hole 10e End face 11 Floor slab member 11a Floor slab side hole 11b End face 12 L-shaped metal fitting (fixing means)
12a Standing surface 12b Bottom surface 13 Segment (tunnel wall surface member)
13a Wall side hole 14, 15, 16 bolt (fastening material)

Claims (6)

In the structure of the tunnel floor slab constructed inside the tunnel with the lower part formed in an arc shape,
A beam member bridged in a string between the inner wall surfaces of the tunnel, a fixing means for fixing the beam member to the inner wall surface of the tunnel, and a floor slab member placed on the plurality of beam members installed at intervals in the tunnel axis direction The tunnel floor slab structure is formed in accordance with the shape of the inner wall surface of the tunnel facing the end surface of the beam member.   The beam member is a convex shape in which a cross section cut in a direction along the tunnel axis is formed by a central protrusion and shelf portions on both sides thereof, and when the floor slab member is placed on the shelf portion, 2. The structure of a tunnel floor slab according to claim 1, wherein an upper surface of the floor slab member and an upper surface of the projection are flush with each other.   The structure of a tunnel floor slab according to claim 1 or 2, wherein an end surface of the floor slab member is formed in accordance with a shape of the inner wall surface of the tunnel facing each other.   The fixing means includes a substantially L-shaped metal fitting formed integrally with a bottom surface fixed to the inner wall surface of the tunnel and a standing surface fixed to the beam member, and a hole through which a fastening material provided on the standing surface is inserted. The structure of a tunnel floor slab according to any one of claims 1 to 3, wherein is a long hole. In the construction method of the tunnel floor slab that constructs the floor slab inside the tunnel whose lower part is formed in an arc shape,
A beam member whose end face is shaped in accordance with the shape of the facing inner wall surface of the tunnel is bridged in a chord shape between the inner wall surfaces of the tunnel, and after positioning the beam member, it is fixed to the inner wall surface of the tunnel by a fixing means, A method for constructing a tunnel floor slab, characterized in that a floor slab member is bridged between beam members similarly installed at intervals in the tunnel axis direction, and the floor slab member is fixed to the beam member.   6. The tunnel floor according to claim 5, wherein holes for fixing a fastening material are provided in advance at predetermined positions of the tunnel wall surface member, the beam member, and the floor slab member that form the inner wall surface of the tunnel. How to build a version.

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