JP4625752B2 - Form for tunnel gate and method of constructing tunnel gate using this form - Google Patents

Description

  The present invention relates to a tunnel gate form and a tunnel gate construction method using the form.

  In recent years, in order to improve the landscape and prevent rock fall from the natural ground, instead of the face wall style (method), the projecting type mine where the pit protrudes from the natural ground and the exit side end surface is almost vertical The gate, the bamboo split type mine whose exit side end face is inclined toward the tunnel side, and the reverse bamboo split type mine whose exit side end face is inclined in the opposite direction to the bamboo split type pit are widely used.

  The type of tunnel tunnel that protrudes from such a natural ground is formed into an inner mold frame having a curved surface along the inner peripheral surface of the tunnel gate and a curved shape along the outer peripheral surface of the tunnel gate. Placing the ready-mixed concrete in the tunnel mine formwork comprising the outer formwork having the formed surface, and the inner formwork and the wife formwork that closes the tunnel entrance side opening portion of the outer formwork, It is formed by demolding the mold after curing for a predetermined period (see, for example, Patent Document 1), but it is necessary to reinforce the mold against the side stress of the concrete that has not yet hardened during concrete placement. is there.

  As a reinforcing method, a method using a pipe support and a method using a separator are conventionally known. Among these, the method using the pipe support is such that a pipe support 53 is disposed between the lower part or side part of the outer mold 51 and the cut 52 as shown in FIG. By utilizing this, deformation of the outer mold 51 is suppressed. On the other hand, as shown in FIG. 13, a method using a separator is performed by keeping the distance between both mold frames 51 and 54 constant by a separator 55 penetrating the outer mold frame 51 and the inner mold frame 54. Deformation of the mold 51 is suppressed.

JP 2003-82993 A

  The method using the pipe support is easy to work, the deformation of the outer mold can be visually confirmed during the concrete placing work, and it is easy to handle such as installing an additional pipe support. Although it has an advantage, in order to support the pipe support stably, the back ground must be a stable cut, and the embankment cannot stably support the pipe support. May not be able to adopt this method. Protruding type tunnel gates were often constructed in cuts, but for the purpose of landscape countermeasures, protruding type tunnels have been planned for various terrain (cutting and embankment). However, the method using the pipe support has a limit to the response.

  On the other hand, since the method using a separator does not require a part that gives a reaction force to the formwork, it can be used for both cutting and embankment, but this method directly connects the inner formwork and the outer formwork. Since it is fixed with the separator, unless the installation error between the inner mold and the outer mold is reduced, it takes time to fit the separator, and it takes time to adjust the peaker. .

  The present invention has been made in view of such circumstances, and can be employed in various terrain, yet has a simple installation work, and can realize a shortened construction period and a reduced construction cost. It aims at providing the construction method of a frame and a tunnel mine using this formwork.

The tunnel gate form of the present invention comprises an inner mold having a surface formed in a curved shape along the inner peripheral surface of the tunnel gate, and a surface formed in a curved shape along the outer peripheral surface of the tunnel gate. A tunnel mine formwork comprising an outer formwork and a wife formwork that closes the inner formwork and the opening part on the tunnel entrance side of the outer formwork,
A thickness holding material for supporting the outer mold frame is disposed between the inner mold frame and the outer mold frame,
This winding thickness holding material is installed between the inner mold frame and the outer mold frame, and when concrete is placed in the mold frame, the deformation of the outer mold frame is suppressed and a predetermined winding thickness is secured. Arranged , and
The winding thickness holding member includes a shaft portion whose length can be adjusted, and a spacer block fixed to both ends of the shaft portion, and is disposed on the inner peripheral surface side of the tunnel gate of both spacer blocks. The spacer block is characterized in that a taper surface for retaining is formed .

  In the tunnel gate mold according to the present invention, the thickness holding material is installed between the inner mold and the outer mold, and when the concrete is placed in the mold, the outer mold is deformed. It is arranged at a place to be restrained, and this thickness holding material functions as a tension rod and prevents deformation (displacement) of the top part or the crown part of the outer mold frame downward (inward). Since the roll thickness holding material is disposed between the inner mold frame and the outer mold frame, it can be used without being affected by the type of ground around the tunnel gate, and between the two mold frames. Since it is only installed, the work is easy and the work can be completed in a short time. Further, since the roll thickness holding material can be embedded in the cast concrete, the removal work is not necessary in this case. Therefore, the construction period can be shortened and the construction cost can be reduced.

Further, the winding thickness holding material includes a shaft portion whose length can be adjusted, and a spacer block fixed to both ends of the shaft portion, and is disposed on the inner peripheral surface side of the tunnel tunnel among the both spacer blocks. the spacer blocks, that have been tapered surface for retaining formation. In this case, it is possible to easily adjust the total length of the thickness holding material simply by adjusting the length of the shaft portion, and the winding thickness between the inner peripheral surface of the outer mold frame and the outer peripheral surface of the inner mold frame. It can arrange | position in the state which held the holding | maintenance material reliably. Further, the winding thickness retaining material in the present invention can be embedded in the concrete constituting the tunnel gate, but the spacer block arranged on the inner peripheral surface side of the tunnel gate is provided with a taper for retaining. Since the surface is formed, it is possible to reliably prevent the spacer block from falling into the tunnel.

  The inner mold is a centle used for tunnel lining, and the centle has a top corresponding to the top surface of the inner peripheral surface of the tunnel pit, and side portions corresponding to side surfaces on both sides in the tunnel circumferential direction of the top surface. Preferably, the top part and the side part are connected by a hinge, and the thickness holding member is preferably arranged at the top part of the centle. When the centle used for tunnel lining is used as the inner formwork for tunnel tunnel construction, the time required for assembling the inner formwork can be reduced and the cost for the formwork can be reduced. In addition, since a lot of bending stress or the like toward the inside of the tunnel occurs in the part of the outer mold corresponding to the top of the centle, by disposing a winding thickness holding material on the top of the centle, Deformation (displacement) in the downward (inward) direction can be prevented.

In addition, the tunnel gate construction method of the present invention includes a step of placing an inner mold having a curved surface along the inner peripheral surface of the tunnel gate at the tunnel entrance,
A step of disposing the outer formwork at the tunnel well opening so as to cover the outer form side of the inner formwork with an outer formwork having a curved surface formed along the outer peripheral surface of the tunnel gate;
A step of closing a tunnel entrance / exit side opening portion of the inner mold frame and the outer mold frame with a wife mold frame, and a winding thickness holding material for supporting the outer mold frame between the inner mold frame and the outer mold frame Including a step of arranging,
The winding thickness holding material is installed between the inner mold frame and the outer mold frame, and when concrete is placed in the mold frame, the deformation of the outer mold frame is suppressed and a predetermined winding thickness is secured. and arranged to, and
The winding thickness holding member includes a shaft portion whose length can be adjusted, and a spacer block fixed to both ends of the shaft portion, and is disposed on the inner peripheral surface side of the tunnel gate of both spacer blocks. a spacer block, has been tapered surface for retaining formation is characterized in Rukoto.

In the construction method of the present invention, the winding thickness holding material is arranged so as to suppress deformation of the outer mold and secure a predetermined winding thickness when placing concrete in the mold. The holding material functions as a tension bar and prevents deformation (displacement) of the top part or the crown part of the outer mold frame downward (inward). Since the roll thickness holding material is disposed between the inner mold frame and the outer mold frame, it can be used without being affected by the type of ground around the tunnel gate, and between the two mold frames. Since it is only installed, the work is easy and the work can be completed in a short time. Further, since the roll thickness holding material can be embedded in the cast concrete, the removal work is not necessary in this case. Therefore, the construction period can be shortened and the construction cost can be reduced.
Further, the winding thickness holding material includes a shaft portion whose length can be adjusted, and a spacer block fixed to both ends of the shaft portion, and is disposed on the inner peripheral surface side of the tunnel tunnel among the both spacer blocks. The spacer block is formed with a taper surface for retaining. In this case, it is possible to easily adjust the total length of the thickness holding material simply by adjusting the length of the shaft portion, and the winding thickness between the inner peripheral surface of the outer mold frame and the outer peripheral surface of the inner mold frame. It can arrange | position in the state which held the holding | maintenance material reliably.

  The tunnel gate form of the present invention and the tunnel gate construction method using this form can be used in various terrain, and the installation work is simple, and the construction period and construction cost can be reduced. Can do.

Hereinafter, embodiments of a tunnel gate form of the present invention and a tunnel gate construction method using the form will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory front view of a bamboo split type tunnel tunnel form (hereinafter also simply referred to as a tunnel form) according to an embodiment of the present invention. This formwork F for the gate is an inner mold 2 having a surface formed in a curved shape along the inner peripheral surface of the tunnel gate 1 and a surface formed in a curved shape along the outer peripheral surface of the tunnel gate 1. And an inner mold 2 and a wife mold (not shown) that closes the tunnel entrance opening portion of the outer mold 3 and the inner mold 2 and the outer mold A plurality of thickness holding members 20 for supporting the outer mold 3 are disposed between the outer frame 3 and the outer frame 3.

  In FIG. 1, the outer mold frame 3 includes side portions 3 s corresponding to the left and right (left and right in FIG. 1) side surfaces of the tunnel gate 1 and a top portion (crown) corresponding to the top surface (ceiling surface) of the tunnel gate 1. Part) 3t and connected in an arch shape. The concrete forming the tunnel pit 1 is joined to the invert 4 embedded in the lower portion of the road surface R to form a substantially horseshoe-shaped structure. On the other hand, the inner formwork 2 is called a centle used when placing lining concrete inside the tunnel. This inner formwork 2 is arranged in the longitudinal direction of the tunnel by a dedicated carriage (moving scaffold). It is movable. The inner formwork (centre) 2 includes a top portion 2t corresponding to the top surface of the inner peripheral surface of the tunnel gate, and side portions 2s corresponding to side surfaces on both sides in the tunnel circumferential direction of the top surface, and the side of the top portion 2t. The portion 2 s is coupled with the hinge 10. When the centle used for tunnel lining is used as the inner mold 2 for tunnel tunnel construction, the time required for assembling the inner mold 2 can be shortened and the cost for the mold can be reduced.

  2 and 3 are an explanatory side view and an explanatory plan view of the outer mold 3, respectively. The outer mold 3 is divided into a plurality of (seven in this example) outer mold sub-units 3A, 3B divided in the direction of the tunnel (the left-right direction in FIG. 2, the up-down direction in FIG. 3) 3C, 3D, 3E, 3F, and 3G are connected in the direction of the tunnel. Outer formwork small units 3A to 3G, outer formwork small units 3A to 3E arranged on the tunnel side have side portions 3s and top portions 3t, respectively, which are connected to form an arch shape. ing. The remaining outer formwork small units 3F and 3G each consist only of side portions 3s. Each of the outer mold small units 3A to 3E is an assembly in which a support 5 having an arch shape as a whole and a linear through beam 6 arranged horizontally are vertically and horizontally assembled. 3F and 3G are assemblies in which a support 5 having a part of the arch shape (base portion) and a straight through beam 6 arranged horizontally are vertically and horizontally assembled. Is made of H-section steel. The lower end portion of the support 5 can be fixed to the invert 4 (see FIG. 1) by an anchor bolt (not shown). Further, a stopper 7 is attached to the lowermost through beam 6, and this and the invert 4 can be fixed to each other via a so-called separator (not shown). A steel plate 8 having a shape corresponding to the shape of the bamboo split type pit is attached to the inner surface side of the outer mold small units 3A to 3G.

  4A is a side view showing a state in which the supporting work 5 and the through beam 6 are assembled in the side portion 3s of the outer formwork small units 3A to 3E, and FIG. 4B is a front view thereof. . There are a pair of left and right side portions 3s. On the other hand, (a) of FIG. 5 is a front view showing a state in which the supporting work 5 and the through beam 6 are assembled at the top 3t of the outer formwork small units 3A to 3E, and (b) is a plan view thereof. It is. Each of the outer formwork small units 3A to 3E is obtained by connecting the supporting work 5 divided into the side portion 3s and the top portion 3t in an arch shape.

As shown in FIG. 1, the feature of the present invention is that the winding thickness holding member 20 is disposed between the inner mold frame 2 and the outer mold frame 3 and concrete is placed in the mold frame. That is, the outer mold 3 is arranged so as to suppress deformation and to secure a predetermined winding thickness. Hereinafter, this point will be described in detail.
FIG. 6 (a) is a front explanatory view of the portal formwork showing the magnitude of the bending moment of the outer formwork (without the roll thickness retaining material) due to the lateral pressure of the concrete placed in the wellwork formwork. (B) is the front explanatory drawing of a mine formwork which shows the magnitude of displacement similarly. As apparent from FIG. 6, bending stress inward toward the tunnel inward is generally generated at the top 3t or the crown of the outer mold 3 and the value is maximum at the center of the tunnel. Further, a bending stress is generated on the side 3 s of the outer mold 3 substantially toward the outside of the tunnel. In addition to bending stress, compressive stress and tensile stress act on the outer mold 3, and the top 3 t or the crown of the outer mold 3 is generally displaced inward of the tunnel mainly corresponding to the bending stress. In addition, generally, the side 3s of the outer mold 3 is displaced outwardly of the tunnel. In the present specification, the “bending stress toward the inside of the tunnel” is a bending stress that causes the corresponding member (in the present invention, the outer mold frame) to protrude toward the inside of the tunnel. The “bending stress toward the direction” refers to a bending stress that causes a member corresponding to the opposite (in the present invention, the outer mold frame) to protrude outward from the tunnel.

  FIG. 7 shows the magnitude of the bending moment of the outer mold frame when the thickness holding member 20 reinforces a total of three locations near the center and both ends of the outer mold frame portion where bending stress inward toward the tunnel in FIG. 6 occurs. It is a front explanatory drawing of a mine formwork, and (b) is a front explanatory view of a mine formwork showing the magnitude of displacement similarly. As can be seen from FIG. 7, in order to support the outer mold part that generates bending stress toward the inside of the tunnel, the roll thickness holding member 20 is disposed between the inner mold 2 and the outer mold 3 to thereby provide concrete. Is distributed to the inner mold 2 and the invert 4, that is, the concrete side pressure is supported by the inner mold 2 and the invert 4, so that the displacement of the outer mold 3 can be greatly reduced. When a centle used for tunnel lining as in this embodiment is used as the inner mold, the outer mold part that generates bending stress toward the inside of the tunnel has side portions at both ends via hinges 10. Since it substantially corresponds to the top 2t of the centle to which 2s is connected, the winding thickness holding member 20 may be disposed on the top 2t of the centle.

  For example, as shown in FIG. 3, the winding thickness holding member 20 can be disposed along the support 5 or the through beam 6, and at the center portion of the tunnel, the right and left of the tunnel center line along the tunnel direction. It can be arranged in a staggered pattern. In FIG. 3, reference numeral 30 denotes an auxiliary support that is disposed between the inner mold frame 2 and the outer mold frame 3 outside the region where the concrete is placed, and suppresses deformation of the outer mold frame 3. .

  FIG. 8 is an explanatory front view of an example of the thickness holding member 20 in the present invention. FIG. 9 is an explanatory front view of the outer frame side piece of the thickness holding member 20 shown in FIG. 8, and FIG. 10 is an explanatory front view of the inner frame side piece. The winding thickness holding member 20 includes a shaft portion 21 whose length can be adjusted, and spacer blocks 22 and 23 fixed to both ends of the shaft portion, so that the spacer block 22 is positioned on the outer mold frame 3 side. In addition, it is disposed between the inner mold 2 and the outer mold 3. The shaft portion 21 is composed of a lower shaft portion 21a made of a deformed reinforcing bar and an upper shaft portion 21b made of a high tension bolt, and a female screw portion 21c is provided at one end (upper end in FIG. 8) of the lower shaft portion 21a. A high tension bolt constituting the upper shaft portion 21b is screwed into the female screw portion 21c. By adjusting the screwing amount, the axial length of the shaft portion 21, that is, the winding thickness holding member 20, can be easily adjusted. And the winding thickness holding | maintenance material 20 can be arrange | positioned in the state stretched reliably between the inner peripheral surface of the outer mold frame 3, and the outer peripheral surface of the inner mold frame 2. In FIG. 8, reference numeral 25 denotes a fixing high tension nut that prevents the lower shaft portion 21a and the upper shaft portion 21b from rotating relative to each other after the length adjustment.

  In the thickness holding member 20 of this example, a rectangular support plate 24 made of a steel plate is disposed between both ends of the shaft portion 21 and the spacer blocks 22 and 23. The end face of the shaft portion 21 and the support plate 24, and the support plate 24 and the spacer blocks 22 and 23 are fixed to each other with an adhesive. Instead of fixing with an adhesive, for example, the end surface of the shaft portion 21 and the support plate 24 may be fixed by welding, and the support plate 24 and the spacer blocks 22 and 23 are included in the spacer blocks 22 and 23. Alternatively, a block body having a female thread portion may be embedded, and a round hole may be formed in the support plate 24, and the support plate 24 may be fixed to the spacer blocks 22 and 23 using bolts.

  The outer periphery of the spacer block 22 and the outer periphery of the lower shaft portion 21a are provided with a seal portion 26 for water stop, and the seal portion 26 is made of a material that can absorb moisture and expand. By providing such a seal portion 26, even if rainwater or the like enters from the boundary between the tunnel pit 1 and the spacer block 22, it is possible to effectively prevent the rainwater or the like from leaking into the tunnel.

  The spacer blocks 22 and 23 are made with high strength, and a taper surface 27 for preventing the spacer block 27 is formed at the end of the spacer block 23 arranged on the inner mold frame 2 side. The tapered surface 27 can be formed by chamfering four corners of the spacer block 23 having a rectangular cross section. With the tapered surface 27, the spacer block 23 has a tapered tip (lower end side in FIG. 8). In other words, the cross-sectional area of the tip portion is smaller than the cross-sectional area of the root portion (see FIG. 11). The winding thickness retaining material 20 remains embedded in the concrete constituting the tunnel gate 1, but such a tapered surface 27 is provided on the spacer block 23 disposed on the inner peripheral surface side of the tunnel gate 1. By forming, it can prevent reliably that the said spacer block 23 falls in a tunnel. The spacer block 23 can be prevented from coming off by forming a protrusion on the side surface of the spacer block 23. In addition, the spacer block 23 itself can be tapered, for example, like a truncated cone, so that it can be prevented from coming off.

Construction of the tunnel mine using the mine formwork can be performed as follows, for example. First, an inner mold having a curved surface formed along the inner peripheral surface of the tunnel mine is placed at the tunnel entrance. At that time, when a centle used for tunnel lining is used as the inner mold, the time required for assembling the inner mold can be shortened and the cost for the mold can be reduced. Next, the outer mold is disposed at the tunnel entrance so as to cover the outer circumference of the inner mold with an outer mold having a curved surface along the outer circumference of the tunnel gate.
Next, a tunnel thickness holding material for supporting the outer mold frame between the inner mold frame and the outer mold frame while closing a tunnel entrance / exit side opening portion of the inner mold frame and the outer mold frame with a wife mold frame. Is disposed at the above-described predetermined position (a position where deformation of the outer mold can be suppressed and a predetermined winding thickness can be secured). As a result, when concrete is placed in the mold, the thickness holding material functions as a tension bar to prevent the outer mold part from being deformed (displaced) downward.

It is front explanatory drawing of one embodiment of the form for tunnel tunnels of this invention. It is side surface explanatory drawing of the outer formwork in the tunnel mine formwork shown by FIG. It is a plane explanatory view of the outer formwork in the tunnel gate formwork shown in FIG. (A) is the side view which shows the state which assembled the support and the through beam in the side part of the outer-form-frame small unit of the outer-form form shown by FIGS. 2-3, (b) is the front view. is there. (A) is a front view which shows the state which assembled the support and the through beam in the top part of the outer-form-frame small unit of the outer-form frame shown by FIGS. 2-3, (b) is the top view. . (A) is front explanatory drawing of a formwork which shows the magnitude | size of the bending moment (without a thickness holding material) of an outer formwork resulting from the side pressure of the concrete cast in the formwork, (b) is the same. It is front explanatory drawing of a formwork which shows the magnitude | size of a displacement. (A) is front explanatory drawing of a formwork which shows the magnitude | size (with a thickness holding material) of the bending moment of an outer formwork resulting from the side pressure of the concrete cast in the formwork, (b) It is front explanatory drawing of a formwork which shows the magnitude | size of a displacement. It is front explanatory drawing of an example of the winding thickness holding | maintenance material in this invention. It is front explanatory drawing of the outer-form-frame side piece of the thickness holding | maintenance material shown by FIG. It is front explanatory drawing of the inner mold side piece of the winding thickness holding | maintenance material shown by FIG. (A) is the sectional view on the AA line of FIG. 10, (b) is the sectional view on the BB line similarly. It is explanatory drawing of the reinforcement method of the conventional outer formwork using a pipe support. It is explanatory drawing of the reinforcement method of the conventional outer formwork using a separator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel mine 2 Inner formwork 3 Outer formwork 4 Invert 5 Support work 6 Through beam 10 Hinge 20 Winding thickness holding material 21 Shaft part 22, 23 Spacer block 27 Tapered surface

Claims (3)

An inner mold frame having a surface formed in a curved shape along the inner peripheral surface of the tunnel gate, an outer mold frame having a surface formed in a curved shape along the outer peripheral surface of the tunnel tunnel, and the inner mold frame, A tunnel tunnel formwork comprising a wife formwork that closes a tunnel entrance side open part of the outer formwork,
A thickness holding material for supporting the outer mold frame is disposed between the inner mold frame and the outer mold frame,
This winding thickness holding material is installed between the inner mold frame and the outer mold frame, and when concrete is placed in the mold frame, the deformation of the outer mold frame is suppressed and a predetermined winding thickness is secured. Arranged , and
The winding thickness holding member includes a shaft portion whose length can be adjusted, and a spacer block fixed to both ends of the shaft portion, and is disposed on the inner peripheral surface side of the tunnel gate of both spacer blocks. A tunnel gate form, wherein the spacer block is formed with a taper surface for retaining . The inner mold is a centle used for tunnel lining, and the centle has a top corresponding to the top surface of the inner peripheral surface of the tunnel pit, and side portions corresponding to side surfaces on both sides in the tunnel circumferential direction of the top surface. 2. The tunnel tunnel form according to claim 1, wherein the top part and the side part are coupled by a hinge, and the thickness holding member is disposed on the top part of the centle. A step of disposing an inner formwork having a curved surface along the inner peripheral surface of the tunnel gate at the tunnel wellhead;
A step of disposing the outer formwork at the tunnel well opening so as to cover the outer form side of the inner formwork with an outer formwork having a curved surface formed along the outer peripheral surface of the tunnel gate;
A step of closing a tunnel entrance / exit side opening portion of the inner mold frame and the outer mold frame with a wife mold frame, and a winding thickness holding material for supporting the outer mold frame between the inner mold frame and the outer mold frame Including a step of arranging,
The winding thickness holding material is installed between the inner mold frame and the outer mold frame, and when concrete is placed in the mold frame, the deformation of the outer mold frame is suppressed and a predetermined winding thickness is secured. and arranged to, and
The winding thickness holding member includes a shaft portion whose length can be adjusted, and a spacer block fixed to both ends of the shaft portion, and is disposed on the inner peripheral surface side of the tunnel gate of both spacer blocks. the spacer blocks, have been tapered surface for retaining formation method of constructing of tunnel gate, wherein Rukoto.

Images