JP2011089390A - Rigid connection structure of corner section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rigid connection structure of a corner section, which stably resists a load even when a partial load is applied. <P>SOLUTION: The rigid connection structure of the corner section 1A includes the upper end of each of vertical wall sections 11 provided on both sides in the width direction, and a form member 4 made of precast concrete laid between the upper ends of the vertical wall sections 11. The vertical wall section 11 includes a hook reinforcement 29 at the upper end. The form member 4 integrally includes an upper reinforcement 23 resisting to a bending moment M1 generated at the corner section 1A. One end of the upper reinforcement 23 is embedded in the form member 4, and the upper reinforcement 23 is engaged with length reinforcements 30 arranged in the hook reinforcement 29. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a rigid connection structure at a corner that is constructed by combining a precast concrete member and a cast-in-place concrete and can be used for a box culvert or a bridge.

As a concrete structure such as a box culvert or bridge using a rigid structure at the corner, it is constructed by on-site construction by placing a formwork on the site, and a precast product formed in a box shape is assembled on-site Some are constructed by combining precast members and cast-in-place concrete.

As an assembly structure constructed by combining the precast member and the cast-in-place concrete, a side wall member made of precast concrete that is provided on both sides in the width direction and integrally has a self-supporting leg at the lower part, and spanned between the upper parts of these side wall members. A precast concrete formwork member, and a concrete assembly structure comprising a top plate part comprising the formwork member and a cast concrete part formed by placing concrete on the formwork member are disclosed. (For example, Patent Document 1). Patent Document 1 describes a concrete assembly structure including a diagonal reinforcing bar that passes through the side wall member and the cast concrete portion. According to the said structure, a concrete assembly structure exhibits the outstanding effect that a side wall member and a top plate part can be firmly integrated by providing a diagonal reinforcement.

JP 2005-61127 A

However, even in the above-described Patent Document 1, when the top plate lower rebar, the side wall inner rebar and the oblique rebar are not sufficiently fixed, when an uneven load due to an earthquake or unequal subsidence acts, There was concern that the load could not be stably resisted.

In view of the above problems, an object of the present invention is to provide a rigid connection structure of a corner portion that can stably resist a load even when an unbalanced load is applied.

In order to achieve the above object, the invention according to claim 1 is characterized in that an upper end of a vertical wall portion provided on both sides in the width direction, and a precast concrete formwork member spanned between the upper end portions of the vertical wall portion, The vertical wall portion includes a hook bar protruding in a U-shape at the upper end, and the formwork member is integrally formed with an upper reinforcing bar that resists a bending moment generated at the corner portion. The upper reinforcing bar is engaged with a length reinforcing bar arranged in the hook bar.

The invention according to claim 2 is characterized in that, in claim 1, the formwork member is integrally provided with truss reinforcing bars continuous in the width direction.

The invention according to claim 3 is characterized in that, in claim 2, the truss reinforcing bar is formed longer than the length in the width direction of the formwork member.

The invention according to claim 4 is characterized in that, in claim 1 or 2, the mold member is provided with a PC steel material extending in the width direction.

Moreover, the invention which concerns on Claim 5 of the corner | angular part which has the upper end of the vertical wall part provided in the width direction both sides, and the precast concrete formwork member spanned between the upper end parts of this vertical wall part In the rigid structure, the vertical wall portion includes a hook bar protruding in a U-shape at an upper end, an upper reinforcing bar engaged with a length reinforcing bar arranged in the hook bar, and a side of the formwork member The reinforcing bar provided at the end is provided.

The invention according to claim 6 is characterized in that, in claim 5, the reinforcing reinforcing bar includes a retaining portion.

Moreover, the invention which concerns on Claim 7 is a corner | angular part which has the upper end of the vertical wall part provided in the width direction both sides, and the formwork member made from a precast concrete spanned between the upper end parts of this vertical wall part. In the rigid structure, the vertical wall portion includes a hook bar protruding in a U-shape at the upper end, and an upper reinforcing bar engaged with a length reinforcing bar arranged in the hook bar, and protruding to the mold member A truss reinforcing bar provided, wherein the truss reinforcing bar is formed to be longer than the length in the width direction of the formwork member.

According to the rigid connection structure of the corner portion according to claim 1 of the present invention, by engaging the upper reinforcing bar with the length reinforcing bar arranged in the hook reinforcing bar, the top plate part lower reinforcing bar, the side wall part Since the inner reinforcing bar and the oblique reinforcing bar can be sufficiently fixed, even when the fixing uneven load is applied, the load can be stably resisted.

Moreover, according to the rigid connection structure of the corner part of Claim 2, a shear deformation | transformation can be reliably prevented by aiming at integration of a formwork member and a placement concrete part.

Further, according to the rigid connection structure of the corner portion according to the third aspect, the corner portion can be more reliably rigidly connected.

Moreover, according to the rigid connection structure of the corner part of Claim 4, the deformation | transformation by a bending moment can be prevented by providing PC steel material extended in the width direction, and workability | operativity can be improved.

Moreover, according to the rigid connection structure of the corner part of Claim 5, even if it does not necessarily provide an upper rebar integrally with a formwork member, it can resist a load stably.

Moreover, according to the rigid structure of the corner part of Claim 6, even if it is a case where a bending moment arises, a rigid connection state can be hold | maintained reliably.

Moreover, according to the rigid connection structure of the corner | angular part of Claim 7, since a corner | angular part can be rigidly connected reliably, a reinforcing bar can be abbreviate | omitted.

It is a longitudinal cross-sectional view which shows the whole structure of the structure provided with the rigid connection structure of the corner | angular part which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the rigid connection structure of a corner part same as the above. It is a longitudinal cross-sectional view which shows arrangement | positioning of the reinforcing bar in a formwork member same as the above. It is a top view of a formwork member same as the above. It is a longitudinal cross-sectional view of a formwork member same as the above. It is sectional drawing which shows a modification as same as the above. It is sectional drawing which shows the rigid connection structure of the corner | angular part which concerns on the 2nd Embodiment of this invention. It is a top view of a formwork member same as the above. It is sectional drawing which shows a modification as same as the above. It is a top view which shows the modification of a formwork member same as the above.

(1) First Embodiment A preferred first embodiment of the present invention will be described below with reference to the drawings. A concrete assembly structure 1 (hereinafter, “structure 1”) shown in FIG. 1 includes a pair of left and right precast concrete side wall members 2 provided in the width direction, and a top plate portion 3 provided on the side wall member 2. The side wall member 2 and the top plate portion 3 are coupled to each other at a corner portion 1A formed at a coupling portion between the upper end of the side wall member 2 and the side end of the top plate portion 3. The top plate portion 3 includes a precast concrete formwork member 4 that is stretched over the side wall member 2, and a cast concrete portion 5 that is formed by placing concrete on the formwork member 4. Consists of.

The side wall member 2 includes a vertical wall portion 11 and a lateral self-standing leg portion 12 provided integrally with a lower portion of the vertical wall portion 11. On the upper surface 13 of the vertical wall portion 11, a placement portion 4W at the end in the width direction of the mold member 4 is placed, and the vertical wall portion 11 has an inner surface side corresponding to the placement portion 4W described above. The overhang receiving portion 14 is provided in a protruding manner.

The mold member 4 is a flat plate having a substantially constant thickness, has a shape of a substantially rectangular plane that is long in the width direction of the structure 1 and short in the length direction of the structure 1. Is provided with a lower step portion 15, and the lower step portion 15 is engaged and placed on the upper surface 13.

The bottom slab portion 16 provided between the free-standing leg portions 12 on both sides in the width direction is formed of spot cast concrete or the like.

In addition, as shown in FIG. 2, a plurality of embedded reinforcing bars 21 in the length direction are provided in the mold member 4 in a line in the width direction, and longitudinal connecting bars 22 are provided in the longitudinal direction on these embedded reinforcing bars 21. Arranged at equal intervals, the upper portions of the connecting reinforcing bars 22 project upward from the upper surface of the mold member 4, and the upper reinforcing bars 23 in the longitudinal direction are coupled to the upper portions of the connecting reinforcing bars 22.

The vertical wall portion 11 is provided with oblique reinforcing bars 24 that are reinforcing bars in an oblique direction. The oblique reinforcing bar 24 includes an inclined portion 25 having an angle of about 45 degrees with respect to the horizontal direction, and a vertical portion 26 that is formed continuously with the inclined portion 25 and extends in the vertical direction. The inclined portion 25 is embedded in the vertical wall portion 11 so that the vertical portion 26 protrudes from the vertical wall portion 11. A fixing tool 27 is integrally provided at the upper end of the vertical portion 26. The fixing tool 27 is provided with a fixing plate having an area larger than the cross-sectional area of the reinforcing bar and a nut screwed to the reinforcing bar, thereby preventing the vertical wall portion 11, the formwork member 4, and the top plate portion from contacting each other. Can be improved.

A plurality of vertical reinforcing bars are embedded in the vertical wall portion 11, and the upper part of the vertical reinforcing bar 28 protrudes from the upper surface 13 of the vertical wall portion 11 on the inner side in the width direction, and is fixed to the upper end of the vertical reinforcing bar 28. A tool 27 is provided integrally. Further, a hook bar 29 which is a vertical reinforcing bar is provided on the outer side in the width direction of the vertical wall portion 11. The hook bars 29 are formed such that the upper part is folded back in a substantially U shape and protrudes above the upper surface 13, and both ends are embedded in the side wall member 2.

The end 23C of the upper rebar 23 extends to the upper position of the vertical rebar 28, and further, a curved downward large bending portion 23A is formed from the upper position to the outside of the hook rebar 29, and this large bending portion 23A A small curved portion 23B substantially equal to the curvature of the upper portion of the hook reinforcing bar 29 is formed at the end, and an end 23C of the upper reinforcing bar 23 extends from the small curved portion 23B to the position of the vertical reinforcing bar 28. 23C is embedded in the mold member 4. Thus, the upper rebar 23 is folded back at the upper position of the hook rebar 29, and the end 23C is embedded in the mold member 4, so that the upper rebar 23 is provided integrally with the mold member 4. The large bending portion 23A, the small bending portion 23B, and the end portion 23C are formed by bending the end portions of the reinforcing bars constituting the upper rebar 23. The large curved portion 23A is approximately a quarter arc (a quarter of a circle), and the small curved portion 23B is also approximately a quarter arc. As described above, the rigid connection structure of the corner portion 1A includes the hook rebar 29 provided on the vertical wall portion 11 and the upper rebar 23 provided integrally with the mold member 4 via the length rebar 30. By coupling, it is possible to reliably resist the bending moment M1 shown in FIG.

Further, the length reinforcing bars 30 are arranged in the hook bars 29 above the upper surface 13. The length reinforcing bar 30 arranged on the upper side and the inner side of the hook bar 29 is connected to the hook bar 29, and the length reinforcing bar 30A arranged on the outer side is connected to the hook bar 29 and the small curved portion 23B side, and the lower side. The length reinforcing bars 30B arranged in the are connected to the end 23C side. Note that this connection can be performed by binding with a binding tool such as a wire or welding.

In addition, the mold member 4 is integrally provided with a truss reinforcing bar 45 that is a framework structure continuous in the width direction of the mold member 4. The truss reinforcing bar 45 uses a reinforcing bar as a string member, and lower chord members 47 are arranged on both lower sides of the upper chord member 46. The chord members 46 and 47 are located at the apexes of the triangles and are connected diagonal members 48 on both sides. Are connected together. This connecting diagonal member 48 is bent and formed into a triangular wave shape in which the upper and lower vertices are alternately formed in the length direction, the upper vertex is welded to the upper chord material 46 by resistance spot welding, and the lower vertex is the lower chord. It is welded to the material 47 by resistance spot welding. The lower chord material 47 is embedded in the mold member 4 and the upper part is exposed at the upper part of the mold member 4, and the truss reinforcing bar 45 is provided integrally with the mold member 4. Further, the mold member 4 is provided with an insertion hole 17 through which the vertical portion 26 of the oblique reinforcing bar 24 is inserted.

Further, as shown in FIG. 3, the formwork member 4 is provided with a PC steel material 51 extending in the length direction of the formwork member 4. An insertion hole (not shown) for inserting the PC steel material 51 is drilled in the mold member 4 in advance, and after the PC steel material 51 inserted into the insertion hole is tensioned and fixed, the PC steel material 51 and the insertion hole The grout is filled in between. Thus, the mold member 4 can reliably resist the bending moment M2 shown in FIG. 1 and prevent deformation.

As shown in FIG. 4, a plurality of PC steel materials 51 are arranged in parallel in the width direction of the mold member 4, and two in this drawing. One end of the PC steel material 51 provided with the support plate 52 is embedded in the mold member 4, the other end is exposed to the stepped portion 53 provided in the mold member 4, and the nut 54 is screwed together with the support plate 52. It is configured to be more nervous. In the present embodiment, one of the two PC steel members 51 is configured so that the left end is embedded in the mold member 4 and the right end is exposed from a stepped portion 53 provided in the mold member 4 in plan view. Has been. Further, the other of the two PC steel members 51 is configured so that the right end is embedded in the mold member 4 and the left end is exposed from a stepped portion 53 provided at the left end of the mold member 4 in plan view. Has been.

As shown in FIG. 5, the stepped portion 53 is formed so that a nut 54 can be screwed onto the other end of the PC steel material 51 from the surface side of the mold member 4.

Next, the construction method of the structure 1 will be described. First, the side wall members 2 are arranged on the left and right according to the width of the structure 1, and further, the side wall members 2 are continuously arranged in the length direction of the structure 1. Since the side wall member 2 has a self-supporting leg portion 12, if the site is leveled flat or set to a place finished with abandoned concrete or the like, the side wall member 2 becomes stable and independent by itself.

Next, the mold member 4 is spanned between the upper portions of the side wall members 2 on both sides, and the mold members 4 are arranged without gaps in the length direction of the structure 1. In this case, the oblique reinforcing bar 24 is provided by embedding the inclined portion 25 in the vertical wall portion 11 so that the portion protruding from the vertical wall portion 11 becomes the vertical portion 26 extending in the vertical direction. Can be easily placed on the side wall member 2 by simply lowering. The formwork member 4 provided with the truss rebars 45 is relatively light and can be easily lifted and installed, and has a stable structure even when the structure 1 is wide. It can be used for scaffolding and formwork when placing concrete. In addition, when the span between the side wall members 2 is large, you may make it support the middle of the formwork member 4 by construction support bodies (not shown), such as a support work, until the placement concrete part 5 hardens | cures. .

Using the formwork member 4 as a scaffold, the placing concrete portion 5 is laid, and the small bending portion 23B, the hook reinforcement 29, and the length reinforcement 30 of the upper reinforcement 23 are connected as described above. Further, in the mold members 4 arranged in the length direction, the upper rebar 23 is connected by a rebar 55 in the length direction that is arranged on site. Moreover, the length reinforcement 30 is also provided over the some formwork member 4 arranged in the length direction, and the adjacent formwork members 4 are integrated. Further, before placing the concrete of the cast concrete part 5, the formwork material of the cast concrete part 5 is provided on the outer periphery of the side wall member 2, and when the concrete of the cast concrete part 5 is hardened, the side wall member Remove from 2.

After completing the bar placement work stably using the mold member 4 in this way, the cast-in-place concrete is cast on the mold member 4 and the upper surface 13 to form the cast concrete portion 5. A truss reinforcing bar 45 is embedded and fixed in the cast concrete portion 5 to obtain a top plate portion 3 in which the cast concrete portion 5 and the formwork member 4 are integrated. Further, by embedding the corner portion 1A in which the end portion 23C of the upper rebar 23 provided integrally with the formwork member 4 is connected to the length rebar 30 through the hook rebar 29 in the placing concrete portion 5, Rigid connection at the corner 1A of the structure 1 is achieved. Further, if necessary, the bottom plate portion 16 is formed of cast-in-place concrete, and the structure 1 can be filled or buried to form a box culvert.

As described above, the present invention rigidly connects the upper end of the vertical wall portion 11 provided on both sides in the width direction and the side end of the precast concrete formwork member 4 spanned between the upper end portions of the vertical wall portion 11. In the rigid connection structure of the corner portion 1A to be connected, the vertical wall portion 11 is provided with a hook bar 29 at the upper end, and the mold member 4 has an upper reinforcing bar 23 that resists a bending moment M1 generated at the corner portion 1A. Provided integrally, the end portion 23c of the upper rebar 23 is embedded in the mold member 4, and the upper rebar 23 is engaged with a length rebar 30 arranged in the hook rebar 29. As a result, the end portion 23C of the upper rebar 23 as the lower rebar of the top plate portion 3 and the vertical rebar 28 and the oblique rebar 24 of the vertical wall portion 11 can be sufficiently fixed. However, it can stably resist the load.

The formwork member 4 is integrally provided with a truss rebar 45 that is continuous in the width direction, and the truss rebar 45 is formed by integrating the formwork member 4 and the placing concrete portion 5. Shear deformation between 4 and the cast concrete part 5 can be reliably prevented.

Further, since the PC member 51 extending in the width direction is provided on the formwork member 4, deformation due to the bending moment M2 can be prevented and workability can be improved.

Further, as shown in FIG. 6, the truss reinforcing bar 45 may be formed so as to be longer than the width direction length of the structure 1 of the mold member 4 so that the end portions 45A protrude from the mold member 4 at both ends. . That is, the truss reinforcing bar 45 is integrally provided on the mold member 4 with both ends projecting from the mold member 4. Thus, in the rigid structure according to the present embodiment, the truss reinforcing bar 45 is formed to be longer than the length in the width direction of the formwork member 4, so that the formwork member 4 and the cast concrete part 5 are more firmly formed. Can be integrated.
(2) Second Embodiment Next, a second embodiment of the present invention will be described. As shown in FIG. 7, the rigid structure according to the present embodiment is such that the upper rebar 23 is provided separately from the formwork member 4, and the reinforcing rebar 61 is provided at the side end of the formwork member 4. This is different from the first embodiment. The reinforcing reinforcing bar 61 is formed in an L shape and is arranged so as to extend in the length direction of the mold member 4. One end extending in the horizontal direction is embedded in the mold member 4, and the other end extending in the vertical direction is the mold. It protrudes from the side end of the frame member 4 and constitutes a retaining portion 61A. In this way, the reinforcing reinforcing bar 61 is secured to the effective fixing length by bending the other end in the vertical direction to form the retaining portion 61A.

Further, as shown in FIG. 8, a plurality of PC steel materials 51 provided on the mold member 4 are arranged in parallel in the width direction of the mold member 51, and four in this figure. One end of the PC steel material 51 provided with the support plate 65 is embedded in the mold member 4, and the other end is exposed to the step portion 66 provided at the side end of the mold member 4, and the nut 67 is screwed together with the support plate 65. It is configured to be tense when worn. In the present embodiment, two of the four PC steel members 51 on the outer side are shown from a step 66 provided with the left end embedded in the mold member 4 and the right end provided on the right end of the mold member 4 in plan view. It is configured to issue. In addition, two of the four PC steel members 51 are exposed from a step portion 66 provided with a right end embedded in the mold member 4 and a left end provided on the left end of the mold member 4 in plan view. It is configured.

As described above, in the rigid connection structure according to the present embodiment, by providing the reinforcing reinforcing bars 61, the upper reinforcing bars 23 can be firmly rigidly connected without necessarily being provided integrally with the mold member 4. Moreover, since the reinforcing reinforcing bar 61 is provided with the retaining portion 61A, even if a bending moment is generated, the rigid reinforcing state can be reliably maintained. Further, since the reinforcing reinforcing bar 61 is formed by bending the other end in the vertical direction to form the retaining portion 61A, the effective fixing length is secured, so that it is possible to reliably prevent the reinforcing steel bar 61 from coming off.

As another embodiment, as shown in FIG. 9, instead of the reinforcing reinforcing bars 61, the truss reinforcing bars 45 may be formed longer than the length in the width direction of the mold member 4. By doing so, the corner portion 1A can be securely bonded by the truss reinforcing bar 45 protruding from the formwork member 4, so that the reinforcing reinforcing bar 61 can be omitted.

The present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, in the present embodiment, the corner portion of the box culvert has been described. However, the present invention is not limited to this, and the present invention can also be applied to corner portions such as bridges and building beams.

In the present embodiment, the side wall member is made of precast concrete. However, the present invention is not limited to this, and the vertical wall member may be formed of cast-in-place concrete.

Further, in the present embodiment, the case where the PC steel material 51 is tensioned by a post-tension method in which grout is filled between the PC steel material 51 and the insertion hole after the PC steel material 51 has been tensioned and fixed in advance has been described, but the present invention is not limited thereto. As shown in FIG. 10, it is good also as tensioning by a pretension system.

1A Corner part 3 Top plate part 4 Formwork member
11 Vertical wall
13 Top (top)
23 Upper rebar
23c End (one end)
29 Hook muscle
30,30A, 30B rebar
45 truss rebar
51 PC steel
61 Reinforcing bar
61A Retaining part
M1 bending moment

Claims (7)

The upper end of the vertical wall provided on both sides in the width direction;
In the rigid connection structure of the corner portion having a precast concrete formwork member spanned between the upper end portions of the vertical wall portion,
The vertical wall portion includes a hook line protruding in a U shape at the upper end,
The formwork member is integrally provided with an upper reinforcing bar that resists a bending moment generated in a corner portion,
A rigid structure of a corner portion, wherein the upper reinforcing bar is engaged with a length reinforcing bar arranged in the hook reinforcing bar. The rigid structure of a corner portion according to claim 1, wherein the mold member is integrally provided with truss reinforcing bars that are continuous in the width direction. The rigid structure of a corner portion according to claim 2, wherein the truss reinforcing bar is formed longer than the length in the width direction of the mold member. The rigid structure of a corner portion according to claim 1 or 2, wherein a PC steel material extending in the width direction is provided on the mold member. The upper end of the vertical wall provided on both sides in the width direction;
In the rigid connection structure of the corner portion having a precast concrete formwork member spanned between the upper end portions of the vertical wall portion,
The vertical wall portion includes a hook line protruding in a U shape at the upper end,
An upper rebar engaged with a length rebar arranged in the hook rebar,
A corner rigid connection structure comprising a reinforcing steel bar provided at a side end of the mold member. The rigid reinforcing structure for a corner portion according to claim 5, wherein the reinforcing reinforcing bar includes a retaining portion. The upper end of the vertical wall provided on both sides in the width direction;
In the rigid connection structure of the corner portion having a precast concrete formwork member spanned between the upper end portions of the vertical wall portion,
The vertical wall portion includes a hook line protruding in a U shape at the upper end,
An upper rebar engaged with a length rebar arranged in the hook rebar,
A truss rebar provided protruding from the formwork member,
The corner truss rigid connection structure characterized in that the truss reinforcing bars are formed longer than the length in the width direction of the formwork member.

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