JP2012077471A - Joint structure of precast members and concrete precast members - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint structure of precast members capable of solving structural and constructional problems associated with the joint part of the precast members, being simple structure, enabling rapid connection and reinforcement work and transmitting bending moment between connected precast members and to provide a concrete precast member provided with the structure.SOLUTION: The joint structure of precast members of the present invention is formed in such a manner that an end plate is disposed on each of joint end surfaces of the precast members facing each other at a joint part, the end plate being fixed to a reinforcing bar inside the precast member and being provided with one or two or more bolt insertion holes, and the end plates facing each other at the joint part are butted each other and are fixed to each other with bolts inserted in the bolt insertion holes, resulting in the precast members connected to each other.

Description

  The present invention relates to a “precast member joint structure” that connects two or more precast members, and a “concrete precast member” provided with this joint structure, and more specifically, a bending moment generated in one member. The present invention relates to a “precast member joint structure” that can be transmitted to the other member, and a “concrete precast member” having this joint structure.

  Various structures such as bridge superstructures and substructures, tunnel linings, dams, retaining walls, and buildings and other buildings are constructed of reinforced concrete. These reinforced concrete structures are usually completed by assembling reinforcing bars at the construction site, installing a formwork, placing concrete, demolding after curing.

  However, in this method of placing concrete on site (hereinafter referred to as “on-site concrete method”), if concrete curing is included, it will take several months to complete the structure. For this reason, this on-site concrete method is not suitable when it is desired to shorten the construction period, such as bridge replacement work in service, disaster recovery work, or work that needs to reduce the impact on subsequent processes.

  Therefore, when it is desired to shorten the construction period, that is, when it is necessary to perform rapid construction, precast concrete members are often used. This “precast” means that a concrete member is manufactured in advance in a place such as a factory or a manufacturing yard (including a construction site), and the member manufactured by precast is called a “precast member”. If precast members are used, only the assembly work needs to be performed at the construction site, and the period for reinforcing bars, formwork, concrete placement, and the concrete curing period can be omitted. Construction can be completed rapidly.

  On the other hand, since a precast member is accompanied by public road transportation from a production place to a construction site, it cannot be a very large member. Therefore, in many cases, one structure is completed by combining a plurality of precast members. For example, in the case of a bridge slab, the divided pieces of the slab are used as precast members, and these precast members are arranged in the direction of the bridge axis (or the direction perpendicular to the bridge axis), and the precast members are connected to each other to complete the entire floor slab. Yes. In addition, segmented precast members are used for segments used in shield methods for urban tunnels, precast plates for earth retaining used for deep earth retaining works, and box culverts with large cross sections.

  When combining a plurality of precast members, the precast member and the precast member are connected to each other. The portion where the precast members are connected is a so-called “joint portion”, and this joint portion has two major problems. One is a structural problem and the other is a construction problem.

  The structure receives various loads such as its own weight, an overload, an earth pressure, and an impact, and as a result, a cross-sectional force (axial force, shear force, bending moment) is generated in the members constituting the structure. If the member is constructed as an integral structure (for example, by a cast-in-place concrete method), the entire member bears a load, and the cross-sectional force does not concentrate at an arbitrary location. On the other hand, when one member is constructed by connecting precast members, there is a structural problem that the joint portion becomes a structural weak point and shear force and bending moment are concentrated.

  The precast member has a great feature of enabling rapid construction, but if the connecting work at the joint portion takes time, the effect of rapid construction is reduced accordingly. However, in the joint portion of the conventional precast member, in order to compensate for the structural problems described above, the steel wire and the steel rod are tensioned to give tension, or adjacent precast members are fixed with a special jig. Various “reinforcement work” has been performed, such as placing concrete or mortar in the joint. As a result, there was a problem that rapid construction, which is a major feature of the precast member, was not fully utilized.

  Therefore, a technique for reducing the labor of connecting work at the joint part as in Patent Document 1 and a technique for allowing a bending moment to be transmitted at the joint part as in Patent Document 2 have been proposed.

JP 2009-41227 A JP 2003-147726 A

  In the joint structure of the precast floor slab according to Patent Document 1, the joint plates 14 fixed to the joint end surface 1a of the precast floor slab 1 are faced to each other and joined with bolts 15, and the concrete reinforcing plate 17 is placed on the joint portion 10. Thus, the grout material 19 is filled in the recessed portion 12 provided under the concrete reinforcing plate 17.

  With the above structure, the connecting operation of the joint portion according to Patent Document 1 is performed by joining with the bolt 15, placing the concrete reinforcing plate 17, and filling with the grout material 19, which requires complicated labor. do not do. Furthermore, since the construction vehicle can pass over the concrete reinforcing plate 17 during the curing period until the grout material 19 is hardened, the entire process is not significantly affected. Thus, patent document 1 is going to solve the construction problem with which the joint part of a precast member is equipped.

  However, the joint structure of the precast floor slab according to Patent Document 1 does not solve the structural problem of the joint part of the precast member. Only the shearing force is transmitted and the bending moment is not transmitted at the joint portion by the bolt 15 in this joint structure. The bending stress generated by the bending moment is absorbed by the concrete reinforcing plate 17. In order for the concrete reinforcing plate 17 to absorb bending stress, it is necessary that the precast floor slab and the concrete reinforcing plate 17 be integrated, and the adhesive strength of the adhesive 18 is extremely important. Further, the joint portion of the precast member, and hence the entire structure (the bridge slab), depends on the bending rigidity of the concrete reinforcing plate 17.

  The construction method of the composite floor slab shown by patent document 2 clamps the joint plates 13 with the volt | bolt 9, and the joint part by this method can transmit a bending moment. However, the method of Patent Document 2 relates to a joint portion of a composite floor slab of a cast-in-place concrete method, and is not a method of connecting joint portions of a precast member. That is, since there are extremely few restrictions in the field work, there is also a degree of freedom in tightening the bolt 9 on the field (concrete can be placed after tightening), and the means for fixing the joint plate 13 to the steel shell is also selected for field welding. be able to. As described above, Patent Document 2 does not attempt to solve the construction problem of the joint portion of the precast member, that is, how quickly the precast member that is a finished product is connected. .

  The object of the present invention is to solve the structural problem and construction problem of the joint part of the precast member, the structure is simple and the rapid construction of the connecting work is possible, and between the precast members to be connected An object is to provide a joint structure of a precast member capable of transmitting a bending moment, and to provide a concrete precast member having the structure.

  The invention of the present application focuses on the fact that the bending moment is reliably transmitted between the members by connecting the precast members with a very simple operation of fixing the end plates by bolts and fixing the end plates to the reinforcing bars inside the members. It was made.

  In the joint structure of the precast member according to the present invention, in the joint part structure in which two or more concrete precast members are connected, an end plate is disposed on each joint end face of the precast member facing the joint part, and the end The plate is fixed to a reinforcing bar inside the precast member, and each end plate is provided with one or more bolt insertion holes, and the end plates facing each other at the joint are abutted with each other. By fixing with the inserted bolt, the precast members are connected to each other.

  The joint structure of the precast member according to the present invention may be a structure in which a box opening portion that forms a space in which a bolt fixing operation can be performed is provided around the bolt insertion hole of the end plate of the precast member. In this case, it is also possible to have a structure in which the boxing portions of the connected precast members are filled with a reinforcing material.

  In the joint structure of the precast member of the present invention, a part of the end plate protrudes outward in the thickness direction of the precast member, and a bolt insertion hole is provided in the protruding portion of the end plate, and the protruding portion of the end plate It can also be set as the structure which fixes the said end plates which oppose in a coupling part with the volt | bolt inserted in the provided bolt insertion hole.

  The concrete precast member of the present invention is a concrete precast member used by connecting two or more, and is disposed on a joint end face facing another connected precast member and fixed to a reinforcing bar in the member A plate is provided, and the end plate is provided with one or more bolt insertion holes into which connection bolts can be inserted.

  The concrete precast member of the present invention may be provided with a box opening portion that forms a space in which a bolt fixing operation can be performed around the bolt insertion hole peripheral portion of the end plate.

  In the concrete precast member of the present invention, a part of the end plate protrudes outward in the thickness direction of the precast member, and a bolt insertion hole is provided in the protruding portion of the end plate.

The joint structure of the precast member of the present invention has the following effects.
(1) Since the adjacent precast members can be connected simply by joining the opposing end plates at the joint with bolts, the connecting operation can be performed easily and quickly.
(2) Since the end plate is fixed to the reinforcing bar inside the precast member, it is possible to reliably transmit the bending moment between the members to be connected, and to avoid the joint from becoming a structural weak point. Can do.
(3) If a box opening portion is provided in the periphery of the bolt insertion hole of the end plate in the precast member, the bolt fixing operation can be performed in the precast member.
(4) If the structure is such that the bolt is fixed at the end plate portion that protrudes outward in the thickness direction of the precast member, the bolt fixing operation is facilitated, and the connecting operation is performed on one side of the precast member (the side on which the end plate does not protrude). Since there are no restrictions, you can work freely.

The concrete precast member of the present invention has the following effects.
(1) It is a precast member provided with the effect which the joint structure of said precast member has.
(2) Since the means for fixing the end plate to the reinforcing bar can adopt conventionally used means (for example, welding, etc.), it has various advantageous effects as compared with the prior art, such as the construction labor being remarkably improved. Nevertheless, the manufacturing cost is not much different from the conventional one.

The partial perspective view which shows the state by which the precast member which is a floor slab of a bridge | bridging has been arrange | positioned on the main girder. The fragmentary sectional view which shows the state by which the precast members were connected. The top view which shows the state by which the precast members were connected. The perspective view which shows the state by which the precast members were connected. (A) is a partial cross-sectional view of the joint when no boxing portion is provided, (b) is a partial cross-sectional view of the joint when the boxing portion is filled with a reinforcing material, and (c) is provided with a fitting plate. The partial sectional view of the joint part at the time of filling a reinforcing material in the box opening part, (d) is the partial sectional view of the joint part when installing a fitting plate and not filling the reinforcing material in the box opening part. (A) is a model figure for demonstrating the bending moment which arises in a joint part, (b) is a model figure for demonstrating the bending shear force which arises in a joint part. (A) is a partial cross-sectional view when only one bolt (per section) is installed near the neutral shaft, and (b) is one bolt (per section) installed in the bolt insertion hole provided in the plate protrusion. (C) is a partial cross-sectional view when bolts are installed at two locations (per cross-section) near the neutral shaft and the plate protrusion. The arrangement | positioning top view in the case of connecting three precast members in one joint part.

[Embodiment]
Embodiments of a joint structure of a precast member and a concrete precast member according to the present invention will be described with reference to the drawings. The present invention has a structure in which an end plate is disposed in a portion (hereinafter referred to as “joint portion”) that becomes a joint when the precast members are connected, and the end plates are connected to each other. Specifically, the end plates are arranged on the surfaces where the precast members are opposed to each other in the joint portion, and the precast members are connected to each other by bolting the end plates facing each other. This end plate is fixed to the end of a reinforcing bar arranged inside the concrete precast member. As used herein, “precast” refers to the production of concrete members in advance in places such as factories and production yards (including construction sites). It is called a “member”. Further, “made of concrete” described here is a concept that means that the member is made of concrete having a reinforcing bar in the member, and naturally includes RC (Reinforced Concrete) and PC (Pressed Concrete).

  FIG. 1 is a partial perspective view showing a state in which a precast member 1 is disposed on a main girder 2 as a floor slab of a bridge. This embodiment demonstrates the case where the precast member 1 is utilized for the floor slab of a bridge as an example. As shown in FIG. 1, when a bridge floor slab is constructed with a precast member 1, a plurality of precast members 1 made of concrete are arranged on a main girder 2 (partially five in the figure), and adjacent precast members 1 are adjacent to each other. And the precast member 1 is fixed to the main beam 2. Normally, the main girder 2 is arranged so as to extend in the bridge axis direction. Therefore, in FIG. 1, the precast members 1 are arranged in the bridge axis direction and connected in the bridge axis direction. In addition, the precast members 1 may be arranged in the direction perpendicular to the bridge axis and connected in the direction perpendicular to the bridge axis.

  As shown in FIG. 1, a precast member 1 used as a bridge floor slab has a rectangular plate shape in plan view, and is manufactured in advance in a factory or a manufacturing yard in the same manner as in the past. The manufacturing method is substantially the same as that in the prior art. Necessary reinforcing bars are arranged in a predetermined formwork, concrete having a predetermined strength is placed, sufficiently cured, and then removed from the mold. What is different from the prior art is that an end plate 12 is arranged on a surface (hereinafter referred to as “joint end surface 11”) of the precast member 1 connected to another precast member 1, and the end plate 12 is arranged inside. It is a point fixed to the reinforcing bar 13.

  FIG. 2 is a partial cross-sectional view showing a state where the precast member 1a and the precast member 1b are connected, and FIG. 3 is a plan view thereof. As shown in FIGS. 2 and 3, the precast member 1a and the precast member 1b are connected to each other with their joint end faces 11 being abutted against each other. Moreover, as shown in FIG. 2, the end plate 12 is arrange | positioned at the joint end surface 11 of each of the precast member 1a and the precast member 1b. The end plate 12 has a plate shape, and one side of the end plate 12 is in contact with the joint end surface 11. The material of the end plate 12 is desirably a material having a relatively resistance to bending stress, and can be made of, for example, steel.

  As shown in FIG. 2, the end plate 12 is fixed to the end portion of the reinforcing bar 13 arranged inside the precast member 1. The purpose of fixing here is to reliably transmit the bending moment borne by the reinforcing bar 13 to the end plate 12 after use. Therefore, if the bending moment can be transmitted, the fixing means for the end plate 12 and the reinforcing bar 13 (the end thereof) can be arbitrarily selected. For example, the end of the reinforcing bar 13 is welded to the end plate 12. Various means such as stud welding, means for welding the nut 4 to the end plate 12, and fixing the reinforcing bar 13 to the nut can be selected. Note that the reinforcing bars 13 for fixing the end plate 12 are arranged so as to be substantially orthogonal (including orthogonal) to the joint end surface 11 and do not designate the main reinforcing bar or the distribution bar. The precast member 1 is a plate, and even if it is a power distribution rod, it may bear a bending moment. Therefore, the power distribution rod and the end plate 12 are connected as necessary, that is, according to the connection direction of the precast member 1. Alternatively, the main muscle and the end plate 12 are connected.

  The connection between the precast member 1a and the precast member 1b is performed by abutting (superimposing) the end plates 12 provided on the joint end surfaces 11 and joining them with the bolts 3. Therefore, the end plate 12 is provided with a bolt insertion hole (not shown) for inserting the bolt 3. Naturally, when the joint end surface 11 of the precast member 1a and the joint end surface 11 of the precast member 1b are abutted, that is, when the end plate 12 of the precast member 1a and the end plate 12 of the precast member 1b are abutted, both bolts The insertion holes coincide and the bolt 3 can be passed therethrough.

  In FIG. 2, two bolt insertion holes are provided in the width direction of the end plate 12 (the thickness direction of the precast member 1, and the vertical direction in FIG. 2), but only one bolt insertion hole is provided in the width direction. It can be provided, or can be provided at three or more locations, and can be appropriately designed according to the thickness of the precast member 1. Similarly, in FIG. 3, four bolt insertion holes are provided in the longitudinal direction of the end plate 12 (the width direction of the precast member 1 and the vertical direction in FIG. 3), but the longitudinal direction is also one or three. It can be set as above, and can be appropriately designed according to the member width of the precast member 1. Further, as shown in FIG. 3, the end plate 12 can be arranged with “one piece” continuous on the joint end face 11, or only intermittently at the place where the bolt 3 is arranged (for example, at four places in FIG. 3). It can also be arranged).

  FIG. 4 is a perspective view showing a state in which the precast member 1a and the precast member 1b are connected. As shown in this figure, the precast member 1 can be provided with a box opening 14. This box opening portion 14 is a peripheral portion of a bolt insertion hole provided in the end plate 12 and is provided on the back side of the end plate 12 (the member main body side of the end plate 12) to fix (join) the bolt 3. The space necessary for work is provided. When the bolt insertion hole is outside the precast member 1 and the bolt 3 can be joined (for example, as shown in FIGS. 5A and 7B), the box opening portion is not necessarily provided. 14 need not be provided.

  Since the joining operation of the bolt 3 (that is, the fastening operation of the bolt 3 and the nut 4) is performed in the space of the box opening portion 14, a part of the box opening portion 14 (upward in FIG. 4) is opened. By providing this open portion (hereinafter referred to as “opening”), it is possible to bring a hand or a jig (tool) to the vicinity of the bolt 3 or the nut 4, so that the bolt 3 can be joined. It becomes extremely easy.

  Since the box opening part 14 does not contribute to the strength of the precast member 1, it is desirable to make it as small as possible, and a partition wall 15 is formed between the box opening part 14 and the box opening part 14 as shown in FIG. It is preferable that the box opening 14 be provided independently (not continuously) around only the periphery of the bolt 3. If the opening part of the box opening part 14 is small, the box opening part 14 can be left hollow even after the precast member 1 is connected. However, as shown in FIG. It can also be filled with a reinforcing material. For this reinforcing material, a non-shrinkable material that exhibits appropriate strength after curing, has a high curing rate, and has a small shrinkage ratio after curing, such as a non-shrinkable material reinforced with short fibers. And ultrafast hard mortar. The reinforcing material filled in the box opening portion 14 is preferable because it can contribute to the compressive force.

  As shown in FIG. 4, the opening of the box opening part 14 and the upper surface of the partition wall 15 can be formed with a slightly depressed height (slightly lower in FIG. 4) than the main body surface of the precast member 1. In this case, in the joint portion of the precast member 1a and the precast member 1b, there is a slightly depressed concave portion (hereinafter referred to as “recessed portion”), but the fitting plate 16 (FIG. 5C) that fits into this recessed portion. (D)) can be installed. Or the level | step difference of a recessed part can also be eliminated by driving continuously the reinforcing material with which the box opening part 14 is filled. The box opening portion 14 in which the fitting plate 16 is installed may be filled with a reinforcing material (FIG. 5C), or the reinforcing material may be left as it is without being filled (FIG. 5). (D)). For example, when temporarily tentatively lining, the state shown in FIG. 5D (the state in which the reinforcing material is not filled) is temporarily changed to the state in FIG. 5C (the state in which the reinforcing material is filled). It can be selected as appropriate according to the conditions.

  In FIG. 4, the opening of the boxing part 14 is provided on the upper surface side of the precast member 1, but the present invention is not limited thereto, and the opening of the boxing part 14 may be provided on the lower surface side of the precast member 1. However, in this case, a formwork for filling the reinforcing material in the box opening portion 14 is required, but the workability is slightly inferior, but on the upper surface side of the precast member 1, it is affected by the joining work of the bolts 3 and the like. There is an effect that it can work efficiently.

  In the present invention, a bending moment generated in one connected precast member 1 (for example, precast member 1a, FIG. 4) is transmitted to the other precast member 1 (for example, precast member 1b, FIG. 4). In a concrete member that generates a bending moment, such as a bridge deck, the reinforcing bars 13 in the member mainly bear the bending moment. That is, in order to transmit the bending moment between the precast members 1, it is effective to transmit the bending moment borne by the reinforcing bars 13. Therefore, in this invention, it was set as the structure which connects the reinforcing bar 13 and the end plate 12. FIG.

  On the other hand, even if the bending moment borne by the reinforcing bar 13 of the precast member 1a can be transmitted to the end plate 12 of the precast member 1a, the bending moment between the members is not transmitted unless the bending moment is transmitted to the end plate 12 of the precast member 1b. Is not transmitted. That is, the bending moment is not transmitted between the precast members 1 in a structure in which both end plates 12 are separated (opened) in response to the bending moment. Therefore, both the end plate 12 of the precast member 1a and the precast member 1b are fastened by the bolt 3 and the nut 4.

  6A and 6B are model diagrams for explaining the cross-sectional force generated in the joint portion between the precast members 1. FIG. 6A is a bending moment of the cross-sectional force, and FIG. 6B is a shear of the cross-sectional force. It explains the power. Generally, when a vertically downward load acts predominately like a bridge deck, the bending moment that attempts to bend the center of the span downward (hereinafter referred to as “positive bending M (+)”). And the bending moment (hereinafter referred to as “negative bending M (−)”) that attempts to bend the center portion of the span upward decreases. In FIG. 6A, the positive bend M (+) is indicated by a solid line, and the negative bend M (−) is indicated by a broken line. When forward bending M (+) occurs in the joint, as shown in FIG. 6A, the upper part of the member becomes a compression region and the lower part of the member becomes a tensile region with the neutral shaft as a boundary. That is, the tensile force P acts on the lower rebar 13 of FIG. 6A, and both end plates 12 try to be separated downward.

  When the end plate 12 is opened, the bending moment is not transmitted accordingly, so that both the end plates 12 behave in the same manner, that is, the two bolts 3 are kept in contact with each other. And a tightening force (bolt axial force N) by the nut 4 is given. In other words, since the bolt axial force N is against the bending moment generated in the joint, the installation position is important as well as the magnitude of the bolt axial force N, and the position away from the neutral shaft on the tension side. It is more effective to install in If it demonstrates in Fig.6 (a), when it opposes the positive bending M (+), the direction which installed the volt | bolt 3 below the neutral axis | shaft is more effective than the neutral axis when it opposes the negative bending M (-). Also, it is more effective to install the bolt 3 on the upper side. Moreover, if the state which both the end plates 12 contacted is maintained, when a bending compressive force will arise, this can be reliably transmitted between members. It should be noted that the bending moment can be counteracted by the end plate 12 itself in a region further on the tension side than the position where the bolt 3 is installed. Therefore, as described above, it is desirable that the material of the end plate 12 is relatively resistant to bending stress.

  As described above, it is desirable that the installation position of the bolt 3 be as far as possible from the neutral shaft (FIG. 6A). However, regarding the installation position, various conditions, bending strength of the end plate 12, and the like are comprehensive. Design accordingly. In general, in the case of a bridge deck, the positive bend M (+) is large and the negative bend M (−) is small for the reasons described above. For example, the bolt 3 that opposes the positive bend M (+) is separated from the neutral axis. For example, the bolt 3 that opposes the negative bend M (−) can be designed flexibly according to the situation, for example, without being separated from the neutral shaft.

  Further, for example, in a joint portion where a small bending moment (denoted as negative bending M (−) in FIG. 6A) is known to act in advance, as shown in FIG. Only one bolt 3 (per section) can be installed in the vicinity. On the other hand, in a joint portion where a large bending moment (the positive bending M (+) in FIG. 6A) acts, a part of the end plate 12 is attached to the precast member 1 as shown in FIG. Only one bolt 3 (per section) can be installed in the bolt insertion hole provided in the protruding portion (hereinafter referred to as “plate protruding portion”) by protruding outward in the thickness direction. Alternatively, in the joint portion where both the positive bending M (+) that is a large bending moment and the negative bending M (−) that is a small bending moment are applied, as shown in FIG. Bolts 3 can be installed at two locations (per section) of the protrusion.

  If the end plate 12 protrudes outward in the thickness direction of the precast member 1 and the bolt 3 is installed on the plate protruding portion, it is advantageous in terms of structure because it is far from the neutral axis, but even after the bridge is completed, the end plate 12 A part, bolt 3, etc. are exposed. It is also possible to project the end plate 12 to both outer sides of the precast member 1 in the thickness direction, that is, to provide plate projections on both sides of the precast member 1 and to join the bolts 3 respectively. In the case of a bridge floor slab, if there are plate protrusions on both sides of the precast member 1, it becomes an obstacle after use, but may be adopted when used as another member such as a precast plate for earth retaining.

(Example of use)
The usage example of the precast member 1 used as a bridge floor slab is demonstrated below.
The concrete precast member 1 is manufactured at the factory. Specifically, it is as follows.
Necessary reinforcing bars 13 are arranged in a predetermined formwork, an end plate 12 is arranged so as to be positioned on the joint end face 11, and the end of the reinforcing bar 13 is fixed to the end plate 12 by stud welding. The end plate 12 is provided with a predetermined number of bolt insertion holes in a predetermined position in advance. Next, a box opening work is performed in the mold so that a predetermined position and a predetermined number of box opening portions 14 are formed. Finally, concrete having a predetermined strength is placed in the mold, sufficiently cured, and then demolded to complete the concrete precast member 1. The steps up to here are repeated a predetermined number of times to produce the required number of precast members 1 made of concrete.
As described above, the required number of precast members 1 manufactured are placed on a transport vehicle and shipped from the factory.
The main girder 2 is constructed at the site, and the precast members 1 are arranged on the main girder 2. Adjacent precast 1 members are both connected at the joint. Specifically, it is as follows.
The positions of the precast members 1 are adjusted while aligning the joint insertion end faces 11, which are adjacent surfaces of the precast members 1, that is, the end plates 12, and aligning both bolt insertion holes. The bolt 3 is inserted into the bolt insertion hole by inserting a hand from the opening of the box opening portion 14, and the bolt 3 and the nut 4 are temporarily tightened in the space of the box opening portion 14. Next, a tool or the like is put into the box removing portion 14 from the opening, and the bolt 3 and the nut 4 are finally tightened. When all the bolts 3 have been joined, the box opening portion 14 is filled with non-shrinkable ultrafast mortar reinforced with short fibers (or non-shrinkable ultrafast hard mortar containing no short fibers) and the like. Carry out period curing. During curing, it is preferable that the fitting plate 16 is installed in the recess formed in the joint portion so that the vehicle or the like can pass. On the other hand, in the case of temporary lining, the filling of the reinforcing material into the box opening portion 14 may be omitted simply by installing the fitting plate 16 in the recess formed in the joint portion.

[Other Embodiments]
The joint structure of the precast member and the concrete precast member according to the present invention are not limited to the case where the two precast members 1 are abutted and connected to each other, but as shown in FIG. In FIG. 8, it can be used even when connecting 1a, 1b, and 3c). Even in this case, the arrangement of the end plate 12, the fixing of the end plate 12 and the reinforcing bar 13, the installation position of the bolt 3, the installation of the box unloading part 14, whether or not the reinforcing material is filled, or the effect of these structures This is the same as the above-described [Embodiment].

  The joint structure of the precast member of the present invention and the precast member made of concrete are not limited to the split precast member of the bridge floor slab, the segment used in the shield method of the city tunnel, the precast plate for earth retaining used for deep earth retaining work, Alternatively, it can be applied to a box culvert with a large cross section.

DESCRIPTION OF SYMBOLS 1 Precast member 1a One precast member connected 1b The other precast member connected 2 Main girder 3 Bolt 4 Nut 11 Joint end surface 12 End plate 13 Reinforcement 14 Box extraction part 15 Bulkhead 16 Fitting plate N Bolt axial force P Tensile force

Claims (7)

In the structure of the joint where two or more concrete precast members are connected,
An end plate is disposed on each joint end surface of the precast member facing the joint portion,
The end plate is fixed to a reinforcing bar inside the precast member, and each end plate is provided with one or more bolt insertion holes,
A joint structure of precast members, wherein the end plates facing each other at the joint portion are abutted with each other and fixed by bolts inserted into the bolt insertion holes. In the joint structure of the precast member according to claim 1,
A joint structure for a precast member, wherein a box opening portion for forming a space in which a bolt can be fixed is provided around a bolt insertion hole of an end plate of the precast member. In the joint structure of the precast member according to claim 2,
A joint structure for a precast member, wherein the box opening portions of the connected precast members are filled with a reinforcing material. In the joint structure of the precast member according to any one of claims 1 to 3,
A part of the end plate protrudes outward in the thickness direction of the precast member, and a bolt insertion hole is provided in the protruding portion of the end plate,
A joint structure for a precast member, wherein the end plates facing each other at a joint portion are fixed with bolts inserted into bolt insertion holes provided in protruding portions of the end plates. In a concrete precast member used by connecting two or more,
An end plate disposed on the joint end face facing the other precast member to be connected, and fixed to the reinforcing bar in the member;
A concrete precast member, wherein the end plate is provided with one or more bolt insertion holes into which connection bolts can be inserted. In the concrete precast member according to claim 5,
A concrete precast member characterized in that a box opening portion for forming a space in which a bolt can be fixed is provided around a bolt insertion hole in an end plate. In the concrete precast member according to claim 5 or 6,
A concrete precast member characterized in that a part of the end plate protrudes outward in the thickness direction of the precast member, and a bolt insertion hole is provided in a protruding portion of the end plate.

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