JP2017101442A - Joining structure and joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining structure and a joining method capable of providing a culvert structure hardly causing opening of a joining part of two precast concrete members.SOLUTION: In a joining structure 100 for mutually joining two precast concrete members 110 and 120 in a culvert structure, one member 110 encloses a PC steel bar 112, and an end part 112a of the PC steel bar 112 projects toward the other member 120, and the other member 120 is provided with a through-hole 121 for penetrating an end part 112a of the PC steel bar 112, and the end part 112a of the PC steel bar 112 is provided with a nut 124 fastened while imparting tensioning force in the axial direction, an anchor plate 123 for pressing the other member 120 to the one member 110 by receiving reaction to the tensioning force from the nut 124 and mortar 125 injected between the through-hole 121 and the end part 112a of the PC steel bar 112.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a joining structure and joining method for joining two precast concrete members to each other in a culvert structure formed by combining a plurality of precast concrete members.

  2. Description of the Related Art Conventionally, a concrete culvert structure that is installed as a water channel, a common groove, or the like is known (see, for example, Patent Document 1). Among such culvert structures, there is a so-called prefabricated culvert structure in which a plurality of precast concrete members previously formed in a factory or the like are combined. By constructing the culvert structure with such a precast concrete member, the work at the site of installation work and the like is simplified, so that the construction period can be shortened.

JP 2005-336710 A

  Here, in the two precast concrete members joined to each other in the prefabricated culvert structure as described above, the load in the direction to open the joint portion of the two may repeatedly act after the field installation of the culvert structure. is there. In such a case, there exists a possibility that the junction part of two precast concrete members may open with load.

  The present invention aims to solve this problem. That is, an object of the present invention is to provide a joining structure and a joining method capable of obtaining a culvert structure in which a joint between two precast concrete members is hardly opened.

  In order to achieve the above object, a joint structure according to the present invention is a joint structure in which two precast concrete members are joined to each other in a culvert structure constituted by combining a plurality of precast concrete members. Among the concrete members, one member incorporates a steel fixing bar and an end of the fixing bar protrudes toward the other member, and the other member includes the end of the fixing bar. A fastening member that is fastened while applying an axial tension to the end of the fixing bar, and a side opposite to the one member in the through hole. A pressing member that is interposed between an edge and the fastening member and receives the reaction force against the tension force from the fastening member to press the other member against the one member; It is characterized by comprising, a filler that is injected between the end portion of the fixing rod and serial through-hole.

  In the joining structure of the present invention, the fastening member is fastened to the end portion of the fixing bar that protrudes from one member and penetrates the through hole of the other member with a pressing member interposed therebetween. Two precast concrete members are joined by injecting a filler between the ends. At this time, according to the joining structure of the present invention, a tension force is applied to the end portion of the fixing rod in the axial direction, and the pressing member receives the reaction member against the tension force from the fastening member, so that the pressing member holds the other member in one direction. Is pressed against the member. Since the pressing force by the pressing member acts as a resistance force against a load that opens the joint between the two precast concrete members, the joint is difficult to open. As described above, according to the joint structure of the present invention, it is possible to obtain a culvert structure in which the joint between the two precast concrete members does not easily open.

  In the joining structure of the present invention, the one member is a standing wall, and the end portion of the fixing bar protrudes from an upper end edge of the standing wall, and the other member is the upper end of the standing wall. It is also preferred that the top plate is disposed on the edge, and the through hole is provided in a portion overlapping the upper end edge so as to penetrate in the thickness direction of the top plate.

  According to this preferred joining structure, it is possible to assemble two precast concrete members simply by placing the other member as the top plate on the upper end edge of one member as the standing wall. Thereby, about the assembly of a precast concrete member, since the operation | work at an installation site is simplified, it can aim at shortening of a construction period and cost reduction.

  Further, in the joining structure of the present invention, an injection port for injecting the filler into the through hole, and a discharge port for overflowing the excess filler after filling the through hole. However, it is also preferable that the other member is provided so as to be connected to the through hole and at least partially deviated from the pressing position by the pressing member.

  According to this preferred joining structure, the filler can be easily injected from the inlet, and the filling of the inside of the through hole can be completed by observing that the filler has overflowed from the outlet. Can be confirmed. Thereby, about the injection | pouring operation | work of a filler, since the operation | work in an installation site is simplified, it can aim at shortening of a construction period and cost reduction.

  Further, in the joining structure of the present invention, the periphery of the opposite edge of the through hole is a recessed portion that is recessed from the outer surface of the other member, and the through hole opens at the bottom of the recessed portion. It is also preferable that the pressing member and the fastening member are accommodated in the recess, and the recess is filled with the filler so as to cover the pressing member and the fastening member.

  According to this preferable joining structure, since the pressing member and the fastening member are accommodated in the concave portion and filled with the filler, these members are protected by the filler, and the fastening strength is improved. In addition, according to a preferred joining structure, a culvert structure having a good appearance can be obtained when the outer surface is smooth and exposed.

  In the joining structure of the present invention, the through-hole has a shape in which at least a part thereof is narrowed from the opposite edge toward the one member in the depth direction. Is also suitable.

  According to this preferable joining structure, the filler filled in the through hole having the narrowed shape as described above functions to resist a load that causes the joint between the two precast concrete members to open. . Thereby, according to this suitable junction structure, the above-mentioned junction part becomes still more difficult to open.

  In order to achieve the above object, the joining method of the present invention is a joining method in which two precast concrete members are joined to each other in a culvert structure formed by combining a plurality of precast concrete members. Of the two precast concrete members, one member incorporates a steel fixing bar and the end of the fixing bar protrudes toward the other member, and the other member includes the fixing bar. An assembling step of combining the two precast concrete members so that the end of the fixing bar passes through the through-hole, and the one of the through-holes is provided in the through-hole. A pressing member that presses the other member against the one member is interposed between the opposite edge of the member and penetrates the through hole. The fastening member is fastened to the end portion of the fixing bar, while applying an axial tension force, and the other member is received by receiving a reaction force against the tension force from the fastening member. A prestressing step of pressing the one member; and an injection step of injecting a filler between the through hole and the end of the fixing rod.

  According to the joining method of the present invention, the tension force is applied in the axial direction to the end portion of the fixing bar by the prestressing process performed after the assembly process of combining the two precast concrete members. By receiving a reaction force against the tension force from the fastening member, the pressing member presses the other member to one member. Since this pressing force acts as a resistance force against a load that opens the joint between the two precast concrete members, the joint becomes difficult to open. As described above, according to the joining method of the present invention, it is possible to obtain a culvert structure in which the joint between the two precast concrete members is not easily opened.

  In addition, about the joining method of this invention, although only the basic form was described and the suitable form was omitted, each of the various suitable forms described about the joining structure of this invention mentioned above is joining of this invention. Needless to say, it also supports methods.

  According to the present invention, it is possible to obtain a culvert structure in which the opening of the joint between two precast concrete members hardly occurs.

It is a figure which shows an example of the culvert structure to which the junction structure which concerns on 1st-3rd embodiment of this invention is applied in common. It is the top view and sectional drawing which show the joining structure of 1st Embodiment of this invention. It is a perspective view which shows the joining structure shown by FIG. It is the top view and sectional drawing which show the junction structure of 2nd Embodiment of this invention. It is a perspective view which shows the joining structure shown by FIG. It is a figure which shows the junction structure of 3rd Embodiment of this invention in the cross section similar to FIG. 2 (B). It is a schematic diagram which shows the pattern of the verification experiment with respect to a connection structure. It is a figure which shows the connection structure of a 1st comparative example in the cross section similar to FIG. It is a figure which shows the connection structure of a 2nd comparative example with the cross section similar to FIG. Static connection to each of the connection structure of the third embodiment shown in FIG. 6, the connection structure of the first comparative example shown in FIG. 8, and the connection structure of the second comparative example shown in FIG. It is a graph which shows the test result of a simple bending load test. It is a schematic diagram which shows an example of the precast concrete member which makes the top plate of a bevel-shaped culvert structure.

  Hereinafter, first to third embodiments of the present invention will be described.

  FIG. 1 is a diagram showing an example of a culvert structure to which a joint structure according to first to third embodiments of the present invention is commonly applied. 1A shows a culvert structure 1 having a single box shape, and FIG. 1B shows a culvert structure 2 having a multi-span box shape.

  The culvert structure 1 in FIG. 1A is a so-called prefabricated culvert structure configured by combining a plurality of precast concrete members formed in advance in a factory, and includes a first precast concrete member 11; And a second precast concrete member 12.

  The first precast concrete member 11 in FIG. 1A is a standing wall that is erected on the installation site of the culvert structure 1, and is provided in two so as to be opposed to each other. The second precast concrete member 12 in FIG. 1 (A) is a rectangular slab-shaped top plate arranged so as to be bridged over the upper edge 11a of the pair of first precast concrete members 11. In the culvert structure 1 of FIG. 1 (A), the first precast concrete member 11 and the second precast concrete member 12 are combined with each other in this manner, and between the pair of first precast concrete members 11, The bottom wall 13 is formed by cast-in-place concrete, and is configured in a single box shape.

  The culvert structure 2 in FIG. 1B is also a prefabricated culvert structure, and includes a first precast concrete member 21 and a second precast concrete member 22.

  The first precast concrete member 21 in FIG. 1 (B) is a standing wall that is erected on the installation site of the culvert structure 2, and is provided so that three are arranged in parallel at a predetermined interval. Two second precast concrete members 22 are provided so as to be arranged over the upper edge 21a of each of the three first precast concrete members 21, and each is a top plate having a rectangular slab shape. ing. In the culvert structure 2 of FIG. 1 (B), the first precast concrete member 21 and the second precast concrete member 22 are combined with each other in this manner, and between the three first precast concrete members 21, A bottom wall 23 is formed by cast-in-place concrete, and is configured in a two-box multi-diameter shape.

  Here, both the first precast concrete member 11 in FIG. 1A and the first precast concrete member 21 in FIG. 1B are made of rod-like PC (Pressed Concrete) steel rods 11b and 21b. As a PC member or a PRC (Prestressed Reinforced Concrete) member.

  On the other hand, the second precast concrete member 12 in FIG. 1A and the second precast concrete member 22 in FIG. 1B are not specified here, but are RC (Reinforced Concrete) members, PC members, and RPC members. Any member may be used.

  From the upper end edges 11a and 21a of the first precast concrete member 11 in FIG. 1 (A) and the second precast concrete member 22 in FIG. 1 (B), the ends of a plurality of PC steel bars 11b and 21b are provided. Projecting toward each second precast concrete member 12,22. And in the part which overlaps with the upper end edges 11a and 21a in the 2nd precast concrete members 12 and 22, the through-holes 12a and 22a which the edge part of PC steel bar 11b and 21b penetrates are provided.

  In these culvert structures 1 and 2, the PC steel bars in which the first precast concrete members 11 and 21 and the second precast concrete members 12 and 22 are joined from the upper end edges 11 a and 21 a are both. This is performed by a joining structure described later using the ends of 11b and 21b.

  Hereinafter, the joining structure and joining method according to the first embodiment of the present invention applied to the culvert structures 1 and 2 of FIG. 1 will be described.

  FIG. 2 is a plan view and a cross-sectional view showing the joint structure of the first embodiment of the present invention. 2A shows a plan view of the bonding structure of the first embodiment, and FIG. 2B shows a cross-sectional view showing a V11-V11 cross section in FIG. 2A. ing. FIG. 3 is a perspective view showing the joining structure shown in FIG.

  The joint structure 100 of the present embodiment is a structure for joining two precast concrete members 110 and 120 to each other in a culvert structure as shown in FIG. In this joining structure 100, the first precast concrete member 110 as a standing wall is a PC member or a PRC member incorporating a plurality of PC steel bars 112 as fixing bars. And the edge part 112a of each PC steel rod 112 protrudes from the upper end edge 111 toward the 2nd precast concrete member 120 as a rectangular slab-shaped top plate. Further, the PC steel rod 112 of this embodiment is threaded at the protruding end 112a.

  In addition, as the PC steel bar 112, not only the end 112a but also a total thread PC steel bar that is threaded over the entire length may be adopted. Alternatively, instead of the PC steel bar 112, a reinforcing bar having a strength that can withstand the introduction of tension in the PC member or the PRC member may be used. Examples of such reinforcing bars include high-strength deformed reinforcing bars SD390, SD490, SD590, and SD685.

  The 2nd precast concrete member 120 is a top board arrange | positioned on the upper end edge 111 of the 1st precast concrete member 110 as a standing wall. And the through-hole 121 which penetrates in the thickness direction of a top plate and the edge part 112a of each PC steel rod 112 penetrates in the part which overlaps with the upper end edge 111 is provided.

  Here, in the present embodiment, the periphery of the edge of the through hole 121 opposite to the first precast concrete member 110 is a recess 122 that is recessed from the outer surface of the second precast concrete member 120. The recess 122 has an inverted quadrangular frustum shape, and a through hole 121 is opened in a rectangular bottom 122a.

  A tension force is applied in the axial direction to the end portion 112a of the PC steel rod 112 penetrating the through hole 121 as described later. Further, the end 112 a is passed through a through hole provided at the center of a rectangular plate-shaped anchor plate 123 that abuts the bottom 122 a of the recess 122 including the edge of the through hole 121. A nut 124 is fastened to the end 112 a that is passed through the anchor plate 123. Thus, in this embodiment, the nut 124 is fastened while applying an axial tension to the end 112a of the PC steel rod 112, and the anchor plate 123 is interposed between the bottom 122a of the recess 122 and the nut 124. However, the second precast concrete member 120 is pressed against the first precast concrete member 110 by receiving a reaction force against the tension force from the nut 124. The anchor plate 123, the nut 124, and the extra length portions of the end 112a are accommodated in the recess 122.

  Here, the tension may be applied to the end 112a of the PC steel rod 112 by pulling the end 112a passed through the through-hole 121 in the axial direction with a hydraulic jack or the like. A method of pulling in the axial direction by fastening with a predetermined tightening torque is employed.

  A mortar 125 as a filler is injected between the through hole 121 and the end 112a of the PC steel rod 112. As the mortar 125, non-shrink mortar is adopted. At this time, an inlet 126 for injecting the mortar 125 into the through hole 121 and an outlet for overflowing the excess mortar 125 after the inside of the through hole 121 is filled in the bottom 122a of the recess 122. 127 is connected to the through-hole 121 and is provided so as to be partly removed from the position pressed by the anchor plate 123.

  The inlet 126 and the outlet 127 are a pair of spaces that expand in a triangular wing shape on both sides of the edge of the through-hole 121, and a part of each rectangular opening that opens in the bottom 122 a of the recess 122 extends from the anchor plate 123. It is off. The mortar 125 is injected from the inlet 126 and is continuously injected until it overflows from the outlet 127. Thereby, the mortar 125 is filled between the through hole 121 and the end 112a of the PC steel rod 112. Furthermore, in this embodiment, the mortar 125 is also filled in the recess 122 so as to cover the extra length portions of the anchor plate 123, the nut 124, and the end 112 a of the PC steel rod 112. In FIG. 3, the illustration of the mortar 125 in the recess 122 is omitted to make the drawing easy to see.

  In the description here, of the pair of spaces that expand on both sides of the edge of the through-hole 121, the right side in the figure is called the inlet 126 and the left side is called the outlet 127 for convenience. Needless to say, any of these may be an inlet and any of them may be an outlet.

  Next, the connection method of the 1st and 2nd precast concrete members 110 and 120 by the connection structure 100 shown by FIG.2 and FIG.3 is demonstrated. This connection method described below corresponds to an embodiment of the connection method of the present invention.

  For example, in the installation site of the culvert structure as shown in FIG. 1, prior to the connection of the first and second precast concrete members 110 and 120 by this connection method, first, the first precast concrete member 110 as a standing wall is used. Are installed in a predetermined number, and a bottom wall is formed between them by cast-in-place concrete. Then, the connection of the 1st and 2nd precast concrete members 110 and 120 is performed by the connection method which has the procedure mentioned later.

  In addition, the installation procedure of such a culvert structure is not limited to the above. For example, after the first precast concrete member 110 serving as a standing wall is erected, the first and second precast concrete members 110 and 120 are installed. The installation procedure may be such that the bottom wall is formed by the cast-in-place concrete.

  In this connection method, first, an assembly process is performed in which the first and second precast concrete members 110 and 120 are combined so that the end 112a of the PC steel rod 112 passes through the through hole 121.

  Next, an anchor plate 123 is interposed between the edge of the through hole 121 and the nut 124 is fastened while applying tension in the axial direction to the end 112a of the PC steel rod 112 that has penetrated the through hole 121. A stress process is performed. In this prestressing process, the first precast concrete member 110 is pressed against the second precast concrete member 120 by causing the anchor plate 123 to receive a reaction force against the tension force from the nut 124. Further, as described above, in this embodiment, the tension is applied by fastening the nut 124 with a predetermined torque.

  And the injection | pouring process which inject | pours the mortar 125 between the through-hole 121 and the edge part 112a of the PC steel rod 112 is performed. In the present embodiment, first, the mortar 125 is injected from the injection port 126, and the injection is continued until the mortar 125 overflows from the discharge port 127. Furthermore, in this embodiment, the mortar 125 is also filled in the recess 122 so as to cover the extra length portions of the anchor plate 123, the nut 124, and the end 112 a of the PC steel rod 112.

  The connection is completed through a curing period until the injected mortar 125 is solidified, and a culvert structure as shown in FIG. 1 is completed.

  In the connection structure 100 according to the first embodiment described above, the anchor plate protrudes from the first precast concrete member 110 to the end 112a of the PC steel rod 112 that penetrates the through hole 121 of the second precast concrete member 120. The nut 124 is fastened with the 123 interposed therebetween, and the mortar 125 is injected between the through hole 121 and the end 112a of the PC steel rod 112, so that the two precast concrete members 110 and 120 are joined. . At this time, according to the joint structure 100 of the present embodiment, a tension force is applied to the end 112a of the PC steel rod 112 in the axial direction, and the anchor plate 123 is received by receiving a reaction force against the tension force from the nut 124. The second precast concrete member 120 is pressed against the first precast concrete member 110. Since the pressing force by the anchor plate 123 acts as a resistance force against a load that causes the joint between the two precast concrete members 110 and 120 to open, the joint becomes difficult to open. As described above, according to the joint structure 100 of the present embodiment, it is possible to obtain a culvert structure in which the joint between the two precast concrete members 110 and 120 is not easily opened.

  Moreover, in the connection structure 100 of 1st Embodiment, the edge part 112a of the PC steel rod 112 protrudes from the upper end edge 111 of the 1st precast concrete member 110 as a standing wall, and the 2nd precast concrete member 120 is It is a top plate arranged on the upper end edge 111, and a through hole 121 is provided through a portion overlapping the upper end edge 111 in the thickness direction of the top plate. For this reason, the two precast concrete members 110 and 120 can be assembled only by mounting the second precast concrete member 120 as the top plate on the first precast concrete member 110 as the standing wall. Thereby, about the assembly of the two precast concrete members 110 and 120, the work at the installation site is simplified, so that the construction period can be shortened and the cost can be reduced.

  Further, in the bonding structure 100 of the present embodiment, the inlet 126 for injecting the mortar 125 into the through hole 121 and the outlet for overflowing the surplus mortar 125 after the inside of the through hole 121 is filled. 127 is provided. For this reason, it is possible to easily inject the mortar 125 from the injection port 126 and confirm that the filling of the through hole 121 has been completed by observing that the mortar 125 has overflowed from the discharge port 127. Can do. Thereby, about the injection | pouring operation | work of the mortar 125, since the operation | work in an installation site is simplified, it can aim at shortening of a construction period and cost reduction.

  In the joint structure 100 of the present embodiment, the periphery of the edge of the through hole 121 is a recess 122 that is recessed from the outer surface of the second precast concrete member 120, and the through hole 121 is formed in the bottom 122 a of the recess 122. Is open. The anchor plate 123 and the nut 124 are housed and provided in the recess 122 together with the extra length of the end 112a. The recess 122 is filled with mortar 125 by covering the anchor plate 123 and the nut 124 together with the extra length of the end 112a. As a result, the anchor plate 123 and the nut 124 are accommodated in the recess 122 and filled with the mortar 125, so that the fastening portion by the nut 124 is protected by the mortar 125, and the fastening strength is improved. Further, according to the bonding structure 100 of the present embodiment, a culvert structure having a good appearance can be obtained when the outer surface is smooth and exposed.

  Moreover, according to the connection method of this embodiment mentioned above, the tension | tensile_strength is given to the edge part 112a of the PC steel rod 112 to the axial direction by the prestress process performed after the assembly process which combines the two precast concrete members 110 and 120. Is done. As described above, the joint between the two precast concrete members 110 and 120 is difficult to open due to this tension. As described above, according to the connection method of the present embodiment, a culvert structure in which the opening of the joint between the two precast concrete members 110 and 120 hardly occurs can be obtained.

  Further, in the connection method of the present embodiment, the nut 124 is fastened to the end 112a of the PC steel bar 112 with a predetermined tightening torque, so that tension is applied to the end 112a. According to the connection method of this embodiment, after assembling the two precast concrete members 110 and 120 at the installation site of the culvert structure, the anchor plate 123 is attached, the nut 124 is fastened, and the mortar 125 is simply injected. Both can be joined together. As a result, since the work on the installation site is simplified with respect to the joining work after the assembly of the two precast concrete members 110, 120, particularly in terms of imparting tension to the end 112a of the PC steel bar 112, the construction period Can be shortened and the cost can be reduced.

  Next, the joining structure and joining method of 2nd Embodiment of this invention are demonstrated. In the second embodiment, the structure around the edge of the through hole in the second precast concrete member as the top plate is different from the first embodiment described above. Hereinafter, the bonding structure and the bonding method of the second embodiment will be described by paying attention to differences from the first embodiment.

  FIG. 4 is a plan view and a cross-sectional view showing the joint structure of the second embodiment of the present invention. FIG. 4A shows a plan view of the joining structure of the second embodiment, and FIG. 4B shows a cross-sectional view showing a V21-V21 cross section in FIG. 4A. ing. FIG. 5 is a perspective view showing the joining structure shown in FIG. 4 and 5, the same components as those shown in FIGS. 2 and 3 described above are denoted by the same reference numerals as those in FIGS. 2 and 3. Omit duplicate descriptions of components.

  In the joint structure 200 of the second embodiment shown in FIGS. 4 and 5, the second precast concrete member 120 is not provided with a structure corresponding to the recess 122 in the joint structure 100 of the first embodiment. In the joint structure 200 of the second embodiment, the through hole 211 is provided so as to penetrate through the front and back surfaces of the second precast concrete member 120 and opens directly on the outer surface of the second precast concrete member 120. And the inlet 212 and the outlet 213 of the mortar 125 are provided on both sides of the edge of the through-hole 211 opened as such, and the inlet 212 and the outlet 213 are also formed on the outer surface of the second precast concrete member 120. Open directly.

  An anchor plate between the edge of the through hole 211 while applying tension to the end 112a of the PC steel rod 112 protruding from the upper end edge 111 of the first precast concrete member 110 as a standing wall and penetrating the through hole 211 Nut 124 is fastened with 123 interposed. The anchor plate 123 comes into contact with the edge of the through hole 211 so as to come into direct contact with the outer surface of the second precast concrete member 120. Also in this embodiment, as in the first embodiment, the tension is applied to the end 112a of the PC steel bar 112 by fastening the nut 124 itself.

  In the present embodiment, since the structure corresponding to the concave portion 122 is not provided as described above, the mortar 125 includes only the inlet 212 and the outlet 213 between the through hole 121 and the end 112a of the PC steel rod 112. Infused to fill. In the completed culvert structure, the anchor plate 123, the nut 124, and the extra length portion of the end 112a of the PC steel rod 112 protrude to the outside.

  Further, since the connection method of the second embodiment is not provided with a structure corresponding to the recess 122 as described above, the mortar 125 is injected until the mortar 125 overflows from the discharge port 127 until the mortar 125 overflows. When the injection is started from 126, the process ends. Other than this, the procedure is the same as the connection method of the first embodiment described above.

  Also by the connection structure 200 and the connection method of the second embodiment described above, the joint between the two precast concrete members 110 and 120 is opened as in the connection structure 100 and the connection method of the first embodiment described above. Needless to say, a difficult culvert structure can be obtained.

  Next, the joining structure and joining method of 3rd Embodiment of this invention are demonstrated. In addition, 3rd Embodiment differs from 1st Embodiment mentioned above in the shape of the through-hole in the 2nd precast concrete member as a top plate. Hereinafter, the bonding structure and the bonding method of the third embodiment will be described by paying attention to differences from the first embodiment.

  FIG. 6 is a view showing the joint structure of the third embodiment of the present invention in the same cross section as FIG. 2 (B). In FIG. 6, the same components as those shown in FIG. 2 described above are denoted by the same reference numerals as those in FIG. 2, and redundant description of those equivalent components will be omitted below.

  In the joint structure 300 of the third embodiment shown in FIG. 6, a through hole 311 that opens to the bottom 122 a (see FIG. 3) of the recess 122 provided in the second precast concrete member 120 is provided on the opening side. The shape is narrowed from the edge toward the first precast concrete member 110. The gradient in the depth direction of the inner surface of the through hole 311 is provided for the purpose of improving the adhesion of the mortar 125 to be injected and filled therein and the pulling-out resistance of the end 112a of the PC steel rod 112. The gradient is 10% (approximately 5%).

  Further, the through hole 311 is opened at the bottom 122a of the recess 122 leaving a portion where the anchor plate 123 abuts and is locked, and a part of the opening is detached from the anchor plate 123 and the mortar 125 It serves as an inlet and outlet. The mortar 125 is injected and filled between the through hole 311 and the end 112 a of the PC steel rod 112 and into the recess 122. Also in this embodiment, the tension is applied to the end 112a of the PC steel bar 112 by fastening the nut 124 itself.

  In addition, the connection method of the third embodiment is performed in the same procedure as the connection method of the first embodiment described above, and therefore redundant description is omitted.

  Also by the connection structure 300 and the connection method of the third embodiment described above, as in the connection structure 100 and the connection method of the first embodiment described above, the joint between the two precast concrete members 110 and 120 is opened. Needless to say, a difficult culvert structure can be obtained.

  Further, according to the connection structure 300 and the connection method of the third embodiment, the mortar 125 filled in the through hole 311 having the narrowed shape as described above opens the joint between the two precast concrete members 110 and 120. It works to resist loads that cause Thereby, the pulling-out proof strength of the edge part 112a of the PC steel rod 112 is improved, and the above-mentioned joint part becomes more difficult to open.

  Next, taking the connection structure 300 of the third embodiment described above as an example, a verification experiment verifying that high resistance can be obtained against a load that opens the joint between the two precast concrete members 110 and 120 Will be described.

  FIG. 7 is a schematic diagram showing a pattern of a verification experiment for the connection structure. As shown in FIG. 7, in the verification experiment, the connection structure 300 of the third embodiment shown in FIG. 6 is used as a verification target. In this verification experiment, an opening sensor M1 that detects how much opening occurs at the joint between the two precast concrete members 110 and 120 in the connection structure 300 of the third embodiment, that is, an opening displacement at the joint. Is attached. A pie-type displacement meter is employed as the opening sensor M1. Then, at a position sufficiently away from the first precast concrete member 110, a static bending load test is performed in which a static bending load F1 is applied to the second precast concrete member 120.

  Here, in this verification experiment, in order to make a comparison with the connection structure 300 of the third embodiment, the same bending load test is performed for the connection structures of the following two comparative examples.

  FIG. 8 is a diagram showing the connection structure of the first comparative example in the same cross section as FIG. 6, and FIG. 9 is a diagram showing the connection structure of the second comparative example in the same cross section as FIG. In FIG. 8 and FIG. 9, the same components as those in FIG. 6 are denoted by the same reference numerals as those in FIG.

  In the connection structure 400 of the first comparative example shown in FIG. 8, the reinforcing bars 401 and 402 of the two precast concrete members 110 and 120 are protruded from the respective edges, and they are overlapped at the installation site. This is a connection structure using a lap joint that is hardened with concrete 403. Further, in the connection structure 500 of the second comparative example shown in FIG. 9, the reinforcing bars 501 and 502 of the two precast concrete members 110 and 120 are inserted into the joint sleeve 503 filled with high-strength special mortar. It is the connection structure by the mechanical rebar joint which connects.

  The connection structures 400 and 500 of the first and second comparative examples both require a certain curing period until the cast-in-place concrete or special mortar reaches a predetermined strength. On the other hand, the connection structures 100, 200, and 300 of the first to third embodiments including those shown in FIG. 6 are all provided with tension to the end portion 112a of the PC steel bar 112 and anchor plates. By fastening the nut 124 via 123, sufficient joining strength can be obtained immediately without waiting for the mortar 125 to be cured. As described above, the connection structures 100, 200, and 300 according to the first to third embodiments are all advantageous in terms of shortening the work period, compared to the connection structures 400 and 500 of the first and second comparative examples. .

  Further, in the connection structure 400 of the first comparative example, cracks may occur between the two precast concrete members 110 and 120 and the cast-in-place concrete 403 due to differences in Young's modulus and shrinkage characteristics. In many cases, thorough maintenance is required. On the other hand, since the connection structures 100, 200, and 300 of the first to third embodiments do not use such cast-in-place concrete, they are advantageous in terms of ease of quality control and maintenance management.

  Further, in the connection structure 500 of the second comparative example, joint materials such as special mortar and joint sleeve 503 are expensive, and the reinforcing bars 501 and 502 must be securely inserted into the joint sleeve 503. There may be problems in terms of workability and economics through manufacturing and construction, such as design disadvantages and the need for special mortar filling workers (qualified special workers) during construction. is there. On the other hand, since the connection structures 100, 200, and 300 of the first to third embodiments do not require expensive materials and special workers as described above, they are advantageous in terms of workability and economy. It is.

  The connection structure of the first to third embodiments is also effective in terms of bonding strength, as can be supported by the verification experiment by the static bending load test using the connection structure 300 of the third embodiment as a representative example. 100, 200, and 300 are advantageous to the connection structures 400 and 500 of the first and second comparative examples.

  10 shows the connection structure of the third embodiment shown in FIG. 6, the connection structure of the first comparative example shown in FIG. 8, and the connection structure of the second comparative example shown in FIG. It is a graph which shows the test result of the static bending load test with respect to each.

  In the static bending load test, the opening displacement of the joint was detected by the opening sensor M1 for each load while changing the static bending load F1 (see FIG. 7). In the graph G1 shown in FIG. 10, the load (kN) is taken on the vertical axis, and the opening displacement (mm) is taken on the horizontal axis. Then, the opening displacement in the connection structure 300 of the third embodiment is plotted with black circle marks, the opening displacement in the connection structure 400 of the first comparative example using the lap joint is plotted with black triangle marks, and mechanical rebar joints are used. The opening displacement in the connection structure 500 of the second comparative example is plotted with black square marks. In addition, the graph G1 shows a load assumed to be applied at all times and a load assumed to be applied during a level 1 (L1) earthquake vibration at the installation location of the culvert structure to which each connection structure 300, 400, 500 is applied. And a load assumed to be applied during a level 2 (L2) earthquake vibration are indicated by dotted lines.

  From the graph G1 in FIG. 10, in the connection structure 300 of the third embodiment, the increase in opening displacement with respect to the increase in load is greatly suppressed compared to the connection structures 400 and 500 of the first and second comparative examples. I understand that. Accordingly, in the connection structures 100 and 200 of the first and second embodiments having basically the same structure, the opening displacement with respect to an increase in load is similarly applied to the connection structures 400 and 500 of the first and second comparative examples. It can be seen that the increase of is suppressed. That is, according to the connection structures 100, 200, and 300 of the first to third embodiments, high resistance can be obtained with respect to a load that opens the joint portion between the two precast concrete members 110 and 120.

  The first to third embodiments described above merely show typical forms of the present invention, and the present invention is not limited to these embodiments. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. As long as the structure of the connection structure and the connection method of the present invention is provided even by such modification, it is, of course, included in the scope of the present invention.

  For example, as an example of the culvert structure to which the connection structures 100, 200, 300 and the connection method of the first to third embodiments are applied, the single box-shaped culvert structure 1 shown in FIG. An inter-box culvert structure 2 is illustrated. However, the culvert structure to which the connection structure and the connection method of the present invention are applied is not limited to these, and the specific shape thereof is not limited. That is, although the culvert structures 1 and 2 shown in FIG. 1 are both straight tubular culvert structures, the culvert structure to be applied is an oblique angle having a substantially parallelogram shape in a top view, for example. The shape may be a culvert structure or the like.

  FIG. 11 is a schematic diagram showing an example of a precast concrete member that forms a top plate of a beveled culvert structure. The precast concrete member 31 in FIG. 11 is a slab member similar to the second precast concrete members 12 and 22 shown in FIG. 1 except that it has a substantially parallelogram shape in top view. And the through-hole 31a which the edge of the PC steel rod protruded from the standing wall penetrates in the part which overlaps with the edge of the standing wall not shown.

  The connection structure and connection method of the present invention can be applied to culvert structures of various shapes including such a beveled culvert structure.

  In the above-described first to third embodiments, the first precast concrete members 11, 21, 110 as standing walls are illustrated as an example of one member according to the present invention, and the other according to the present invention is illustrated. As an example of the member, second precast concrete members 12, 22, and 120 as top plates are illustrated. However, the one member and the other member referred to in the present invention are not limited to these, and any one of the two members according to the present invention may be used as long as it is two precast concrete members combined with each other in the culvert structure. Any of them may be the other member referred to in the present invention.

  In the first to third embodiments described above, the nut 124 is exemplified as an example of the fastening member according to the present invention. However, the fastening member referred to in the present invention is not limited to this, and may be, for example, a wedge driven between the through hole and the fixing rod.

  In the first to third embodiments described above, a rectangular plate-shaped anchor plate 123 is illustrated as an example of the pressing member according to the present invention. However, the pressing member referred to in the present invention is not limited to this, and any specific shape or the like may be used as long as it exerts a pressing force by receiving a reaction force against the tension force from the fastening member.

  Moreover, in 1st-3rd embodiment mentioned above, the mortar 125 is illustrated as an example of the filler said to this invention. However, the filler referred to in the present invention is not limited to this, and may be, for example, a resin adhesive.

1, 2, Calvert structure 11, 21, 110 First precast concrete member (an example of one member)
11a, 21a, 111 Upper edge 11b, 21b, 112 PC steel bar (an example of a fixing bar)
12, 22, 120 Second precast concrete member (an example of the other member)
12a, 22a, 23a, 31a, 1211, 211, 311 Through hole 100, 200, 300 Joining structure 112a End 122 Recess 122a Bottom 123 Anchor plate (an example of a pressing member)
124 nut (an example of a fastening member)
125 mortar (example of filler)
126,212 Inlet 127,213 Outlet

Claims (6)

A joint structure for joining two precast concrete members to each other in a culvert structure formed by combining a plurality of precast concrete members,
Of the two precast concrete members, one member incorporates a steel fixing bar and the end of the fixing bar protrudes toward the other member,
The other member is provided with a through-hole through which the end of the fixing bar passes.
A fastening member that is fastened to the end portion of the fixing bar while applying an axial tension force;
By interposing between the edge of the through hole opposite to the one member and the fastening member, and receiving the reaction force against the tension force from the fastening member, the other member becomes the one member. A pressing member for pressing;
A filler injected between the through-hole and the end of the fixing rod;
A joining structure characterized by comprising: The one member is a standing wall, and the end of the fixing bar protrudes from an upper end edge of the standing wall;
The other member is a top plate disposed on the upper end edge of the standing wall, and the through hole is provided in a portion overlapping the upper end edge so as to penetrate in the thickness direction of the top plate. The joining structure according to claim 1.   An inlet for injecting the filler into the through hole and an outlet for overflowing the excess filler after filling the through hole are connected to the through hole. 3. The joint structure according to claim 1, wherein the joint member is provided on the other member so that at least a part thereof deviates from a pressing position by the pressing member. The periphery of the opposite edge of the through hole is a recess recessed from the outer surface of the other member, and the through hole is open at the bottom of the recess,
The said pressing member and the said fastening member are accommodated and provided in the said recessed part, and this recessed part is filled with the said filler so that the said pressing member and the said fastening member may be covered. Bonding structure as described in any one of them.   5. The through hole has a shape in which at least a part thereof is narrowed from the opposite edge toward the one member in the depth direction. The junction structure according to any one of the above. A joining method for joining two precast concrete members to each other in a culvert structure configured by combining a plurality of precast concrete members,
Of the two precast concrete members, one member incorporates a steel fixing bar and the end of the fixing bar protrudes toward the other member,
The other member is provided with a through-hole through which the end of the fixing bar passes.
An assembly step of combining the two precast concrete members so that the end of the fixing bar passes through the through hole;
Between the edge of the through hole opposite to the one member, a pressing member that presses the other member against the one member is interposed, and the fixing rod member that penetrates the through hole The fastening member is fastened while applying an axial tension force to the end, and the pressing member receives a reaction force against the tension force from the fastening member to press the other member against the one member. Stress process,
An injection step of injecting a filler between the through hole and the end of the fixing rod;
A joining method characterized by comprising:

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