JP2017040052A - Expansion device of road bridge and construction method of expansion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion device of a road bridge which can favorably prevent that a load which is locally concentrated is applied by diffusing the load when the load is applied from above to a bridge member such as a floor plate.SOLUTION: An expansion device 10 of a road bridge which is arranged at a connecting portion between bridge members composed of floor plates 108 or the like, and installed by using notched steps 18 which are formed at opposing positions of the connecting portion comprises: an expansion part main body 12 which is installed long along a joint gap 20; hang-out members 14 which are protrusively arranged while hanging out of the expansion part main body 12, aligned at prescribed intervals, and integrated with the bridge members 108 with concrete 22; and load diffusion means 16 which are connected to a plurality of the hang-out members 14, installed while spreading into a plane shape at a lower layer side of a plurality of the hang-out members 14, diffuse a load which is applied in a lower direction from a road face side, transmit the load to the bridge members 108, and are integrated with the bridge members 108 with the concrete 22.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a telescopic device that absorbs expansion and contraction by connecting floor slabs of a road bridge or between a floor slab and an abutment, and a construction method of the expansion device of the road bridge.

  Bridges are built for people and cars to cross over traffic, rivers, seas, roads, railroads, and other traffic. For example, as shown in FIG. 8, the bridge 100 has a bridge upper structure including a main girder 106 and a floor slab 108 by a bridge lower structure of an abutment 102 at both ends and a bridge pier 104 that is arranged separately between the abutments 102. It has a structure that supports. The bridge members constituting the bridge upper structure such as the main girder 106 and the floor slab 108 expand and contract in the longitudinal direction due to a temperature change due to the season and the climate, and a live load by a moving body such as a person or a car. In order to absorb the expansion and contraction displacement of the bridge, expansion devices (also called expansion joints and joints) that expand and contract according to the expansion and contraction displacement of the bridge are provided between the floor slabs and between the floor slab and the pier. (For example, refer to Patent Document 1 and Patent Document 2). The expansion and contraction device for the bridge needs to have durability for a long period of time while maintaining the function of expanding and contracting according to the expansion and contraction of the floor slab. Further, since the bridge expansion and contraction device deteriorates over time, it is repaired or replaced periodically or according to the degree of damage.

  As shown in Patent Document 2, a conventional road bridge expansion / contraction device is installed using, for example, a notch step portion formed at a position opposite to a connection portion between floor slabs, and in the joint longitudinal direction of the road bridge. A telescopic part main body including a pair of corrugated plates facing each other so as to form an extended corrugated play, and a large number of protrusions projecting horizontally from the elastic part main body toward the notch step part and arranged along the longitudinal direction of the seam Including anchors and a number of reinforcing connecting bars projecting perpendicularly to the notch step portions of the floor slab and directly coupled to the plurality of anchors, and post-cast concrete is cast on the notch step portion of the floor slab Met.

Japanese Patent No. 5728048 JP 2001-123406 A

  For example, when exchanging the expansion device of a road bridge, a predetermined step on the opposite edge of the floor slab is formed with a tool to form a notch step, and concrete is once placed in the notch of the floor slab to place the surface. After smoothing, drilling holes for reinforcing connecting bars, driving reinforcing connecting bars, connecting the reinforcing connecting bars and anchors of expansion and contracting devices by welding, etc., to the notch step of the floor slab Was laid. However, in the road bridge telescopic device of Patent Document 2, as shown in FIG. 3 of Patent Document 2, a large number of reinforcing connecting bars are driven into the floor slab and fixed according to the number of anchors protruding from the telescopic body. As a result, the load of the automobile or the like passing through the road surface is transmitted through the vertical reinforcing connecting rod, and as a result, the part through which the tire of the automobile passes well (for example, the part that can be wrinkled) ) Is intensively loaded, and there is a high risk of premature deterioration of the local portion of the floor slab. In addition, the slabs of bridges that have deteriorated over time often have small cracks that are not visible due to damage caused by the load of automobiles passing through the road, but it is necessary to drive in many reinforcing connecting bars. For this reason, there is a problem that the floor slab is further damaged, and the strength and durability of the floor slab and the bridge are lowered. Furthermore, there is a problem that the work of drilling the driving hole into the floor slab and the work of driving the reinforcing connecting bar are complicated, which takes a lot of labor and increases the work time.

  The present invention has been made in view of the above-described conventional problems, and one object of the present invention is that when a load is applied from above in a bridge member such as a floor slab, the load is dispersed and a locally concentrated load is applied. It is an object of the present invention to provide a road bridge expansion / contraction device and a road bridge expansion / contraction device construction method that can prevent the deterioration of the floor slab and improve the strength and durability of the road bridge.

  In order to solve the above-mentioned problem, the present invention uses a notch step portion 18 provided at a connection portion 112, 114 between bridge members made of an abutment 102 or a floor slab 108 and formed at a position opposite to the connection portion 112, 114. The telescopic device of the road bridge is installed in the road longitudinal direction L of the bridge member from the telescopic unit body 12 and the telescopic unit body 12 installed long along the gap 20 between the bridge members (102, 108). A plurality of projecting members that are protruded and arranged at predetermined intervals, and are connected to the projecting members 14 that are integrated with the bridge members (102, 108) by the concrete 22 and the plurality of projecting members 14. 14 is a load distribution means that spreads in a plane on the lower layer side of 14 and distributes the load applied downward from the road surface side to transmit it to the bridge members (102, 108). A load distribution unit 16 which is integral with the bridge member (102, 108) at 22, and a telescopic device 10 of a road bridge having a.

  Further, the load distribution means 16 has a plurality of vertical connection members 32 that extend downward by connecting the upper portion or the intermediate portion to the plurality of overhanging members 14, and spread in a planar shape on the lower layer side of the plurality of overhanging members 14. It is good also as having the load distribution board 34 which is arrange | positioned in this way and connects with the lower end of the some vertical connection member 32, and distributes and supports the load applied to a downward direction from a road surface side.

  Further, the load distribution plate 34 may be fixedly installed at a predetermined height from the notch step portion 18 by an anchor bar 36 driven into the bottom portion 18A of the notch step portion 18 of the bridge member (102, 108). Concrete 22 is placed in the space between the load distribution plate 34 and the bottom 18A of the notch step portion 18 of the bridge members (102, 108).

  Further, the load distribution plate 34 is moved up and down so that it can be confirmed that the concrete 22 is filled between the load distribution plate 34 and the bottom portion 18A of the notch step portion 18 of the bridge member (102, 108). It is good also as having the penetration hole 44 which penetrated.

  Further, a plurality of confirmation holes 44 of the load distribution plate 34 may be provided and arranged corresponding to the intermediate positions of the adjacent overhanging members 14.

  Moreover, the load distribution board 34 is good also as consisting of a substantially plane board which has arrange | positioned the board surface up and down.

  Further, the load distribution plate 34 is formed in a size smaller than the bottom portion 18A of the notch step portion 18 in a plan view so that a concrete charging gap P1 is provided between the load distribution plate 34 and the end wall 18B of the notch step portion 18. It is good also as being done.

  Further, the present invention provides a notch step portion 18 formed at a position opposed to a connection portion (112, 114) between bridge members made of the abutment 102 or the floor slab 108 at a predetermined height from the bottom portion of the notch step portion 18. The load distribution means installation step S12 in which the load distribution means 16 including the load distribution plate 34 to be fixed is installed, and the expansion / contraction section main body 14 of the road bridge expansion / contraction device 10 are provided along the gap 20 between the bridge members (102, 108). A telescopic device that is disposed long and connects a plurality of projecting members 14 projecting in the road longitudinal direction L of the bridge members (102, 108) from the telescopic unit body 14 and the load distribution means 16 arranged at a predetermined interval. The first concrete placement work in which the concrete 22 is poured into the notch step portion 16 of the connecting member S14 and the bridge members (102, 108) and is placed to a height that is substantially flush with the upper surface of the load distribution plate 34. After placing in S161 and the first concrete placing step S161, the second concrete placing in which concrete is placed in the notch step portion 18 of the bridge member (102, 108) so as to be flush with the road surface. Step S162, and the construction method of the expansion and contraction device for the road bridge.

  According to the road bridge expansion and contraction device of the present invention, the expansion and contraction of the road bridge that is provided at the connection portion between the bridge members made of the abutment or the floor slab and is installed using the notch step portion formed at the opposite position of the connection portion. It is a device, a telescopic part main body that is installed long along the gap between the bridge members, and a plurality of projecting members that project from the telescopic part main body in the longitudinal direction of the road of the bridge member and are arranged at predetermined intervals. Overhang members that are integrated with the bridge member with concrete, and are connected to a plurality of overhang members, spread in a plane on the lower layer side of the overhang members, and distribute the load applied downward from the road surface side Load distribution means to be transmitted to the bridge member, and load distribution means integrated with the bridge member with concrete, so load is applied from above at the connection part of the bridge member such as abutment and floor slab by the load distribution means And distribute the load in such a case, it is possible to prevent the load which is concentrated locally it take to prevent early deterioration of the bridge member can be improved strength of the road bridge, the durability. Furthermore, it is not necessary to drive a large number of anchor bars into a bridge member such as a floor slab, and damage to the bridge member can be prevented. In particular, damage to bridge members such as floor slabs that have deteriorated over time can be greatly reduced during replacement work of the telescopic device. In addition, the labor and time required for the anchor rod driving operation can be greatly reduced, the construction can be carried out smoothly, the construction period can be shortened, and the cost can be reduced.

  In addition, the load distribution means is arranged so that the upper or middle portion is connected to the plurality of overhang members, and the plurality of vertical connection members are extended downward, and are spread in a plane on the lower layer side of the plurality of overhang members. The load distribution means is concretely realized with a simple configuration by including a load distribution plate that is connected to the lower ends of the plurality of vertical connection members and distributes and supports the load applied downward from the road surface side. it can.

  In addition, the load distribution plate is configured to be fixedly installed at a predetermined height from the notch step portion with an anchor bar driven into the bottom portion of the notch step portion of the bridge member, so that the bottom portion of the notch step portion is in a non-landing state. It is possible to securely fix the load distribution plate to the bridge member while maintaining an appropriate arrangement state capable of exhibiting load distribution support such as a horizontal state via the anchor bars.

  Also, the load distribution plate has a confirmation hole penetrating up and down the plate surface so that it can be confirmed that the concrete is filled between the load distribution plate and the bottom of the notch step portion of the bridge member. Thus, it can be confirmed whether or not concrete has been placed between the load distribution plate and the bottom of the notch step portion of the bridge member, and reliable concrete molding can be realized. Further, the confirmation hole can function as an air hole, and the concrete disposed above and below the load distribution plate can be integrated through the confirmation hole, so that strength can be secured.

  Further, by providing a plurality of confirmation holes in the load distribution plate corresponding to the intermediate positions of the adjacent overhang members, the concrete placement state can be confirmed more reliably.

  In addition, the load distribution plate can be manufactured at a low cost by supporting the load with a simple configuration by adopting a configuration composed of a substantially flat plate with plate surfaces arranged vertically.

  In addition, the load distribution plate is configured to be smaller in size than the bottom of the notch step portion in plan view so that a gap for introducing concrete is provided between the end wall of the load distribution plate and the notch step portion. As a result, the concrete placement operation between the load distribution plate and the bottom of the notch step portion can be performed smoothly and reliably, and the concrete can be reliably integrated into the bridge member.

  Furthermore, according to the construction method of the expansion device for a road bridge of the present invention, a predetermined height is formed from the bottom of the notch step portion to the notch step portion formed at a position opposite to the connection portion between the bridge members made of abutments or floor slabs. A load distribution means installation step for installing a load distribution means including a load distribution plate fixed at a position, and a telescopic part body of a road bridge telescopic device is arranged long along the gap between the bridge members, and the bridge from the telescopic part main body A telescopic device connecting step for connecting a plurality of projecting members projecting in the longitudinal direction of the member and arranged at predetermined intervals and the load distribution means, and pouring concrete into the notch step portion of the bridge member, After placing in the first concrete placing step, which is placed to a level substantially flush with the upper surface, and in the first concrete placing step, so that the notch step portion of the bridge member is flush with the road surface The second to cast concrete The concrete placement process can be used to distribute the load when the load is applied from above at the connection part of the bridge member such as the abutment or floor slab by the load distribution means, and a locally concentrated load is applied. As a result, the strength and durability of the road bridge can be improved. Furthermore, it is not necessary to drive a large number of anchor bars into a bridge member such as a floor slab, and damage to the bridge member can be prevented. In addition, the labor and time required for the anchor rod driving operation can be greatly reduced, the construction can be carried out smoothly, the construction period can be shortened, and the cost can be reduced. Furthermore, the concrete between the load distribution plate and the bottom of the notch step can be reliably performed, and the concrete can be formed without gaps or defects, and the concrete can be reliably integrated with the bridge member of the expansion / contraction device.

It is the principal part perspective view which notched a part of expansion-contraction apparatus of the road bridge which concerns on the 1st Embodiment of this invention. It is principal part longitudinal cross-section explanatory drawing of the expansion-contraction apparatus of the road bridge of FIG. It is a top view of the state before integrating the expansion-contraction apparatus of the road bridge of FIG. 1 with concrete. It is the sectional view on the AA line of FIG. It is a perspective view of the state which installed the load distribution board in the notch step part of a floor slab with the expansion-contraction apparatus of the road bridge of FIG. It is explanatory drawing of the construction method of the expansion-contraction apparatus of the road bridge which concerns on the 1st Embodiment of this invention. It is the schematic of the longitudinal cross-section of the expansion-contraction apparatus of the road bridge which concerns on other embodiment of this invention. It is a schematic explanatory drawing of a road bridge.

  Embodiments of a telescopic device for a road bridge according to the present invention will be described below with reference to the accompanying drawings. The expansion / contraction device for a road bridge according to the present invention is a expansion / contraction device that absorbs expansion / contraction displacement of a bridge, which is a joint structure at a connection portion between floor slabs or a floor slab and an abutment in a road bridge. 1 to 3 show a first embodiment of a road bridge telescopic device of the present invention. As shown in FIGS. 1, 2, and 3, in the present embodiment, the road bridge telescopic device 10 includes an elastic body 12, a plurality of projecting members 14 projecting from the elastic body 12, and Load distribution means 16 connected to the plurality of overhanging members 14.

  As shown in FIG. 7, for example, a road bridge (bridge) 100 has an abutment 102 disposed at both ends of the road bridge and a bridge pier 104 disposed therebetween. A main girder 106, which is an upper structure, is installed with a support portion 105 interposed therebetween. For example, a concrete floor slab 108 is formed on the upper side of the main girder 106, and a pavement 110 is formed on the upper surface side of the floor slab 108 with asphalt or the like. The road bridge telescopic device 10 according to the present embodiment is connected to the connecting portions 112 and 114 between the bridge members made of the abutment 102 or the floor slab 108, which are portions where the respective constituent members are cut in the longitudinal direction of the road. Provided. That is, the expansion / contraction device 10 for a road bridge is applied to a connection portion 112 between the abutment 102 and one end portion of the floor slab 108 and a connection portion 114 between opposite ends of the floor slab 108 of the bridge girder supported on the pier 104. The In the present embodiment, for example, a case where floor slabs 108 are connected as a bridge member to be connected will be described.

  As shown in FIGS. 1, 2, and 3, for example, in the present embodiment, the floor slabs 108 are arranged to face each other with a gap 20 of about several centimeters interposed. At a position opposite to the connecting end portion of the floor slab 108, there is a notch step portion 18 formed by cutting each part into a substantially L shape. The notch step 18 is formed long along the gap 16. The expansion / contraction device 10 for the road bridge is installed using the notched step portion 18 formed on the floor slab 108 and is integrated with the floor slab 108 via the post-cast concrete 22.

  The expansion / contraction part main body 12 is a main body part of the expansion / contraction apparatus installed long along the gap 20 between the floor slabs 108. As shown in FIGS. 1, 2, and 3, in this embodiment, for example, a stretchable rubber 24 that closes the gap 20 and expands and contracts itself, and a support plate that is opposed to sandwich the stretchable rubber 24. 26, and a rubber-type joint structure. The elastic rubber 24 is formed, for example, in a honeycomb shape having a plurality of hollow portions. The support plate 26 is made of a metal plate member such as a steel plate, for example, and sandwiches and supports the stretchable rubber 24 in a state of being fixed with an adhesive or the like. A locking portion 28 for receiving and locking the elastic rubber 24 from below is provided at the lower portion of the support plate 26 on the opposite inner surface side. In addition, the structure of the expansion-contraction part main body 12 is not restricted to said structure, For example, arbitrary structures according to the magnitude | size of a road bridge, such as a finger joint which meshed | combined the steel comb shape, the magnitude | size of play, and other conditions But you can.

  As shown in FIG. 1, FIG. 2, and FIG. 3, the plurality of projecting members 14 project from the stretchable body 12 toward the notch step 18 of the floor slab 108 in the lateral direction, and the notch step 18 It is a means for fixing to the floor slab that allows the stretchable body 12 to be integrally supported by the floor slab 108 by being integrated with the floor slab 108 by the post-cast concrete 22 placed on the floor slab. In this embodiment, as shown in FIGS. 1, 2, and 3, the overhang member 14 is made of, for example, a straight bar-shaped deformed reinforcing bar, and one end is fixed to the support plate 26 of the telescopic part body 12 and the other end is fixed. The floor slab 108 extends along the road longitudinal direction L and protrudes from the support plate 26 in a substantially horizontal direction, and is arranged at predetermined intervals (equal intervals or unequal intervals) along the longitudinal direction of the gap 22. ing. As shown in FIG. 4, a plurality of projecting members 14 are connected to through bars 30 that are reinforcing reinforcing bars that reinforce the post-cast concrete 22. The threading bars 30 are connected to the threading bars 30 that are long in the horizontal direction orthogonal to the overhang members 14, that is, in the direction parallel to the longitudinal direction of the gap 20 and the elastic rubber 24. The through bar 30 is made of, for example, a straight bar-shaped deformed bar, is extended across a plurality of overhang members, and is fixed to an intermediate position in the longitudinal direction of the overhang member 14 by welding or the like. In the present embodiment, the two through bars 30 are joined to be spaced apart from each other at the intermediate position in the longitudinal direction of the overhang member and the other end side. In addition, the overhanging member 14 is not limited to the above-described one. For example, as illustrated in FIG. 7, a substantially U-shaped, a substantially J-shaped or a substantially L-shaped reinforcing bar, a plate shape, a rib plate, or the like. It may be configured. Further, the number of through bars 30 and the connecting position with the overhanging member may be arbitrarily configured corresponding to the configuration of the overhanging member.

  The load distribution means 16 is a load distribution means for distributing a load (load) applied downward from the road surface side to the bridge member in a portion where the overhanging member 14 is integrated with the bridge member with the post-cast concrete 22. is there. In the present embodiment, as shown in FIGS. 1, 2, and 3, the load distribution means 16 is installed on the bottom portion 18 </ b> A of the notch step portion 18 of the floor slab 108, and faces the lower layer side of the plurality of overhang members 14. It arrange | positions so that it may spread in a shape, and is simultaneously connected with the several overhang | projection member arranged at predetermined intervals. The load distribution means 16 is integrated with the floor slab 108 with concrete 22 cast on the notched step portion 18 of the floor slab 108. The load distribution means 18 includes, for example, a plurality of vertical connection members 32 respectively connected to the plurality of extending members 14 and a load distribution plate 34 in which the plurality of vertical connection members 32 are erected.

  As shown in FIGS. 1, 2, and 6, the vertical connection member 32 is made of, for example, a rod-shaped steel material, and is arranged with its longitudinal direction directed in the vertical direction. It is fixed and extends downward. The vertical connecting member 32 is connected to, for example, two positions, that is, a middle position in the longitudinal direction and a position closer to the other end of each overhang member 14. Therefore, the vertical connecting members 32 have the number of “number of overhanging members × 2”, and are arranged in the direction W along the longitudinal direction of the gap 20 at substantially the same interval as the interval between the overhanging members 14. The plurality of vertical connecting members 32 are integrated with the load distribution plate 34 by fixing their lower ends to the load distribution plate 34 by welding or the like. Furthermore, the vertical connection member 32 is fixed to the thread 30 by contact or the like as necessary.

  The load distribution plate 34 is arranged so as to spread in a planar shape on the lower layer side of the plurality of overhang members 14, and is connected to the lower ends of the plurality of vertical connection members 32 to distribute the load (load) applied downward from the road surface side. To support. The load distribution plate 34 is formed of, for example, an elongated belt-like metal rectangular plate on one side, and is formed of a substantially flat plate having plate surfaces arranged on the top and bottom. The load distribution plate 34 is, for example, long disposed along the gap 20 and is connected to the plurality of overhanging members 14 via the plurality of vertical connection members 32. It is transmitted to the load distribution plate 34 via the member 32. As a result, even if a load is locally applied from the road surface, the load is distributed by the load distribution plate 34 and transmitted to the bridge member such as the floor slab 108, so that the floor slab 108 and the like are prevented from premature local deterioration. And durability can be improved.

  The load distribution plate 34 is fixedly installed at a predetermined height from the bottom of the notch step 18 by an anchor bar 36 driven into the bottom 18B of the notch 18 of the floor slab 108. The anchor bars 36 for fixing the load distribution plate 34 are made of, for example, embedded bolts. The lower part of the bolts are driven into a driving hole 38 previously drilled in the bottom 18B of the notch step 18 with a drill or the like, and the floor 108 is fixed. It is fixed. The anchor bar 36 is screwed into a portion projecting upward from the bottom of the notch step 18, and the nut 40 in a state where the anchor bar 36 penetrates the bolt hole 40 drilled in the load distribution plate 34. The load distribution plate 34 is fixed so as to be sandwiched from above and below. The bolt holes 40 of the load distribution plate 34 are long holes, and can be connected and fixed while driving the anchor bars 36 to avoid the reinforcing bars in the floor slab 108 made of concrete and adjusting the position. The number of anchor bars 36 fixing the load distribution plate 34 is set to be smaller than the number of the longitudinal connecting members 32. For example, in the present embodiment, the anchor bars 36 are arranged in one row (two) for every five protruding members 14 in the direction W along the longitudinal direction of the gap 20. That is, the load distribution plate 34 is fixed to the floor slab 108 with a relatively small number of anchor bars 36 with respect to the overhanging member 14. Thereby, compared with the conventional expansion-contraction apparatus, the number of anchor muscles driven into the floor slab 108 is reduced, and the damage to the floor slab is reduced. When the post-cast concrete 22 is placed in the notched step portion 18 of the floor slab 108, the concrete 22 is filled into the space between the load distribution plate 34 and the bottom portion 18 </ b> A of the notched step portion 18. Is integrated with the floor slab 108.

  The load distribution plate 34 is formed in a size smaller than the bottom portion 18A of the notch step portion 18 of the floor slab 108 in plan view. The load distribution plate 34 is installed such that a gap P1 for putting concrete is provided between the load distribution plate 34 and the end wall 18B of the notch step portion 18. At the same time, the load distribution plate 34 is not connected to the support plate 26 of the expansion / contraction section main body 12 and is arranged at a predetermined interval from the support plate 26 in plan view, and the load distribution plate 34 and the notch step portion 18. It is installed so that the space | gap which can be filled with concrete is provided also between the bottom part edge part side (gap side). As a result, the load distribution plate 34 is completely buried in the post-cast concrete 30 and integrated with the concrete, and the post-cast concrete 22 is filled between the load distribution plate 34 and the support plate 26. I can confirm.

  Furthermore, as shown in FIGS. 2 and 6, it can be confirmed that the concrete is filled in the load distribution plate 34 between the load distribution plate 34 and the bottom portion 18 </ b> B of the notch step portion 18 of the floor slab 108. Thus, a confirmation hole 44 penetrating up and down the plate surface is provided. The confirmation holes 44 are, for example, circular through holes having a diameter of about 10 mm, and a plurality of confirmation holes 44 are provided at predetermined intervals along the longitudinal direction of the gap 20. For example, the confirmation holes 44 are arranged one by one at an intermediate position between the adjacent overhang members 14, and the filling state of the concrete 22 can be confirmed at a plurality of positions, so that the construction can be performed reliably. In addition, the confirmation hole 44 serves as an air escape hole when filling concrete, and the upper and lower concrete 22 of the load distribution plate 34 are integrated through the confirmation hole 44, so that strength can be secured. The number, size, shape, position, and the like of the confirmation holes are not limited to those described above, and may be arbitrarily set according to the construction site according to the load distribution plate 34, the overhang member 14, and the like.

  The post-cast concrete 22 is placed in the notch step portion of the bridge member, and the overhang member 14 and the load distribution means 16 are integrated with the bridge member, and is substantially flush with the road surface. Note that a back-up material 46 made of a foam material that is long along the gap 20 is filled in the gap 20 portion below the stretchable body 12 so that the post-cast concrete 22 does not flow into the gap 20. The backup material also serves as a water stop function in the play. In the present embodiment, the post-cast concrete 22 is placed between the load distribution plate 34 and the bottom of the notch step portion 18 and is formed to a position that is flush with the load distribution plate, and the load distribution And an upper layer portion placed on the upper side of the plate 34. The concrete 22 may basically be normal concrete, mortar, or the like. In the present embodiment, the lower layer portion of the concrete 22 is casted with, for example, super early-hardened concrete or non-shrink mortar that has high fluidity and hardens in an early time of about several hours. For example, super fast-hardened concrete is placed in the upper layer portion of the concrete 22. The post-cast concrete 22 is preferably placed in two layers in order to reliably fill the concrete between the load distribution plate 34 and the bottom portion of the notch step portion 18, but without being divided into two layers. It is good also as forming by once placement. In addition, when the space between the load distribution plate 34 and the bottom portion of the notch step portion 18 is narrow, the lower layer portion of the concrete 22 does not include coarse aggregate and may be placed with high fluidity mortar or the like. When the space between the load distribution plate 34 and the bottom portion of the notch step portion 18 can be secured and formed, concrete including coarse aggregate may be placed. The upper layer portion of the concrete 22 is preferably made of high-strength concrete including coarse aggregate in terms of strength.

  As described above, the road bridge expansion and contraction device 10 is configured by connecting the load distribution plates horizontally on both sides of the support plates 26 fixed on both sides of the expansion / contraction section main body 12 via barbs such as reinforcing bars. Has been. In other words, the load distribution plate is horizontally installed as a base for supporting the support plate 26 of the telescopic device in a cantilevered manner, thereby distributing the load load from above at the connecting portion of the bridge member and preventing local concentrated load. This will prevent early deterioration of bridge members and improve the strength and durability of road bridges.

  FIG. 7 shows another embodiment of the expansion / contraction device for the road bridge, but the same members as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In Fig.7 (a)-(c), the overhang | projection member 14 of the expansion-contraction apparatus 10 becomes a different aspect. As shown in FIG. 7A, for example, the overhanging member 14 is formed in a substantially J shape by bending the protruding tip side. The through bar 30 is connected to the substantially J-shaped projecting member 14 as in the above-described embodiment, and the vertical connecting member 32 of the load distribution means 16 is fixed. As shown in FIG. 7B, for example, the overhanging member 14 is formed in a substantially U shape by bending the protruding distal end side, and the base end side of the expansion / contraction part main body 14 is located at two upper and lower portions. It is fixed to the support plate. Similar to the above-described embodiment, the thread member 30 is connected to the projecting member 14 and the vertical connection member 32 of the load distribution means 16 is fixed. As shown in FIG. 7C, for example, the projecting member 14 is formed in a plate shape that is arranged with its plate surface upright. The plate-like projecting member 14 is preceded by a through-hole penetrating in the horizontal direction at an intermediate position. As with the above-described embodiment, the projecting member 14 is connected to the thread through and the vertical connecting member 32 of the load distribution means 16 is fixed. In addition, it is good also as connecting the load distribution means 16 to the structure of the expansion-contraction part main body and overhang | projection member of arbitrary structures, and integrating with concrete and comprising an expansion-contraction apparatus.

  Next, with reference to FIG. 7, the construction method of the expansion-contraction apparatus of the road bridge which concerns on this embodiment is demonstrated. In this embodiment, the construction method of the expansion device for the road bridge includes a load distribution means installation step S12, an expansion device installation step S14, and a concrete placing step S16. In the load distribution means installation step S12, for example, when constructing a new road bridge, first, the anchor bars 36 are driven into the bottom of the notch step portion 18 formed at the position opposite to the connection portion between the floor slabs 108. A plurality of driving holes 38 are drilled with a drill. (Step S121) When exchanging the existing expansion / contraction device, the opposing position of the connecting portion between the floor slabs 108 is connected with a tool to form the notch step portion 18, and after the deteriorated expansion / contraction device is removed, the notch A driving hole 38 is drilled in the bottom of the step portion 18 with a drill or the like. Next, the anchor bars 36 are driven into the respective driving holes 38 at the bottom of the notch 18 of the floor slab 108 (step S122). A vertical coupling member 32 and a load distribution plate 34 integrated in advance at a factory or the like are fixed to a predetermined height position from the bottom of the notch step portion via the anchor bar 36 of the notch step portion 18. The load distribution means is installed at the notch step (step S123).

  In the expansion / contraction device connecting step S14, the expansion / contraction part main body 14 is arranged long along the gap 20 between the floor slabs 108, and the plurality of extending members 14 protruding from the expansion / contraction part main body 14 are vertically connected to the load distribution means. The member 32 is connected and fixed by welding or the like. The gap 20 is filled with a backup material 46. Further, a thread 30 is connected and fixed to the projecting member 14 by welding or the like.

  In the present embodiment, the concrete placing step S16 includes a two-step process including a first concrete placing step S161 and a second concrete placing step S162. In the first concrete placing step S161, the concrete is poured into the notch step portion 18 of the floor slab 108 and filled between the load distribution plate 34 and the bottom portion of the notch step portion 18, and substantially the same as the upper surface of the load distribution plate 34. Placing to the same height. At this time, the concrete is introduced from the gap between the load distribution plate 34 and the end 18B side of the notch step 18. Further, since there is a gap between the support plate 26 and the load distribution plate 34 of the expansion / contraction unit body 12 and the load distribution plate 34 is provided with a confirmation hole 44, the load distribution plate 34 and the notch step portion are provided. Whether or not concrete is filled between the bottoms of the 18 can be surely confirmed. In the second concrete placing step S162 after placing in the first concrete placing step, concrete is placed on the notch step portion 18 of the floor slab 108 so as to be flush with the road surface. As described above, even when the load distribution means 16 is installed, by placing the concrete in two stages, it is possible to reliably place the concrete and prevent the occurrence of concrete defects such as voids and defects. It is possible to construct a telescopic device that is strong and has high durability. In the above-described embodiment, the example of the expansion device for connecting the floor slabs has been described in the expansion device and the construction method for the road bridge, but it can also be applied to the expansion device for connecting the abutment and the floor slab.

  The above-described road bridge expansion and contraction device of the present invention is not limited to the configuration of the above-described embodiment alone, and may be arbitrarily modified without departing from the essence of the present invention described in the claims. May be.

  The expansion device for a road bridge according to the present invention can be suitably used, for example, in some cases.

DESCRIPTION OF SYMBOLS 10 Road bridge expansion / contraction device 12 Telescopic part main body 14 Overhang member 16 Load distribution means 18 Notch step part 20 Free space 22 Concrete 32 Vertical connection member 34 Load distribution board 36 Anchor muscle 44 Check hole

Claims (8)

A telescopic device for a road bridge, which is provided at a connecting part between bridge members made of abutments or floor slabs, and is installed using a notch step portion formed at the opposite position of the connecting part,
A telescopic part body installed long along the gap between the bridge members;
A plurality of projecting members projecting in the road longitudinal direction of the bridge member from the stretchable part main body and arranged at predetermined intervals, and a projecting member integrated with the bridge member with concrete;
It is a load distribution means that is connected to a plurality of overhang members, spreads in a plane on the lower layer side of the plurality of overhang members, disperses the load applied downward from the road surface side, and transmits it to the bridge member. A road bridge expansion and contraction device comprising load distribution means integrated with a bridge member. The load distribution means includes a plurality of vertical connection members extending downward by connecting the upper part or the intermediate part to the plurality of overhanging members,
A load distribution plate that is arranged so as to spread in a planar shape on the lower layer side of the plurality of overhang members, and is connected to the lower ends of the plurality of vertical connection members to disperse and support a load applied downward from the road surface side. The expansion / contraction device for a road bridge according to claim 1.   The expansion / contraction device for a road bridge according to claim 1 or 2, wherein the load distribution plate is fixedly installed at a predetermined height from the notch step portion by an anchor bar driven into the bottom portion of the notch step portion of the bridge member.   The load distribution plate has a confirmation hole penetrating up and down the plate surface so that it can be confirmed that the concrete is filled between the load distribution plate and the bottom of the notch step portion of the bridge member. The expansion device for a road bridge according to Item 2 or 3.   5. The expansion / contraction device for a road bridge according to claim 4, wherein a plurality of confirmation holes of the load distribution plate are provided corresponding to an intermediate position between adjacent projecting members.   The road bridge expansion and contraction device according to any one of claims 2 to 5, wherein the load distribution plate is formed of a substantially flat plate having plate surfaces arranged vertically.   The load distribution plate is formed in a size smaller than a bottom portion of the notch step portion in a plan view so that a gap for introducing concrete is provided between the end wall of the load distribution plate and the notch step portion. Item 7. The expansion device for a road bridge according to any one of Items 2 to 6. A load in which a load distribution means including a load distribution plate fixed at a predetermined height from the bottom of the notch step is formed at a notch step formed at a position opposite to a connection portion between bridge members made of abutments or floor slabs. A dispersion means installation step;
A plurality of projecting members arranged in a projecting manner in the road longitudinal direction of the bridge member from the telescopic unit body, and arranged in a predetermined interval; An expansion device connecting step for connecting the load distribution means;
A first concrete placement step in which concrete is poured into a notch step portion of a bridge member and is placed to a height substantially flush with an upper surface of a load distribution plate;
And a second concrete placing step of placing concrete so that the notch step portion of the bridge member is flush with the road surface after placing in the first concrete placing step. Construction method of expansion device for road bridge.

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