JP2016196800A - Bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bridge having a high strength capable of swift construction and deconstruction.SOLUTION: The bridge includes: a bottom slab; a pair of side slabs uprising from the bottom slab; and a top slab which is bridged across the side slabs and extend in full width between the banks being interposed by a river. The bridge includes: a precast box culvert which is constituted of plural concrete members connected to each other being arranged in a direction perpendicular to a direction the top slab extends; a road forming part which covers the upper side of the top slab, and the upper plane of which is a road face allowing traffic of vehicles: and load dispersion means capable of dispersing a load, which is applied to one of the plural concrete members from the top, to the other concrete members.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bridge constructed in a river.

  At present, there are many existing bridges built in rivers that are approaching the deadline in which a preset useful life elapses (see, for example, Patent Document 1). Therefore, replacement works are currently being carried out on many bridges that are close to their deadlines.

  When reconstructing such a bridge, a temporary bridge is once constructed in another location, the old bridge is demolished in the meantime, and a new bridge is constructed. It is common to go through procedures such as removing bridges. And most of the newly built bridges are now made of concrete (for example, see Patent Document 1).

Japanese Patent Laying-Open No. 2015-055131

  However, as described above, in the current situation where there are many bridges that need to be replaced, a large work period and work amount are required for each bridge in order to go through the above procedure. Under such circumstances, with a limited amount of work, the replacement of the bridge cannot catch up and the replacement work cannot be performed before the end of its useful life, resulting in a bridge that has been left aging. There is also concern about the problem of letting it go.

  In addition, in order to guarantee the required traffic during the above-mentioned replacement work, not only the bridge to replace the existing bridge but also the temporary bridge to be used at the time of construction of the bridge is assumed. As described above, rapid construction and withdrawal are required as well as providing strength that can effectively withstand the load caused by the passing of vehicles.

  This invention pays attention to such a malfunction, and it aims at providing the bridge which has a high intensity | strength and can be promptly constructed and withdrawn.

  In order to achieve such an object, the present invention takes the following measures.

  That is, the bridge according to the present invention is built on a river whose distance between both riverbanks is less than 15 m, and includes a bottom plate, a side plate standing up from the bottom plate, and the river sandwiched between the side plates. A precast box culvert formed by joining a plurality of concrete members arranged side by side in a direction perpendicular to the extending direction of the top plate, and a top plate extending across the entire area between the riverbanks. A road surface forming portion that covers the upper surface of the road and allows a vehicle to pass therethrough, and load distribution means that can distribute a load applied from above to one of the plurality of concrete members to other concrete members. It is characterized by that.

  That is, according to the present invention, most of the bridges that need to be rebuilt at present are constructed on a place where the river width of the river is 15 m or less, that is, installed on a medium or small river. The size of the concrete structure that can be mounted on small and medium rivers was achieved by focusing attention on two points, which can be more suitably dealt with by precast concrete products.

Further, the “precast box culvert” is not limited to the so-called B-shaped in front view. For example, a concrete secondary product in which the bottom plate is divided in front view may be used. In that case, you may construct so that a part may be filled between the precast bottom slabs with the concrete on the spot and the plate-shaped concrete member which is another body.
The “precast box culvert” may be, for example, a concrete U-shaped secondary product viewed from the front. For example, as a concrete secondary product, a bottom plate and left and right side plates erected from both ends of the bottom plate are integrally configured, and a U-shaped front view is applied. A precast box culvert having a generally square-shaped portion in front view is constructed by laying a top plate, which is a floor slab, which is another concrete secondary product, between the upper ends of the side plates of the concrete secondary product forming the mold. You may make it comprise.
Moreover, the said precast box culvert is not restricted to a single thing, The top plate may be plural as long as it continues so that it may extend over the whole area between both riverbanks.

  If this is the case, among the concrete members constituting the precast box culvert, for example, when a large load is applied only to some of the concrete members due to the load of the tires of the vehicle, a load due to bending will occur. Distributing the load by providing a dispersing means effectively avoids the problem that the load concentrates locally on the precast box culvert, causing a step and causing an adverse effect such as unnecessary irregularities on the road surface. Can do. As a result, the substantial strength of the entire bridge can be effectively improved. By using precast concrete products, it is possible to contribute to shortening the construction period by realizing rapid construction while avoiding unnecessary increase in construction scale. Also, the use of precast concrete products means that withdrawal after construction can be performed more quickly than in-situ concrete. In other words, the bridge according to the present invention can be applied as an object to replace an existing bridge, or it can be applied as a temporary bridge that is temporarily constructed at the time of bridge replacement, while avoiding an unnecessary increase in construction scale and prompt construction. This can contribute to shortening the construction period.

  Here, the manner in which the load is “dispersed” does not matter before and after the load is actually applied to the concrete member. In other words, after the load is applied to the concrete member, the load is distributed among the concrete members and distributed to other concrete members. This is a concept that also includes a mode in which is transmitted to a plurality of concrete members after being dispersed in a plan view. Even if the load distribution is realized by any one of the above modes, the problem that unnecessary unevenness is generated on the road surface due to the formation of a step between the concrete members can be effectively avoided.

  That is, as an aspect of the load distribution means that effectively utilizes the characteristics of the precast box culvert, the aspect in which the load distribution means is a top plate side tightening portion that applies prestress to the top plate in the joining direction of a plurality of concrete members. Can be mentioned. By providing the top plate side tightening portion, the strength of the precast box culvert itself is also improved.

  In addition, as a mode of dispersing the load before the load is directly transmitted to the precast box culvert, the load dispersing means is provided between the top plate and the road surface forming portion and is provided to overlap the plurality of concrete members in plan view. The aspect which is a level | step difference suppression plate which makes a plate-like can be mentioned. Of course, the step-suppressing plate may be on-site concrete or precast concrete, or may be other than or including concrete. Thereby, the load distribution means which is easy to apply according to the construction site as appropriate is realized.

In addition, in order to easily eliminate unnecessary steps between the road surface on the bridge and the road surface on the riverbank connected to it, and effectively improve the performance as a bridge, the road surface on the riverbank side at both ends in the extension direction of the top plate If the precast box culvert is integrally formed with a plate support that supports the end of the stepping plate from below in a configuration that is adjacent to the stepping plate for continuation of the plate, the precast concrete is laid Since the tread plate can be positioned according to the situation, it can contribute to the rapid construction of the bridge.
Further, as another aspect capable of effectively reducing the steps related to the bridge installation after the precast box culvert laying, the concrete member is integrally formed with the top plate and the stepping plate for continuing the road surface on the river bank side. The aspect provided with the overhanging floor slab comprised in can be mentioned.

  In addition, as another measure for realizing further shortening of the construction period and easy construction, the precast box culvert has a ground cover forming portion for standing from the outside in the width direction of the road surface to form a ground cover. If this is the case, the process after laying the precast box culvert can be effectively shortened.

Another aspect that can effectively reduce the steps related to bridge installation after precast box culvert laying is that the precast box culvert has a space forming portion that forms a space in the vicinity of the road surface along the extending direction of the road surface. The aspect which is doing can be mentioned. The space forming part accommodates a snow melting device that melts snow and ice on the road surface, for example, as a drainage groove that can discharge water on the road surface, as a pipe housing part that houses various pipes laid along the road surface It can be used for various applications that can add the function of a bridge, such as a snow melting device housing.
As a configuration in which the concrete member can be suitably supported with respect to a support layer such as the ground, an aspect in which the bottom plate is connected to the support layer by a plurality of piles can be exemplified.

  According to the present invention, it is possible to provide a bridge that has a high strength and can be quickly constructed and removed.

The perspective view which concerns on 1st embodiment of this invention. The exploded perspective view concerning the embodiment. Structure explanatory drawing which concerns on 2nd embodiment of this invention. Structure explanatory drawing which concerns on 3rd embodiment of this invention. Explanatory drawing of the principal part which concerns on the same embodiment. Same as above. Structure explanatory drawing which concerns on 4th embodiment of this invention. Same as above. Structure explanatory drawing which concerns on 5th embodiment of this invention.

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  The bridge B according to the present embodiment is constructed over a so-called medium and small river R in which the distance between both river banks R2 is less than 15 m, for example. This bridge B has been replaced by a new one after removing the existing bridge that has reached the end of its useful life, or upstream or downstream of the target bridge at the time of the replacement It is used as a temporary bridge that is temporarily built to secure traffic at a position close to the road.

  As shown in FIG. 1, the river R has a riverbank R2 formed by on-site concrete placed so as to harden the surface of the earth and sand D in the region near the bridge B, and the riverbed R1 has gravel as usual. The earth and sand consisting of etc. are arranged. Of course, water flows from the upstream to the downstream while maintaining a constant water level in the river R, but the illustration of the water is omitted in this embodiment.

  As shown in FIGS. 1 and 2, the bridge B according to the present embodiment mainly includes a precast box culvert (hereinafter referred to as a box culvert) 1 arranged so that the opening portion is opened in the flow direction of the river water. The upper side of the box culvert 1 has a road surface forming portion 4 mainly composed of concrete or asphalt, for example. The road surface 40 is continuous with the pavement surface H1 of the road H on the riverbank R2 side so that a vehicle or the like can appropriately travel on the road surface 40 which is the upper surface of the road surface forming portion 4. Further, below the road H adjacent to the bridge B, a tread plate F made of, for example, a concrete plate is provided.

  As shown in the figure, the box culvert 1 has, for example, a square ring shape in front view, which includes a bottom plate 11, a side plate 12 raised from the bottom plate 11, and a top plate 13 installed between the side plates 12. It is a concrete secondary product. The box culvert 1 has a plurality of concrete members 2 divided along the extending direction of the river R. In this embodiment, for example, as shown in FIGS. 1, 3, and 4, the box culvert 1 is configured by continuously arranging six concrete members 2 in the same figure in a plan view. The number and dimensions of the concrete members 2 are appropriately changed according to the size of the bridge B and the like. Of the plurality of concrete members 2, at the upper ends of the end concrete members 21 arranged at both ends, there is a ground cover forming portion 9 for standing from the outside of both ends in the width direction of the road surface 40 to form a ground cover. Is provided. Specifically, the end concrete member 21 constituting the box culvert 1 is integrally provided with a ground cover forming portion 9 formed with handrails and the like. And in the example of illustration which intervenes between these both ends concrete members 21 in the part except the ground cover formation part 9 in the end concrete 21, the upper surface of four intermediate concrete members 20 is a support surface to which a load from a road surface is transmitted 22 In this embodiment, as shown in FIG. 2, when the box culvert 1 is constructed, the foundation concrete SC is placed on the support layer S mainly composed of crushed stones provided in advance. The box culvert 1 is disposed on the foundation concrete SC.

  Moreover, since the bottom of the bottom slab 11 of the box culvert 1 is made of earth or sand or cast-in-place concrete up to a height equal to the top surface in the present embodiment, the top surface becomes the river bottom forming surface 15. The side plate 12 is erected upward from both sides of the bottom plate 11, and in this embodiment, the inward surface is a river bank forming surface 19 configured to be substantially flush with the river bank R2. The top plate 13 is set so that the entire upper surface 16 receives a load from above. In the present embodiment, the road surface forming portion 4 is directly provided over substantially the entire upper surface 16 of the top plate 13. In this embodiment, the haunch 1h is formed by thickening the concrete so that a part of the inner surface side between the bottom plate 11 and the side plate 12 and between the side plate 12 and the top plate 13 is inclined. Is provided. Further, in the present embodiment, a duct 14 for forming a tightening portion 30 is formed in order to allow a tension material such as a PC steel material (not shown) to pass through the haunch 1h. In the present embodiment, for example, four ducts 14 are formed on the top plate 13, but the duct 14 formed on the top plate 13 will be described later.

  As shown in FIGS. 1 and 2, the road surface forming portion 4 is made of, for example, asphalt or concrete that is normally provided in order to form a road surface 40 that allows a vehicle or the like to pass through on the upper surface. . In the present embodiment, the road surface forming portion 4 formed in a single layer is illustrated, but of course, a road surface sign required for road traffic is separately provided on the road surface 40, or a median strip or illumination lamp is separately installed. For example, various modes can be applied.

  In the present embodiment, the tightening portion 30 uses a total of four ducts provided in the haunch 1h, for example, using PC steel, draws the concrete members 2 together, and compresses the concrete members 2 together. It is for introducing stress. In the present specification and the drawings, only the duct 14 provided in the haunch 1h for attaching the tightening portion 30 is illustrated, and the nut and other accommodation holes are not shown. Although the illustration and detailed description of the tightening portion 30 are omitted, the PC steel material, a plate for inserting the PC steel material, and an end of the PC steel material to press the plate are screwed as an example. It is an existing one with a nut.

  Usually, prestress is applied to the plurality of concrete members 2 arranged on the foundation concrete SC by the tightening portion 30. Thereby, the laying of the box culvert 1 having a high strength is almost completed.

  Therefore, the bridge B according to the present embodiment has a load applied to one of the plurality of concrete members 2 constituting the box culvert 1 in addition to the box culvert 1 and the road surface forming portion 4. As an example of load distribution means that can be distributed to the concrete member 2, the top plate side tightening portion 3 is provided. The top plate side tightening portion 3 applies prestress to the top plate 13 in the joining direction of the plurality of concrete members 2. That is, prestress greater than that on the bottom plate 11 side is applied to the top plate 13 side. The specific configuration of the top plate side tightening portion 3 is the same as that of the tightening portion 30. Therefore, when laying the box culvert 1, after the concrete members 2 are installed, prestressing work by the top plate side tightening part 3 is performed together with prestressing work by the tightening part 30.

  That is, for example, when a vehicle or the like passes on the road surface 40, depending on the width dimension of the roadway, for example, the concrete member 2 having the support surface 22 that the tire frequently passes and receives the load is adjacent to the concrete member 2. Steps in other words, in other words, there is a step at the boundary between the support surfaces 22, and the step may give an unnecessary external force to the road surface forming portion 4, and as a result, an unnecessary step may be formed on the road surface 40. .

  On the other hand, the concrete member 2 that frequently receives a load may deteriorate in a shorter period of time than the concrete member 2 that has a relatively small opportunity to receive a large load from the support surface 22. Then, the strength and durability of the former concrete member 2 alone are set as the strength of the entire box culvert 1 as it is, and the original strength of the box culvert 1 itself may not be effectively utilized.

  Therefore, in this embodiment, when the support surface of any concrete member receives a load, the load is distributed to the other concrete member 2 via the top plate side tightening portion 3, and the top plate of the box culvert 1. As a whole, the load can be received. Accordingly, the problem that unnecessary external force is applied to the road surface forming portion 4 due to the step generated at the boundary between the support surfaces 22 and unnecessary irregularities are formed on the road surface 40 is solved. In addition, the bridge B having both high strength and durability as a whole is realized without causing only the specific concrete member 2 to directly cause local deterioration due to the traffic situation on the road surface 40.

  By adopting the above-described configuration, the bridge B according to the present embodiment applies a large load only to some of the concrete members 2 due to, for example, a load of a vehicle tire among the concrete members 2 constituting the box culvert 1. When the top plate side tightening portion 3 serving as a load dispersing means is provided when bending is caused, a step that causes an unnecessary external force to be applied to the road surface forming portion 4 by dispersing the load is generated. It is effectively avoided. In addition, by providing the top plate side tightening portion 3, it is possible to effectively avoid the problem that the load is dispersed and the load is locally concentrated on the box culvert 1, and the bridge B as a whole has a substantial strength. It is effectively improved. By using the box culvert 1 that is a precast concrete product, the construction period can be shortened by realizing rapid construction while avoiding unnecessary increase in construction scale. Also, by using precast concrete products, withdrawal after construction can be performed more quickly than in-situ concrete. Therefore, even if the bridge B according to the present embodiment is applied as an object to be replaced with an existing bridge, or is applied as a temporary bridge to be temporarily constructed when the bridge is replaced, an unnecessary increase in the construction scale is avoided. Realizing a quick construction can substantially contribute to shortening the construction period.

  That is, in this embodiment, the top plate side tightening portion 3 is applied as one aspect of the load distribution means that can be realized labor-saving while effectively utilizing the characteristics of the box culvert 1. Providing the top plate side tightening portion 3 contributes to the improvement of the strength of the box culvert 1 itself.

  Further, in this embodiment, as a measure for realizing further shortening of the construction period and easy construction, the box culvert 1 is erected from the outside of both ends in the width direction of the road surface 40 to form a ground cover. Part 9 is provided. Thereby, the process after laying of the box culvert 1 at the time of bridge B construction is shortened effectively.

  Hereinafter, each embodiment according to the present invention will be sequentially described. Here, among the constituent elements described below, those corresponding to the constituent elements described in the embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

<Second embodiment>
A second embodiment of the present invention will be described with reference to FIG. In this embodiment, a load distribution unit according to an aspect different from the aspect disclosed in the first embodiment will be described. That is, the aspect in which the load is “dispersed” by the load distributing means according to the present invention may be before or after the load is actually applied to the concrete member 2. That is, after the load is applied to the concrete member 2, the load is distributed among the concrete members 2 to be distributed to the other concrete members 2. A mode in which the load is transmitted to the plurality of concrete members 2 after the load is dispersed in plan view in advance is also included.

  That is, in the present embodiment, as load distribution means different from the top plate side tightening portion 3 according to the above embodiment, the plan view overlaps over the plurality of concrete members 2 provided between the top plate 13 and the road surface forming portion 4. It is assumed that a step-suppressing plate 5 having a plate shape is provided.

  The step-suppressing plate 5 is, for example, a cast-in-place concrete placed over substantially the entire area of the top plate 13 after the box culvert 1 is laid. You may comprise by.

  In addition to the embodiment shown in the figure, the step suppressing plate 5 is not limited to a single one as long as it is configured to extend over a plurality of concrete members 2, and is orthogonal to the connection direction of the plurality of concrete members 2. A plurality of plate-like members connected in the direction may cover substantially the entire area on the top plate 13.

<Third embodiment>
A third embodiment of the present invention will be described with reference to FIGS. 4, 5 and 6. In the present embodiment, the load distribution means has the top plate side tightening portion 3 as in the first embodiment, and the top plate 13 is adjacent to the tread plate F for allowing the road surface 40 to continue to the river bank at both ends in the extending direction. In this embodiment, the box culvert 1 is integrally formed with a plate support 10 that supports the end of the stepping plate F from below. According to this aspect, it is possible to easily eliminate unnecessary steps between the road surface 40 on the bridge B and the road surface 40 on the river bank side connected to the road surface 40, and the performance as the bridge B can be effectively improved. Hereinafter, specific modes of the present embodiment will be described with reference to FIGS. 5 and 6. In both of these figures, in the vertically spaced space formed between the receiving surface 10a, which is the upper side surface of the plate receiving base 10, and the bottom surface of the end portion of the stepping plate F, the receiving surface 10a and the surface of the stepping plate F are provided. An intervening member 8 made of a cushioning material such as urethane is provided for adjusting slight unevenness, in other words, unevenness. In the space formed on the plate receiving base 10 between the end surface of the top plate 13 and the end surface of the tread plate F and separated in the surface direction, the bitumen 6 made of asphalt or the like is arranged in FIG. FIG. 6 shows an embodiment in which the high elastic adhesive 7 is filled.

  The highly elastic adhesive 7 shown in FIG. 6 will be described. In the present embodiment, the high elastic adhesive 7 exhibits an excellent value of, for example, 100% to 300% in the elongation capacity, and an appropriate density can be selected. As this highly elastic adhesive 7, for example, a material for an injection method or a material for a caulking method mainly composed of a main agent made of an epoxy resin and a curing agent made of a modified silicone can be used. In addition to the main agent and the curing agent, an ultralight powder or the like may be appropriately added to the highly elastic adhesive 7 in order to obtain the above density. This high-elasticity adhesive 7 has four types according to the temperature conditions that change depending on the season and environment of construction. Among them, the most suitable one for the caulking method can be selected from the three types for general use, winter use and cold district use. Furthermore, by appropriately adding a catalyst to the curing agent and controlling the reaction rate, it is possible to obtain an appropriate pot life suitable for the outside air temperature and to keep the construction completion time within an appropriate range suitable for the outside air temperature. it can.

  If the high-elastic adhesive 7 is filled in this way, it is possible to more effectively avoid the formation of an unnecessary gap between the box culvert 1 and the stepping plate F due to vibration after the bridge B is constructed. .

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the present embodiment, as shown in the figure, the box culvert 1 has a drainage groove 91 and a pipe accommodating portion 92 as a space forming portion that forms a space in the vicinity of the road surface 40 along the extending direction of the road surface 40. The aspect which is shown is shown. More specifically, a space forming portion is provided below the ground cover forming portion 9, the ground cover forming portion 9 is configured separately from the concrete member 2, and an embodiment in which the space forming portion 9 is assembled on the support surface 22 is illustrated. Yes. That is, the ground cover forming portion 9 may be integral with or separate from the concrete member 2. In the embodiment shown in FIGS. 7 and 8, the ground member is covered with the concrete member 2 having the same shape. Can be provided.

  FIG. 7 shows a mode in which the space forming portion is used as a drainage groove 91 for discharging water flowing from the road surface 40 to the outside of the road surface 40. More specifically, water such as rainwater on the road surface 40 is guided to the drainage groove 91 via the slit 91a provided at a position close to the road surface 40, and can be quickly discharged.

  FIG. 8 shows a mode in which the space forming part is used as the pipe housing part 92 by passing the pipe through the cavity formed on the lower side inside the ground cover forming part 9. Of course, the pipes accommodated in the pipe accommodating part 92 can accommodate the pipes provided on the bridge before the replacement and various new pipes.

In addition to the above, the space forming portion may be used as a snow melting device housing portion for housing a snow melting device that melts snow and ice on the road surface.
<Fifth embodiment>
A fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, as the concrete member 2 constituting the box culvert 1, a configuration having an overhanging floor slab HD, that is, a configuration in which the top plate 13 and the tread plate F are integrally formed is applied. More specifically, the concrete member 2 includes a lower concrete member constituting portion 2a having a U-shape in front view formed by integrally forming a bottom plate 11 and a lower plate portion 121 erected from both ends of the bottom plate 11, and A pair of upper plate portions 122 connected to the upper end portion of the lower plate portion 121, a top plate 13 installed between the upper end portions of the upper plate portion 122, and horizontal edges from the left and right edges of the top plate 13, respectively. And an upper concrete component 2b having a getter shape in a front view formed integrally with a foot plate F extending in the direction. The tread plate F is supported in the form of a cantilever at the upper end portion of the upper plate portion 122 and the left and right edge portions of the top plate 13. The free end (outward end) of the tread plate F can be connected to the riverbank R2. The side plate 12 is mainly composed of a lower plate portion 121 and an upper plate portion 122. Note that the overhanging floor slab HD in which the top plate 13 and the stepping plate F are integrally formed is prestressed in the horizontal direction by a tension material such as a PC steel material (not shown). In addition, the bottom slab 11 is configured so that a plurality of piles K can be driven from the upper surface side of the bottom slab 11 toward the support layer S side in order to favorably support the foundation concrete SC and the support layer S. . In this embodiment, a twisted flat steel pile formed by twisting a flat steel material is used as the pile K. The plurality of piles K uses a pile driving machine or employs a manual hitting method to closely connect the bottom slab 11 to the foundation concrete SC and the support layer S. Thus, if it is a thing of 5th embodiment, since it has the structure with the overhanging floor slab HD which integrally provided the top plate 13 and the tread plate F, it constructs as it is, without destroying the existing revetment This will contribute to the simplification of the construction and the shortening of the construction period.
Further, since the bottom plate 11 is closely connected to the support layer S by the pile K, the box culvert 1 is prevented from sinking due to the load applied from above while suppressing the sliding of the box culvert 1 due to the collision of water flow or drifting material. be able to.

  Although the embodiment of the present invention has been described above, the specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, a mode is described in which the bridge is configured by a single precast box culvert having a square ring shape in front view. However, the present invention is not limited to a precast box culvert having an opening that is closed in front view. For example, a precast box culvert in which the bottom plate is divided in the width direction in front view is installed, and then the separated bottom plates are connected to each other by precast concrete forming a separate plate or cast-in-place concrete. May be. Of course, the precast box culvert need not be a single one as long as the top plate is arranged over the entire area between both riverbanks. That is, the bridge may be configured by arranging two or more precast box culverts so that the top plates are continuous. In addition, as a shape of the precast box culvert, a shape in which three or more side plates are continuous with respect to a single top plate may be used.
The precast box culvert may have a configuration having a U-shaped concrete member when viewed from the front. For example, a bottom plate and left and right side plates standing upright from both ends of the bottom plate are integrally formed to form a U-shaped concrete member and a side of the concrete member forming the U-shaped front view. You may make it comprise the box culvert which has the structure of a square shape in front view with the top plate which is another concrete member erected between the plates.

In the above embodiment, the bridge constructed so that the riverbank and the side plate are flush with each other is disclosed, but depending on the shape of the riverbank, the side plate is arranged at a position where the side plate is recessed from the surface of the riverbank. In addition, the cast-in-place concrete may be placed on the inner surface side of the side plate so as to be flush with the riverbank. In addition, specific aspects such as the top plate side tightening part, the ground cover forming part, and the use form of the space forming part are not limited to those of the above-described embodiment, but various aspects including the existing ones. Can be applied.
In order to favorably support the bottom plate to the foundation concrete and the support layer, a plurality of piles may be driven from the upper surface side of the bottom plate toward the support layer side. In other words, the bottom plate may be connected to the support layer by a plurality of piles. Various types of piles can be used, and an example is a twisted flat steel pile formed by twisting a flat steel material. A plurality of flat steel piles can connect a bottom slab closely to foundation concrete or a support layer by using a pile driving machine or using a hitting method by human power.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used as a bridge constructed in a river.

1. Precast box culvert (box culvert)
DESCRIPTION OF SYMBOLS 10 ... Plate stand 11 ... Bottom plate 12 ... Side plate 13 ... Top plate 2 ... Concrete member 3 ... Load distribution means (top plate side tightening part)
4 ... Road surface formation part 40 ... Road surface 5 ... Load distribution means (step suppression plate)
9 ... Ground cover forming part 91 ... Space forming part (drainage groove)
92 ... Space forming part (pipe housing part)
B ... Bridge R ... River F ... Staddle version

Claims (8)

A bridge built over a river with a distance of less than 15m between the two banks,
A bottom plate, a side plate standing up from the bottom plate, and a top plate extending between the two riverbanks sandwiched between the side plates and sandwiching the river, and arranged side by side in a direction perpendicular to the extending direction of the top plate A precast box culvert formed by joining a plurality of concrete members,
A road surface forming part that covers the upper side of the top plate and that has an upper surface as a road surface that allows passage of the vehicle;
A bridge having load distribution means capable of distributing a load applied from above to one of the plurality of concrete members to other concrete members. The bridge according to claim 1, wherein the load distribution means is a top plate side tightening portion that applies prestress to the top plate in a joining direction of the plurality of concrete members. 2. The step suppressing plate according to claim 1, wherein the load distribution means is a step-suppressing plate that is provided between the top plate and the road surface forming portion and has a plate shape that overlaps the plurality of concrete members in plan view. Bridge. The top plate is adjacent to a stepping plate for continuation of the road surface on the river bank at both ends in the extending direction, and the precast box culvert is integrally formed with a plate base that supports the end of the stepping plate from below. The bridge according to claim 1, 2 or 3, which is formed. The bridge according to claim 1, 2, 3, or 4, wherein the precast box culvert has a ground cover forming portion for standing from the outside in the width direction of the road surface to form a ground cover. The bridge according to claim 1, 2, 3, 4, or 5, wherein the precast box culvert has a space forming portion that forms a space in the vicinity of the road surface along the extending direction of the road surface. The bridge according to claim 1, wherein the concrete member is provided with an overhanging slab in which the top plate and a stepping plate for continuing the road surface on the river bank side are integrally formed. The bridge reinforcing method according to claim 1, wherein the bottom plate is connected to the support layer by a plurality of piles.

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