JP4491820B2 - Precast bridge - Google Patents

Description

  The present invention relates to a precast bridge constituting, for example, an interchange on a highway.

  Many roads in narrow cities such as the Metropolitan Expressway have curved roads such as interchanges.

  The development of such a road network is proceeding at a rapid pace in conjunction with the Tokyo Olympics, etc., and the construction of bridges that make up interchanges, etc., emphasizes how to shorten the construction period. Suitable steel bridges were frequently used.

  However, in the conventional technologies as described above, there is a problem that the cost increases due to the heavy use of steel bridges, and this problem is inherited even now, and even if there are bridges that have passed the useful life, they are replaced due to the budget. There was a problem that was left unattended.

  On the other hand, a method has been developed to reduce the cost of bridge construction by converting the structural parts of the bridge into precast concrete to save labor at the construction site. For example, as shown in FIG. 8, a precast concrete abutment 1 is connected to the beginning of the bridge. In addition, a structure in which a main girder 2 made of precast concrete is installed on both ends and supported by both abutments 1 is known.

  However, in this structure, since the main girder 2 is supported at the top end of the anchor wall, there is a problem that a part of the ground reaction force increases, the strength against falling is insufficient, and a pile support structure is required.

  Further, in such a conventional bridge, a scorpion is interposed between the abutment and the main girder, and there is a problem that the cost is increased because this scorpio, particularly the seismic scorpio is expensive.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a precast bridge capable of reducing cost and having excellent earthquake resistance.

  In order to solve the conventional problems as described above and achieve the intended purpose, the invention according to claim 1 is the precast concrete in which precast concrete abutments are installed at the start and end of the bridge and supported by the abutment. In the precast bridge constructed with a main girder made of steel, the abutment protrudes toward the other end of the bridge integrally with the vertical retaining wall portion sharing the retaining wall and the lower end of the retaining wall portion. A precast concrete abutment unit comprising a bottom plate portion provided and a top portion of the retaining wall portion as a parapet portion, and a pedestal projecting downward toward the other end of the bridge integrally therewith, The main girder is configured by arranging a plurality of the girder in the width direction, and a rectangular plate-shaped portion, a downward side wall hanging downward and a wall hanging from both ends projecting integrally from the lower surface periphery. And said Wherein the parts hanging wall and the said parapet portion is fixed precast bridge with a coupler.

  The invention according to claim 2 is characterized in that, in addition to the structure of claim 1, a plurality of main girders are installed side by side on the pedestal of the abutment provided at the start and end of the bridge, side by side.

  According to a third aspect of the present invention, in addition to the configuration of the first aspect, one or more piers are erected at an intermediate position of the bridge, and an end portion of the main girder is provided on a pedestal provided at the upper end of the pier. And the end hanging wall of the main girder is fixed with a connecting tool.

  In addition to the structure of claim 3, the invention according to claim 4 has an inverted T-shaped cross section in which a wall pier-shaped support column is integrally erected on a flat horizontal base. A plurality of precast concrete pier units in which a pedestal is integrally formed at the upper end of the support column are arranged in the bridge width direction.

  In addition to the structure of Claims 1-3 or 4, the invention of Claim 5 interposes a saddle between the base of the abutment and the pier and the main girder, and fixed between the pedestal and the main girder with a connecting bolt. It is characterized by that.

  The precast bridge according to the present invention has precast concrete abutments installed at the beginning and end of the bridge, and precast concrete main girders are installed on the abutment so that not only the superstructure but also the substructure can be precast. Labor saving and construction time can be reduced at the construction site, cost can be reduced, and quality is improved because everything is a factory product.

  The abutment includes a vertical retaining wall portion that shares a retaining wall, a bottom plate portion projecting toward the other end of the bridge integrally with the lower end of the retaining wall portion, and an upper end of the retaining wall portion. By configuring a parapet part and installing a plurality of precast concrete abutment units arranged side by side in the width direction of the bridge. The ground reaction force is distributed in a trapezoidal shape, and a stable state can be obtained without supporting piles.

  The main girder has a rectangular flat plate portion, and downward facing both side hanging walls and both side hanging walls continuously projecting from the peripheral edge of the lower surface, thereby reducing the cost by reducing the cross section. Can be planned.

  By fixing the end hanging wall and the parapet part with a connector, an earthquake-resistant structure can be obtained with a simple structure without using an expensive saddle.

  Moreover, transportation and construction are facilitated by laying a plurality of main girders side by side while supporting both ends on the pedestal of the abutment provided at the start and end of the bridge.

  Further, one or a plurality of piers are erected at an intermediate position of the bridge, and are supported on a pedestal provided at the upper end of the pier with the ends of the main girders being abutted against each other. By fixing the hanging wall with a connector, the main girder can be suitably connected and a long bridge can be constructed.

  Furthermore, the bridge pier is made of precast concrete in which a cross-section in which a wall-plate-like column portion is erected on a flat horizontal base is an inverted T-shape, and a pedestal is integrally formed at the upper end of the column portion. Conveying and construction can be efficiently performed by arranging a plurality of bridge pier units in the bridge width direction.

  Moreover, by providing a saddle between the pedestal of the abutment and the pier and the main girder and fixing between the pedestal and the main girder with a connecting bolt, earthquake resistance can be obtained with an easy structure.

  Next, the precast bridge according to the present invention will be described.

  1 and 2 show an outline of an example of a precast bridge according to the present invention, and reference numeral 10 in the figure denotes a precast bridge.

  The precast bridge 10 includes an abutment 11 installed at the start and end of the bridge, and main girders 12, 12... Supported by the abutments 11, 11. A floor board 13 is formed on the main girder 12. Yes. In the figure, reference numeral 14 denotes a high column.

  The abutment 11 is formed by arranging precast concrete abutment units 16, 16... In the bridge width direction on the foundation 15.

  Each unit 16, 16... Is preferably integrated by inserting a PC tendon in the bridge width direction and introducing prestress with the PC tendon.

  The abutment unit 16 includes a vertical retaining wall portion 17 sharing a retaining wall, a bottom plate portion 18 projecting from the lower end of the retaining wall portion 17 toward the other end of the bridge, and an upper end of the retaining wall portion 17 as a parapet portion. 17a, and a pedestal portion 19 projecting toward the other end of the bridge integrally therewith.

  Retaining wall part 17 is formed in the shape where the back was inclined, and receives earth pressure from back side ground 20.

  The bottom plate portion 18 projects integrally with the lower end of the retaining wall portion 17 and supports the retaining wall portion 17.

  The parapet portion 17a is formed with a connector insertion hole 21 penetrating in the thickness direction of the retaining wall, a fixing portion 22 is formed at the outer opening thereof, and a support plate 23 is disposed at the bottom thereof.

  The pedestal portion 19 includes a flat surface portion 19a on which the end portion of the main girder 12 is placed on the upper surface, and the end portion of the main girder 12 is placed on the flat surface portion 19a via a flange 24 made of a rubber plate or the like. It has become so.

  In addition, anchor bolts 25 are embedded in the pedestal portion 19 in an arrangement in which one end side protrudes upward from the flat surface portion 19a.

  As shown in FIG. 3, the main girder 12 has a rectangular flat plate portion 30, both end hanging walls 31 and both side hanging walls 32 that are integrally projected continuously from the peripheral edge of the lower surface, Both ends thereof are supported by the pedestal of the abutment 11, and a plurality of them are installed side by side in the bridge width direction.

  In the end hanging wall 31, a connector insertion hole 33 penetrating in the thickness direction is formed in an arrangement communicating with the connector insertion hole 21 of the parapet portion 17a.

  As shown in FIG. 4 and FIG. 5, bolts 34 having threaded portions at both ends are inserted into the connecting tool insertion holes 21 and 33 of the parapet portion 17a and the end hanging wall 31 as shown in FIGS. The nuts 35 and 35 are tightened, both end portions are fixed to the parapet portion 17 a and the end portion hanging wall 31, respectively, and the parapet portion 17 a and the end portion hanging wall 31 are integrated.

  In addition, a vertical bolt insertion hole 36 is formed in the end hanging wall 31 in accordance with the position of the anchor bolt 25.

  A bolt mounting portion 37 is formed at the upper end of the bolt insertion hole 36, and when the main girder 12 is placed on the abutment 11, that is, when the end of the main girder 12 is disposed on the pedestal portion 19. The tip of the anchor bolt 25 protruding from the portion 19 is inserted into the bolt insertion hole 36 and protrudes into the bolt mounting portion 37. The main girder 12 is fixed to the pedestal portion 19 by screwing a nut 38 into the tip of the projecting bolt 25 and fixing the nut 38 to the bearing plate 39 arranged at the bottom of the bolt mounting portion.

  The side hanging wall 32 is integrally provided with an arcuate arch portion 40 whose lower edge portions 40a and the end surface of the pedestal portion 19 are in contact with each other.

  As described above, the side edge portion 40a of the arch portion 40 and the pedestal portion 19 are in an associated arrangement, thereby restricting movement in the horizontal direction.

  Further, by providing the arch portion 40 in this manner, the comfort and aesthetics of the lower road 41 formed under the girder are improved.

  In addition, a plurality of connecting bolt holes are formed in the side portion hanging wall 32 at intervals in the longitudinal direction, and the connecting portions are connected to the side portion hanging walls 32 and 32 of adjacent main girders arranged to face each other. The bolts 42, 42.

  In the figure, reference numeral 43 denotes an expansion joint.

  In the precast bridge 10 configured in this way, since the superstructure and the substructure are composed of precast members, labor saving and improvement in product quality are achieved at the site, and costs are reduced. .

  In addition, by providing a base 19 on the abutment 11 and supporting the main girder 12 there, the ground reaction force distribution becomes trapezoidal as shown in FIG. 6, and the abutment 11 is stabilized without using foundation piles or the like. .

  Furthermore, the abutment 11 and the main girder 12 are integrated by connecting the parapet portion 17a and the end hanging wall 31 with a connecting tool, that is, a bolt, so that the earthquake resistance can be shared.

  In addition, since the parapet portion 17a and the end hanging wall 31 are connected by a connecting tool, an inexpensive hook member such as a rubber plate can be used without using an expensive hook used in a conventional bridge. Economical.

  Further, as shown in FIG. 7, the bridge according to the present invention has abutments 11 and 11 arranged at the start and end of the bridge, and a pier 50 is erected at an intermediate position of the bridge, and the abutment 11 and the pier 50 are connected to each other. While supporting the both ends, the main girders 12 and 12 may be supported in a butt arrangement on a pedestal provided at the upper end of the pier 50. In addition, the same code | symbol is attached | subjected to the part same as the above-mentioned Example, and description is abbreviate | omitted.

  The main girder 12 has a rectangular flat plate portion 30 and a downward end hanging wall 31 and a side hanging wall 32 that are integrally projected on the peripheral edge of the lower surface of the flat plate portion 30 as in the above-described embodiment. Then, bolts are inserted between the end drooping walls 31 and 31 abutted with each other on the pedestal of the bridge pier 50, and nuts are fastened to both ends thereof and fixed to the outer surface portion of the end drooping wall 31, thereby the both end drooping walls 31. , 31 are connected.

  The bridge pier 50 is formed in a reverse T-shaped cross-section in which a wall-plate-like column part 52 is erected on a flat horizontal base 51, and a pedestal on which the end of the main girder 12 is supported at the upper end of the column part 52. The part 53 is integrally formed.

  Anchor bolts 54, 54 are embedded in the pedestal 53 so that one end protrudes upward from the upper surface of the pedestal 53, and passes through a bolt insertion hole 36 formed in the end hanging wall 31 of the main girder 12. The base 53 and the main girder 12 are fixed by tightening the nut.

  An expansion joint is interposed between the main girders 12 butted on the pedestal 19.

  In the above-described embodiment, the example in which the end portion hanging wall 31 and the parapet portion 17a or the hanging wall is connected by a bolt has been described. However, a PC tension material or the like may be used as a connecting tool.

It is a side view which shows an example of the precast bridge which concerns on this invention. It is a top view same as the above. It is a bottom view which shows the main beam in FIG. It is a partial expanded sectional view which shows the junction part of the abutment and main girder in FIG. It is a top view same as the above. It is a figure which shows the distribution state of a ground reaction force. It is a side view which shows another example of the precast bridge which concerns on this invention. It is a side view which shows an example of the conventional precast bridge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Precast bridge 11 Abutment 12 Main girder 13 Floor board 14 Rail 15 Base 16 Abutment unit 17 Retaining wall part 17a Parapet part 18 Bottom plate part 19 Base part 19a Plane part 20 Ground 21 Connector insertion hole 22 Fixing part 23 Support plate 24 Rubber (Rubber) Board)
25 anchor bolt 30 flat plate portion 31 end portion hanging wall 32 side portion hanging wall 33 connecting tool insertion hole 34 PC steel rod 35 nut 36 bolt insertion hole 37 bolt mounting portion 38 nut 39 bearing plate 40 arch portion 40a edge portion 41 lower road 42 bolts 43 expansion joints 50 piers 51 horizontal foundations 52 support sections 53 pedestal sections 54 anchor bolts

Claims (5)

In precast bridges where precast concrete abutments are installed at the beginning and end of the bridge, and precast concrete main girders are installed on the abutment,
The abutment includes a vertical retaining wall portion sharing a retaining wall, a bottom plate portion projecting toward the other end of the bridge integrally with the lower end of the retaining wall portion, and an upper end of the retaining wall portion. The parapet part is constructed by installing a plurality of precast concrete abutment units arranged side by side in the width direction of the bridge, and a pedestal projecting toward the other end of the bridge integrally with the parapet part.
The main girder has a rectangular flat plate portion, a downward both side hanging wall and both end hanging walls continuously projecting integrally from the lower surface peripheral edge portion thereof,
The precast bridge characterized by fixing the said end drooping wall and the said parapet part with the connection tool.   The precast bridge according to claim 1, wherein a plurality of main girders are arranged side by side on the pedestal of the abutment provided at the start and end of the bridge, with both ends supported.   One or a plurality of piers are erected at an intermediate position of the bridge, and supported on the pedestal provided at the upper end of the pier with the ends of the main girder butted against each other, and the end hanging wall of the main girder The precast bridge according to claim 1, which is fixed by a connecting tool.   The bridge pier unit is a precast concrete pier unit in which a wall-plate-like column part is integrally erected on a flat horizontal base, and the cross section has an inverted T shape, and a pedestal is integrally formed at the upper end of the column part. The precast bridge according to claim 3, which is configured by arranging a plurality of bridges in the bridge width direction.   5. The precast bridge according to claim 1, wherein a pedestal is interposed between the base of the abutment and the pier and the main girder, and the space between the pedestal and the main girder is fixed with a connecting bolt.