JP2011089276A - Reinforcing structure and reinforcing method of bridge pier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing structure and a reinforcing method of a bridge pier, which achieves excellent workability of construction work and reinforces the existing bridge pier certainly. <P>SOLUTION: In this reinforcing method, concrete 19a as first concrete is placed between the pair of webs 27 of a bridge girder, a plurality of holes are formed in the web 27, a steel material 13a as a first steel material is provided to sandwich in the concrete 19a between the pair of webs 27 and pass through the webs 27 and the concrete 19a, the steel material 13a is inserted into a sheath, the inside of the sheath is filled with grout while it is tightly stretched in substantially horizontal direction between both of the webs 27, and the steel product 13a (PC steel product) is fixed on the webs 27 on both sides through an anchor plate or the like. That is, a prestress force in the horizontal direction is applied on the concrete 19a, thereby generating a strong frictional force on a contact face with the webs 27. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reinforcing structure for a bridge that reinforces an existing aging bridge and a method for reinforcing the same.

  Conventionally, new bridges have been constructed and bridges have been replaced for aging bridges. However, since such bridge replacement requires a long construction period and site, it is necessary to reinforce existing bridges for bridges that are continuously used, such as railways.

  Various methods for reinforcing such bridges have been proposed. For example, a steel girder part and a pier part or an abutment part are joined, and the steel girder interface contacting the concrete of the joint part has a slip prevention. There is a method in which a perforated steel plate is provided and a steel girder portion and a bridge pier portion are directly integrally joined (for example, Patent Document 1).

JP 2000-319816 A

  In order to integrate the bridge girder (steel girder) and the abutment (concrete) as in Patent Document 1, it is necessary to prevent the concrete abutment and the steel girder from slipping. As such a shift prevention, there are a method using a perforated steel sheet as in Patent Document 1, a method in which a stud gibber is welded to a steel girder, a method in which other steel mold is welded, and the like. Further, there is a method of making a perforated steel plate gibber by perforating the web steel plate.

  However, as in the case of reinforcing an existing bridge, in the reinforcement of an aging bridge, there are cases where the material is not necessarily suitable for welding steel materials or stud gibber. In addition, it is necessary to form a large number of through holes in a steel beam in a method in which a large number of holes are provided in a steel plate to make a perforated steel plate dowel or a method in which reinforcing bars are arranged in a large number of holes. There is a risk that the strength will be insufficient due to the reduced cross-section of the hole. Also, such holes may promote the extension of existing fatigue cracks.

  In addition, in order to place concrete between steel girders, it is necessary to perform bar arrangement work in a narrow place, so that there is a problem that workability is poor. Furthermore, there is a method of reinforcing the steel girder and the abutment with a cane-like member, but there is a problem that the space under the girder is eroded and the necessary space cannot be secured, such as the construction limit cannot be secured. In addition, when the abutment is old, drilling is not appropriate due to strength problems and deterioration of the concrete, and it may be difficult to reinforce the abutment itself.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a bridge reinforcing method and a reinforcing structure that are excellent in workability and can reliably reinforce existing bridges.

  In order to achieve the above-described object, the first invention includes an abutment, a plurality of bridge girders installed on the abutment, a first concrete provided between the adjacent bridge girders, the bridge girder, and the first A second steel provided between the first concrete and the seat surface of the abutment, and the second steel A second steel material provided in a substantially vertical direction between the abutment and the first concrete so as to penetrate the concrete, the first concrete, the second concrete, and the abutment Is a reinforcing structure of a bridge characterized by being integrated with each other.

  The bridge girder has a web standing up in a substantially vertical direction, and an upper flange and a lower flange substantially perpendicular to the web at upper and lower ends of the web, respectively, and the first concrete is the web facing the adjacent bridge girder. The first steel material may be tensioned in a substantially horizontal direction so as to penetrate the web and the first concrete.

  The surface of the web may be subjected to surface roughening, and the upper surface of the upper flange that is the upper flange of the bridge girder and / or the upper surface of the lower flange that is the lower flange of the bridge girder An edge cutting material may be provided between the first concrete and the first concrete.

  Blocks are provided on the outer sides of the web, and the second steel material is provided between the abutment and the block instead of being provided between the abutment and the first concrete. It may be provided in the direction and strained.

  The bridge girder is provided on a support member provided on a seat surface of the abutment, and a buffer member is sandwiched between the support member and the abutment or between the support member and the bridge girder. It may be rare.

  A steel plate may be provided between the front surface of the abutment and above the bridge girder, and the steel plate may be joined to the first concrete and the second concrete. Moreover, a connection member may be provided between the first concrete and the embankment on the back surface of the abutment, and the abutment and the embankment may be integrated.

  According to the first invention, the first concrete is placed between the adjacent bridge girders (the web of the bridge girders), and the first concrete is sandwiched between the bridge girders, and is tensioned in the horizontal direction by the first steel material. Therefore, it is possible to prevent the first concrete and the bridge girder from being displaced by the friction of the contact surface between the first concrete and the web.

  In addition, the second concrete is placed between the first concrete placed between the web and the abutment, and the first concrete and the abutment are second so as to penetrate the second concrete. Since the steel material is tensioned in the vertical direction, the abutment and the first and second concrete are surely integrated. For this reason, an abutment and a bridge girder can be integrated.

  Further, a block is provided outside the bridge girder (the side opposite to the side where the first concrete is placed), and the block and the abutment can be tensioned with the second steel material. Also by this method, the bridge girder and the abutment can be reliably integrated.

  In addition, a steel plate is provided on the front surface of the abutment, and by joining the steel plate and the first and second concrete, against the positive bending moment applied to the bridge girder (direction in which the concrete on the front side of the abutment is pulled) The bridge girder (and the first concrete joined) is securely fixed.

  Further, by providing a connecting member that connects the first concrete and the embankment on the back surface of the abutment, the abutment and the embankment can be reliably integrated, and the embankment can be reinforced.

  In addition, the surface roughening process is applied to the surface of the web, so that the effect of preventing slippage due to friction can be obtained more reliably.If edge cutting materials are provided on the lower surface of the upper flange and the upper surface of the lower flange, When the first concrete is tensioned in the horizontal direction, the flange portion does not restrain the first concrete, and the tension force is efficiently introduced into the first concrete.

  In addition, if a buffer member is provided between the support member and the abutment or between the support member and the bridge girder, the support member directly receives the force received in the vertical direction when the second steel material is tensioned. There is no telling above. For this reason, for example, when a metal support member is used, the support member receives a tensile force in the vertical direction because the support member has higher rigidity than the surrounding concrete, and the support member becomes a seat surface of the abutment ( An excessive compressive force is not applied to the contact portion with the support member.

  According to a second aspect of the present invention, there is provided a bridge having an abutment, a plurality of bridge girders that are installed on the abutment and have a substantially vertically rising web, and flanges perpendicular to the web at the upper and lower ends of the web. A reinforcing method, comprising: placing a first concrete between the webs of adjacent bridge girders facing each other on the abutment, and extending the first concrete in a substantially horizontal direction so as to penetrate the web and the first concrete. The step (a) of providing and tensioning the steel material 1, and placing the second concrete between the first concrete and the abutment, and penetrating the second concrete, the abutment and the A step (b) in which a second steel material is provided in a substantially vertical direction and tensioned between the first concrete and the first concrete, and the first concrete, the second concrete, and the abutment are integrated. Specially It is a bridge method of reinforcement to be.

  According to the second invention, it is not necessary to perform welding such as welding of steel materials, stud-jiveled blasting, and providing a large number of holes in the steel plate and arranging reinforcing bars in the numerous holes, and in a narrow space. Since the bar arrangement work is not necessary, the workability is excellent, and the displacement between the first concrete and the web can be prevented by friction with the tension applied in the horizontal direction. Therefore, it is possible to obtain a bridge reinforcement structure that is reliably integrated with the abutment and is reinforced.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in workability | operativity and the reinforcement structure of a bridge which can reinforce an existing bridge reliably, and this reinforcement method can be provided.

It is a figure which shows the structure of the bridge 1, (a) is a whole front view, (b) is the AA sectional view taken on the line of (a) (cross-sectional view seen from the bridge axial direction). It is a figure which shows the construction process of the bridge 1, (a) is a whole front view, (b) is the sectional view on the AA line of (a). It is a figure which shows the construction process of the bridge 1, (a) is a whole front view, (b) is the sectional view on the AA line of (a). It is a figure which shows the construction process of the bridge 1, (a) is sectional drawing seen from the axial direction of the bridge 1, (b), (c) is an enlarged view of the abutment 3 vicinity in a front view. It is a figure which shows other embodiment of the bridge 1, (a), (b) is sectional drawing seen from the axial direction of the bridge 1. FIG. It is a figure which shows the state which provided the steel plate 39 in the bridge 1, (a) is an enlarged view of the abutment 3 vicinity in a front view, (b) is sectional drawing seen from the axial direction of the bridge 1. FIG. It is a figure which shows the state which provided the steel plate 41 in the bridge 1, (a) is an enlarged view of the abutment 3 vicinity in a front view, (b) is sectional drawing seen from the axial direction of the bridge 1. FIG. The figure which shows the state which provided the anchor 43. FIG. It is a figure which shows the state which provided the connection member 47, (a) is an enlarged view of the abutment 3 vicinity in a front view, (b) is a top view of the abutment 3 vicinity.

  Hereinafter, a method for reinforcing a bridge according to an embodiment of the present invention will be described. 1A and 1B are views showing the bridge 1, FIG. 1A is a front view of the bridge 1, and FIG. 1B is a cross-sectional view taken along line AA in FIG. The bridge 1 is provided with an abutment 3 on both sides so as to straddle a river or the like, and a bridge girder 5 is hung on the abutment 3.

  A bank 11 is formed on the back of the abutment 3. Above the abutment 3, a seat surface 7 on which the bridge girder 5 is installed is formed, and on the embankment 11 side, an abutment wall portion 21 that protrudes upward from the seat surface 7 and substantially matches the height of the upper surface of the bridge girder 5 is formed. Is done. A support member 9 that supports the bridge girder 5 is provided on the seat surface 7. A buffer member 23 is provided between the support member 9 and the seat surface 7 of the abutment 3. The buffer member 23 may be made of any material as long as it has elasticity such as foamed polystyrene and can be easily compressed and deformed. The buffer member 23 may be provided between the support member 9 and the bridge girder 5.

  The bridge girder 5 has an I-shaped cross section, and includes an upper flange 25a and a lower flange 25b projecting in a substantially horizontal direction vertically and a web 27 provided in a substantially vertical direction so as to connect the upper and lower flanges. The bridge girder 5 provided on the seat surface 7 (supporting member 9) of the abutment 3 is provided in plural (one pair in the figure) with a predetermined interval. A sleeper 15 is provided on the bridge girder 5 so as to straddle the pair of bridge girders 5, and a track 17 is further formed on the sleeper 15. The sleepers 15 and the tracks 17 pass through the bridge girder 5 and are laid on the bank 11 on both banks.

  As shown in FIG. 1B, concrete 19a, which is the first concrete, is provided between the webs 27 of the pair of bridge girders. A plurality of holes are formed in the web 27, and a steel material 13a that is a first steel material is provided so as to penetrate the web 27 and the concrete 19a (so that the concrete 19a is sandwiched between the pair of webs 27). The steel material 13a is inserted into a sheath (not shown), and the sheath is filled with grout and the like while being tensioned between both webs 27 in a substantially horizontal direction. The steel material 13a (PC steel material, for example, a PC steel rod is suitable) is fixed to the webs 27 on both sides with fixing plates or the like. That is, a prestressing force in the horizontal direction is applied to the concrete 19a, thereby generating a large frictional force on the contact surface with the web 27.

  Below the bridge girder 5, concrete 19 b that is second concrete is placed so as to fill the space between the concrete 19 a and the seat surface 7. The concrete 19a, 19b is integrated. At this time, the support member 9 and the buffer member 23 are embedded by the concrete 19b.

  A sheath (not shown) is provided so as to penetrate the concrete 19a, 19b and the abutment 3 in the vertical direction, and a steel material 13b, which is a second steel material, is provided in the sheath. The steel material 13b is inserted into the sheath, and grout or the like is filled in the sheath while being tensioned between the upper portion of the concrete 19a and the inside of the abutment 3. The steel material 13b, the concrete 19a, and the abutment 3 are fixed with a fixing plate or the like. That is, the prestressing force in the vertical direction is applied to the concrete 19a, 19b, and thereby the concrete 19a, 19b and the abutment 3 are integrated.

  The concrete 19a may be in close contact (joining) with the front side of the abutment wall 21 or may not be in close contact (joining) (in the drawing, the concrete 19a is provided up to the front of the abutment wall 21). However, a gap may be formed). Moreover, although illustration is abbreviate | omitted, the contact surface (The lower surface of the upper flange 25a, the upper surface of the lower flange 25b) of the concrete 19a, the upper flange 25a, and the lower flange 25b is not integrated, and an edge cutting material is provided. The edge cutting material may be any material that does not easily generate a horizontal restraining force between the concrete 19a and the flange surface, such as grease or polystyrene foam.

  As described above, the concrete 19a and the bridge girder 3 are prevented from being displaced by the friction of the contact surface, and the concrete 19a and 19b are integrated with the abutment 3, so that the bridge girder 5 and the abutment 3 are reliably integrated. For this reason, a rigid frame structure can be formed with the bridge girder 5 and the abutment 3.

  Next, the construction procedure for reinforcing the bridge 1 will be described. 2-4 is a figure which shows the reinforcement process of the bridge 1. FIG. In the following drawings, unless otherwise specified, an overall front view as shown in FIG. 1 or an AA line cross-sectional view in the overall front view is shown.

  First, as shown in FIG. 2A, in the existing bridge, the bridge girder 5 is supported by the support member 9 installed on the seat surface 7 of the abutment 3. In this state, the bridge girder 5 is not integrated with the abutment 3.

  From this state, first, concrete 19a can be placed between the webs 27 of the pair of bridge girders 5, and the molds 31a (for example, the front side of the abutment 3) and 31b (for example, the position of the lower flange 25b) are placed at predetermined positions. 19a (bottom side of 19a), 31c (in the vicinity of the fixing portion of the steel material 13b above the concrete 19a), and the like.

  A hole 29 is provided at a predetermined position of the web 27 (concrete 19a placement position). In addition, a sheath 33a is arranged in advance in the horizontal direction so as to match the position of the hole 29. The sheath 33 a is provided between the webs 27. At a predetermined position of the seat surface 7, a hole is provided in the vertical direction, and the sheath 33b is inserted into the hole. The upper end of the sheath 33b is provided up to the mold 31c. A steel material in the vertical direction, which will be described later, is fixed in the hole.

  At this time, the surface of the inner surface side (concrete 19a placement side) of the web 27 is roughened in advance. For example, unevenness may be formed on the surface of the web 27 by shot blasting using a steel ball or the like, or grid blasting using steel crushed particles, or the surface of the web 27 is cleaned and then an adhesive is applied. Unevenness is formed by blowing sand. By applying various surface roughening processes and roughening the surface of the web 27, the friction coefficient with the concrete can be increased. In addition, edge cutting materials are provided on the lower surface of the upper flange 25a and the upper surface of the lower flange 25b.

  Next, as shown in FIG. 3, concrete 19a is placed in the molds 31a, 31b, 31c and the like. The concrete 19a is placed between the webs 27 and between the upper flange 25a and the lower flange 25b. After the concrete 19a is consolidated, the formwork is removed. A steel material 13a is inserted into a sheath 33a (not shown) provided in the horizontal direction, the steel material 13a is tensioned in the horizontal direction, both ends are fixed to the web 27, and fixed by performing grouting.

  Next, as shown in FIG. 4A, the formwork 31d (for example, the front side of the abutment 3) and 31e (for example, the side of the concrete 19b) are placed at predetermined positions so that the concrete 19b can be placed below the concrete 19a. ) Etc. are arranged. FIG. 4A is a diagram showing a state viewed in the same field of view as FIG. At this time, the buffer member 23 is provided between the support member 9 and the seat surface 7. A buffer member 23 may be provided between the support member 9 and the bridge girder 5. Further, the support member 9 itself may be removed instead of the arrangement of the buffer member 23.

  Next, concrete 19b is placed in the molds 31d and 31e. After the concrete 19b is consolidated, the formwork is removed. A steel material 13b is inserted into the sheath 33b provided in the vertical direction, and the steel material 13b is tensioned in the vertical direction and the lower end thereof may be inside the abutment 3 (a footing of the abutment 3 or near the top of the abutment 3). The upper end is fixed to the upper part of the concrete 19a and fixed by grouting. In addition, the steel material 13b does not need to arrange | position completely at a perpendicular direction, According to the shape of the abutment 3, etc., you may provide some inclination. Moreover, a steel pipe and H steel can also be used as the steel material 13b. In this case, for example, H steel or the like may be disposed instead of the sheath 33b. There is no need to be nervous when using H steel or the like.

  As shown in FIG. 4 (b), the steel material 13b that is tensioned in the vertical direction may be evenly arranged with respect to the width of the concrete 19a and 19b to be placed (the width of the seating surface 7). In this case, it is necessary to arrange the steel material 13a and the steel material 13b so as not to interfere with each other. For example, as shown in FIG. 4B, a vertical steel material 13b may be arranged between the horizontal steel materials 13a.

  On the other hand, as shown in FIG.4 (c), the steel material 13b can also be shifted and arrange | positioned to the abutment wall part 21 side. That is, the steel material 13b can be shifted to the abutment wall portion 21 side from the center of the seat surface 7 (center in the front-rear direction of the seat surface), and the steel material 13b can be arranged along the abutment wall portion 21. In this case, the effect is higher for the bending moment of the bridge girder 5 in the negative direction (the side where the front surface of the abutment 3 is compressed, the direction of arrow B in the figure). Further, since the steel material 13a is not arranged on the abutment wall portion 21 side, it is not necessary to install the steel material 13b between the steel materials 13a and there is no interference with the steel material 13a, so that the steel material 13b having a larger cross-sectional area is used. be able to. In addition, arrangement | positioning of the steel material 13b is not restricted to this, You may combine the arrangement | positioning mentioned above.

  According to the method for reinforcing a bridge according to the present embodiment, the bridge can be reliably reinforced by a simple method. That is, it is possible to resist the bending moment at the corners of the bridge girder and the abutment. Moreover, since the concrete 19a and the bridge girder 5 are not joined by a gibber or the like but are constrained by the mutual frictional force due to the prestressing force applied to the concrete 19a, it is not necessary to provide a diver or a reinforcing bar. For this reason, it can be applied to the aging bridge girder 5 as well. In addition, there is no work such as reinforcing bar arrangement or gibber arrangement in a narrow part, and the workability is excellent. In addition, since prestressing force is applied in the horizontal direction and the vertical direction, the frame such as the abutment 3 is reliably reinforced.

  Further, since it is sufficient to place the concrete 19 a only between the webs 27, the concrete 19 a is not necessary outside the bridge girder 5. For this reason, the amount of concrete used can be reduced.

  Moreover, since the surface of the web 27 is roughened in advance, the frictional force with the concrete 19a is increased, and the effect of preventing the bridge girder 5 and the concrete 19a from slipping is high. Moreover, since the concrete 19a fixed to the bridge girder 5 (constrained by friction) and the abutment 3 are integrated, the bridge can be reliably reinforced. At this time, it is not necessary to install a wand or the like. At this time, since the edge cutting material is provided between the concrete 19a and the flange surface (the lower surface of the upper flange and the upper surface of the lower flange), the concrete 19a is not restrained in the horizontal direction by the flange surface. Thereby, generation | occurrence | production of the local bending stress etc. in the web 27 and a flange junction part can be suppressed.

  Further, since the buffer member 23 is provided below the support member 9 before the concrete 19b is placed (or the support member 9 is removed), the support member 9 is applied to the seat surface 7 by a vertical tension force or the like. On the other hand, the compression force is not transmitted directly. For this reason, it is possible to prevent the metal support member 9 having higher rigidity than concrete from transmitting a vertical tension force to the contact surface with the seat surface 7 and applying an excessive compressive force to the contact portion. it can.

  Next, another embodiment will be described. In the following embodiments, configurations having the same functions as those shown in FIG. 1 and the like are denoted by the same reference numerals as those in FIG.

  FIG. 5 is a modified example of the installation of the steel materials 13a and 13b, which are tendon materials. In FIG. 5A, the concrete 19 c is also placed outside the web 27. In this case, the horizontal steel material 13a is provided through the concrete 19c in addition to the concrete 19a and the web 27. Therefore, both ends of the steel material 13a are fixed to the concrete 19c.

  The steel material 13b in the vertical direction is arranged not only between the pair of bridge girders 5, but also outside the bridge girders 5 (on the opposite side to the placement of the concrete 19a). That is, a part of the steel material 13b penetrates the concrete 19b, 19c and is fixed to the abutment 3. By doing in this way, more tension materials in the vertical direction can be arranged.

  Further, as shown in FIG. 5B, a separate block 37 may be provided outside the bridge beam 5 (outside the web 27). The block 37 is, for example, a steel structure, and is joined to the bridge girder 5 by welding, friction joining, mechanical joining such as bolts, or the like. Note that a steel material 13 a that is a horizontal tension material may be provided so as to penetrate the block 37, and both ends may be fixed to the block 37.

  A part of the steel material 13b is fixed to the upper end of the block 37, passes through the block 37, the lower flange 25b, the concrete 19b, and the like, and the lower end is fixed to the abutment 3. By doing in this way, the effect similar to Fig.5 (a) can be acquired. In addition, the amount of concrete used can be reduced.

  6 is a view showing an example in which a steel plate 39 is provided on the front surface of the abutment 3. FIG. 6 (a) is a front enlarged view of the vicinity of the abutment 3, and FIG. 6 (b) is a view corresponding to FIG. 1 (b). It is.

  The steel plate 39 is provided on the front surface of the abutment 3, and is installed so as to straddle the front surface of the abutment 3 and the concrete 19a, 19b. For example, it is provided from a part above the front surface of the abutment 3 to the upper end of the concrete 19a, and is joined to the front surface of the abutment 3 and the front surfaces of the concrete 19a and 19b, respectively. The steel plate 39 and the concrete 19a, 19b may be joined by bonding or bolting. The steel plate 39 becomes resistant to the force in the positive direction (the direction in which the front side of the abutment 3 is pulled and the direction of the arrow C in the figure). Note that the steel plate 39 is compressed with respect to a negative moment, and there is a risk of buckling or the like. For this reason, it is desirable that the concrete 19a, 19b and the abutment 3 are rigidly connected in a state in which a load on the tension side is loaded in advance when the steel plate 39 is installed.

  In addition, in the reinforcement process mentioned above, the steel plate 39 can also be utilized as a formwork at the time of concrete 19a, 19b placement by installing the steel plate 39 before concrete 19a, 19b placement. In this case, it suffices to separately install a formwork only in a portion other than the steel plate 39 installation portion.

  FIG. 7 is a view showing an example in which a steel plate 41 is provided on the side surface of the abutment 3. FIG. 7 (a) is a front enlarged view of the vicinity of the abutment 3, and FIG. 7 (b) is a view corresponding to FIG. 1 (b). It is.

  The steel plate 41 is provided on the side surface of the abutment 3 and installed so as to straddle the side surface of the abutment 3 and the concrete 19a, 19b. In this case, as shown in FIG. 7B, concrete 19a, 19b is placed so as to cover the entire width of the abutment 3. Therefore, the side surfaces of the concrete 19a and 19b and the side surface of the abutment 3 are substantially the same surface. In this state, the steel plate 41 is provided, for example, from a part above the side surface of the abutment 3 to the upper end of the concrete 19a. The steel plate 41 is joined to the side surface of the abutment 3 and the side surfaces of the concrete 19a, 19b. The steel plate 41 and the concrete 19a, 19b may be joined by bonding or bolting. Further, as shown in FIG. 7B, if the steel material 13a is provided so as to penetrate the steel plate 41, the concrete 19a, the web 27, etc., and the steel material 13a is tensioned and fixed by the steel plates 41 on both sides, the steel plate 41 and the concrete are provided. 19a etc. are more reliably joined by friction. By the steel plate 41, the concrete 19a, 19b and the like and the abutment 3 are more reliably integrated, and the bending moment at the corners of the bridge girder 5 and the abutment 3 can be resisted.

  In addition, in the reinforcement process mentioned above, the steel plate 41 can also be utilized as a formwork at the time of placement of concrete 19a, 19b by installing the steel plate 41 before placing concrete 19a, 19b. In this case, the formwork may be installed only at the site other than the steel plate 41 installation part.

  FIG. 8 is a diagram illustrating an example in which an anchor 43 is provided on the back surface of the abutment 3. An anchor 43 is provided obliquely downward toward the back of the abutment 3. The tip of the anchor 43 is fixed by providing a fixing block on the front surface of the concrete 19a. The abutment 3 is drilled so as to penetrate the abutment 3 (the abutment wall portion 21), the anchor 43 is inserted inside, and the other end of the anchor 43 is fixed inside the embankment 11. The anchor 43 is disposed at a position where it does not interfere with the steel materials 13a and 13b.

  The arrangement of the anchors 43 is not limited to between the pair of bridge girders 5. For example, as shown in FIG. 5 (a), when concrete is also placed outside the bridge girders 5, the outer sides of the bridge girders 5 are arranged. May be provided. The anchor 43 integrates the abutment 3 and the embankment 11 and further reinforces the embankment 11 on the back of the abutment 3.

  FIG. 9 is a view showing an example in which a pile 47 is provided on the embankment 11 on the back surface of the abutment 3 and a connecting member 47 is provided between the pile 47 and the abutment 3, and FIG. 9A is a front view. FIG. 9B is an enlarged view of the vicinity of the abutment 3, and FIG.

  As shown in FIG. 9B, piles 47 are provided on both sides of the track 17 on the back surface of the abutment 3. A connecting member 47 that penetrates the concrete 19a, the abutment 3 (the abutment wall portion 21), and the embankment 11 is provided so as to connect the vicinity of the pile head of the pile 47 and the vicinity of the front surface of the abutment 3 (concrete 19a). That is, the connecting member 47 is provided so that the width is slightly widened from the front side of the abutment 3 toward the embankment 11 on the back side of the abutment 3. In addition, as shown to Fig.9 (a), the connection member 47 may be diagonally arrange | positioned slightly toward the back direction of the abutment 3, or may be provided in a substantially horizontal direction.

  One end of the connecting member 47 is fixed to the front surface of the concrete 19a. The abutment 3 is drilled so as to penetrate the abutment 3 (the abutment wall portion 21), the anchor connecting member 47 is inserted therein, and the other end of the connecting member 47 is fixed near the pile head of the pile 45. In addition, the connection member 47 is arrange | positioned in the position which does not interfere with steel materials 13a and 13b. The abutment 3 and the embankment 11 are integrated by the pile 45 and the connecting member 47, and the embankment 11 on the back of the abutment 3 is also reinforced.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, the embodiments can be combined with each other, and the shape, installation range, installation number, and the like of each component can be set as appropriate.

  2 shows a design example according to the present invention. For simple girder bridges with spans of 10, 15, and 20 m, the bending moment generated at the corners when the fulcrum and the abutment frame were rigidly connected was calculated. The results are shown in Table 1.

  The bending moment at the center portion of the span was reduced to about half of the value before the integration by integrating the bridge girder and the abutment as in the present invention. On the other hand, when the span is 20 m or less, the negative bending moment generated at the corner (girder end) is 1000 kN · m or less. Therefore, in the following example, an integration condition that can withstand 1000 kN · m will be examined.

  It is assumed that a bending moment of 1000 kN · m acts on the rigid joint due to the integration of the bridge girder and the abutment, and resistance is caused by shear friction between the web and the concrete placed between the webs. Here, the friction coefficient μ between the web surface and the concrete is 0.3.

If the girder height is 1.5 m and the length in the axial direction of the winding bridge is 1 m, the contact area between the web and the concrete is 1.5 m ² . For simplicity, when the calculation is performed by replacing the rectangular contact portion with a circle, the radius r of the circle having the same contact area is 0.7 m. Here, when the average compressive stress acting between the web and the concrete due to the tension of the PC steel material is σ, the resistance moment T is expressed by the following equation.

From the above equation, in order to satisfy T ≧ 1000 kN · m, σ ≧ 2326 kN / m ² . Here, the tension P of the PC steel is σ · Ac = 2326 × 1.5 = 3488 kN. If the tensile strength σ _SA of PC steel is 0.55 f _pu (f _pu : tensile strength), and a PC steel rod having a tensile strength of 1080 N / mm ² and 32 mmφ (As = 804.2 mm ² ) is used as the PC steel, From σ _SA × As × n = 3488 kN, n = 7.3. That is, if there are eight PC steel materials, a necessary resistance moment can be obtained. For example, a necessary resistance moment can be obtained by arranging four x2 rows of PC steel materials and applying a predetermined tension force.

On the other hand, the steel material in the vertical direction is designed and determined so that the tensile stress is not generated in the first and second concrete with respect to the acting bending moment. When a trial calculation for vertical PC steel as PC steel, by using of a tensile strength ^{1860N / mm 2, As = 970.9mm} 2, by using the six PC steel under the same conditions, a predetermined resistance moment Obtainable.

  Actually, reinforcing ribs, anti-tilting steel, horizontal steel, and the like are disposed between the bridge girders, and therefore there are elements that contribute to prevention of slippage in addition to the frictional force. Further, if the surface of the web is roughened to increase the friction coefficient, the design on the safer side is achieved.

  In addition, although detailed calculation is omitted, in order to obtain the same effect, when a hole is provided in the web and a steel plate gibber is used, a hole larger than the hole for the PC steel material is set to the number of PC steel materials installed. Therefore, it is necessary to form about three times as many. For this reason, the stress increase accompanying the drilling to the web of the existing bridge becomes a problem. According to the present invention, the resistance moment is obtained by the friction between the web and the concrete due to the tension of the PC steel material, so that an excellent reinforcing structure with excellent workability can be obtained.

DESCRIPTION OF SYMBOLS 1 ......... Bridge 3 ......... Abutment 5 ......... Bridge girder 7 ......... Seat surface 9 ......... Supporting member 11 ......... Fills 13a, 13b ......... Steel 15 ......... Riding 17 ......... Track 19a , 19b ......... Concrete 21 ......... Abutment wall 23 ......... Buffer members 25a, 25b ......... Upper flange 27 ......... Web 29 ......... Holes 31a, 31b, 31c, 31d, 31e ......... Frames 33a, 33b ......... Sheath 37 ......... Block 39 ......... Steel 41 ......... Steel 43 ......... Anchor 45 ......... Pile 47 ......... Connecting member

Claims (9)

Abutment,
A plurality of bridge girders installed on the abutment,
A first concrete provided between the adjacent bridge girders;
A first steel material provided to be tensioned in a substantially horizontal direction so as to penetrate the bridge girder and the first concrete;
A second concrete provided between the first concrete and the abutment surface;
A second steel material provided in a substantially vertical direction between the abutment and the first concrete so as to penetrate the second concrete;
Comprising
A reinforcing structure for a bridge, wherein the first concrete, the second concrete, and the abutment are integrated. The bridge girder has a web standing up in a substantially vertical direction, and an upper flange and a lower flange substantially perpendicular to the web at upper and lower ends of the web, respectively.
The first concrete is provided between the webs facing each other of the adjacent bridge girders,
The bridge reinforcing structure according to claim 1, wherein the first steel material is tensioned in a substantially horizontal direction so as to penetrate the web and the first concrete.   The reinforcing structure for a bridge according to claim 2, wherein the surface of the web is subjected to surface roughening.   An edge cutting material is provided between the lower surface of the upper flange that is the upper flange of the bridge girder and / or the upper surface of the lower flange that is the lower flange of the bridge girder and the first concrete. The bridge reinforcing structure according to claim 2 or claim 3. Blocks are provided on the outer sides of the web,
Instead of being provided between the abutment and the first concrete, the second steel material is provided between the abutment and the block in a substantially vertical direction and is tensioned. The bridge reinforcing structure according to claim 2. The bridge girder is provided on a support member provided on the seat surface of the abutment,
6. The bridge according to claim 1, wherein a buffer member is sandwiched between the support member and the abutment or between the support member and the bridge girder. Reinforced structure.   The steel plate is provided between the front surface of the abutment and above the bridge girder, and the steel plate, the first concrete, and the second concrete are joined to each other. A reinforcing structure for a bridge according to any one of the above.   The connecting member is provided between the first concrete and the embankment on the back of the abutment, and the abutment and the embankment are integrated with each other. Bridge reinforcement structure. A method of reinforcing a bridge, comprising: an abutment; a plurality of bridge girders provided on the abutment and provided with a web standing up in a substantially vertical direction and flanges perpendicular to the web at the upper and lower ends of the web;
On the abutment, a first concrete is placed between the webs of the adjacent bridge beams facing each other, and a first steel material is provided in a substantially horizontal direction so as to penetrate the web and the first concrete. A tensioning step (a);
A second concrete is placed between the first concrete and the abutment, and a second is provided in a substantially vertical direction between the abutment and the first concrete so as to penetrate the second concrete. A step (b) in which the steel material is provided and tensioned;
A method of reinforcing a bridge, wherein the first concrete, the second concrete, and the abutment are integrated.

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