JP2007321452A - Construction method for bridge and bridge structure thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method for a bridge which has a robust strength and withstands earthquake and the bridge structure thereof. <P>SOLUTION: In the construction method for a bridge, geotextile 2 and sandbags 3 are used according to a procedure of a reinforced soil wall construction method for constructing a reinforcing banking 4. When a support ground 1 is soft, a foundation such as a foundation pile 5 or the like is constructed after a ground sinkage by banking up of the reinforcing banking 4 is settled, and at the same time the geotextile 2 and the sandbags 3 are used for constructing the reinforcing banking 4 at the opposing side. When the support ground 1 is soft, the foundation such as the foundation pile 5 or the like is constructed after the ground sinkage by banking up of the reinforcing banking 4 is setteled, the wall faces 6 of the reinforcing banking 4 facing to each other and a beam part of a bridge girder 7 are integrated, and then reinforced concrete for a rigid frame bridge part 8 is placed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for constructing a bridge in a river, a road crossing portion, and the like and a bridge structure thereof.

  Conventionally, when a bridge is constructed in a river part or a road intersection, first, as shown in FIG. 6 (a), the foundation pile 102 (if the support ground 101 is strong, the foundation pile 102 is May be unnecessary), and the abutment 103 is constructed thereon. Thereafter, as shown in FIG. 6 (b), the bank 104 is raised on the back of the abutment 103, the fixed support 105 and the free support 106 are installed on the abutment 103, and the bridge girder 107 is constructed between the abutments 103. It has been constructed in Here, the abutment 103 has a role of resisting earth pressure caused by the embankment 104 and supporting a girder's own weight, a train mounted on the girder, and the like as a girder of the bridge girder 107.

In addition, the inventors of the present application have already proposed (1) a stabilization method and a structure thereof (reinforced earth wall method) associated with construction of embankment by stacking sandbags and stiffening the concrete ( See Patent Document 1 below). (2) A tension reinforcing body for reinforcing the ground immediately after cutting or general ground has been proposed (see Patent Document 2 below). (3) The construction method of the abutment accompanying the bridge reconstruction and the abutment structure have been proposed (see Patent Document 3 below).
Japanese Examined Patent Publication No. 4-53204 Japanese Patent No. 2575329 JP 2005-68816 A

  However, in the bridge construction method and the bridge structure described above, a large horizontal force, vertical force, and moment act on the abutment foundation, so a large footing and a large number of foundation piles are required. In addition, in the conventional construction method, after the pile foundation is constructed, the embankment on the back of the abutment is raised, so there is a possibility that excessive earth pressure is applied to the abutment structure when embankment is raised, The ground may sink excessively or may be displaced laterally and push the pile foundation. In order to suppress this, a larger foundation is required.

  Even after construction, the abutment and the embankment on the back of the abutment tend to be weak points. In particular, as shown in FIG. 7, when the back embankment sinks, a step is generated between the abutment and the travel safety of trains and automobiles is hindered. Moreover, not only may there be an excessive earth pressure on the abutment structure during an earthquake (particularly level 2 ground motion), it is difficult to suppress the settlement of the embankment behind the abutment. In addition, with conventional bridges, maintenance of bridge girder support is also a problem. Furthermore, since it is composed of a large number of work types, the abutment of the conventional structure type generally has a high construction cost and a long construction period.

  In view of the above circumstances, an object of the present invention is to provide a bridge construction method and a bridge structure that are strong in strength and strong against earthquakes.

In order to achieve the above object, the present invention provides
[1] In the construction method of the bridge, reinforced embankment is constructed using wall materials with high flexibility (deformability following) such as geotextiles and sandbags. When foundation subsidence has converged, foundations such as foundation piles are constructed, and reinforced embankments are constructed on the facing side using a highly flexible wall member such as geotextile and sandbags at the same time, If the supporting ground is soft, foundations such as foundation piles are constructed when the ground subsidence due to the embankment of the reinforced embankment has converged, and the wall work of the reinforced embankment facing above and the beam part of the bridge girder are integrated. It is characterized by placing reinforced concrete in the ramen bridge.

  [2] In the construction method of the bridge, a retaining wall is placed on the existing embankment on both sides, and then a small excavation is performed, a tensile reinforcement is placed on the excavation surface, and these steps are repeated. Excavate to a predetermined depth, install foundation piles in the empty space in front of the retaining wall, if necessary, connect with the tensile reinforcement and the retaining wall, and integrate them, reinforced concrete of the ramen bridge part It is characterized by placing.

  [3] In the bridge construction method described in [1] or [2] above, when the girder length of the ramen bridge portion is long, a bridge pier with roller support is provided in the middle portion of the ramen bridge portion, It is characterized by supporting only force.

  [4] In bridge structures, reinforced embankments are constructed using highly flexible wall surfaces such as geotextiles and sandbags, and if the supporting ground is soft, the ground by raising the reinforced embankment When subsidence has converged, foundations such as foundation piles are constructed, and on the facing side, if the reinforced embankment and the supporting ground are soft, the subsidence due to the embankment of the reinforced embankment has converged. It is characterized by comprising a foundation such as a foundation pile, and a wall work of reinforcing embankments facing each other, and a ramen bridge part in which reinforced concrete is cast so that the beam part of the bridge girder is integrated.

  [5] In a bridge structure, a retaining wall that is placed on both sides of the existing embankment on both sides, a tensile reinforcement member that is placed against the excavation surface, and an empty space in front of the retaining wall Further, the present invention is characterized by comprising a foundation pile installed as necessary, a ramen bridge portion in which reinforced concrete is cast so as to be connected to and integrated with the tensile reinforcement member and the retaining wall.

  [6] In the bridge structure described in [4] or [5] above, when the girder length of the ramen bridge portion is long, a roller bearing that supports only the vertical force of the ramen bridge portion at the middle portion of the ramen bridge portion A pier is provided.

  According to the present invention, the following effects can be achieved.

  The bridge construction method of the present invention is a procedure of the reinforced earth wall construction method, when a reinforced embankment is constructed using a highly flexible wall member such as geotextile and sandbag, and the supporting ground is soft. The foundation is constructed when the ground subsidence due to the embankment of the reinforced embankment has converged, and the reinforced embankment is also constructed on the facing side at the same time. If the supporting ground is soft, the ground by the embankment of the reinforced embankment When subsidence has converged, foundations such as foundation piles are constructed, and the reinforced concrete wall of the facing reinforcement embankment and the beam part of the bridge girder are integrated into the reinforced concrete of the ramen bridge part.

  Hereinafter, embodiments of the present invention will be described in detail.

  First, a bridge construction method according to the first embodiment of the present invention will be described.

  FIG. 1 is a schematic view showing a bridge construction method according to a first embodiment of the present invention.

  This embodiment relates to a method for constructing a bridge in a river or a road crossing section.

  (1) As shown to Fig.1 (a), the reinforcement embankment 4 is first constructed | assembled using the geotextile 2, the sandbag 3, etc. in the procedure of a reinforcement earth wall construction method.

  (2) Next, as shown in FIG. 1A, when the supporting ground 1 is soft, the foundation such as the foundation pile 5 is constructed at the stage where the ground subsidence due to the embankment of the reinforcing embankment 4 has converged. . However, when the supporting ground 1 is firm, the foundation pile 5 is not necessary.

  (3) Next, as shown in FIG. 1 (b), when the wall work 6 is constructed, the upper part of the wall work 6 is left with a predetermined thickness (the thickness of a bridge girder described later).

  (4) Next, as shown in FIG.1 (c), the reinforcement embankment 4 and the foundation pile 5 etc. are constructed simultaneously also on the facing side.

  (5) Next, as shown in FIG.1 (c), the wall surface construction 6 of the reinforcement embankment 4 which faces and the beam part of the bridge girder 7 are integrated, reinforced concrete is cast, and it is set as the ramen bridge part 8. FIG. That is, the reinforced concrete cast in the beam portion of the bridge girder 7 sufficiently eats the sandbag 3 and the geotextile 2, and the bridge girder 7 and the reinforcing embankment 4 are firmly constructed. Therefore, even if the train 9 travels on the bridge girder 7, for example, the bridge girder 7 and the reinforcing embankment 4 are firmly integrated with each other, so that the gap between the bridge girder 7 and the reinforcing embankment 4 does not collapse.

  Thus, by constructing the embankment part with a reinforced embankment structure first, it is possible to ensure high followability to the embankment and ground deformation that occurs during construction and at the initial stage of construction. This method is called a reinforced earth wall method and has many achievements as an alternative to retaining walls. Since the embankment is constructed before the ramen bridge part is placed by placing reinforced concrete with the reinforcement earth wall method and the wall part (wall work) of the reinforcement earth wall method and the bridge girder integrated, There is no need for foundation piles or ground improvement to suppress the deformation of the ground due to the uplifting of the ground.

  However, the pile foundation 5 is necessary when it is necessary to prevent long-term residual settlement of the ramen bridge portion 8 (wall surface work 6 + bridge girder 7) due to its own weight or traffic load after completion. In addition, the wall surface work 6 is integrated with the reinforcing embankment 4, and the live load is also distributed in the reinforcing embankment 4. Further, even when a horizontal inertia force acts on the ramen bridge portion 8 during an earthquake or the like, since the geotextile 2 on the back of the embankment resists, the horizontal force and moment acting on the foundation pile 5 are significantly reduced. Therefore, the number of foundation piles 5 can be greatly reduced.

  In addition, it has an abutment / bridge girder integrated structure that does not have a support, so there is no need to produce, install and maintain the support.

  Here, a ramen bridge where the back embankment does not have a reinforced embankment structure is also conceivable, and is actually used frequently in Europe and the like (FIG. 5). However, in this case, due to forced repeated horizontal displacement (annual cycle) of the wall work accompanying the thermal expansion and contraction accompanying the temperature change of the bridge girder, the embankment behind the wall work may sink and the maximum earth pressure may increase. Therefore, in the case of a ramen bridge that does not use reinforced embankment, the wall work must be structurally countered against this increased earth pressure. On the other hand, the construction method of the present invention is characterized in that a geotextile is arranged on the back embankment and integrated with the ramen bridge. That is, as shown in FIG. 2, since it is reinforced by the geotextile 2, the restraint pressure is increased, the rigidity of the backfill 4 is increased, and the forced repeated horizontal displacement of the wall surface work 6 due to temperature change is also reduced. Moreover, the cumulative settlement of the embankment can be prevented by the geotextile 2 coupled to the back surface of the wall surface work 6. Furthermore, since the location where the wall work 6 and the geotextile 2 are joined functions as a fulcrum for the wall work 6, the wall work 6 functions as a continuous beam supported by multiple fulcrums even if the working earth pressure increases. The wall construction 6 does not require high structural strength.

  Furthermore, as a structural feature, the seismic resistance is improved by integrating the wall work 6 and the bridge girder 7 as the abutments on both sides. These synergistic effects can further prevent embankment settlement behind the wall surface work 6 due to temperature change and embankment settlement behind the wall surface work 6 due to seismic load.

  As shown in FIG. 1 (b), when the wall surface construction 6 is constructed, the upper portion of the wall surface construction 6 is not left with a predetermined thickness (the thickness of the bridge girder described later), but is a portal type from the beginning. It is also possible to pick up the reinforcing bars and simultaneously place the reinforced concrete in the ramen bridge between the wall work and the bridge girder. Even in this case, it is possible to achieve a strong integration between the reinforcing embankment and the ramen bridge portion.

  FIG. 3 is a schematic view showing a bridge construction method according to the second embodiment of the present invention.

Although the above-mentioned embodiment was a construction procedure when a new bridge was newly constructed, the present invention can be applied even when an existing bridge is replaced. In other words, if the reinforced embankment part is constructed by the natural ground reinforced earth method and integrated with the ramen bridge, the same structure as above is obtained. The specific construction procedure is as follows.
(1) An earth retaining wall (H steel, steel sheet pile, soil cement wall, etc.) 12 is placed on the existing embankment 11, and then excavation of a small step is performed.
(2) Tensile reinforcing material 13 such as nailing, micropiling, and douring is placed on the excavation surface, and these steps are repeated to excavate to a predetermined depth.
(3) A foundation pile 14 is installed in an empty space in front of the retaining wall 12 as necessary.
(4) Finally, the reinforced concrete of the ramen bridge portion 15 is placed so as to be connected and integrated with the tensile reinforcement member 13 and the retaining wall 12.

  In this way, the reinforced concrete of the ramen bridge part is placed so that the reinforced embankment part is connected and integrated with the natural ground reinforced earth method, the tensile reinforcement, and the retaining wall, and the same as in the first embodiment. Cumulative settlement of the embankment can be prevented, and earthquake resistance is improved by integrating the abutments on both sides. These synergistic effects can further prevent embankment sinking behind the wall work due to temperature changes and embankment sinking behind the wall work due to seismic load.

  FIG. 4 is a schematic view showing a bridge construction method according to the third embodiment of the present invention.

  In this figure, reference numeral 22 denotes a bridge pier provided when the girder length is long in the bridge, and this pier 22 has a structure in which only a vertical force is supported by a roller bearing 23 on a foundation pile 21 at an intermediate portion of the girder.

  As described above, when the girder length is long in the rigid frame bridge portion of the present invention, the support force of the rigid frame bridge portion is increased by providing a bridge pier having a structure that supports only the vertical force by the roller support in the intermediate portion. Can do.

  In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.

  The bridge construction method and the bridge structure according to the present invention are strong in strength and can be used as a construction method of a bridge for a railway or road and a bridge structure that are resistant to earthquakes.

It is a schematic diagram which shows the construction method of the bridge which shows 1st Example of this invention. It is a schematic diagram which shows the structure of the bridge by the construction method of the bridge which shows 1st Example of this invention. It is a schematic diagram which shows the construction method of the bridge which shows 2nd Example of this invention. It is a schematic diagram which shows the construction method of the bridge which shows 3rd Example of this invention. It is a schematic diagram which shows the bridge constructed by the conventional unfilled embankment. It is a figure which shows the construction method of the conventional bridge. It is a figure which shows the problem of the construction method of the conventional bridge shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support ground 2 Geotextile 3 Sandbag 4 Reinforcement embankment 5, 14, 21 Foundation pile 6 Wall construction 7 Bridge girder 8,15 Ramen bridge part 9 Train 11 Existing embankment 12 Earth retaining wall 13 Tensile reinforcement material 22 Pier base 23 Roller support

Claims (6)

(A) Using a highly flexible wall surface member such as geotextile and sandbag, construct a reinforced embankment,
(B) If the supporting ground is soft, construct foundations such as foundation piles at the stage where ground subsidence due to the embankment of the reinforced embankment has converged,
(C) Construct a reinforced embankment on the facing side using a highly flexible wall member such as geotextile and sandbag at the same time,
(D) If the supporting ground is soft, construct foundations such as foundation piles at the stage when the ground subsidence due to the embankment of the reinforced embankment has converged,
(E) A construction method of a bridge characterized in that the above-mentioned wall construction of the reinforcing embankment facing and the beam portion of the bridge girder are integrated and reinforced concrete of the ramen bridge portion is cast. (A) Placing a retaining wall on the existing embankment on both sides, then excavating a small step,
(B) Placing a tensile reinforcement on the excavation surface, repeating these steps, excavating to a predetermined depth,
(C) If necessary, install foundation piles in the vacant space in front of the retaining wall,
(D) A method for constructing a bridge, comprising connecting and integrating the tensile reinforcement member and the retaining wall, and placing reinforced concrete in a ramen bridge portion.   In the construction method of the bridge according to claim 1 or 2, when the girder length of the ramen bridge part is long, a bridge pier with roller support is provided in the middle part of the ramen bridge part to support only the vertical force of the ramen bridge part. A construction method for bridges. (A) Using a highly flexible wall surface member such as geotextile and sandbag, construct a reinforced embankment,
(B) If the supporting ground is soft, construct foundations such as foundation piles at the stage where ground subsidence due to the embankment of the reinforced embankment has converged,
(C) If the reinforced embankment and the supporting ground are soft at the same time, construct foundations such as foundation piles at the stage where ground subsidence due to the embankment of the reinforced embankment has converged,
(D) A bridge structure characterized by comprising a wall construction of a reinforced embankment facing each other and a ramen bridge portion in which reinforced concrete is cast so that the beam portion of the bridge girder is integrated. (A) earth retaining walls placed on both sides of the existing embankment on both sides;
(B) a tensile reinforcement member to be placed against the excavation surface;
(C) a foundation pile installed as needed in a vacant space in front of the retaining wall;
(D) A bridge structure comprising: a reinforcing frame and a ramen bridge portion in which reinforced concrete is cast so as to be connected to and integrated with the retaining wall.   In the bridge structure according to claim 4 or 5, when the girder length of the ramen bridge portion is long, a bridge pier by a roller support that supports only the vertical force of the ramen bridge portion is provided in the middle portion of the ramen bridge portion. Characteristic bridge structure.

Images