JP2014133971A - Seismic strengthening method for retaining wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seismic strengthening method for a retaining wall, which imparts a resistance force to the retaining wall by integrating a fixing reinforcement material, a masking member and a wall surface together.SOLUTION: In a seismic strengthening method for a retaining wall, a masking member 3 for covering a wall surface 2A of the retaining wall 2, and concrete fixing members 4 and 5 for firmly fixing upper and lower parts of the masking material 3 and tightening the masking material 3 are arranged, and the wall surface 2A and the masking member 3 are integrated together to prevent the collapse of the retaining wall 2 and reduce the deformation of the wall surface 2A.

Description

  The present invention relates to a seismic strengthening method for retaining walls such as masonry / block retaining walls and unreinforced concrete retaining walls, and more particularly to retaining masonry / block retaining walls and unreinforced concrete retaining walls installed along railway lines. It relates to the seismic reinforcement method for walls.

  Many of the existing earth retaining walls are aged structures, and in the event of a large-scale earthquake, seismic reinforcement is required to prevent collapse. Masonry and block retaining walls that have a long construction extension among railroad retaining walls are not integrated and may exhibit a brittle collapse in the event of an earthquake, but effective reinforcement technology has not been developed so far. There was room for improvement in terms of effect, cost, and construction (see Patent Document 1 below).

FIG. 8 is a schematic diagram showing a procedure for reinforcing a conventional masonry / block pile retaining wall.
FIG. 8A shows a state before the reinforcement work of the masonry / blocking retaining wall 100. First, as shown in FIG. 8B, prior to the placement of the reinforcing material, the disturbance at the time of placing the reinforcing material. In order to prevent the masonry wall from being deformed, joint injection 101 is performed. After that, as shown in FIG. 8C, when the wall work is not finally constructed, the reinforcing material 102 is densely placed. Alternatively, as shown in FIG. 8 (d), when the quantity of the reinforcing material 102 'is reduced, the wall concrete 103 is finally placed and the existing stone masonry / block masonry retaining wall is constructed. Complete.

  Further, retaining walls such as a leaning wall whose wall surface is constructed of unreinforced concrete may cause the wall body to be brittlely destroyed or toppled.

  Japanese Patent No. 4190360

Fumio Tatsuoka: “Reinforced soil structure for restoration / reconstruction from the 2011 Great East Japan Earthquake, News from RRR Construction Method Association, No. 13, August 2011 Japan Society for Earthquake Engineering: “Problems and Countermeasures for Ground Disasters during Earthquakes: Lessons and Recommendations from the 2011 Great East Japan Earthquake” (1st), July 2011 Nikkei Construction, pp. 34-43, 2011.10.20

As described above, the masonry / blocking retaining walls and the like have no unity and are brittle when collapsed. Therefore, even when resistance is applied by placing a reinforcing material, the wall surface is not integrated, and the wall surface collapses with a small displacement. This results in an increase in the amount of reinforcement.
Furthermore, even if collapse can be prevented by the conventional reinforcing procedure, the wall surface may be deformed during a large earthquake. This deformation can induce orbital deformation if there is a track on the back.

More specifically, the conventional procedures for reinforcing masonry and block retaining walls have the following problems.
(1) Costs due to joint injection for placing the reinforcing material increase.
(2) In placing a reinforcing material on a wall surface having no unity, it is necessary to lengthen the reinforcing material and increase the number of reinforcing materials, which increases costs.
(3) In the case of constructing wall concrete, the number of reinforcing materials can be reduced, but the construction cost and construction site due to construction of concrete wall construction will increase.

In particular, in the collapse of masonry and block masonry walls along railway lines, even the collapse of a single masonry or block masonry wall may cause a major railway accident due to a fall on the railway track. Therefore, it is desirable to prevent a railway accident by flexibly restraining the collapse of masonry and block retaining walls with a covering member.
From this point of view, the prevention of masonry collapse by the net has come to be attempted.

  In view of the above situation, the present invention provides a retaining wall that provides resistance to a retaining wall of a masonry / blocking retaining wall or an unreinforced concrete retaining wall by integrating a fixing member, a covering member, and a wall surface. The purpose is to provide a seismic reinforcement method.

In order to achieve the above object, the present invention provides
[1] In the seismic reinforcement method of the retaining wall, a covering member that covers the wall surface of the retaining wall, and a concrete fixing member that firmly fixes the upper and lower portions of the covering member and tightens the covering member are disposed. By integrating the wall surface and the covering member, it is possible to prevent the retaining wall from collapsing and to reduce the deformation of the wall surface.

  [2] In the seismic reinforcement method for retaining walls according to [1] above, the covering member is further tightened by further including a rod-shaped reinforcing member placed from the wall surface side, and the covering member and the wall surface And the rod-shaped reinforcing member are integrated to prevent the retaining wall from collapsing and to reduce the deformation of the wall surface, and to increase the slip resistance of the natural ground and to retreat the slip surface.

[3] In the seismic reinforcement method for retaining walls according to [1] or [2] above, the upper concrete fixing member is a concrete fixing member for entrainment.
[4] In the seismic reinforcement method for retaining walls according to [1] or [2], the lower concrete fixing member is a solidified concrete fixing member.
[5] In the seismic reinforcement method for retaining walls according to the above [3] or [4], a reinforcing pile is provided on the concrete fixing member.

[6] In the seismic reinforcement method for retaining walls according to [3] or [4], a sheet pile is provided on the concrete fixing member.
[7] The retaining wall seismic reinforcement method according to [1], wherein the covering member is formed of a collapse prevention net or sheet for the wall surface.
[8] The seismic reinforcement method for retaining walls according to [7] above, wherein the collapse prevention net of the wall surface is two overlapping nets having different mesh directions.

According to the present invention, the following effects can be achieved.
In addition to preventing the collapse of masonry and block retaining walls with a collapse prevention net or sheet, tightening the sheet and net by constructing the concrete for wrapping in the upper part of the natural ground and the solidified concrete in the lower part of the natural ground. Due to the tightening effect, the masonry / blocking retaining wall and the net can be integrated, and the deformation of the wall surface can be reduced.

  Furthermore, by further providing a rod-shaped reinforcing material placed from the wall surface side, the covering member is further tightened, and the covering member, the wall surface, and the rod-shaped reinforcing material are integrated, thereby While preventing the collapse of the wall and reducing the deformation of the wall surface, it is possible to retreat the slip surface by increasing the slip resistance of the natural ground.

It is a schematic diagram of the seismic reinforcement method of the retaining wall which shows 1st Example of this invention. It is a schematic diagram of the seismic reinforcement construction method of the retaining wall which shows 2nd Example of this invention. It is a schematic diagram of the seismic reinforcement construction method of the retaining wall which shows 3rd Example of this invention. It is a schematic diagram of the seismic reinforcement construction method of the retaining wall which shows 4th Example of this invention. It is a schematic diagram of the seismic reinforcement construction method of the retaining wall which shows 5th Example of this invention. It is a schematic diagram of the seismic reinforcement construction method of the retaining wall which shows 6th Example of this invention. It is a schematic diagram of the seismic reinforcement construction method of the retaining wall which shows 7th Example of this invention. It is a schematic diagram which shows the reinforcement procedure of the conventional masonry and block pile retaining wall.

  The seismic reinforcement method of the retaining wall of the present invention includes a covering member that covers the wall surface of the retaining wall, and a concrete fixing member that firmly fixes the upper and lower portions of the covering member and tightens the covering member. By integrating the wall surface and the covering member, the retaining wall can be prevented from collapsing and the deformation of the wall surface can be reduced.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic view of a seismic reinforcement method for retaining walls showing a first embodiment of the present invention.
In this figure, 1 is a natural ground, 2 is a masonry / blocking retaining wall, 2A is a wall surface, 3 is a covering member made of a collapse prevention net or sheet 3A, 4 is a concrete for wrapping in the upper part of the natural ground (clamping of the covering member) 4A is a reinforcing pile of concrete for entrainment 4, 5 is a reinforced concrete of the bottom of the natural ground (clamping of the covering member), 5 A is a reinforced pile of the reinforced concrete 5.

  In this embodiment, in particular, construction of a covering member made of a collapse prevention net or sheet and construction of concrete for entrainment 4 in the upper part of the natural ground and concrete concrete 5 in the lower part of the natural ground are performed. In other words, the collapse / prevention net or the sheet 3A prevents the masonry / blocking retaining wall 2 from collapsing, and the sheet net is formed by constructing the concrete 4 for entrainment at the upper part of the natural ground and the concrete 5 for consolidation of the lower part of the natural ground. By tightening, and the tightening effect by this tightening, the masonry / block stack retaining wall 2 and the net are integrated, and the deformation of the wall surface 2A is also reduced. In addition, reinforcing piles 4A and 5A may be placed on the concrete 4 for entrainment and the concrete 5 as required.

FIG. 2 is a schematic view of a seismic reinforcement method for retaining walls showing a second embodiment of the present invention.
In this figure, 11 is a natural ground, 12 is a masonry / blocking retaining wall, 12A is a wall surface, 13 is a covering member made of a collapse-preventing net or sheet 13A, and 14 is a concrete for entrainment in the upper part of the natural mountain (tightening of the covering member). 15) Root concrete under the ground (tightening of the cover member), 16 is a rod-like long reinforcement placed from the wall surface 12A, A is an assumed slip line before reinforcement, and B is an assumed slip line after reinforcement. Is shown.

  In this embodiment, the rod-like long reinforcing material 16 is further applied to the retaining wall reinforcing method shown in the first embodiment, so that the sheet or the net 13A is further tightened (initial tension is applied), and the masonry block By further integrating the covering wall member 13, the covering member 13 made of the collapse preventing net or sheet 13 </ b> A, and the rod-like long reinforcing material 16, a further deformation reduction effect is achieved. Further, the integration using the rod-like long body 16 provides the effect of suppressing the slip soil mass, thereby increasing the slip resistance, retreating the slip surface, and increasing the pull-out resistance of the rod-shaped reinforcing material. Can do. In addition, it can be expected to reduce the amount of the reinforcing material as compared with the case where the reinforcing material is reinforced alone. FIG. 3 is a schematic view of a seismic reinforcement method for retaining walls showing a third embodiment of the present invention.

  In this figure, 21 is a natural ground, 22 is a masonry / blocking retaining wall, 22A is a wall surface, 23 is a covering member made of a collapse-preventing net or sheet 23A, 24 is a concrete for wrapping in the upper part of the natural ground (tightening of the covering member 24A is a rod-shaped reinforcing material for concrete 24, 25 is a root-solidified concrete (clamping of a covering member) at the bottom of the natural ground, 25A is a rod-shaped reinforcing material for concrete 25, and 26 is a long rod-shaped material cast from the wall surface 22A. Reinforcing material, A indicates an assumed slip line before reinforcement, and B indicates an assumed slip line after reinforcement.

In this embodiment, in addition to the effects of the second embodiment, a supporting force reinforcing effect can be obtained by fixing the lower surface with the rod-shaped reinforcing material 25A.
FIG. 4 is a schematic view of a seismic reinforcement method for retaining walls showing a fourth embodiment of the present invention.
In this figure, 31 is a natural ground, 32 is a masonry / blocking retaining wall, 32A is a wall surface, 33 is a covering member made of a collapse-preventing net or sheet 33A, 34 is a concrete for wrapping in the upper part of the natural ground (clamping of the covering member) , 34A is a sheet pile of concrete 34, 35 is a solidified concrete in the lower part of the natural ground (clamping of the covering member), 35A is a sheet pile of concrete 35, 36 is a rod-like long reinforcement placed from the wall surface 32A, A Indicates an assumed slip line before reinforcement, and B indicates an assumed slip line after reinforcement.

In this embodiment, by placing the sheet pile 34A and the sheet pile 35A of the solidified concrete 35 in the lower part of the natural ground in the concrete for winding in the upper part of the natural ground, in addition to the effect in the second example, along the river It can be expected to prevent scouring.
FIG. 5 is a schematic view of a seismic reinforcement method for retaining walls showing a fifth embodiment of the present invention.
In this figure, 41 is a natural ground, 42 is a masonry / blocking retaining wall, 42A is a wall surface, 43 is a covering member made of a collapse-preventing net or sheet 43A, 44 is concrete for wrapping in the upper part of the natural ground (tightening of the covering member) 44A is a pile of concrete 44, 45 is a solidified concrete at the bottom of the natural ground (clamping of the cover member), 45A is a pile of concrete 45, 46 is a rod-like long reinforcement placed from the wall surface 42A, A Indicates an assumed slip line before reinforcement, and B indicates an assumed slip line after reinforcement.

This embodiment has a structure in which the sheet piles 34A and 35A in the fourth embodiment are replaced with the piles 44A and 45A, and a supporting force reinforcing effect can be obtained.
FIG. 6 is a schematic view of a seismic reinforcement method for retaining walls showing a sixth embodiment of the present invention, and shows a covering member made of a net as a modification of the covering member shown in the above embodiment.
In this embodiment, a first covering member 52 by a first net 51 is disposed on the wall surface 50. A second covering member 54 composed of a second net 53 having a different mesh direction is combined with the surface of the first covering member 52. Thereby, the improvement of the elongation capability and breaking strength of a covering member can be aimed at.

Figure 7 is a schematic diagram of a Seismic Retrofit for retaining wall consisting of covering surface member according to the net of the present invention, FIGS. 7 (a) is a plan view, FIG. 7 (b) is a cross-sectional view thereof.
In this embodiment, placing the first covering section member 62 according to the first net 61 on the wall 60. A second covering member 64 composed of a second net 63 having a different mesh direction is combined with the surface of the first covering member 62. Thereby, improvement of elongation ability and breaking strength can be aimed at.

Moreover, by applying vegetation to the covering member described above, it is possible to impart resistance to the masonry / blocking retaining walls and to perform greening.
In addition, in each said Example, although the masonry and the block pile retaining wall were shown as a retaining wall, it is applicable also to an unreinforced concrete retaining wall.
In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The seismic reinforcement method for retaining walls according to the present invention can be used as a seismic reinforcement method for retaining walls in which a retaining member, a covering member, and a wall surface are integrated to impart resistance to the retaining wall.

1,11,21,31,41 Ground mountain 2,12,22,32,42 Masonry / Block building retaining wall 2A, 12A, 22A, 32A, 42A, 50, 60 Wall surface 3, 13, 23, 33, 43 Member 3A, 13A, 23A, 33A, 43A Collapse prevention net or sheet 4, 14, 24, 34, 44 Concrete for entrainment in the upper part of natural ground (tightening of covering member)
4A Reinforcement piles for concrete for entrainment 5, 15, 25, 35, 45 Root concrete under the natural ground (tightening of cover material)
5A Reinforced piles of hardened concrete 16, 26, 36, 46 Rod-like long reinforcement A Presumed slip line before reinforcement B Post-reinforcement slip line 24A, 25A Concrete rod-like reinforcement 34A, 35A Concrete sheet pile 44A, 45A Pile 51, 61 First net 52, 62 First covering member 53, 63 Second net 54, 64 Second covering member

Claims (8)

  A covering member that covers the wall surface of the retaining wall and a concrete fixing member that firmly fixes the upper and lower portions of the covering member and tightens the covering member are disposed, and the wall surface and the covering member are integrated. Thus, a seismic reinforcement method for retaining walls, which prevents collapse of the retaining walls and reduces deformation of the wall surfaces.   The seismic reinforcement method for retaining walls according to claim 1, further comprising a rod-shaped reinforcing member placed from the wall surface side, further tightening the covering member, and the covering member, the wall surface, and the rod-shaped reinforcing member. Seismic reinforcement of retaining wall, which is intended to prevent collapse of the retaining wall and reduce deformation of the wall surface by integrating the material, and to increase the sliding resistance of the natural ground and to retreat the sliding surface Construction method.   The seismic reinforcement method for retaining walls according to claim 1 or 2, wherein the upper concrete fixing member is a concrete fixing member for entrainment.   The seismic reinforcement method for retaining walls according to claim 1 or 2, wherein the lower concrete fixing member is a reinforced concrete fixing member.   5. The seismic reinforcement method for retaining walls according to claim 3 or 4, wherein a reinforcing pile is provided on the concrete fixing member.   The seismic reinforcement method for retaining walls according to claim 3 or 4, wherein a sheet pile is provided on the concrete fixing member.   The seismic reinforcement method for retaining walls according to claim 1, wherein the covering member is made of a collapse prevention net or sheet for the wall surface.   8. The seismic reinforcement method for retaining walls according to claim 7, wherein the collapse prevention net of the wall surface is two overlapping nets having different mesh directions.

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