JPH0378444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a girder widening method for bridge substructures.

(Prior Art) When a bridge comes off during an earthquake and falls onto the ground, into a river, or into the sea, it is not easy to restore it. Especially if the bridge in question is on an emergency transportation route, it will cause a great deal of trouble to recovery efforts.

In order to prevent such serious damage, one measure to prevent bridge collapses is to widen the girders of bridge substructures.

Figure 3 shows the conventional widening method.
After drilling a hole in the side of the substructure, fill it with mortar, insert reinforcing bars b and plant them, and add reinforced concrete to the existing substructure a on site to form the widening section c.

Figure 4 shows another example of the conventional width widening method, in which an anchor hole d is drilled on the side of the existing substructure a, an anchor bolt e is inserted and fixed, and the steel width is widened through the anchor bolt e. Part f is fixed to the existing substructure a.

(Problem to be solved by the invention) However, in the former method, it is necessary to roughen the surface of the existing concrete in order to improve the mutual adhesion between the existing concrete and the new concrete, and it is also necessary to roughen the surface of the existing concrete and remove the reinforcements and anchors. It will take time to establish and construct reinforced concrete in the widening section.

In addition, in the latter method, the widening section is fixed only by anchor bolts and existing concrete, but if the existing substructure is not thick enough, it may not be possible to secure a sufficient anchor length. .

(Means for Solving the Problems) The present invention has been proposed to solve these problems, and it provides vertical anchors and horizontal anchors on the top and outside surfaces of existing substructures of bridges, respectively. and then the lower ends of the horizontal part of the inverted L-shaped mounting member fixed to the inner surface of the width-expanding member that protrudes inward from the top of the width-expanding member and the vertical piece along the inner surface of the width-expanding member. The protruding part
The above problem is solved by fixing to the existing substructure via the vertical anchor and the horizontal anchor, respectively.

(Function) In the present invention, the vertical part of the inverted L-shaped mounting member is attached to the inner surface of the widening member made of precast concrete, precast reinforced concrete, or steel, so that the lower end of the vertical part of the member protrudes downward from the lower end of the widening member. After installing vertical anchors and horizontal anchors on the top and outer surfaces of the existing substructure, the inverted L-shaped mounting member fixed to the width expansion member will protrude inward from the top of the width expansion member. The lower end protrusions of the widening members in the horizontal piece and the vertical piece are fixed to the existing substructure via the vertical anchor and the horizontal anchor, respectively, and thus the widening member is fixed to the outer surface of the existing substructure. It is something to do.

Therefore, the widening member is fixed to the existing substructure not only on the outer surface but also on the top surface, so that high fixing strength can be obtained.

(Effects of the Invention) According to the present invention, the width expanding member has an inverted L-shaped mounting member fixed to the member, and vertical anchors and horizontal anchors installed on the top and outer surfaces of the existing substructure. Since it is fixed to the existing substructure at two points, the outside surface and the top surface, through the anchor, high fixing strength is obtained, and there is no thickness of the existing substructure, allowing for sufficient anchorage length between the anchor and the existing concrete. Even if there is no existing substructure, the widening member can be reliably attached to the existing substructure.

Further, according to the present invention, as described above, when installing the widening member, on-site reinforcement work and concrete pouring work are not required, so the construction is simplified.
This can shorten the construction period.

(Example) The present invention will be described below with reference to the illustrated embodiments.

1 is an existing substructure, 2 is a widening member made of precast concrete, precast reinforced concrete, or steel, and the vertical part 3a of the inverted L-shaped mounting member 3, which is made of a steel plate on the inside surface, is the same part 3a.
It is fixed so that its lower end protrudes below the lower end of the width widening member 2.

Therefore, in the existing substructure 1, the same substructure 1
Vertical anchor holes 5 and horizontal anchor holes 6 are drilled at the top and outside of the adjacent main girders 4 that are constructed above, and vertical anchors 7 and horizontal anchors are installed in each of the anchor holes 5 and 6, respectively. 8
The horizontal part 3b of the inverted L-shaped mounting member 3 protrudes inward from the top of the widening member 2, and the vertical part 3a protrudes from the lower end of the member 2, respectively. The widening member 2 is fixed to the top and outer side of the existing substructure 1 via horizontal anchors 8, and thus the widening member 2 is fixed to the existing substructure 1.

In this way, according to the embodiment, the inverted L-shaped mounting member 3 to which the width expanding member 2 is fixed;
The widening member 2 is fixed to the existing substructure 1 at two locations, at the top and outside, via vertical anchors 7 and horizontal anchors 8 installed on the top and outer surfaces of the existing substructure 1. is firmly fixed to the existing substructure 1, and even if the existing substructure 1 is not thick enough to allow sufficient anchoring length between the concrete of the same substructure 1 and the anchor, the existing substructure 1 of the widening member 2
It becomes possible to attach to.

Further, according to the above embodiment, when installing the width widening member 2, there is no need for on-site reinforcing and concrete pouring work, so the construction is simplified and the construction period is shortened.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the implementation status of one embodiment of the bridge substructure widening method of bridge substructure according to the present invention.
2 is a plan view thereof, and FIGS. 3 and 4 are vertical cross-sectional views showing the state of implementation of the conventional bridge substructure widening method. 1... Existing substructure, 2... Widening member, 3... Inverted L-shaped mounting member, 3a... Vertical piece, 3b... Horizontal piece, 5... Vertical anchor hole, 6... Horizontal anchor hole, 7... Vertical anchor bolt, 8...
…Horizontal anchor bolt.

Claims (1)

[Claims] 1. Vertical anchors and horizontal anchors are installed on the top and outside surfaces of the existing substructure of the bridge, respectively, and then an inverted L-shaped mounting member fixed to the inside surface of the widening member protrudes inward from the top of the widening member. The lower end protrusion of the horizontal part and the vertical part along the inner surface of the widening member are fixed to the existing substructure via the vertical anchor and the horizontal anchor, respectively. girder widening method.