JPH09221719A - Method for reinforcing pier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the lower end of a reinforcing steel plate even if the plate is formed into a hinge due to a great earthquake by restraining the lower end of the reinforcing steel plate on the outer surface of a pier frame using a structure in which concrete is placed on a steel plate, with its lower end restrained, to which a stud is attached. SOLUTION: A reinforcing steel plate 2 is divided into a corner part and a center part of a pier frame 1 and placed along the outer surface of the frame 1, and a lower end restraining steel plate 3, on which a plurality of studs 4 are erected, is welded integrally to the lower end of the plate 2. A bracket 5 fixed to the plate 2 fixes an anchor bars 7 for fixing the plate 2 to a footing 6 of the frame 1. The plate 2 integral to the plate 3 is temporarily fixed to the frame 1 by means of bolts, and a lower end restraining steel plate 11 making a pair with the plate 3, in which a plurality of studs 12 are oriented inwards, is spaced apart from the plate 3 by a predetermined interval at the corner part and center part of the frame 1 and adjoining parts are welded. And the frame 1 is attached to the plate 2 and concrete is placed between the plate 3 and the plate 11.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for reinforcing a pier of an existing bridge.

[0002]

2. Description of the Related Art In reinforcing existing bridges, it is important to improve the toughness of the entire bridge system and to make the structure tough.
For this reason, bridges supported by reinforced concrete piers are required to have improved toughness and strength. Improving the horizontal strength of the pier structure during an earthquake increases the seismic force transmitted from the pier structure to the foundation structure in the event of a large earthquake, which may require large-scale reinforcement including the foundation. is there. Basically, it is desirable to use a construction method that improves the toughness of the pier and minimizes the proof stress as much as possible. However, if only the toughness of the pier is expected to improve when the pier skeleton is insufficient, large residual mutations may occur in the pier after the earthquake.

Therefore, as a method of improving the strength of a required pier skeleton within a range where the foundation can be supported and balancing the improvement of toughness and strength, a steel sheet winding method of bending strength control type is adopted ( Reference materials (draft) for the mutatis mutandis of the Japan Road Association, "Specifications for Restoration of Road Bridges Damaged by the Hyogoken-Nanbu Earthquake" (June 1995).

[0004] As shown in Figs. 5 and 6,
A bridge pier body 1 having a rectangular cross section is wound around a reinforcing steel plate 2, and the reinforcing steel plate 2
And the pier frame 1 are integrated by non-shrink mortar or epoxy resin, and the reinforcing steel plate 2 and footing 6 are provided at the base of the pier.
And the reinforcing steel plate 2 is fixed to the footing 6 by the anchor bar 7 via the bracket 5.

[0005] In this construction method, in order to prepare for the case where the lower end of the pier is hinge-plasticized due to a large earthquake, a mold steel such as H steel 20 is installed at the lower end of the reinforcing steel plate 2 and the lower end of the reinforcing steel plate 2 is fixed. Measures are taken to prevent the lower end of the reinforcing steel plate 2 from splashing by being restrained.

[0006]

In this method, it is recognized that restraining the lower end of the reinforced steel sheet by the mold steel is extremely effective, but has some problems to be solved.

[0007] First, since the dimensions of the shape steel are determined based on a fixed formula in accordance with the dimensions of the pier frame, a large number of sizes must be prepared. Due to the weight, the workability is inferior, and the field welding extension connecting the members becomes longer.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention first provides a pier reinforcement method for attaching a reinforcing steel plate to the outer surface of a pier frame. The lower end constrained steel plate with the studs attached to the steel plate is integrated so that the studs face outward, and a space is provided outside the lower end constrained steel plate to form a stud that also serves as a formwork paired with the lower end constrained steel plate. Provided is a pier reinforcement method characterized in that a lower end constrained steel plate composed of an attached steel plate is positioned so that a stud faces inward, and concrete is poured between both lower end constrained steel plates.

In order to solve such a problem, in a pier reinforcement method for attaching a reinforcing steel plate to the outer surface of a pier frame, a lower end restraining steel plate having a stud attached to the lower end of the reinforcing steel plate attached to the outer surface of the pier frame is provided. Are integrated so that they face outward, and anchoring the footing to the footing with the upper end of the anchoring bar protruding above the upper end of the lower end restraint steel plate and providing a space with the lower end restraint steel plate outside thereof. A lower end restraint steel plate consisting of a steel plate attached with a stud that also serves as a formwork that forms a pair with the lower end restraint steel plate is positioned so that the stud faces inward, and concrete is poured between both lower end restraint steel plates and protruded upward. A bridge characterized in that concrete is also cast on the anchor streak and the anchor streak is buried in the concrete and settled. To provide a reinforcement method.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

First, an embodiment of the present invention will be described with reference to FIGS. 1, 3 and 4. Here, FIG. 1 is a vertical sectional view showing an embodiment in which the upper part is omitted, and FIG.
FIG. 4 is an exploded view of FIG. 3.

The reinforcing steel plate 2 is divided into a corner portion and a center portion of the outer surface of the pier frame 1, and the steel plate is bent at the corner portion and flattened at the central portion to form a shape along the outer surface of the pier frame 1. The lower end constrained steel plate 3 having an appropriate height along each shape is integrated thereunder by welding, bonding with an adhesive such as epoxy resin, or bolting. The lower end constraining steel plate 3 is planted so that the plurality of studs 4 face outward in the width direction and the height direction of the outer surface thereof. Reference numeral 5 denotes a bracket for fixing an anchoring bar 7 for fixing the reinforcing steel plate 2 to the footing 6 of the pier frame 1. The bracket 5 is fixed to the reinforcing steel plate 2 and has an insertion hole 8 through which the anchoring bar 7 is inserted. The lower portion of the anchoring bar 7 forms a fixing portion to the footing 6, and the upper portion is threaded, inserted into the insertion hole 8 of the bracket 5, and fixed by a nut 9. In addition,
The structure for fixing the anchor bar to the bracket 5 is known.

Numeral 11 denotes a lower end constrained steel plate which is paired with the lower end constrained steel plate 3 described above. The lower end constrained steel plate 3 is bent at the corners of the pier frame 1 and flattened at the central portion so as to have a size capable of coping with the lower end constrained steel plate 3. A plurality of studs 1 formed in the width direction and the height direction
Two are planted.

Reinforcing steel plate 2 with lower end constraining steel plate 3 integrated
Are arranged at the corner and the center of the pier frame 1, respectively, and temporarily fixed to the pier frame 1 with bolts.
The studs 12 face inward on the styrofoam 14 placed for positioning on the footing 6, and a fixed interval is provided between the lower end restraining steel plate 3 at each of the corner and the center of the pier frame 1. It is positioned and doubles as a formwork. Each adjacent part is welded and continuous.

The anchor bar 7 is inserted into a hole 15 formed on the upper surface of the footing 6, and an adhesive such as epoxy resin flows between the anchor bar 7 and the hole 15 to be fixed.

An adhesive such as resin mortar or epoxy resin is poured between the pier frame 1 and the reinforcing steel plate 2, and the two are integrated by bonding.

Concrete is poured between the lower end restraint steel plate 3 and the lower end restraint steel plate 11. In addition, 10 and 13 are auxiliary reinforcing bars.

In this way, in the reinforcing method of attaching the reinforcing steel plate to the outer surface of the pier frame, the reinforcing structure and the structure for restraining the lower end of the reinforcing steel plate are completed.

Next, another embodiment of the present invention will be described with reference to FIG. 3 and 4 are incorporated in this embodiment.

The reinforcing steel plate 2 is divided into a corner portion and a center portion of the outer surface of the pier frame 1. The steel plate is bent at the corner portion and flattened at the center portion, and each has a shape along the outer surface of the pier frame 1. The lower end constrained steel plate 3 having an appropriate height along each shape is integrated thereunder by welding, bonding with an adhesive such as epoxy resin, or bolting. The lower end restraint steel plate 3 is implanted such that the plurality of studs 4 face outward in the width direction and the height direction of the outer surface. Reference numeral 7 denotes an anchor bar, and the lower portion of the anchor bar 7 has a fixing portion to the footing 6, and has a length whose upper end protrudes above the upper end of the lower end restraining steel plate 3 in a fixed state. In addition, 16 is a stud attached to the reinforcing steel plate 2 and is integrated with concrete in which the anchor 7 described later is embedded.

Numeral 11 denotes a lower end constrained steel plate which is paired with the lower end constrained steel plate 3 described above. The lower end constrained steel plate 3 is bent at the corners of the pier frame 1 and flattened at the central portion to have a size which can accommodate the lower end constrained steel plate 3. A plurality of studs 1 formed in the width direction and the height direction
Two are planted.

Reinforced steel plate 2 integrated with lower end restraint steel plate 3
Are located at the corners and the center of the pier skeleton 1.
And the lower end restraint steel plate 11 is placed on the footing 6 for alignment with a polystyrene foam 14.
With the stud 12 facing upward, the pier frame 1
Are located at a constant interval between the lower end restraint steel plate 3 at the corner and the center, respectively, and also serve as a mold. Each adjacent part is welded and continuous.

The anchor bar 7 is inserted into a hole 15 formed on the upper surface of the footing, and the anchor bar 7 and the hole 1 are drilled.
An adhesive such as an epoxy resin flows into the gap 5 and is fixed.

Concrete is cast between the lower end restraint steel plate 3 and the lower end restraint steel plate 11. In addition, 10 and 13 are auxiliary reinforcing bars.

An adhesive such as resin mortar or epoxy resin is poured between the pier frame 1 and the reinforcing steel plate 2,
Both are integrated by adhesion.

In this manner, in the reinforcing method for attaching the reinforcing steel plate to the outer surface of the pier frame, the reinforcing structure and the structure for restraining the lower end of the reinforcing steel plate are completed.

[0027]

Since the present invention has been made as described above,
It has the following effects.

In the first and second aspects, the lower end of the reinforcing steel plate attached to the outer surface of the pier frame has a structure in which a co-crete is cast into a pair of lower end restraining steel plates to which studs are attached to form a composite cross section. Because it is constrained, the lower end of the reinforced steel plate is constrained even when hinged due to a large earthquake.

The integration of the lower end restraint steel plate and the reinforcing steel plate can be easily carried out in a factory, and this integrated product is lighter and simpler than a die steel, so that it is easy to carry and has good workability.

Since the distance between the pair of lower constrained steel plates can be changed simply by moving the lower constrained steel plates also serving as the formwork positioned on the outside, the lower constrained steel plates also serving as the formwork positioned on the outer side can be changed. In addition, multiple dimensions of the pier body can be dealt with.

According to the second aspect, the upper end of the anchoring bar fixed to the footing projects upward from the upper end of the lower end restraining steel plate attached to the reinforcing steel plate, and the anchoring bar is formed by casting concrete. And is fixed to the concrete together with the studs of the lower end restraining steel plate, so that there is no need to attach a bracket to the reinforcing steel plate as in the related art.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment.

FIG. 3 is a cross-sectional view taken along the line AA of FIGS. 1 and 2.

FIG. 4 is an exploded view of FIG.

FIG. 5 is a vertical sectional view showing a conventional example.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bridge pier body 2 Reinforcement steel plate 3 Lower end restraint steel plate 4 Stud 5 Bracket 6 Footing 7 Anchor bar 11 Lower end restraint steel plate 12 Stud 16 Stud

Claims (2)

[Claims] 1. A pier reinforcement method for attaching a reinforcing steel plate to an outer surface of a pier skeleton, wherein a lower end restraining steel plate having a stud attached to a steel plate at a lower end of the reinforcing steel plate attached to the outer surface of the pier skeleton is integrated such that the stud faces outward. Along with the lower end restraint steel plate, an interval is provided, and a lower end restraint steel plate made of a steel plate attached with a stud also serving as a formwork paired with the lower end restraint steel plate is positioned so that the stud faces inward, A pier reinforcement method characterized by placing concrete between the steel plates restrained at both ends. 2. A pier reinforcing method for attaching a reinforcing steel plate to an outer surface of a pier skeleton, wherein a lower end restraining steel plate having a stud attached to a lower end of the reinforcing steel plate attached to the outer surface of the pier skeleton is integrated so that the stud faces outward, and footing is performed. The anchor bar is fixed in a state where the upper end of the anchor bar protrudes above the upper end of the lower constrained steel plate, and at the outside thereof, a space is provided with the lower constrained steel plate to serve as a formwork paired with the lower constrained steel plate. The lower end constrained steel plate consisting of the steel plate with the studs attached is positioned so that the stud faces inward, concrete is poured between both lower end constrained steel plates, and concrete is also cast on the anchor bars projecting upward. A pier reinforcement method characterized in that anchor bars are buried in concrete and settled.