JPH0246489Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on the use of anchor pipes in movement-limiting anchor devices used to prevent movable bearings of bridges from falling from their supports such as bridge abutments and piers when a strong earthquake occurs. This invention relates to a center holding device.

Conventionally, as a movement restriction anchor device for preventing the movable end of a bridge from falling from a support base such as an abutment or a bridge pier due to large hydroseismic force, the first type of anchor device is
As shown in the figure and FIG. 2, the lower part of the vertical anchor rod 7 is embedded and fixed in a support base 4 such as an abutment or a bridge pier, and a corrosion-resistant and holder 8 made of rubber sponge is fitted to the upper part of the anchor rod 7. An anchor pipe 1 is inserted into the anchor pipe, and its corrosion-resistant and cradle 8 is placed on a support pedestal 4, and further has a cross section that is elongated in the longitudinal direction of the bridge.
is placed over the top of the anchor rod 7 and placed on the anti-corrosion pedestal 8, and in this state bridge concrete 9 such as cross girder concrete is poured, and the anchor pipe 1 is embedded and fixed in the bridge concrete 9. It is known that the structure is as follows.

Since a large number of these movement-limiting anchor devices are installed side by side in the width direction of the bridge, the anchor rod 7 and the anchor pipe 1 in each movement-limiting anchor device are
If the distances between the bridges and the longitudinal ends of the bridge are not the same, when a strong horizontal seismic force acts on the bridge in the longitudinal direction, the load will only act on some of the movement-limiting anchor devices, and some of them will be affected. The movement-limiting anchor system may be destroyed.

As a countermeasure for this, when installing each movement-limiting anchor device, it is necessary to arrange the anchor rod 7 at the center of the cross section of the anchor pipe.

Conventionally, as a means to hold the anchor rod in the center of the anchor pipe, the anchor rod is placed in the center of the anchor pipe, and an asphalt-based cool solidifying material that is heated and melted is placed between the anchor pipe and the anchor rod. It is known to form a relatively soft corrosion-resistant spacer by injecting the material and then cooling and solidifying the material. However, in the case of this central holding means, the position of the anchor rod is likely to be misaligned when the cooling solidifying material is injected, and the corrosion-resistant spacer is also likely to be plastically deformed after solidification, so even after the solidification, the position of the anchor rod is easily misaligned. The problem is that it's easy to go crazy.

The object of this invention is to provide an anchor pipe movable holding device for a bridge movable bearing that advantageously solves the above-mentioned problems.

Next, the invention will be explained in detail using the illustrated example.

Figures 3 and 4 show a flat annular center holding packing 3 made of an elastic material such as rubber used in this invention, and is attached to semicircular inner surfaces on both sides of an anchor pipe with an oval cross section. a central support portion 11 having two semicircular portions 10 to be fitted together, an anchor rod fitting concave surface 2 to be fitted to both side surfaces of the anchor rod at the central portion in the longitudinal direction of the cross section of the anchor pipe; It has a bearing part 11 and an inwardly protruding circular arc part 12 connecting the semicircular parts 10, and a bearing surface 13 that comes into contact with the inner surface of the central part of the anchor pipe is formed on the outside of the central bearing part 11. ing.

5 to 7 show a first embodiment of this invention using the center holding packing 3, in which nylon resin is used on the circumferential surface and upper end surface of a steel anchor rod body 14 having a circular cross section. A coating or other anti-corrosion coating 15 is applied to form an anchor rod 5, the lower part of which is vertically arranged and supported by a support 4 such as a concrete abutment or pier.
The anchor rod 5, which is embedded in and fixed to the support base 4 and protrudes from the support base 4, has a ring-shaped base body 16 made of an elastic material such as rubber, and a base made of tetrafluoroethylene or other material that is integrally fixed to the upper surface of the base body 16. A sliding elastic pedestal 18 made of a synthetic resin sliding layer 17 is inserted,
The sliding elastic cradle 18 is placed on the upper surface of the support pedestal 4.

A plurality of center-holding packings 3 are fitted at intervals in the longitudinal direction of the pipe into a steel anchor pipe 1 having an oval cross section and a lid 19 fixed to the upper end thereof, and are fixed with adhesive. The anchor rod fitting concave surface 2 of the support part 11 is fitted to both side surfaces of the anchor rod 5, and the lower end surface of the anchor pipe 1 is placed on the upper surface of the sliding elastic pedestal 18. The longitudinal direction of the surface faces the longitudinal direction of the bridge,
Furthermore, the anchor pipe 1 is held at a predetermined height by the sliding elastic pedestal 18.

A reinforcing steel coil (not shown) is placed on the outside of the anchor pipe 1 to surround it, and the coil and the rest of the anchor pipe 1 except for the lower end are connected to a horizontal wall cast between adjacent PC girders. Embedded and fixed in bridge concrete 9 such as girder concrete,
In addition, an anchor rod movement allowing space 6 is provided between both longitudinal sides of the packing 3 and the anchor rod 5, and when the bridge moves in the longitudinal direction, the anchor rod 5 moves inwardly projecting arcuate portions 12. While pressing and deforming the packing 3 outward, it moves relatively toward the longitudinal end of the packing 3.

FIG. 8 shows a second embodiment of this invention, in which the anchor rod insertion holes are designed such that the lower end opening of the anchor pipe 1 is always closed by the sliding elastic cradle within the permissible range of movement of the bridge. A sliding elastic pedestal 18' having a large area and a circular cross-section steel anchor rod 5 without anti-corrosion coating are used, but the other configurations are the same as in the first embodiment. be.

In the case of the second embodiment, since the lower end opening of the anchor pipe 1 is always closed by the sliding elastic pedestal 18', it is possible to prevent moisture and foreign matter from entering the anchor pipe, and the anchor Corrosion of the inner surface of the pipe 1 and the anchor rod 5 can be suppressed. In the case of the second embodiment, the anchor rod 5 may be galvanized or chrome plated.

When implementing this idea, instead of fitting a plurality of packings 3 into the anchor pipe 1, one packing of the required length may be fitted.

According to this invention, an anchor pipe 1 having a cross section that is elongated in the longitudinal direction of the bridge has a flat annular shape having concave surfaces 2 for fitting anchor rods disposed on both sides of the longitudinal center of the cross section of the anchor pipe. A center holding packing 3 made of an elastic material is fitted, and the anchor rod fitting concave surfaces 2 of the packing 3 are fitted into both sides of the upper part of a vertical anchor rod 5 whose lower part is fixed to a support base 4. As a result, the anchor rod 5 can hold the anchor pipe 1 through the packing 3 with the anchor rod 5 placed precisely in the longitudinal center of the cross section of the anchor pipe 1, so that the anchor rod 5 can hold the anchor pipe 1 through the packing 3. When the devices are installed side by side in the width direction of the bridge, the distance between the anchor rod 5 of each movement-limiting anchor device and the longitudinal end of the cross section of the anchor pipe 1 can be set evenly, and therefore a strong horizontal If the bridge attempts to move significantly in its longitudinal direction due to seismic force, each movement-limiting anchor device can act as a stopper at the same time to restrict the movement of the bridge and prevent it from collapsing. If the longitudinal end of the cross section of the anchor pipe 1 is about to collide with the anchor rod 5, since there is a packing 3 made of elastic material between them, the bridge can be effectively buffered and stopped, and the bridge can be stopped. Effects such as being able to evenly distribute and transmit the moving force to the anchor rods 5 of each movement-limiting anchor device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing a conventional bridge movement restricting anchor device, and FIG. 2 is a cross-sectional view taken along the line A--A. FIG. 3 is a plan view of the center-holding packing made of elastic material used in this invention, FIG. 4 is a side view thereof, and FIG. 5 is a longitudinal sectional side view showing the first embodiment of this invention using the packing. 6 is an enlarged sectional view taken along the line B--B in FIG. 5, and FIG. 7 is an enlarged vertical sectional side view showing the lower part of FIG. 5. FIG. 8 is a longitudinal sectional side view showing a second embodiment of this invention. In the figure, 1 is an anchor pipe, 2 is a concave surface for fitting an anchor rod, 3 is a packing for center holding, 4
is a support base, 5 is an anchor rod, 6 is a space that allows anchor rod movement, 9 is bridge concrete, 10 is a semicircular part, 11 is a central support part, 12 is an inwardly projecting arc-shaped part, 14 is a steel anchor rod body , 15 is a corrosion-resistant coating, 16 is a pedestal main body, 17 is a sliding layer, and 18 is a sliding elastic pedestal.

Claims (1)

[Scope of utility model registration request] An anchor pipe 1 having a cross section that is elongated in the longitudinal direction of the bridge has a flat annular center-retaining concave surface 2 for fitting an anchor rod disposed on both sides of the central part in the longitudinal direction of the cross section of the anchor pipe. The anchor rod fitting concave surface 2 of the packing 3 is fitted into both sides of the upper part of the vertical anchor rod 5 whose lower part is fixed to the support base 4, into which the packing 3 is fitted, and the longitudinal direction of the packing 3 is A center holding device for an anchor pipe for restricting bridge movement, characterized in that an anchor rod movement permissible space 6 is provided between both side portions and the anchor rod 5.