JPH0312171B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A bridge is composed of piers, girders placed on the piers, and deck slabs placed on the girders.

The girders are not fixed to the piers, but are designed with a support structure that allows for expansion and contraction of the superstructure and changes in the angle of the support point (distortion relative to the support point) due to applied loads and temperature changes.

There are various types of this support structure, such as the pin type support structure, roller type support structure, and pendulum type support structure as shown in Figures 4, 2, and 3, but all of them use cast iron, cold steel, cast steel, etc. Since it is made of iron, it has the disadvantage of inevitably rusting.

Furthermore, river bridges are prone to rust due to humidity, and even land bridges are susceptible to rust due to contaminated air.

Expansion and contraction are generally 20 to 30 mm, and 50 to 50 mm for long span bridges.
Although it is 100mm, it is characterized by extremely slow expansion and contraction speed and extremely large load.

It is natural to paint the entire surface of the support structure to prevent rust, but even if the load is supported by surfaces or lines, such as the slip surface of surface contact, the cylindrical surface of the roller, and its rolling surface, even if the load is This causes the paint film to be crushed and peeled off, which then causes rust.

In addition to rust, the accumulation of flying sand, floating dust, objects brought in by birds and animals, etc. will naturally accelerate the formation of rust, impair the original operation of the support structure, and cause strain on the attachment parts of girders and piers. become.

The present invention provides a method for solving these problems, and involves surrounding various types of support structures in bridges with a sealing material that has elasticity that adapts to the expansion and contraction of girders and angular changes. is adhered to the bearing surface and the surface on which the bearing structure is attached to protect the bearing structure in a sealed state, and grease or lubricating oil is interposed between the sealing material and the bearing structure. .

The existing bridge bearings have a gap of about 100 to 200 mm between the top of the pier and the bottom of the girder, which is narrow and the depth is about 1.0 m, making it impossible to carry out construction work freely. Only a limited range of tools, such as force, manpower, and extremely small power tools, can be used, and the construction process is restricted. For new bridges, the restrictions are relaxed because the construction process can proceed to a certain extent before girders are placed on the piers.

Therefore, the construction method for an existing bridge will be described below as an example of the implementation of the present invention.

(1) First, clean the support part 1.

(2) Surface treatment of the concrete on the lower surface of the girder 2 and the upper surface of the pier 3 near the bearing part 1 involves removing defective areas of the concrete and adjusting unevenness using epoxy resin mortar, etc., although it is difficult to do so in a narrow space.

(3) Attach sealing material 4.

For the sealing material 4, a long band of synthetic rubber material having a cross-sectional structure as shown in FIGS. 2 to 4 and 6 to 10 is used, and it is bent or curved where necessary. surrounding the bearing part,
For the joint, a short flexible rubber hose is used as the joint material 5.
A method is adopted in which the sealing material 4 is inserted into both ends and tightened.

Wrinkles were formed on the inside of the bent or curved portions, but no grease leaked in the next step even if the wrinkles were formed.

(4) For the sealing material 4 shown in Figure 4, pass two rubber hoses through it before joining the ends, and use metal wires to hold the rubber hoses in the air at several locations so that the rubber hoses are in the designated positions. Before attaching and connecting, I cut the rubber hose and press-fitted the epoxy resin injection agent into it.

(5) Figures 2 and 3 also show the cavity 4' of the sealing material 4.
Urethane foam was press-fitted into the.

As a result, the cavity 4' expands, and a force is exerted that presses the lower surface of the girder 2 and the upper surface of the pier 3, and this force is permanent.

(6) Grease is injected into the sealing material 4 through an injection port that has been installed in advance at key points or joints of the sealing material 4.

At this time, it is necessary to vent air.

(7) In areas where blown sand is severe, a rubber plate may be attached to protect the outer surface of the sealant, or an FRP plate made of glass cloth impregnated with epoxy resin may be applied on-site to cover the seal.

In this case, since the epoxy resin will adhere to the outer surface of the sealing material 4, a release agent (paraffin, etc.) is applied to the outer surface of the sealing material 4.

(8) The sealing material 4 is pressed against the lower surface of the girder 2 and the upper surface of the pier 3 in surface contact, but if necessary, it may also be adhered to the upper surface of the pier 3 or the lower surface of the girder 2.

If the length of expansion and contraction of girder 2 is about 20 mm, the height of sealing material 4 will be 100 mm even if the upper and lower surfaces of sealing material 4 are glued together.
Even mm can sufficiently absorb the amount of movement.

(9) In addition to the urethane foam resin, the material press-injected into the cavity 4' of the sealing material 4 may be simply air.

(10) Seal material 4 is made of the shape material studied, as well as
Various types as shown in Figs. to 10 can be used.

Although an example of implementation has been described in detail above, the present invention protects the support structure by surrounding the support structure with a sealing material and putting grease or lubricating oil therein. An excellent bridge girder that permanently prevents foreign matter from entering from the outside world, and permanently maintains a supporting structure that always adapts to the girder's expansion/contraction and angular changes and operates as expected. This is a rust prevention method for the bearing part.

[Brief explanation of drawings]

Figure 1 is an explanatory side view of a bridge support structure, Figure 2 is a side sectional view of a roller type support structure, Figure 3 is a side sectional view of a pendulum type support structure, and Figure 4 is a side sectional view of a pin type support structure. , Fig. 5 is a plan sectional view of the support structure, Fig. 6,
Figures 7, 8, 9, and 10 are cross-sectional views of the sealing material. 2...digit, 4...sealing material.

Claims (1)

[Claims] 1. Various types of support structures in a bridge are surrounded by a sealing material having elasticity that adapts to the expansion and contraction of the girder and angular changes, and the top and bottom of the sealing material are provided with a bearing surface and a surface to which the support structure is attached. A rust prevention method for bridge girder bearing parts, characterized in that the bearing structure is protected in a sealed state by adhering the sealing material to the bearing structure, and grease or lubricating oil is interposed between the sealing material and the bearing structure. 2. Surround the various types of support structures in bridges with sealing material that has elasticity that adapts to the expansion and contraction of girders and angular changes, and apply expansion force to the sealing material to support the top and bottom of the sealing material by pressing force in the vertical direction. Claim No. 1, characterized in that the support structure is protected in a sealed state by bonding the support structure to the surface to which the support structure is attached, and that grease or lubricating oil is interposed between the sealing material and the support structure. Rust prevention method for bridge girder bearings described in Section 1. 3. The rust prevention method for a bridge girder support according to claim 2, characterized in that the sealing material is expanded vertically using the expansion force of the sealing material itself. 4. The rust prevention method for a bridge girder support according to claim 2, which comprises injecting an expanding substance into the interior of the sealing material to cause the sealing material to expand vertically.