JPH0321703A - Anchoring device for bridge - Google Patents

Abstract

PURPOSE:To easily perform low cost construction work by integrally fitting a coating elastic member provided with a flange like elastic member on its outer peripheral face on an anchor bar and fitting an anchor cap on the anchor bar so as to be movable along the direction of expansion of a bridge. CONSTITUTION:The lower part of an anchor bar 1 is buried in a bridge pier 2 or an abutment with the upper part of the anchor bar 1 protruding from the bridge pier 2 or the abutment. Then, a flange like elastic member 6 is provided on the circumference of a coating elastic member 5 with which the protruding part of the anchor bar 1 is covered. The coating elastic member 5 is mounted on the peripheral face of the anchor bar 1. Next, an anchor cap 4 is fitted on the protruding part of the anchor bar 1. On the top face of the coating elastic member 5, a tip support elastic member 8 for securing a clearance toward the ceiling face of the anchor cap 4 is provided. When a bridge girder after construction is expanded by contracted due to change of temperature or the like, the peripheral part of the flange like elastic member 6 is deformed to absorb the displacement of the anchor cap 4. Vertical deformation is absorbed by the elastic deformation of the support elastic member 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bridge anchor device provided on the upper part of a bridge pier or abutment to support a bridge girder.

In bridges where both sides of the bridge girder are supported by piers or abutments, the bridge girder expands and contracts in the horizontal direction due to drying shrinkage of the concrete and deflection of the bridge girder due to its own weight, causing the girder to fall from the piers or abutment. A so-called bridge collapse may occur.

As shown in Fig. 5, an anchor device for preventing this bridge collapse is an anchor bar with an
Usually used is a structure in which the protrusion of the anchor par 01 is fitted into anchor caps 04 and 05 buried at both ends of the bridge girder 03, and the protruding parts of the anchor par 01 are embedded and fixed in the bridge pier 02.

Here, a spiral thread 06 is embedded around the anchor caps 04 and 05 to maintain hole strength, and an anticorrosive material 07 made of bitumen or the like is provided in the gap between the inner surface of the anchor caps 04 and 05 and the anchor bar Ol. is filled. Furthermore, a packing material 08 such as rubber is arranged in the gap between the bridge girder 03 and the bridge pier 02.

When the bridge girder 03 expands or contracts due to drying shrinkage of concrete, creep, temperature equalization, etc., the cylindrical anchor cap 04, which is slightly larger than the outer diameter of the anchor par 01 as shown in FIG. 6(a), One end of the bridge girder 03 is fixed, and the longitudinal expansion and contraction of the bridge girder 03 is allowed within a certain range by the anchor par 05 of the oval anchor cap 05 as shown in FIG. 6('b). ing.

In the anchor device having this structure, when the anchor par 01 is correctly positioned in the center of the anchor cap 05, the desired displacement absorber is set. ability is demonstrated.

However, since the filling anticorrosion 07 has fluidity, it is not attached to the bridge girder 03 with the anchor cap 05 positioned at the center of the anchor OX. When attempting to cast concrete, the anchor cap 05 may shift from its center position relative to the anchor bar due to the flow resistance of the fresh concrete.

If the bridge is completed with the anchor par 01 deviated from the center of the anchor cap 05 in this way, there will not be enough room to absorb the expansion and contraction of the bridge girder 03, which may cause the anchor par 01 to bend or cause unexpected damage to the bridge. A horizontal force is generated,
This can cause cracks and bridge collapse during earthquakes, etc.

In addition, since the anchor cap 05 into which the anchor par 01 is inserted is wide open, the filled anticorrosion 07 easily flows out of the anchor cap 05, and the gap between the anchor par 01 and the inner surface of the anchor cap 05 is Due to the wide area, there are some areas where the filling fat material 07 does not reach, and as a result, the amount of the filling preventive material 07 is insufficient, and the anchor par 0
1 will corrode over a long period of time, causing a decrease in strength.

Moreover, filling the anti-corrosive material 07 on-site is not only difficult and uncertain, but also causes the worker and the surrounding area to get dirty easily. The use of parts is unavoidable.

As an anchor device that prevents the anchor bar from shifting with respect to the anchor cap and prevents corrosion of the anchor bar without using a filling anti-corrosive material, a holding packing 09 as shown in Fig. 7 is used to prevent this holding. There is one in which the packing 09 is fitted into the anchor par 01.

This holding packing 09 has a side wall extending in the axial direction G, and as shown in FIG. It has an irregularly shaped horizontal cross section that fits closely together.

By arranging this holding packing 09 between the anchor bar Ol and the anchor packing 05, the anchor bar 01 is held in the central portion of the anchor packing 05.

Furthermore, by coating the anchor par 01 with a resin, the anchor par 01 is protected from corrosion without requiring a filling material such as bitumen.

However, the holding bunkin 09 used in this anchor device has a very special shape, making it difficult to handle manually, and as shown in Fig. 8, the holding bunkin 09 is axially Since the side wall 010 is long, it becomes difficult to insert the retaining packing 09 into the inner surface of the anchor packing 05 in close contact with the inner surface of the anchor packing 05.

Additionally, the size of the anchor par 01 and anchor cap 05 will vary depending on the type and size of the bridge.
Accordingly, it is required to prepare holding packings 09 of various sizes.

Moreover, since the anchor bar 01 is protected from corrosion by resin coating, there is also the drawback that a normal anchor bar cannot be used.

The present invention relates to an improvement of a bridge anchor device that overcomes these difficulties, and includes an anchor bar buried integrally in a bridge pier or an abutment, and a support portion formed at the tip, and A covered elastic body integrally fitted to the anchor bar, a flange-like elastic body provided integrally or separately on the peripheral surface of the covered elastic body, and embedded integrally in the bridge girder or the bridge body, The present invention is characterized by comprising an anchor cap fitted to the anchor bar via the brim-like elastic body and the covering elastic body so as to be movable along the expansion and contraction direction of the bridge girder or the bridge body.

Since the present invention is constructed as described above, the anchor bolt is accurately held in the center of the anchor cap by the collar-like elastic body located between the inner surface of the anchor cap and the anchor bolt. Displacements caused by expansion and contraction of the bridge girder are reliably absorbed by the elastic deformation of the brim-like elastic body.

Moreover, the anchor bar is shielded from corrosive atmospheres such as moisture and air by the covering elastic body that is integrally fitted to the anchor bar.

Below, the embodiments illustrated in FIGS. 1 to 3 will be described.

In the anchor device of this embodiment, as its cross section is shown in FIG. 1, the upper part of the anchor par 1 is projected from the pier 2 or the abutment, and the lower part of the anchor par 1 is buried in the pier 2 or the abutment. There is. Then, the anchor cap 4 provided on the movable side of the bridge girder 3 is fitted into the protrusion of the anchor par 1. Note that arranging a spiral striation (not shown) around the anchor cap 4 to ensure hole strength is
This is the same as the case explained in FIG.

5 is a covering elastic body that covers the protrusion of the anchor par 1;
It is attached to the peripheral surface of the anchor bar l. The covering elastic body 5 is made of rubber having a hardness of about 60° and a wall thickness of about 1 mm, for example, and is integrated with the anchor part 1 by appropriate means such as baking or adhesion.

Reference numeral 6 denotes a collar-like elastic body provided around the covering elastic body 5, and is shaped to match the inner cross section of the anchor cap 4. This collar-like elastic body 6 is made of rubber and has a thickness of about 3M, for example, and is attached to at least two positions in the axial direction of the covered elastic body 5.

7 is a space formed between these collar-like elastic bodies 6.

Further, a tip support elastic body 8 is provided on the top surface of the covering elastic body 5 to ensure clearance with the ceiling surface of the anchor cap 4. This tip support elastic body 8 also forms a space 7 between the uppermost collar-shaped elastic body 6 and the ceiling surface of the anchor cap 4.

Next, the function of this anchor device will be explained.

Since the flange-like elastic body 6 provided around the covering elastic body 5 integrated with the anchor par 1 has a shape that matches the inner cross section of the anchor cap 4, the anchor cap 4 can be fitted onto the anchor par 1. At this time, the positional relationship between the anchor par 1 and the anchor cap 4 is regulated by the collar-like elastic body 6.

Therefore, the anchor cap 4 can be fitted without causing any displacement.

The bridge girder 3 after construction expands and contracts due to drying shrinkage of concrete, temperature changes, creep, and the like. Depending on this expansion and contraction,
The anchor cap 4 is displaced relative to the anchor bar l as indicated by the arrow in FIG.

At this time, the surrounding surface of the anchor par 1 and the anchor cap 4
On the side where the distance between the anchor cap and the inner circumferential surface of the anchor cap is shortened, the peripheral portion of the brim-like elastic body 6 is elastically deformed to absorb the displacement of the anchor cap 4. This elastic deformation of the flanged elastic bodies 6 is reliably performed without hindering the movement of the anchor cap 4, since each flanged elastic body 6 is arranged with an appropriate space 7.

Furthermore, the bridge girder 3 is also displaced in the vertical direction due to changes in load, etc., and this displacement due to expansion and contraction is absorbed by the elastic deformation of the tip support elastic body 8.

In this way, during construction, the positional relationship between the anchor par 1 and the anchor cap 4 can be accurately determined with simple work, and displacement of the anchor cap 4 caused by expansion and contraction of the bridge girder 3 can be absorbed without any problem. be able to. In addition, in the above description, the anchor device on the movable side was explained.

However, the present invention is not limited to this, and can also be applied to fixed-side anchor devices. In this case, the flanged elastic body 5 used is one that is rounded to match the inner cross section of the anchor cap 4.

Moreover, not only the upper part of the anchor par 1 protruding from the abutment 2 but also the part of the anchor par 1 corresponding to the gap between the bridge girder 3 and the bridge pier 2 can be covered with the covering elastic body 5. Furthermore, the portion buried in the pier 2 may be covered with the covering elastic body 5.

? The shaped elastic body 5 and the tip support elastic body 8 are covered elastic body 5.
It can be prepared as a separate piece (7) and attached to the covered elastic body 5 by fitting, gluing, or other means. 5 can also be used.

The flanged elastic body 6 can be easily cut with a cutter or the like. Therefore, the flange-shaped elastic body 6 is manufactured widely in advance,
By cutting along the cutting line 9 shown by the dotted line in FIG. 3, anchor caps 4 of various sizes can be obtained.

As the collar-like elastic body 6, in addition to a flat plate-shaped one, a fourth
A radial shape is also used as shown in the figure.

Furthermore, if it is necessary to position the anchor par 1 at a special position other than the center of the anchor cap d, various requests can be easily met by selecting the shape of the cutting line 9 according to the purpose. .

The anchor cap 4 may be made of resin or the like with excellent corrosion resistance, in addition to being made of steel pipe.

As explained above, according to the anchor device of the present invention, the positional relationship between the anchor bar and the anchor cap can be maintained with high accuracy simply by fitting the anchor cap to the anchor bar. .

Further, the displacement of the anchor cap caused by the expansion and contraction of the bridge girder due to L7 is absorbed without any problem by the deformation of the brim-like elastic body. As a result, unexpected stress is not generated in the bridge, and the desired strength is maintained over a long period of time.

In addition, there is no need for a special shape such as a holding packing, and a flanged elastic body with a normal shape can be used, so construction can be carried out at low cost. Furthermore, since this collar-shaped elastic body can be cut, it is highly versatile and can be applied to anchors and caps of various sizes.

Furthermore, the anchor bar is integrated with the covering elastic body and is isolated from the corrosive atmosphere. Therefore, there is no need to fill with anti-corrosion agents such as Bichi J,-men, and construction can be carried out without contaminating workers or the work environment.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the anchor device according to the embodiment of the present invention, Fig. 2 is a sectional view showing a state in which displacement of the anchor cap is absorbed, Fig. 3 is a plan view of the brim-like elastic body 2, and Fig. 4 is a sectional view showing the anchor device according to the embodiment of the present invention. Figure 5 is a plan view of another embodiment, Figure 5 is a cross-sectional view showing a normal anchor device, and Figures 6 (a) and (l) are anchor bars and anchor caps in fixed and movable anchor devices, respectively. 7 is a sectional view showing an anchor device using a specially shaped holding packing, and FIG. 8 is a horizontal sectional view showing the relationship between an anchor bar and an anchor cap in the same device. . 1... Anchor par 2... Bridge abutment, 3... Bridge girder,
4... Anchor cap, 5... Covered elastic body, 6.
... Flange-shaped elastic body, 7... Space portion, 8... Tip support elastic body, 9... Cutting line.

Claims (1)

[Claims] An anchor bar embedded integrally in a pier or abutment, a covered elastic body having a support portion formed at its tip and fitted integrally with the anchor bar, and an anchor bar embedded integrally or separately on the outer peripheral surface of the covered elastic body. A flange-shaped elastic body provided therein, and a bridge girder or a bridge body that is integrally embedded in the bridge girder or the bridge body, and is movable to the anchor bar via the flanges-shaped elastic body and the covered elastic body along the expansion and contraction direction of the bridge girder or the bridge body. An anchor device for a bridge, comprising an anchor cap fitted with the anchor cap.