JP3125653B2 - Bridge girder construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of erection of a bridge girder, and more particularly to a method of erection of a bridge girder by sequentially adding bridge girder blocks from above a pier toward the center of a span.

[0002]

2. Description of the Related Art As a kind of bridge girder construction method, an overhanging cast-in-place construction method is known. The overhang cast-in-place construction method is a method of constructing a bridge girder block having a length of about 2 to 5 m while successively adding. In this type of construction,
First, a pier is set up on the upper side of the pier to build a capital,
A pair of movable erection devices are installed on the column caps, and a bridge girder block is added and formed toward the center of the span while maintaining the right and left balance.

FIG. 8 shows an example of a mobile erection apparatus used in this type of erection method. The mobile erection device shown in FIG. 1 is assembled in a truss-like shape, and is provided on a top surface of an existing bridge girder 1 with a pair of main frames 2 that are detachably locked and supported at one end, and are provided orthogonally between the main frames 2. A cross beam 3 is provided, a plurality of suspension rods 4 suspended from an end of the cross beam 3, and a work carriage 5 supported at a lower end of the suspension rod 4. Each main frame 2 extends obliquely above a new bridge girder block 6 to be formed.

[0004] When constructing a new bridge girder block 6 at the end of the existing bridge girder 1, a formwork is installed on the work carriage 5, and then concrete is arranged by placing reinforcing bars and the bridge girder block 6 is constructed. Is formed. Then, at the stage where the strength of the poured concrete is developed, the bridge girder block 6 is subjected to PC construction. When the formation of the new bridge girder block 6 is completed, after removing the mold, the main frame 2 is unlocked, and the main frame 2 is extended with a jack or the like. Blocks are added and formed.

[0005] However, the conventional erection method using such an erection apparatus has the following technical problems.

[0006]

That is, in the mobile erection apparatus having the above-described structure, the main frame 2 is obliquely extended from above the existing bridge girder 1 to above the new bridge girder block 6. Cross beam 3 between frames 2
, It was difficult to work from above the new bridge girder block 6.

[0007] For this reason, for example, since a pre-assembled reinforcing bar cannot be erected from above the work cart 4, the reinforcing work has to be performed on site and it is difficult to shorten the construction period. was there. In addition, the suspension rod 4
Since the main frame 2 extends obliquely upward from the new bridge girder block 6 and extends below the lower surface of the bridge girder 1, the length of the suspension material becomes longer. There is also a problem that it is easy to perform and lacks stability.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a bridge girder capable of performing work from above and performing construction in a stable state with little lateral deflection. It is to provide an erection method.

[0009]

In order to achieve the above-mentioned object, the present invention provides a method for installing a concrete casting form on a movable work vehicle, and reinforcing a part separated by the form with a reinforcing bar. In the bridge girder erection method in which concrete is cast after installing the bridge girder and a bridge girder block of a predetermined length is sequentially formed in the bridge girder forming direction, the work vehicle is movable on guide rails installed on the existing bridge girder. Installed on the existing bridge girder, detachably locked to the existing bridge girder, suspended and supported by one main frame extending in the width direction of the bridge girder, and released from the locking by the locking means, along the guide rail, said work carriage with to overhang with the main frame, the mold frame are mutually predetermined intervals septum
The work cart is composed of inner and outer formwork
The outer formwork is moved with the movement of
The iron that is installed in place and pre-assembled and prefabricated
After the streaks are erected from above, they are temporarily supported by the work cart.
So that the inner formwork is installed inside the outer formwork.
I made it . According to this configuration, since there is nothing above the new bridge girder block, it can be built even if the reinforcing bars are prefabricated and prefabricated. Further, the work vehicle is extended to a main frame extending along the width direction of the bridge girder and a lower part of the lower surface of the bridge girder, but its suspension length is shorter than that of the conventional one.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 4
1 shows an embodiment of a bridge girder erection method according to the present invention. As shown in FIG. 5, the erection method shown in FIG. 5 includes a bridge girder body A having a hollow rectangular cross section and a pair of projecting portions projecting substantially horizontally at both upper ends of the bridge girder body A. B has a case where the present invention is applied to the construction of a so-called PC girder that introduces a prestressing force into the bridge girder main body A.

The bridge girder main body A includes a bottom plate portion C, a pair of side wall portions D, and an upper floor plate portion E. First, before describing the erection method, an erection apparatus used for carrying out the present invention will be described. 5 to 7 show details of the erection apparatus. In the figures, a column cap is constructed at the upper end of the pier, and a bridge girder block is being formed from this portion toward the center of the span. The process is shown. In FIGS. 6 and 7, in a portion of the bridge girder block portion has already been formed as shown, a portion indicated by symbol A ₁ is an existing bridge deck block formed just before, a portion indicated by symbol A ₂ is now It is a new bridge girder block to be formed.

The erection apparatus has a guide rail 10, one main frame 12, locking means 14, two suspension rods 16, a movable work cart 18, and a propulsion means 19. I have. The guide rails 10 are made of H-shaped steel or the like. A pair of guide rails 10 are provided at equal intervals from the center of the bridge girder main body A, and extend along the longitudinal axis direction of the bridge girder main body A. The guide rail 10 is an existing bridge girder block A ₁
And are sequentially removed from unnecessary parts.

The main frame 12 is extended in the width direction of the bridge girder main body A and has a length slightly larger than the width including the overhang portion B. A pair of leg portions 20 is fixedly provided on the lower surface side of the main frame 12, and the lower end surfaces of the leg portions 20 are placed on the upper surface side of the guide rail 10 with a slide plate 22 interposed therebetween. The frame 12 is movably installed on the guide rail 10.

The locking means 14 holds the main frame 12 already.
Bridge girder block A₁The upper part is detachably locked.
A pair is provided outside the leg 20. This locking hand
The step 14 specifically includes a pair of anchor rods 14a.
And an adjustment jaw installed between the anchor rods 14a.
And a hook 14b. Anchor rod 14
a is an existing bridge girder block A at one end₁Buried in the other end
Penetrates the main frame 12 in the vertical direction, and
Screwed to the main frame 12
It is. The adjustment jack 14b is connected to the existing bridge girder block A. ₁Up
To the main frame 12
Abut on the lower surface.

According to the locking means 14 configured as described above, the horizontal level of the main frame 12 can be adjusted by loosening the nut of the anchor rod 14a and expanding and contracting the adjusting jack 14b. When the plunger of the adjustment jack 14b is contracted and the screwing of the anchor rod 14a is released, the locked state of the main frame 12 is released.

The two suspension rods 16 are suspended from the longitudinal end portion of the main frame 12 and extend from the existing bridge girder A.
It extends downward along _one side. Work cart 1
8 is supported by the lower ends of the two suspension rods 16.
The work cart 18 has a width approximately equal to that of the main frame 12 and a floor 26 having a length approximately twice that of the bridge girder blocks A _{1 and} A ₂ , and a plurality of columns 28 standing upright on the floor 26. And

The two suspension rods 16 are arranged on the center of the floor 26 in the longitudinal direction. The struts 28 are arranged in two rows of three each along the axial direction of the bridge girder main body A, and the cross beams 30 are connected so as to connect the upper ends of the three struts 28.
Is fixed. On the pair of cross beams 30, a locking means 32 composed of an anchor rod 32a and an adjustment jack 32b is installed at a position coinciding with the central axis in the longitudinal direction of the main frame 12.

[0018] Then, between a pair of horizontal beams 30, formwork support beam receiving material 34 for connecting them in front of the new bridge girder block A ₂ is fixed. One end of a pair of form supporting girders 36 is placed and supported on the upper part of the form supporting girders 34, and the other end of the form supporting girders 36 extends along the axial direction of the bridge girder main body A. At the same time, the other end is supported by an existing bridge girder via a girder support 38.

The girder support 38 is a bolt and nut that is inserted into a through hole formed in advance in the existing bridge girder block.
A pair of bridge girder bodies A are provided at equally spaced positions across the longitudinal axis of the bridge girder body A. The rear side of the work cart 18 is connected to a lower surface side of the overhang portion B by a support 39 that is detachably mounted. In addition, for example, a polytetrafluoroethylene is provided at a portion where the support 39 abuts on the lower surface side of the overhang portion B.
A sliding plate made of resin is attached.

The propulsion means 19, specifically, it consists of propulsion jacks, the propulsion jacks with telescopic plunger is coupled to the main frame 12, the jack body is fixed to the existing bridge deck block A ₁ I have.
Mold 40 for forming a bridge girder block A ₁ A ₂ is a forming outer frame 42 and inner mold 44 of the bridge girder body A, it is composed of the lower mold 46 for forming the projecting portion B I have. The outer mold frame 42 is installed on the floor 26 of the work cart 18 and has a bottom 42a and a pair of side portions 42b erected at both ends of the bottom 42a, and the bottom 42a is formed. It can move up and down according to the height of the bridge girder block.

The inner mold 44 is formed in a closed hollow cross section having a substantially rectangular shape, and is set on the mold support girder 36. The lower mold frame 46 separates the lower surface side of the overhang portion B, continues to the upper end of the side portion 42b of the outer mold frame 42, and is supported by a stay 48. Next, a method of constructing a bridge girder using the erection apparatus having the above configuration will be described. In the erection method according to the present embodiment, first, a column capital G is constructed at the upper end of the pier F. FIG. 1 shows the construction state at that time.

In constructing the column capital G, a pair of work vehicles 18, 18 are installed at the upper end of the pier F by providing a support H around the outer periphery of the pier F so as to be adjacent to each other. Then, a formwork (not shown) is installed on each of the work vehicles 18 and necessary reinforcement is provided, and then concrete is cast to construct the column capital G. Shoring H in this case is
Only the work cart 18 needs to be supported, and a relatively simple one is sufficient. When the construction of the column capital G is completed, the guide rail 10 is installed on the column capital, the main frame 12 is installed on the guide rail 10, and the main frame 12 is fixed by the locking means 14.

Then, the work cart 18 is supported by the suspension rods 16 to construct the bridge girder portion. 2 to 4 show steps in constructing the bridge girder portion. In the figure, in a part of the bridge girder block portion has already been formed as shown, a portion indicated by symbol A ₁ is an existing bridge deck block formed immediately before portions formed therefrom as shown by reference numeral A ₂ It is a new bridge girder block to be tried.

The existing bridge girder block A ₁ is formed, concrete is a predetermined period curing, at the stage where the intensity is expressed, with prestress is introduced into the bridge girder block A _1, removal of the mold 42, 44, 46 Type is done. Before or after fit therewith, the guide rail 10 is extended on the existing bridge deck blocks A _1, to release the locked state of the locking means 14, 32, and remove the attachment of the support 39, propulsion jacks 1
9 is activated.

When the propulsion jack 19 is operated to extend the plunger, the main frame 12 is moved to the guide rail 10.
Move along. Since the work carriage 18 supported by the suspension rod 16 is connected to the main frame 12, the work carriage 18 is moved with the movement of the main frame 12.
There are flared to new block A ₂ side to be formed in the future.

In this case, since the removed outer mold frame 42 and lower mold frame 46 are mounted and supported on the work carriage 18,
It is moved together with the work cart 18. Also, the inner mold 44
Is to temporarily receive the front end side of the support girder 36 without removing the girder support 38, and after moving the work cart 18,
Move forward. The propulsion stroke of the propulsion jack 19 at this time corresponds to the length of the bridge girder block. When the main frame 12 is propelled to the vicinity front end of the existing bridge girder block A _1, a main frame 12 by locking means 14, 32 at the position after locked and fixed to the existing bridge deck blocks A _1, contract the propulsion Jatsuki 19 Then, the main body is fixed to the newly installed guide rail 10.

After this, the adjusting jack 14b,
32b is operated to adjust the horizontal level of the main frame 12, and nuts are screwed to the anchor rods 14a and 32a to fix the main frame 12. At the same time, the support 39 is mounted on the overhang portion B again, and the rear side of the work vehicle 18 is fixed to the existing bridge girder. When the fixing of the main frame 12 and the work carriage 18 is completed, the outer form 4
2 and the lower mold frame 46 are set. At this time, the height position of the bottom portion 42a of the outer formwork 42 is adjusted according to the height of the bridge girder block to be formed.

When the setting of the outer mold frame 42 and the lower mold frame 46 is completed, the reinforcing bars assembled in advance from above are set up. This work is the erection method of this embodiment, above the new bridge girder block A _2, nothing since there is no reinforcing steel pre-assembled prefabricated also can easily Tatekomu by the, this by working efficiency It can be greatly improved.

In this case, the inner formwork 44 is temporarily received behind the work vehicle 18 until the rebar is completely erected, and the girder support 38 is removed after the rebar is erected. It is desirable to pull it forward and set it inside the rebar because it does not hinder the rebar construction. When the molds 42, 44, 46 are set in this way, concrete is poured into the portions separated by the molds, and the same procedure is repeated sequentially thereafter, so that a predetermined bridge girder is formed. Be built.

According to the construction method of the bridge girder constructed as described above, only one main frame 12 and the propulsion jack 19 are installed on the existing bridge girder, and the new bridge girder block A ₂ is formed. Nothing is provided above.
Therefore, even if the rebar is pre-assembled and made into a prefabricated one, there is no hindrance to the erection work, thereby greatly improving the construction efficiency and shortening the construction period.

In the erection method according to the present embodiment, the movable work vehicle 18 is suspended and supported at the end of the main frame 12 provided on the existing bridge girder. Since it is shorter than this type, the roll is reduced and it is stable. In addition, in the case of the present embodiment, by installing two movable work carts 18 at the upper end of the pier F, the capital G can be constructed, so that the work of supporting the capital G is simplified.

In the above-described embodiment, the case where the erection method of the present invention is applied to the construction of a PC girder is exemplified. However, the present invention is not limited to this, and the present invention is not limited to this. It can also be applied to construction.

[0033]

As described above in detail in the embodiments,
According to the bridge girder erection method according to the present invention, since the movable work vehicle is suspended and supported by one main frame detachably installed on the existing bridge girder, the bridge surface portion is opened, Various equipment can be carried in from the top, etc., and work efficiency is improved, and construction efficiency is improved because rebars can be easily built even if they are prefabricated.

In the erection method according to the present invention, since the suspension length is short, the roll is reduced, the stability of the work cart is improved, and the safety of the construction is improved.

[Brief description of the drawings]

FIG. 1 is a process explanatory diagram when a capital is constructed by a erection method according to the present invention.

FIG. 2 is an explanatory view of a process when a bridge girder is constructed by the erection method according to the present invention.

FIG. 3 is an explanatory side view of a step performed subsequent to FIG. 2;

FIG. 4 is an explanatory side view of a step performed subsequent to FIG. 3;

FIG. 5 is a front view of an installation state showing an example of a bridge girder erection device used in the erection method according to the present invention.

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

FIG. 7 is a sectional view taken along line BB of FIG. 5;

FIG. 8 is a side view and a front view of an installation state of a conventional mobile erection apparatus.

[Explanation of symbols]

A Bridge girder body A ₁ Existing bridge girder block A ₂ New bridge girder block B Overhang 10 Guide rail 12 Main frame 14 Locking means 14a Anchor rod 14b Adjusting jack 16 Suspension rod 18 Work carriage 19 Propulsion means (propulsion jack) 32 Locking means 42 outer formwork 44 inner formwork 46 lower formwork

Claims (1)

(57) [Claims] A concrete casting form is installed on a movable work vehicle, a reinforcing bar is installed in a portion separated by the form, concrete is cast, and a bridge girder of a predetermined length is provided. In the method of erection of a bridge girder that sequentially forms blocks in a bridge girder forming direction, the work vehicle is movably installed on a guide rail installed on an existing bridge girder, and is detachably locked to the existing bridge girder. The work carriage is extended along the guide rail along the guide rail in a state where the work carriage is suspended from and supported by one main frame extending in the width direction of the bridge girder, and released by the locking means. And the formwork is installed at a predetermined interval from each other.
It is composed of an outer formwork and moves with the work cart.
Move the outer formwork, place this outer formwork in place,
The pre-assembled and prefabricated rebar is built from above
After that, the inner formwork temporarily supported by the work vehicle
Is installed inside the outer formwork .