JP3466136B2 - Method and apparatus for overhanging PC bridge - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhanging method and apparatus for a PC bridge.

[0002]

2. Description of the Related Art A bridge overhanging method for constructing a bridge by dividing it from the top of a pier in the axial direction of the bridge every 3 to 5 m and projecting it to the left and right is suitable for erection of bridges with long spans It is widely adopted because it is not regulated.
In this overhanging method, the pillar head, which is the base point (overhanging start point), is first constructed from reinforced concrete on the head of the pier, and then the bridge block is balanced from the pillar head to the left and right, and cantilevered in a yajiro-bei style. Overhang the bridge and extend the bridge to build it. In this case, the bridge block is constructed of post-tensioned prestressed concrete. Bridge blocks are made by casting in-situ or as precast concrete blocks prepared in advance at the production yard. In any case, the post-stress method is used to introduce prestress to the bridge blocks.

This post-tensioning type prestressed concrete is formed by embedding a PC steel material insertion duct (sheath) in concrete, and PC is inserted in this sheath.
It pushes through a steel material and tensions it. After introducing the prestress, grout such as cement milk is injected into the sheath to adhere the PC steel material to the sheath. This grout must completely fill the sheath and prevent the ingress of moisture at a later date. However, conventionally, it has been pointed out that a method for confirming the filling and filling property has not been established, and an unexpected void may occur to cause corrosion of PC steel and the like, which may cause a problem in durability of the structure. . Further, the post tension method involves complicated operations such as sheath arrangement, fixing tool attachment, and grouting.

[0004]

As described above, the conventional PC bridge overhanging method tensions the PC steel material by the post tension method. In that technology, after tensioning the PC steel,
C The inside of the sheath, which is the steel material insertion hole, is grouting with cement milk or the like. It is difficult to completely fill the inside of the sheath by this grouting, and voids are likely to occur. There is a problem that the durability of the PC steel material is deteriorated by water or the like that has entered the voids. As one measure for ensuring the durability of PC steel materials, it has been proposed to use a new material that is resistant to corrosion, but the new material PC material is generally expensive, and there are structural problems in the fixing part. Has not been adopted.

An object of the present invention is to develop and provide a method and apparatus for overhanging a PC bridge to solve the above problems. The problem to be solved by the present invention is to provide a technique that does not require grouting without using a sheath, which is accompanied by the introduction of prestress when the bridge body is extended and installed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a PC bridge overhanging method and apparatus characterized by the following technical means. That is, according to the present invention, when the PC bridge is cantilevered , the rear anchor beads are provided above and below the upper deck of the existing bridge.
The upper and lower anchor beams on the upper floor slab.
Connect and fix with a tension rod that passes through the vertical through hole
A reaction force device is formed, and a reaction force beam is forwarded from the reaction force device.
Installation, installing a tension unit at the tip of the reaction force beam, existing
PC steel material is arranged from the bridge body to the tension unit, a form of one block of the bridge body is bulged forward from the existing bridge body, and tension force is applied to the PC steel material by the tension unit. Placing 1 block of concrete,
After concrete hardening, by opening tension of the PC steel material for prestressed concrete. The above process is repeated and the PC bridge is cantilevered and erected.
This is the method of erection of C bridge.

The present invention is a method of constructing prestressed concrete on-site by a pretensioning method which does not require a sheath for the bridge block because the conventional posttensioning method has a problem with grouting in the sheath. When the bridge block is cantilevered and constructed, PC steel is placed in the form of the bridge block in advance, after tensioning the PC steel using the jack, concrete is placed in the form and allowed some time. After the strength of the concrete develops, loosen the jack and introduce prestress into the concrete. By repeating this process, the PC bridges are extended and erected alternately on the left and right sides.
The method of the present invention can be used in combination with an external cable system or the like, has a wide range of applications, and is an extremely effective technique.

Further, according to the present invention, the laterally tightened PC steel material is arranged in the mold, and a tension force is applied to the laterally tightened PC steel material.
It is preferable to cast concrete. That is, the tension of the PC steel material is introduced not only in the bridge axis direction but also in the direction perpendicular to the bridge axis (transverse direction) by applying prestress to the upper deck of the girder by the pretension method. Furthermore, the upper floor slab of the column head, which is the base point of cantilever overhanging, should be constructed with pretensioned prestressed concrete. Starting
In addition, install a bracket on the upper side of the pier.
, The abdomen of the stigma and the lower floor slab, and then the upper floor slab
PC steel material is arranged so that it passes through, and a tension unit for stilts
To the upper deck position, assemble the formwork of the upper deck, PC steel
Tension the material, fix it to the fixing plate, and hit the concrete on the upper deck.
After the concrete is hardened, the tension of PC steel is released.
Introducing prestress to the upper deck to prestress the stilts on the pier.
Constructed by the tension method, and then erection of the PC bridge
This is preferable.

The apparatus of the present invention capable of suitably carrying out the above-mentioned method of the present invention is a mold for one block which is placed on an existing bridge body so as to be freely movable in the bridge axis direction and cantilevered and erected. An erection work vehicle that projects and holds forward from the existing bridge, and the existing bridge
Forward from the rear anchor beam attached to the upper floor slab of the body
A PC bridge overhanging device, comprising: a tension unit attached to the tip of an extended reaction force beam and tensioning a bridge axial PC steel material extended from an existing bridge body. Further, it is preferable that a tensioning device that is attached to the side surface of the mold and that tensions the horizontally tightened PC steel material is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views for explaining an embodiment of an erection work vehicle and an erection work for erection and erection of a PC bridge by a pretension system according to an embodiment of the present invention. 1 is a side view, FIG. 2 is a view taken along the line AA of FIG. 1, FIG. 3 is a front view in the traveling direction, and a view taken along the line BB of FIG.

1 to 3 show construction of a bridge block 130 adjacent to an overhanging portion (existing bridge body) 120 protruding from a column head 110 on the pier 100. In this embodiment, the erection work vehicle 10 is used, and the rebar and the like are assembled in the formwork 40 supported by the erection work vehicle 10 and the PC steel material is arranged (extended).
Then, the concrete of the bridge block 130 to be extended is cast, and the bridge is cantilevered and erected. Construction work vehicle 10
Is suspended by a suspension member 12 from a main beam 11 arranged on the existing bridge body. Side truss frames 14 and 15 are provided on the lower beam 13 arranged at the lower end, and the side truss frames 14 and 15 project to the front of the existing bridge to support the form 40. The front and rear lower beams 13 are connected by a lower connecting beam 16. The rear lower beam 13 is stiffened by a rear lower beam stiffening member 17. The tail end of the side truss frame 14 is supported by the rear support device 20 on the lower surface of the floor slab of the existing bridge. In the rear support device 20, the traveling roller 21 is attached to the roller bracket 23, and the erection work vehicle 10 can easily move forward. Further, since the jack 22 is provided, the support height can be easily adjusted. A form supporting beam 42 is suspended from the side truss frame 14 via the jacks 41 and 43, and a form 40 is assembled on the form supporting beam 42 via a receiving member 45.

Tensioning unit 5 for tensioning the PC steel material 140
No. 0 has rear anchor beams 51 and 52 arranged above and below the upper deck of the existing bridge 120. The tension rod 57 penetrating the existing bridge body passes through the through hole provided in the upper deck of the existing bridge body 120, and the upper and lower anchor beams 51,
52 is connected and fixed to form a reaction force device against the tension force of the PC steel material 140. Upper and lower anchor beams 51, 52
A reaction force beam 53 extends from the front to the front, and a jack 54 is attached to the tip thereof. The front frame 55 is a PC
The steel material 140 is temporarily fixed to the fixing frame 56, and the jack 54 acts on the front frame 55 to press the fixing frame 56 and apply tension to the PC steel material 140. The fixing frame 56 is supported by the lateral beam 31 of the erection work vehicle 10 via the jack 32. Tension unit 5
0 is a structure that supports the reaction force of the tension of PC steel by itself, and introduces prestress to the bridge by the pretensioning method.

After the PC steel material is tensioned by the tension jack 54 of the tension unit 50, concrete is placed in the formwork. After the concrete reaches the desired strength, the tension jacks 54 are loosened to introduce prestress to the concrete block. After that, the erection work vehicle 10 and the tension unit 50 are advanced by one block length, and the next block is prepared for construction. The above cycle is repeated to perform cantilever overhanging of the bridge. Although the PC steel materials 140 are simultaneously tensioned by using the fixing frame 56 in the above case, the PC steel materials 140 may be tensioned one by one. The erection work vehicle uses a lower suspension type as a type in which a work space such as a tension unit can be effectively secured, but it is of course possible to use an upper mounting type placed on a general bridge surface.

Next, the construction of the column head and the construction of the middle portion will be described below, including the means for supporting the PC steel material. Figure 4
[Fig. 3] is a construction explanatory view of a pillar 110 on the pier 100. The bracket 70 is attached to the pier 100, and the lower portion 111 of the pillar head 110 is constructed with reinforced concrete. At this time, the upper floor slab 112 is not constructed. A frame platform 71 is provided at each of two positions in the bridge axis direction on the bracket 70, a reel 72 around which a PC steel material 140 is wound is placed on one of them, and the PC steel material 140 is unwound to pass through the construction position of the upper floor plate 112 of the pillar head 110. , Is wound around the other reel 73. Figure 5
Is a conceptual perspective view showing this, and the traveling direction of the PC steel material 140 is indicated by an arrow 74. FIG. 6 is a side view of FIG.

7 to 9 show a method of constructing the stilt top slab 112. 7 is a side view, and FIGS. 8 and 9 are C thereof, respectively.
FIG. 6 is a view as viewed in the direction of arrow C and a view in the direction of arrow D-D. Tension unit 80
Is provided above and below the position for constructing the upper floor slab 112 on the stilt head 110, and is provided with upper and lower compression main beams 81 and 82 that project to both sides in the bridge axial direction.
(FIG. 8) and the end cross beams 84, 85 (FIG. 9). On the end lateral beams 84 and 85 at both ends of the main beams 81 and 82,
A large number of vertical auxiliary members 86 are laid over, and the vertical auxiliary members 8
A fixing plate 87 made of PC steel 140 is attached to the plate 6. 10 is a detailed view of the fixing plate 87, and FIGS. 11 and 12 are EE arrow and FF arrow views of FIG. 10, respectively. The fixing plate 86 is locked to the end cross beams 84 and 85, and supports the fixing portion 91 via the tensioning jack 92. Fixing unit 91
Has a seat of a fixing grip 93 for fixing the PC steel material 140.

Construction of the stigma is as follows. As shown in FIG. 4, a bracket 70 is installed on the upper end side surface of the pier 100. The abdomen and lower deck of the stigma 110 (lower part 11
Perform 1). Then, as shown in FIG.
The PC steel material 140 is arranged so as to pass through, and the stilt head tension unit is attached to the position of the upper floor slab 112. The formwork and steel material of the upper floor slab 112 are assembled. The PC steel material 140 is tensioned and fixed to the fixing plate 87. The concrete of the upper floor slab 112 is placed. After hardening concrete, PC steel material 1
When the tension of 40 is released, prestress is introduced into the upper floor slab 112. Dismantle the formwork and dismantle the stigma tension unit.

Next, the overhang bridge body is constructed. Construction of the overhanging part is done by installing a construction work vehicle, installing a reaction force receiving beam, installing a tension unit, assembling the formwork and rebar, then tensioning the PC steel material and placing concrete, and after hardening the concrete. Release the tension and introduce prestress into the concrete, then follow the steps of formwork dismantling, erection work vehicle and tensioning unit movement . FIG. 13 is a side view of a construction example of the overhanging bridge body of the present invention, FIG. 14 is a view taken along the line EE of FIG. 13, and FIG.
5 is a view on arrow F-F in FIG. The erection work vehicle 10 and the tension unit 50 shown in FIG. 13 are the same as those shown in FIG. The PC steel material 140 pre-stresses the concrete in the existing bridge body 120, and the extension part thereof is fixed to the fixing frame 56 of the tension unit 50 so that the inside of the upper floor slab of the bridge block 130 before the concrete is placed. The part is tense. PC steel 140 is further extended to PC
Guide plate 1 attached to steel support guide rail 170
Guided by 71. PC steel support guide rail 1
Reference numeral 70 denotes a vertically downward direction change from the front of the erection work vehicle 10, and further bends horizontally toward the rear, and the horizontal portion is supported by the lateral beam 13 of the erection work vehicle 10.

FIG. 16 is a side view showing the support of the PC steel material 140, and FIG. 17 is a front view of FIG. 16 and 17
The erection work vehicle 10 is not shown. Existing bridge 1
Cable reels 164 are hung below the existing bridge body 120 via a frame 163 from a cable truck 160 traveling on 20. The cable reel 164 holds the PC steel material 140. The PC steel material 140 unwound from the cable reel 164 is guided by a large number of guide plates 171 attached to the guide rails 170, and is rotated around the tip of the bridge block 130 to be extended and supplied to the upper floor slab portion thereof. And beyond that, the concrete is prestressed in the upper deck of the constructed bridge. FIG. 17 is a front view of FIG. 16, in which wheels 16 are placed on the existing bridge 120.
2 shows a cable trolley 160 traveling by 2,
The state where the cable reel 164 is supported by the suspension frames 163 suspended from both ends of the beam 161 of the cable truck 160 is shown. By using such a dedicated cable reel, the present invention can be implemented easily and rationally.

FIG. 18 is a side view of the tension unit 150, FIG. 19 is a view taken along the line H--H of FIG. 18, and FIG.
FIG. 21 is a view on arrow K in FIG. 18, and FIG. 22 is a view on arrow L in FIG. The tension unit 150 is basically the same as the tension unit 50 shown in FIG.

The tension unit 150 includes rear anchor beams 151, 152 attached to a tension rod 157 that penetrates the upper deck of the existing bridge 120.
Reaction beam 1 from upper and lower anchor beams 151, 152
53 extends and has end cross beams 158, 159 at its tip.
The end cross beams 158 and 159 are provided with a front frame 155, a jack 154, and a fixing frame 156. The jack 154 acts on the front frame 155 to press the fixing frame 156 and apply a tension force to the PC steel material 140, and at this time, the reaction beam 153 supports the reaction force of the tension force. Normally, dozens of PC steel materials are arranged. Therefore, in order to efficiently perform tension and release of PC steel materials, the front frame tensions the PC steel materials collectively,
Configure to release tension. Further, since the middle portion of the PC steel material is tensioned in order, a long chuck is used to prevent the PC steel material from being damaged by the tension. In addition, it is necessary to consider the return of the PC steel material due to the adhesion breakage at the time of introducing prestress. Since the method of the present invention basically does not have a fixing tool, there is a possibility that the adhesive will be cut off. Strand material is not a problem, but if there is a risk of problems, attach a crimp grip or the like.

Prestress is introduced into the bridge block 130 by a pretensioning method. Further, the bridge block 130 is applied to the upper floor slab of the bridge block 130 by applying a tension force to the horizontally tightened PC steel material 142 stretched between the members 141 attached to both ends of the cross beam as shown in FIG. Horizontal tightening can be applied with prestress.

21 and 22 show the rear anchor beam 15
1 and 152 and the tension rod 157 are shown. The tension rod 157 is a through bolt penetrating the existing upper floor slab, and is fastened between the upper and lower anchor beams 151 and 152 by the jack 180.

In the above description, the means for suspending the drum of the PC steel material on the bridge or from the bridge and feeding and operating the PC steel material is supplied, but the support and handling of the PC steel material are not limited to this. As shown in FIG. 23, the messenger wire 190 is stretched in the bridge axis direction, and
The PC steel material 140 may be suspended from the messenger wire according to the above, or the PC steel material 140 may be guided by placing a drum on the ground and providing a guideway depending on the erection conditions of the bridge. further,
The PC steel materials may be connected to each other by a suitable length with a coupler, etc., the ends are fixed to each appropriate length, and another PC steel material is overlapped to be mechanically continuous, or the cable is U-shaped. It can be designed according to the actual situation such as bending to be embedded in concrete to form a fixing end.

[0024]

The present invention replaces the introduction of prestress in the PC bridge to be erected and extended with the conventional post tension system,
Pretension method The prestress is introduced in the main direction of erection during overhanging, in the lateral direction of the slab, and in the center of the span.

According to the present invention, the grouting after the tensioning of the PC steel material due to the introduction of the pre-stress of the conventional post-tension system is unnecessary, and the PC steel material is completely buried in the concrete. Therefore, since the grouting defect does not occur, a problem such as corrosion of PC steel material due to incomplete filling does not occur, and a bridge body having extremely high reliability can be constructed. In addition, complicated work such as sheath arrangement, fixing tool attachment, and grouting associated with the post-tension system is unnecessary.

Further, in the conventional overhanging construction, the overhanging work of the bridge body is performed simultaneously on the left and right sides, but in the present invention, it can be performed separately on the left and right sides. Therefore, although the construction period of one cycle is almost the same, it is possible to eliminate the waste of labor that occurs during concrete curing.

Further, according to the present invention, since the reinforcing steel in the bridge axis direction arranged in the upper deck can be replaced with the PC steel material, the amount of reinforcing steel can be reduced or omitted.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a view on arrow AA of FIG.

FIG. 3 is a view taken along the line BB of FIG.

FIG. 4 is an explanatory diagram of the construction of a pillar head on a pier.

FIG. 5 is a conceptual perspective view showing construction of a pillar head.

FIG. 6 is a side view of FIG.

FIG. 7 is a side view.

FIG. 8 is a view on arrow CC.

FIG. 9 is a view on arrow D-D.

FIG. 10 is a detailed view of a fixing plate.

FIG. 11 is a view of the fixing plate taken along the line EE.

FIG. 12 is a view of the fixing plate viewed from the arrow F-F.

FIG. 13 is a side view of a construction example of the present invention.

FIG. 14 is a view on arrow EE in FIG. 13;

FIG. 15 is a view on arrow FF in FIG.

FIG. 16 is a side view of a PC steel material supporting example of a construction example of the present invention.

FIG. 17 is a view taken along the line GG in FIG.

FIG. 18 is a side view of the tension unit attached.

19 is a view as seen from the arrow HH of FIG.

FIG. 20 is a view taken along the arrow JJ of FIG.

FIG. 21 is a view on arrow K in FIG. 18.

22 is a view on arrow L in FIG. 18. FIG.

FIG. 23 is an explanatory diagram in which a PC steel material is suspended by a messenger wire. .

[Explanation of symbols]

10 erection work vehicle 11 main beam 12 hanging materials 13 Lower beam 14,15 Side truss frame 16 Lower connecting beam 17 Rear lower beam stiffener 20 Rear support device 21 Traveling roller 22 jack 23 Roller bracket 31 horizontal beam 32 jacks 40 formwork 41,43 jack 42 formwork support beam 45 Receiving material 50 tension unit 51,52 anchor beam 53 Reaction beam 54 jack 55 front frame 56 fixing frame 57 Tension rod 70 bracket 71 Framework 72 reel 73 reels 74 arrow 80 tension unit 81, 82 Main beam 83 Middle horizontal beam 84, 85 end beam 86 Vertical auxiliary member 87 Fixing plate 91 fixing unit 92 Tension jack 100 piers 110 Pillars 111 Lower part 112 Upper deck 120 Overhanging part (existing bridge) 130 Bridge block 140 PC steel 141 member 142 Horizontal tightening PC steel 150 tension unit 151, 152 anchor beam 153 Reaction beam 154 jack 155 front frame 156 fixing frame 157 Tension rod 158,159 End cross beam 160 reel cart 162 wheels 163 hanging frame 170 PC steel support guide rail 171 Information board

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-21820 (JP, A) JP-A-11-293629 (JP, A) JP-A-10-60823 (JP, A) JP-B 7- 91812 (JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) E01D 21/00 E01D 2/00

Claims (5)

(57) [Claims] 1. When constructing a cantilevered PC bridge,
Rear anchor beams are installed above and below the upper deck of the existing bridge
The upper and lower rear anchor beams are installed on the upper floor slab.
Reaction force device by connecting and fixing with a tension rod that passes through the through hole
And attach a reaction force beam forward from the reaction force device,
Attaching a tension unit to the tip of the reaction force beam, from the existing bridge
The tensioning unit to disposed the PC steel, and overhanging installed in front of the mold of one block of the bridge member from the existing bridge member, said frettage
A tension unit applies tension to the PC steel, and then
And Da設concrete of the one block, after concrete curing, the open tension PC steel introduced prestress concrete, characterized by erection overhang has repeatedly PC bridge piece above steps PC bridge overhang method. 2. A horizontally tightened PC steel material is arranged in the mold,
The method for overhanging a PC bridge according to claim 1, wherein concrete is placed after applying tension to the laterally tightened PC steel material. 3. A bracket is provided on the upper end side surface of the pier,
Build the abdomen of the head and lower floor slab, then pass through the upper floor slab
, PC steel material is installed, and the tension unit for the stigma is on the upper floor.
Attach it to the plate position, assemble the formwork of the upper floor slab, and tighten the PC steel material.
Tighten and fix it to the fixing plate, place the upper deck concrete,
After hardening the concrete, release the tension of the PC steel material
3. The method for overhanging a PC bridge according to claim 1 or 2 , wherein prestressing is introduced into the pier, the stilts on the pier are constructed by a pretensioning method, and then the PC bridge is erected and erected. 4. A placed on the bridge axis direction to the traveling freely existing bridge on the body, the erection work vehicle for projecting holding forward a mold of one block of erection projecting cantilevered from the existing bridge member, the existing On the bridge
Extends forward from the rear anchor beam attached to the floor slab
And a tension unit attached to the tip of the reaction beam for tensioning the PC steel material in the bridge axial direction extending from the existing bridge body. 5. A lateral fastening P mounted on the side surface of the formwork.
The overhanging device for a PC bridge according to claim 4, further comprising a tensioning device for tensioning the C steel material.