JP3326724B2 - Construction method of concrete cable-stayed bridge and form support trolley used for it - 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 for erection of a concrete cable-stayed bridge and a form supporting trolley used for the method.

[0002]

2. Description of the Related Art As is well known, a concrete cable-stayed bridge is
When the span of the main girder to be erected becomes long, erection erection is often performed, and a method using a melan material or the like has been proposed as a method of such erection erection.

As a method using this melan material, a method of erection of a concrete cable-stayed bridge described in Japanese Patent Application Laid-Open No. 5-106210 is known. In the method of erection of this concrete cable-stayed bridge, when erection of the main girder, a melan material such as H-shaped steel buried in the main girder for each girder construction section is erected, and this melan material is connected to the cable-stayed cable of the cable-stayed bridge. The main girder is sequentially extended by mounting the main girder form, assembling the reinforcing bar, and placing concrete while moving the work carriage placed on the melan material and holding it.

[0006] As shown in FIG. 6, in this method, a work vehicle S used for erection of a cable-stayed bridge is made of a melan material 2.
A beam 22 on which a movable chain block 21 for erection of the beam 0 is mounted, and four columns 23 for supporting the beam 22 ...
And the joined melan material 2
Concrete casting formwork 25 around zero and formwork support 2 for supporting the weight of concrete placed in formwork 25
6 and a lower structure 29 having a work scaffold 28 suspended by PC steel bars 27 by the form support 26.

[0005]

However, the conventional method of erection of a cable-stayed concrete bridge has the following problems to be solved. Since the work vehicle S is placed on the melancane 20 before the construction of the bridge girder concrete, before the concrete is cast and hardened and the strength is developed, the work vehicle S The load will be applied to the melan material 20. For this reason, the impact load during the construction work due to the lifting of the work cart S will shake the existing melanctic material 20,
In addition, it is necessary to perform operations such as assembling the formwork 25 and reinforcing bars (not shown) and placing concrete in an unstable state in which the work cart S is loaded on the melan material 20. Therefore, it is necessary to increase the structural strength of the melan material 20 in order to ensure safety in construction, and there is a problem that the self-weight of the melan material 20 becomes heavy. Since the formwork support 26 which receives the load of the concrete form 25 and the concrete to be cast is suspended by four PC steel rods 27 at the front end and the rear end, respectively, a long section is collectively constructed. In this case, the bending rigidity of the beam of the form support 26 must be increased, and in such a case, the shape of the structural material increases, and the weight of the form support 26 increases. There is a problem. Since the work cart S is a large-scale structure including the upper structure 24 and the lower structure 29, not only is the wind load large and the working conditions are disadvantageous, but also the shape and dimensions of the melan material that can withstand the wind load are required. There is a problem that is. In order to lift materials necessary for the construction of the main girder, such as reinforcing bars and melange, by the chain block 21 of the upper structure 24, these materials temporarily lifted and temporarily placed by a tower crane or the like are lifted by any means. After transporting to the rear of the work cart S, it was necessary to load the chain block again and perform the construction work, which was very troublesome. In addition, since the upper structure 24 of the work vehicle S exists on the main girder (melan material) for performing construction work such as assembling of a formwork, a reinforcing bar, and concrete casting, the work becomes difficult, and the construction work is difficult. There is also a problem.

The present invention has been made in view of the above problems, and provides a method of erection of a concrete cable-stayed bridge that can shorten a construction period by extending a section where concrete can be cast at one time. It is intended to be. Another object of the present invention is to provide a form-supporting bogie that can be used in the method of constructing a concrete cable-stayed bridge and that can provide a stable working environment during the construction.

[0007]

According to a first aspect of the present invention, there is provided a method for erection of a cable-stayed bridge, wherein a form-supporting bogie is provided below the existing bridge girder and on a steel girder projecting forward from the existing bridge girder. Is movably suspended in the erection direction, and the steel frame is lifted in front of the steel girder by a mobile lifting device arranged on the existing bridge girder, and the steel girder is joined and extended,
The form supporting trolley is moved forward and suspended below the extended steel girder, and a cable staying material suspended from a column or a tower is fixed to the tip of the extended steel girder. Prestress is applied to the upholstery material to bring it into a tension state, and the form support trolley is suspended from the steel girder at multiple points with hanger bolts, and then the tip of the steel girder is left around the steel girder. It is characterized in that concrete is cast to form a concrete bridge girder having a predetermined span, and this is repeated so that the concrete bridge girder is successively joined to construct a cable-stayed bridge body.

[0008] A form-supporting trolley according to a second aspect of the present invention relates to the form-supporting trolley used in the method for erection of a concrete cable-stayed bridge according to the first aspect, and is suspended and supported below a steel girder. A frame main body, and a scaffold plate disposed on the frame main body. The frame main body suspends and supports the frame main body on the existing bridge girder and a steel girder projecting forward from the existing bridge girder. An arm is provided, and a plurality of hanger bolts for suspending and supporting the frame body on the steel girder during concrete casting are provided.

[0009]

In the method for erection of a cable-stayed bridge according to the first aspect, the form supporting trolley is movably movable in the erection direction below the existing bridge girder and on the steel girder projecting forward from the existing bridge girder. In the suspended support state, the movable lifting device lifts a steel frame from above the existing bridge girder to the front of the steel girder, and this steel frame is joined to the tip of the steel girder to extend the steel girder. Is done. Then, the form support trolley is moved forward and suspended below the extended steel girder, and at the tip of the steel girder, a cable staying material suspended from a column or a tower is fixed. You. further,
When the prestress is applied to the cable staying material to be in a tensioned state, a bending moment is applied to the steel girder and the existing bridge girder so that the lower side thereof is pulled, and in this state, concrete is poured around the steel girder. As a result, a bending moment acts on the steel girder and the existing bridge girder, and the bending moment acts on the upper side of the girder, thereby canceling out the bending moment on the lower side of the steel girder and the existing bridge girder.

[0010] In the form supporting trolley according to the second aspect, the frame body is suspended and supported by the existing bridge girder and the steel girder projecting forward from the existing bridge girder by an arm provided on the frame body. . And at the time of concrete casting, since the said frame main body is suspendedly supported by several hanger bolts, the radius of a frame main body is suppressed.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing the erection state of a concrete cable-stayed bridge in the method for erection of a concrete cable-stayed bridge according to the present invention, wherein reference numeral 1 denotes a concrete cable-stayed bridge, 2 denotes an existing bridge girder, 5. Indicates a form supporting trolley.

The existing bridge girder 2 shown in FIG. 1 extends horizontally from an extension base of a pier (not shown) and has a plurality of steel frames of a predetermined length joined therein. And a reinforcing bar (not shown), and concrete C is cast around these steel beam girders 3 and 3 and the reinforcing bar to be integrally constructed.

The cable stay fixing jigs 4 and 4 are fixed to the upper end flanges of the distal ends of the steel beam girders 3 and 3, respectively. Cable stays 5, 5 suspended on pillars (not shown) erected above the piers
Is fixed at one end, and the tension thereof is adjustable. Further, a bolt insertion hole (not shown) is formed in the lower end flange 3a of the steel beam 3 at a predetermined interval in the length direction.

Below the existing bridge girder 2, the form supporting trolley 6 is disposed. This form support trolley 6 is shown in FIG.
As shown in (c), horizontal frame members 8 are joined in a grid pattern to two beam frame members 7, 7 arranged below the steel frame beams 3, 3, at predetermined intervals in the beam row direction. And a frame main body 9 formed integrally with the scaffold, and a U-shaped scaffold plate 10 (see FIG. 2B) disposed on the frame main body 9 in plan view. The scaffold 10 has holes 10 through which front arms 11, 11 and rear arms 12, 12, which will be described later, can be inserted.
a, 10a, 10b, and 10b are formed.

A portion where the horizontal frame member 8 and the girder frame member 7 at the forefront of the frame body 9 intersect with each other so as to sandwich the web 3b of the steel girder 3 projecting forward from the tip of the existing bridge girder 2. A front arm (arm) 11, 11 is formed upright, and each of the front arms 11 has a guide roller 11a abutting on the upper surface of the lower end flange 3a of the steel girder 3, and a web of the steel girder 3. A guide roller 11b is in contact with the side surface of 3b, a jack 11c is in contact with and presses the web 3b, and a jack 11d is in contact with and presses the upper surface of the lower end flange 3a.

On the upper surface of the projecting end of the horizontal frame member 8 at the rear end in the girder row direction, a rear arm (arm) having a substantially inverted L-shape when viewed from the front facing the existing bridge girder 2 so as to sandwich it from the side. 12,
12 is formed upright, and the rear arm 12 has
A guide roller 12a abutting on the upper surface of the existing bridge girder 3,
A jack 12c provided with a guide roller 12b abutting on the side surface thereof, and a jack 12d abutting on and pressing the upper surface of the existing bridge girder 2 are provided.

At the intersection of the horizontal frame members 8 and the girder frame members 7 at the middle part in the girder direction of the main body frame 9, hanger bolts 13 are arranged on both sides of the steel frame girder 3. 13 are inserted through bolt insertion holes (not shown) formed in the lower end flange 3a of the steel girder 3 to attach the frame main body 9 to the steel frame 3 '.

Further, on the body frame 9, a concrete casting formwork 14 whose length is set so as to be arranged between the front arms 11, 11 and the rear arms 12, 12 is placed. I have. As shown in FIG. 2 (a), this formwork 14 is configured such that the plate material forming each formwork surface is joined at the top, and can be disassembled for each plate material, and the construction of one section is completed. Later, it is configured to be able to be diverted as a formwork of a newly constructed section. In the formwork surface for the end face in the girder direction, substantially H-shaped holes 14a, 14a through which the steel beams 3, 3 can be inserted are formed so that the diversion is possible.

Next, a method for erection of a concrete cable-stayed bridge according to the present embodiment will be described. First, while constructing the pier (not shown) of the concrete cable-stayed bridge to be erected,
A pillar (not shown) is erected above the bridge, and a bridge girder of a predetermined length is constructed horizontally from the pier (hereinafter referred to as an existing bridge girder 2).
And ). Here, the steel beam girders 3, 3 are projected from the end face of the existing bridge girder 2 at least as far as the attachment plate can be attached, as a margin for joining the steel frames to the tips of the steel girder beams 3, 3. The form supporting truck 6 is suspended below the existing bridge girder 2 (see FIG. 1). At this time, the formwork 14 is disposed on the formwork support truck 6.

Next, using a tower crane (not shown), a steel frame (not shown) of a predetermined length provided with a jig (not shown) for fixing a cable staying material at an end temporarily placed on the existing bridge girder 2. To
As shown in FIG. 3, while being lifted by a tire-type crane (movable lifting device) 15 and moved onto the tip of the existing bridge girder 2, the steel girder 3 is projected from the end face of the existing bridge girder 2. Lift it forward and join it to the tip of steel girder 3 to extend it. Here, the connection of the steel frame 3 'is performed by first connecting only the upper end flange by a bolt joint or a welded joint, and then moving the form supporting truck 6 forward to connect only the front arm 11 of the steel frame 3'. After passing to the side, the web and the lower end flange of the steel frame 3 ′ are joined, and the steel beam 3 and the steel frame 3 ′ are joined.
And are firmly joined.

Then, the form supporting truck 6 is mounted on the front arm 1 with the rear arms 12, 12 on the front end of the existing bridge girder 2.
The cable-stayed member 5 fixed to the column (not shown) is moved forward so that the first and the first 11 are positioned at the tip of the steel frame 3 '.
Are fixed to the cable staying material fixing jig 4 at the distal end of the steel frame 3 ', and a prestress is applied to the jig 4 to bring it into a tensioned state.
The prestress applied to the cable stay members 5 here is set to such an extent that a slight tensile stress is generated at the upper edge of the cross section of the existing bridge girder 2 by the subsequent concrete casting.

Further, jacks 11d, 12c provided on the front arms 11, 11, and the rear arms 12, 12, respectively.
To bring the frame body 9 close to the lower surface of the lower end flange of the elongated steel girder 3, and
By operating 2d, the frame body 9 is fixed. Then, the hanger bolts 13 are respectively inserted into the bolt insertion holes of the lower end flange of the steel girder 3 and tightened, and the form support truck 6 is inserted into the steel girder 3 together with the formwork 14 disposed thereabove. Make sure to suspend it.

Thereafter, the jacks 11c, 11d, 12c
And 12d are released, and the form support truck 6 is suspended from the steel frame 3 'with only the hanger bolts 13. Then, after reinforcing bars (not shown) are arranged in the formwork 14, concrete C is poured. Here concrete C
Is set to such a length that the distal end of the steel girder 3 projects from the end face of the concrete C in the girder direction in such a manner that at least the mounting plate can be attached to the distal end of the steel frame 3 'as described above.
Then, after the cast concrete C is cured and a predetermined strength is obtained, the hanger bolts 13 are removed, and the formwork 14 is dismantled to complete the construction of the concrete bridge girder 2 '. Then, the tension of the foremost cable stays 5 of the concrete bridge girder 2 ′ and the existing bridge girder 2 is adjusted so that the bending moment acting on them is almost zero. By repeating the above steps, concrete bridge girders are successively connected at predetermined intervals to construct a cable-stayed bridge main body.

In the method of erection of the concrete cable-stayed bridge 1 of the above embodiment, the form supporting truck 6 is erected on the existing bridge girder 2 and on the steel girder 3 projecting forward from the existing bridge girder 2 below the existing bridge girder 2. The steel frame 3 'is lifted from the existing bridge girder 2 to the front of the steel girder 3 by the tire type crane 15 in a state where the steel girder 3 is movably suspended, and the steel frame 3' is joined to the tip of the steel girder 3. Then, the steel girder 3 is extended. Then, the form-supporting trolley 6 was moved forward, and the rear arm 12 was positioned on the existing bridge girder 2 and the front arm 11 was positioned on the distal end of the extended jointed girder 3 ′ and extended. The cable girder 3 is suspended below the steel girder 3 and, at the tip of the steel girder 3, a cable stay 5 hung on a column or a tower is fixed. As a result, a bending moment is applied to the steel girder 3 and the existing bridge girder 2 so that the lower side thereof is tensile. In this state, the concrete C is poured around the steel frame 3 ′, whereby a bending moment is applied to the steel frame girder 3 and the existing bridge girder 2 so that the upper side thereof is tensile,
The lower side of the steel girder 3 and the existing bridge girder 2 cancel each other out with the bending moment that becomes tensile. When concrete is cast, the frame body 9 of the form supporting truck 6 is suspended and supported on the steel frame 3 'by the front arms 11, 11, the rear arms 12, 12 and the hanger bolts 13.

In the form supporting truck 6 of the above embodiment, the frame body 9 is moved forward by the front arm 11 and the rear arm 12 provided on the frame body 9 from the existing bridge girder and the existing bridge girder 2. And is suspended and supported by the steel girder 3 projecting therefrom. When the concrete is cast, the frame body 9 is suspended and supported by the plurality of hanger bolts 13, so that the radius of the frame body 9 is suppressed.

As described above, according to the method of erection of the cable-stayed bridge 1 of the above embodiment, the form supporting truck is attached to the existing bridge girder 2 and the steel girder 3 projecting forward from the existing bridge girder 2 below the existing bridge girder 2. In a state in which the steel frame 6 is suspended and movably supported in the installation direction, a steel crane 15 lifts the steel frame 3 ′ from above the existing bridge girder 2 to the front of the steel frame girder 3, and the steel frame 3 ′ is attached to the tip of the steel girder 3. Since the steel girder 3 is extended by joining to the part, as in the conventional case, the temporarily placed material is lifted by some means and transported to the rear of the work cart, and then the chain There is no need to carry out construction work with the blocks loaded, and the work can be carried in and lifted directly by the mobile work equipment, so that construction work can be performed efficiently and the impact load due to the lifting of the steel frame 3 can be applied to the existing steel frame. Shake the girder (Melan) 3 There is no, slowing it. In addition to moving the support trolley 6 forward after extending the steel frame girder 3, the assembling of the formwork 14 and the reinforcing bars (not shown) is performed by suspending the extended steel frame 3 ′ with the cable stay 5. Since the operation is performed later, the operation can be performed in a stable state. In addition, it is not necessary to increase the structural strength of the steel girder 3 in particular for ensuring such construction safety. Therefore, the weight of the steel girder 3 does not increase compared to the related art.

Further, the form supporting trolley 6 is suspended and supported by the existing bridge girder 2 and the steel girder 3 projecting forward from the tip of the existing bridge girder 2, and the form supporting trolley 6 is attached to the steel frame 3 '. The concrete C is cast around the steel girder 3 in a state of being suspended and supported by the hanger bolts 13. Therefore, even when the span of one section to be constructed is lengthened, the girder frame of the form supporting trolley 6. The rigidity of the material 7 itself does not need to be increased, and the weight of the form-supporting trolley 6 itself can be reduced, and the number of times of joining the cable-stayed bridge main body can be reduced, so that the construction period can be shortened.

Further, the cable staying member 5 suspended from the column is fixed to the fixing hanging jig 4 at the tip of the steel frame 3 'joined to the tip of the steel beam 3 and prestress is applied to the cable staying member 5. In this state, a bending moment is applied to the steel girder 3 and the existing bridge girder so that the lower side of the girder becomes tensile. In this state, concrete is poured around the steel girder 3 and the weight of the concrete C is reduced. As a result, the upper side of the steel girder 3 and the existing bridge girder 2 is subjected to a bending moment of tension, and the lower side of the steel girder 3 and the existing bridge girder 2 is offset by the bending moment of the tension. By introducing the pre-stress and placing concrete, the bending moment acting on the steel girder 3 acting on the steel girder 3 becomes small, and the steel weight of the steel girder 3 can be reduced.

Further, according to the form supporting trolley 6 of the above embodiment, the frame body 9 is connected to the existing bridge girders 2 and 2 by the front arm 11 and the rear arm 12 provided on the frame main body 9. Since it is suspended from the steel girder 3 protruding forward from the bridge girder, there is no large-scale equipment on the bridge girder to be constructed, and construction can be performed smoothly without hindrance to material loading. When concrete is cast, the frame body 9 is suspended and supported on the steel beam 3 by a plurality of hanger bolts 13.
The length of the concrete can be cast at one time without making the configuration of the formwork support truck 6 large, so that the construction period can be shortened. Can be. Furthermore, since the form support truck 6 itself is small and has a smaller wind load than before, it is less likely to be affected by wind during construction, and a stable working environment can be provided.

In the above embodiment, the steel frame 3 'is joined to the steel frame girder 3 projecting forward from the tip of the existing bridge girder 2, and the form supporting truck 6 is moved below the steel frame 3'. The pre-stress is applied by fixing the cable staying material 5 to the tip of the steel frame 3 ′. However, the cable staying material 5 is fixed to the tip of the steel frame 3 ′ in advance, and this is connected to the tip of the steel beam 3. After the joining, the prestress may be applied to the cable staying member 5 after the form supporting truck 6 is moved below the steel frame 3 '.

Also, a column is constructed above the pier and the cable staying member 5 is suspended by this. However, a tower assembled from members such as steel frames is constructed above the pier and the cable staying member 5 is thereby constructed.
It is needless to say that it is also possible to hang the camera.

The formwork 14 is desirably one that can be diverted as in the above embodiment, but is not limited to this, and it goes without saying that a well-known concrete casting formwork may be used. is there.

Further, in the above embodiment, the mold 14 is
Although it is set so that concrete can be poured in accordance with the length of the form supporting trolley 6 at one time, and is always disposed on the form supporting trolley 6, the frame body 9 A box-shaped formwork that can be inserted between the girder frame material 7 and the horizontal frame material 8 may be used. In this case, as shown by the two-dot chain line in FIG.
A drive mechanism (not shown) such as a hydraulically controlled pinion rack mechanism for vertically moving the girder frame member 7 and the horizontal frame member 8 is installed inside or outside the front arm 11,
11 The rear arms 12, 12 and the beam frame member 7 and the horizontal frame member 8 of the frame main body 9 are configured so as to be able to move up and down separately, and when casting concrete, raise the formwork. When moving the form supporting truck 6, the form may be lowered.

[0034]

According to the method for erection of a concrete cable-stayed bridge and the form supporting trolley used in the present invention, the following effects can be obtained. According to the method for temporarily installing a concrete cable-stayed bridge according to claim 1, the form-supporting trolley is suspended below the existing bridge girder and the steel girder projecting forward from the existing bridge girder so as to be movable in the installation direction. In this state, the steel frame is lifted from above the existing bridge girder to the front of the steel girder by a mobile lifting device, and the steel girder is joined to the tip of the steel girder to extend the steel girder. Therefore, it is not necessary to lift the temporarily placed material by some means and transport it to the rear of the work cart, and then load it on the chain block again and carry out the construction work. The construction work can be carried out efficiently, and the impact load due to the lifting of the steel frame does not shake the existing steel girder. In addition, since the form support trolley is moved forward after extending the steel girder as described above, it is not necessary to increase the structural strength of the steel girder, especially in order to ensure safety during construction. Therefore, the weight of the steel girder does not increase.

The form support trolley is suspended and supported by an existing bridge girder and a steel girder projecting forward from the tip of the existing bridge girder, and the form support trolley is suspended by a hanger bolt on a steel frame. In, because concrete was cast around the steel frame, compared to the conventional, even if the span of one section to be constructed is longer, the rigidity of the girder frame material itself of the formwork support truck does not need to be increased It is also possible to reduce the weight of the form-supporting trolley itself and to reduce the number of joints, thereby shortening the construction period.

Further, a cable staying material suspended from a column or a tower is fixed to the tip of the steel frame, and a prestress is applied to the cable staying material so that the steel beam and the existing bridge beam are tensioned. A bending moment acting as a tension is applied, and the form supporting trolley is moved below the steel frame, and a bending moment at which the upper side of the steel girders and the existing bridge girder is tensioned by the weight of the form supporting trolley and concrete by its own weight. And the lower side of the existing steel girder and existing bridge girder compensated for the bending moment of tension, so that the upper side acting on the steel girder acting on the steel girder by introducing prestress into the cable-stayed material and placing concrete was tensile. The moment is reduced, and the steel weight of the steel girder can be reduced.

According to the form supporting truck of the second aspect, the frame main body is suspended and supported by the existing bridge girder and the steel girder projecting forward from the existing bridge girder by the arm provided on the frame main body. As a result, there is no large-scale equipment on the bridge girder to be constructed, and the construction can be smoothly performed without hindering the import of materials. In addition, when concrete is cast, the frame body is suspended and supported on a steel girder by a plurality of hanger bolts, so that the radius of the frame body at the time of concrete casting is suppressed. It is possible to lengthen the section in which concrete can be cast at once without making it large-scale, and it is possible to shorten the construction period. Furthermore, since the form supporting trolley itself is small and the wind load is smaller than before, it is possible to provide a stable working environment that is hardly affected by wind even during construction.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a process of a method for erection of a concrete cable-stayed bridge according to the present invention, and is a perspective view showing a state where a form supporting truck is arranged below an existing form.

FIG. 2 is a schematic view showing an example of a formwork and a formwork support truck used in the method for erection of a concrete cable-stayed bridge according to the present invention, and (a) a perspective view showing the entire structure of the formwork; b)
FIG. 3 is a perspective view showing an entire configuration of a scaffold plate, and FIG. 3C is a perspective view showing an appearance of a frame main body of a form supporting truck.

FIG. 3 is a schematic view showing steps of a method for erection of a concrete cable-stayed bridge according to the present invention, and is a side view showing a state where a steel frame is joined to a steel girder projecting from the tip of an existing bridge girder and extended. .

FIG. 4 is a schematic view showing the steps of the installation method, and is a side view showing a state in which a form supporting truck is suspended below an extended steel girder and prestress is introduced into a cable staying member. .

FIG. 5 is a side view showing a state in which a bridge body is constructed by casting concrete after hanging a form supporting truck at multiple points on a steel frame with hanger bolts.

FIG. 6 is a view showing a state of erection of a conventional concrete cable-stayed bridge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concrete creed cable-stayed bridge 2 Existing formwork 3 Steel girder 3 'Steel frame 5 Cable-stayed material 6 Formwork support truck 9 Frame body 11, 12 Arm 13 ... Hanger bolt 15 Mobile lifting device C Concrete

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-106210 (JP, A) JP-A-54-10530 (JP, A) JP-A-49-9026 (JP, A) (58) Investigation Field (Int.Cl. ⁷ , DB name) E01D 11/00-11/04 E01D 21/00

Claims (2)

(57) [Claims] 1. A form-supporting trolley is suspended below and supported by an existing bridge girder and a steel girder projecting forward from the existing bridge girder so as to be movable in an installation direction, and is disposed on the existing bridge girder. Lifting the steel frame in front of the steel girder by a mobile lifting device and joining and extending it, moving the form support truck forward below the extended steel girder and suspending and supporting it, At the tip of the extended steel girder, a cable staying material suspended from a column or a tower is fixed, and the cable staying material is prestressed to be in a tensioned state, and the form supporting truck is moved from the steel beam to a hanger. Bolts are suspended at multiple points by bolts, and then concrete is poured around the steel girder leaving the tip of the steel girder to form a concrete bridge girder of a predetermined span, and this is repeated to sequentially form the concrete girder. Obliquely A method for erection of a concrete cable-stayed bridge, wherein the main body of the cable-stayed bridge is erected. 2. A form support trolley for use in the method for erection of a concrete cable-stayed bridge according to claim 1, wherein the frame body is suspended and supported below a steel girder, and is disposed on the frame body. An arm provided with a guide roller for suspending and supporting the frame body on the existing bridge girder and a steel girder projecting forward from the existing bridge girder. A form supporting trolley, wherein a plurality of hanger bolts for suspending and supporting the frame body are provided on a steel girder.