JP2526116B2 - Extrusion method for PC bridge - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention is a method of extruding a PC girder (prestressed concrete girder) of a required length onto a feed frame with adjustable height of piers while continuously and integrally molding it. The present invention relates to a method for extruding a PC bridge to construct various vertical alignment bridges by movably supporting it.

"Problems to be solved by conventional techniques and inventions" Conventionally, the required number of bridge piers were constructed along the bridge construction section,
A skid is installed on each pier, and a PC girder of the required length is molded with a formwork in the production yard provided at the end of the erection section.
A hand girder is attached to the tip of this PC girder and extruded along the erection section, and as it is extruded on each pier, a Teflon plate is appropriately inserted between the PC girder and the sliding gear and supported and continuously and integrally molded PC There is known a PC bridge extrusion method in which a girder is extruded to build a bridge.

However, in the conventional extrusion method for PC bridges, the PC girders are always extruded along the longitudinal alignment of the bridge as much as possible, and as a result of the extrusion on each pier, there is a large gap between the PC girders and the slips. Since a method was adopted in which an adjustment plate that can be easily handled, such as a plywood plate, was inserted and supported together with the Teflon plate each time, the vertical alignment of the bridge was limited to those with almost constant linear changes such as straight lines or single curves. It had been.

By the way, in crossing bridges and overpasses in flat areas, it is often the case that the vertical alignment of the bridge is not a straight line such as a straight line or a single curve due to the location conditions, but a bridge in which the line shape changes intricately. There is no PC, but when such a bridge is constructed by the extrusion method, PC
Since the gap between the PC girder and the sliding gear changes in a complicated manner each time as the girder extrusion progresses, such a complicated and drastically changing gap cannot be dealt with by the conventional simple extrusion construction. There was a problem.

In addition, in the conventional construction method, the hand girder that was used once cannot be reused for other extrusion methods because it was manufactured or modified each time to a shape corresponding to the longitudinal alignment of the bridge on which the hand girder was constructed. There were also problems with economics.

[Means for Solving Problems] In order to solve the above-mentioned conventional problems, the present invention installs a height adjustable feed platform on a required pier constructed over an erection section, and installs an end portion of the erection section. The PC girder manufactured in the manufacturing yard provided in the above is extruded onto the pier, and the hand-carried girder is movably supported on the pedestal above it. Every time the girder is extended and manufactured, the PC girder is sequentially extruded while moving on each feed gantry, and sequentially supported on the feed gantry on each adjacent bridge pier, thereby extruding the PC girder on the bridge where the alignment changes intricately. Even if the gap between the PC girder and the sliding trough changes in a complex manner as it progresses, it is possible to construct various vertical linear bridges by responding to this and smoothly and reliably sending the feed platform while adjusting the height. And We propose a method for extruding PC bridges that enables repeated use of straight hand-held girders to construct bridges of various vertical alignments.

[Example] An example of constructing a bridge having a longitudinal line diameter with a radius R at the center and a gradient of x, y% on both sides will be described below with reference to the drawings of the present invention. The required number of bridge piers (including abutments installed at both ends) 1 ₁ , 1 ₂ ·· _n were constructed with the required spans S ₁ , S ₂ ··· S _n-1 at one end of the erection section. A PC girder of the required length is manufactured using a formwork, and a manufacturing yard 2 for introducing prestress to it is installed.

The PC girder 3 (the span S
₍ Produced following the curvature of _n-1 ) Attach a steel hand-held girder 4 with a straight bottom surface to the tip of the first pier along the erection section.
Extruding the jack on 1 _1.

First pier 1 ₁ and the second on piers _2, the feed cradle 5 without advance height adjustable on the circumference of the curvature R of the bridge center portion in advance installed respectively on the feed platform 5,5 hands total digits 4 PC digit 3 was extruded toward the direction connecting movably supporting the first pier 1 ₁ above.

Next, a PC girder of the required length was continuously and integrally manufactured behind the PC girder 3 that was initially manufactured in the manufacturing yard 2, and the first pier 1 ₁
Movably supporting the PC digit 3 which is extended from the upper hand total digit 4 of the tip is extruded onto the feed cradle 5 on the second pier 1 ₂ by a jack.

After that, in the same way, in the production yard 2, the PC girders of the required length are successively extended and manufactured behind the PC girders 3 in sequence, and the extended PC girders 3 are extruded from the top of the first pier 1 ₂ with a jack. The hand-held girders 4 are sequentially movably supported on a feed frame 6 whose height is adjustable on a second pier 1 ₃ ·· 1 _n .

The feed base 5 is made of, for example, a rectangular parallelepiped steel or concrete block, and a friction-reducing plate 7 made of a metal such as a stainless plate having high corrosion resistance and wear resistance or a synthetic resin is attached to the upper surface of the block so as to be replaceable. The feed base 6 which is constructed as a slide support and one of which is adjustable in height is a steel block similar to the above, and the lower part of which is hydraulically fitted to a cylinder-shaped lifting / pressurizing table 8 so that the vertical height is increased. The height can be adjusted.

Then, when the PC girder 3 is extruded, a plurality of sliding plates 9 having high wear resistance are interposed in the gap between the friction-reducing plates 7 of the feed frames 5 and 6 and the PC girder 3 or the hand girder 4, and the PC girder 3 The slide plate 9 is sequentially inserted into the rear clearance while sliding on the friction-reducing plate 7 by being pushed out and dropping from the front end in the pushing direction.
Alternatively, slide the hand girder 4 on the platforms 5 and 6.

As the sliding plate 9, for example, a plate material having excellent low abrasion resistance and abrasion resistance and high rigidity is used, such as one in which a tetrafluoroethylene resin layer is provided on one surface of hard rubber reinforced by putting a steel sheet in the core.

In this way, each time the PC girder 3 is sequentially extended and manufactured, the hand-carried girder 4 and the PC girder 3 are slid and moved on the respective feed racks 6, and the feed racks for the piers 1 _{3 and} after are interlocked with the moving distance. Lower the height of 6 as appropriate.

In this case, at the time of extrusion in the process of transitioning from the uphill slope to the downhill slope, the distance between the hand girder 4 and the upper end of the front pier (the pier 1 _{n-1 in the} figure) supporting it increases, so A horse (space adjustment material) is installed on the top.

Further, before the extrusion of PC digit 3 for bridged final S ₁ span begins, the feed frame of the PC digits of x% on the first pier 1 ₁ advance so as to support in conformity with vertical alignment of the gradient 5 is replaced by a height-adjustable feed base 6, and the height of support is increased by interlocking with the distance of extrusion.

Further, the height adjustable feed cradle 6 installed on the piers 1 ₁ , 1 ₃ ··· 1 _n-1 was changed to the main gear after the PC girder 3 passed through the final span S _n-1. 1 ₂ The feed rack 6 on the upper side is changed to the main gear after the extrusion of the PC girder 3 is completed.

The feed base 6 is not limited to the sliding gear shown in the embodiment of the present invention, and may have another structure such as a plurality of rollers for rolling to move the PC girder.

[Advantages of the Invention] As described above, according to the present invention, the height adjustable feed platform is installed on the required pier constructed over the erection section, and the PC is manufactured in the manufacturing yard provided at the end of the erection section. The girder is pushed out onto the bridge pier and the hand-carried girder is movably supported on the feed pedestal above it.After that, the PC girders are successively extended and integrally produced in the rear, and each time the PC girder is extended and produced, the PC girder is produced. Are moved on each feed frame, the height is adjusted in tandem with the amount of movement, and they are extruded sequentially, and are sequentially supported on the feed frames on each adjacent pier, so in a bridge where the alignment changes intricately, Even if the gap between the PC girder and the feed frame changes intricately as the extrusion progresses, the height of the feed frame is adjusted accordingly to smoothly and surely feed the various types of vertical linear bridges. Can be built.

Even if the hand girder does not have a shape corresponding to the vertical alignment of the bridge, it can be surely extruded and supported on the adjacent bridge pier. It is economical because it can be used repeatedly.

[Brief description of drawings]

FIG. 1 is a side view showing an example of an extrusion process according to the present invention, FIG. 2 is a perspective view of a feed moving base with a height adjusting function according to the present invention, and FIG. 3 is a feed moving base according to the present invention.
It is a side view which shows the movement state of a PC girder. 1 ₁ , 1 ₂ , 1 ₃ , 1 _n ... Pier, S ₁ , S ₂ , S ₃ , S _n-1 ... span,
2 …… PC girder production yard, 3 …… PC girder, 4 …… Hand girder,
5 ... Feeding base (immovable), 6 ... Feeding base (height adjustable), 7 ... Reducing friction plate, 8 ... Elevating and holding base, 9 ... Sliding plate.

Claims (1)

(57) [Claims] 1. A required number of piers are constructed over the erection section,
A height-adjustable feed frame is installed on the required pier, and a PC girder of the required length is manufactured using a formwork in the production yard provided at the end of the erection section.This PC girder is installed along the erection section. Push it onto the bridge pier and support the linear hand-held girder on the feed frame above it, and then continuously and integrally rearward the required length.
The PC girders are sequentially extended and manufactured, and each time the PC girders are extended and manufactured, the PC girders are moved on each feed rack, and the feed racks are extruded sequentially while adjusting the height of the feed rack in accordance with the movement amount, and each adjacent An extrusion method for PC bridges, characterized in that they are sequentially supported on a feed frame on the pier.