JPS621044B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cantilever construction method for a bridge girder, and its purpose is to prevent damage to bridge girders, piers, and supporting devices during construction.

Conventionally, in the cantilever construction method for bridge girders, when the bridge girder G is pushed forward and erected on the pier B as shown in Fig. 1, the extrusion of the bridge girder G is carried out on a production table installed behind the abutment. After the concrete has hardened, a bridge girder G manufactured in a unit shape of several meters to several tens of meters is attached with a hand-stretched garter A, and a temporary support device C is attached to the bridge pier B.
For example, the bridge girder G is loaded onto a structure with sliding members arranged on an appropriate support base such as a steel base or concrete block, and the bridge girder G is loaded directly onto the bridge girder G or the bridge pier B
Using a pushing device D attached to the bridge girder G, the bridge girder G can be pushed out by sliding between the bridge girder G and the support base, or the support base can be slid on a flat plate fixed to the bridge pier B etc. A method such as placing the bridge girder G on the movable support table and pushing and sliding the support table on the flat plate using the extrusion device D to push out the bridge girder G. is taken.

However, these methods have various problems. In other words, in any of the methods described above, after the bridge girder G reaches the erection position and the erection, so-called extrusion, is completed, the temporary support device C is removed, the regular support device is installed, and the bridge girder G
It is necessary to support the bridge girder G, and the work to remove the temporary support device C is carried out by lifting the bridge girder G using vertical jacks, but because the amount of lifting of the bridge girder G cannot be increased due to construction reasons. There was a problem that the gap between the bridge girder G and the bridge pier B was not sufficient, and therefore the work was often done manually, and the work was complicated and economically unfavorable.

In order to solve these problems, various studies have been carried out, and the construction method shown in Figures 2 and 3 has been developed. A bearing device having a movable part 3, for example a rolling bearing device in which the movable part is a roller or a rocker, a hinge bearing device such as a pin, a sliding bearing device such as a sliding plate or a bearing plate having a curved surface portion, and a rubber bearing device such as rubber, or A regular support device 4 that combines these is used from the beginning, and when the regular support device C is erected without using the temporary support device C, it functions as a temporary support device, and after the construction is completed, the support device A construction method in which the device 4 is fixed as it is to exert the desired supporting function, and more specifically, it is an extrusion device in which the bridge girder G is loaded on the support device 4 and is directly attached to the pier B or the bridge girder G. A construction method in which G is pushed out on the upper shoe 1 of the support device to the erection position (in the direction of the arrow in the figure) and the support device 4 and the bridge girder G are engaged and fixed, or the support device 4 itself is repeatedly moved with the movable part 3 using a push-out device. An erection method has been developed in which the bridge girder G is pushed out to the erection position by sliding, and the support device 4 and the bridge girder G are engaged and fixed.

However, even in this construction method, due to irregularities in the flatness, so-called height, of the support devices 4 disposed on each of the plurality of piers B, as well as irregularities in the flatness of the lower surface of the bridge girder G, the piers are There remains the problem that the excessive load of the bridge girder G acts on a specific support device 4 disposed on the support device B, causing damage to the support device 4 and eventually to the bridge girder G and the bridge pier B.

In other words, there is no problem if the height of each support device 4 arranged on a plurality of piers B and the flatness of the lower surface of the bridge girder G are all constant, but it is difficult to make the height and flatness constant during construction. Therefore, if a height deviation (or a deviation in the flatness of the lower surface of the bridge girder G) occurs in a specific bearing device 4, the bearing device 4 designed to support the load of the bridge girder almost evenly A load greater than the design load acts on either of the bearings 4, and the bridge girder G and the piers B are damaged by the concentrated load.

The present invention was made in order to solve these inconveniences.The present invention has been made in order to solve these inconveniences, and when constructing a bridge, supporting devices that support the bridge girders are arranged on the piers via vertical jacks that communicate with each other, and the height of the supporting devices is adjusted by the vertical jacks. By making adjustments, the height is made constant, and in this state, the series of vertical jacks is closed.The so-called individual vertical jacks are kept in communication, but by closing certain parts, a flat surface is formed on the underside of the bridge girder. This prevents an excessive load from acting on a specific bearing device even in the event of a misalignment.Since the so-called vertical jacks are connected, even if an excessive force is applied to a specific vertical jack, all vertical jacks will not be affected. Adjustments are made to support the load evenly, preventing excessive loads from being applied to specific bearing devices.
This invention provides a cantilever construction method for a bridge girder in which the bridge girder is pushed out to the erection position, and after erection, the supporting device is fixed to the pier B by removing the vertical jack.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

10 is a support device disposed between the pier B and the bridge girder G, and the support device 10 has an upper shoe 11 and a lower shoe 12,
The bridge girder G is arranged between these upper and lower shoes 11 and 12.
The sole plate 1 is fixed to the movable part 13 and the bridge girder G, which eliminates displacement such as inclination and expansion and contraction.
It is composed of 4.

Reference numeral 15 denotes a vertical jack arranged between the pier B and the support device 10 during construction, and each of the vertical jacks 15 is communicated with one pipe 16.

17 is a valve arranged on the pipe 16, and 18 is a hydraulic pump. Reference numeral 19 denotes a recess provided in the pier B, and the recess 19 is formed to a size in which the vertical jack 15 is placed.

20 is a locking member that locks the support device 10 during erection; 21 is a temporary support member supported by the vertical jacks 15; the temporary support member 21 is used when the width of the bridge girder G is large.

Next, a method for extruding the bridge girder G and fixing the support device 10 will be described in detail.

That is, the vertical jack 1 is placed in the recess 19 of the pier B.
5 is placed, the support device 10 is arranged on the vertical jack 15, and the height of the support device 10 is adjusted by operating the vertical jack 15.

Next, a pipe 1 that communicates with the vertical jack 15
The valves 17 of 6 are closed with the respective vertical jacks 15 communicating with each other, and the locking member 2 is used to prevent the support device 10 from moving in the extrusion direction (in the direction of the arrow in the figure) during the extrusion and erection of the support device 10.
Lock it at 0.

Thereafter, the bridge girder G manufactured on a manufacturing table provided behind the abutment is loaded onto the support device 10, and the bridge girder G is pushed forward (see FIG. 6).

Then, on the empty production table, concrete is poured onto the bridge girder G pushed forward, and the sole plate 14 fixed to the bridge girder G in advance is pushed out one after another until it reaches a predetermined support device 10, and when the sole reaches the predetermined position. The plate 14 is engaged with the upper shoe 13 by bolts or the like.

After removing the locking member 20, the vertical jack 15 is lowered by opening the valve 16, the supporting device 10 is placed on the pier B, and the vertical jack 15 is removed.

After that, the construction is completed by placing anchor bolts on the lower shoe 12 of the bearing device and pouring concrete into the recess 19 of the pier B to fix the bearing device 10 (No. 7). (see figure).

Here, when pushing out the bridge girder G, an appropriate sliding member is interposed between the bridge girder G and the support device 10 so that the pushing out can be performed smoothly.

With this configuration, the flatness, so-called height, of the support device 10 can be easily made constant, and even if the flatness of the lower surface of the bridge girder G is out of alignment, the load can always be evenly distributed between the vertical jacks 15. In other words, by closing the valve 17 while the vertical jacks 15 are in communication with each other, even if an excessive load is applied to a particular vertical jack 15 and its internal pressure increases, the pressure will not increase. Another vertical jack 1 connected by pipe 16
5, and each vertical jack 15 is adjusted to maintain a constant internal pressure at all times.

In other words, a constant load is maintained to always act on all the supporting devices 10.

However, it is possible to prevent an excessive load from acting on a specific support device 10, and to prevent damage to the support device 10, the bridge girder G, and the bridge pier B.

8 and 9 show the support device 10 during erection.
Fig. 11 shows another embodiment in which the movement in the extrusion direction is stopped.

That is, FIG. 8 shows an embodiment in which ribs 22, 22 are provided on the lower surface of the lower shoe 12, which can be engaged with the vertical jack 15, and FIG.
This figure shows a mode in which the lower shoe 12 and the receiving plates 23, 23 are locked with the holding pieces 24, 24 and the bolts 25, 25.

Here, the vertical jacks 15 should have the same ram area when the load of the bridge girder G is evenly distributed, and when the load distribution ratio differs for each support point, the vertical jack 15 should be used according to the distribution ratio. A device having a ram area is used.

The present invention has the above-mentioned configuration, and can maintain the flatness (height) of the support device constant when constructing a bridge girder using the cantilever construction method, and can prevent the flatness (height) of the bridge girder from becoming uneven when the flatness (lower surface) of the bridge girder is uneven. Even if an excessive load is applied to the support device, the vertical jacks that support the support device will adjust the support load to be constant at all times. It has a great effect.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the bridge girder cantilever construction method, Figure 2
3 and 3 are explanatory diagrams of a cantilever construction method for a bridge girder using a conventional bearing device, FIGS. 4 and 5 are explanatory diagrams of a cantilever construction method for a bridge girder according to the present invention, and FIG.
The figure is a partial vertical side view of the bearing device during extrusion of the bridge girder, FIG. 7 is a partial vertical side view of the bearing device after erection, and FIGS. 8 and 9 are bearing devices of other embodiments. FIG. 10: Support device, 11: Upper shoe, 12: Lower shoe, 1
3: Movable part, 14: Sole plate, 15: Vertical jack.

Claims (1)

[Scope of Claims] 1. A cantilever construction method for bridge girders in which the bridge girder is continuously pushed out by sliding on a support device arranged on the piers, which includes: (1) fixing vertical jacks in recesses formed on the piers; A step of arranging a support device on the vertical jack and operating the vertical jack to adjust the height of the support device, and then closing each vertical jack in a state where they are in communication; (2) during extrusion erection; a step of providing a locking means for restraining the movement of the bearing device in the extrusion direction between the bearing device and the pier or the vertical jack; (3) loading the bridge girder on the bearing device and fixing the sole to the bridge girder in advance; (4) When the sole plate fixed to the bridge girder reaches the predetermined support device, the sole plate and the upper shoe of the support device are pushed out one after another until the plate reaches the predetermined support device; (5) A step of operating and lowering the vertical jack to support the bearing device on the pier and removing the vertical jack; (6) Placing an anchor bolt on the lower foot of the bearing device and The process of pouring concrete into the recess of the pier and fixing the bearing device on the pier, consisting of the above steps (1), (2), (3), (4), (5) and (6). A cantilever construction method for bridge girders. 2. The bridge girder cantilever construction method according to claim 1, wherein the locking means for restraining movement of the support device in the extrusion direction is a locking member fixed on the bridge pier. 3. The bridge girder according to claim 1, wherein the locking means for restraining the movement of the support device in the extrusion direction is a rib that locks to the vertical jack provided on the lower shoe of the support device. Cantilever construction method. 4. A patent claim characterized in that the locking means for restraining the movement of the support device in the extrusion direction comprises a receiving plate fixed to the pier, a holding piece and a bolt for locking the receiving plate and the lower foot of the supporting device. Cantilever construction method for bridge girders as described in item 1.