KR20030093680A - The construction method of double-t girder bridge by underslung movable scaffolding system - Google Patents

Abstract

PURPOSE: A construction method for a double-T bridge by an underslung movable scaffolding system is provided to improve constructability and to shorten a period of construction by automation using mechanical equipment. CONSTITUTION: The construction method for a double-T bridge by an underslung movable scaffolding system comprises the steps of: after installing a rail for moving a reinforcement jig on a pre-installed bridge, installing a reinforcement jig on the center of the pre-installed bridge; arranging reinforcing bars per span to fit on the installed reinforcement jig, then assembling a sheath tube; if the assembly of reinforcing bars and sheath tubes is completed, executing an inspection; lifting up the reinforcement jig to a box girder installed for concrete on the next span using a hoist(10) of a gantry crane(11) installed on a bridge; installing the lifted reinforcement jig to a movable scaffolding form using a hoist(10); after placing concrete, moving the whole equipment using a main jack to descend an outer form(1) and an inner form(2) downward; removing a strut(12), a turn buckle(13) and a pin(14) fixed on the from to dismantle the inner form(2); after removing the steel rod fixed on a joint of a cross beam(4), moving the whole form from side to side using a hydraulic jack attached to the cross beam(4); widening the box girder(5) and the whole form from side to side using a hydraulic jack attached to a pier bracket(7) to get ready for moving a movable scaffolding system; and moving the outer form(1) and the inner form(2) to the next span simultaneously using a shift unit(6) installed on the pier bracket(7).

Description

Construction method of double-t girder bridge by underslung movable scaffolding system

The present invention relates to a system for prefabricating and installing reinforcing bars in span units during construction of a mobile non-porous double-tee bridge, and to mechanical equipment during simultaneous movement and assembly and disassembly of external formwork (1) and internal formwork (2). The present invention relates to a construction method that improves workability and shortens construction period by introducing an automated system.

Typical mobile scaffold type bridges include one-stage scaffolding and external formwork setting and inspection; Assembly and installation of two-stage floor slab reinforcement, wall reinforcement and sheath pipe; 3-step internal formwork installation; Assembly and installation of four-stage upper slab rebar; Concrete finishing and curing after completion of the 5th step of camber adjustment; Tensioning the sixth internal strand; Step 7 Disassemble one set of rear piercing brackets and move them in the forward direction to install them in the piers; 8th stage preparation work for dismantling formwork; 9 steps of external formwork (1) dismantling work step; 10 steps to move the external formwork (1) and mobile non-pore equipment; 11 steps of disassembling the inner formwork and setting the outer formwork (1); The 12-step internal formwork (2) moving and setting work step was composed of 12-step process, it took a lot of detection time and work time by process.

Assembling and installing the reinforcing bar is done by assembling the reinforcing bar after installing the external formwork, and by making the reinforcing jig site in which the abdominal and lower flange rebars are arranged in 3 ~ 5m units on the upper surface of the bridge or under the bridge. The method of transporting reinforcing bars assembled with cranes and arranging them on the external formwork and arranging the final reinforcing bars was mainly used.

However, when pre-assembled rebars are used at intervals of 3 to 5 m, many joints are generated in the case pipe and reinforcing bars, and additional work for connecting the rebars carried in units of 3 to 5 m is required. In addition, due to the increase in the number of transportation and installation processes and additional equipment, there were unreasonable points in terms of workability and economics.

In particular, in the case of the double-tee bridge, the width of the lower part of the wall is narrow, making it difficult to assemble and install the reinforcing bar directly in the formwork.

In addition, the dismantling and moving of the seventh stage piercing bracket (7) and the dismantling and moving of the 11 and 12-stage inner formwork (2) had to use separate equipment or to install the moving device and the rail in advance.

As described above, the additional work required for operating the internal formwork (2) and the external formwork (1) is increased, and the required air and construction costs are increased due to the mobilization of heavy equipment. In addition, when the pre-process is wrong, the increase of the detection time can not proceed with other processes, which causes enormous disruption to the air.

A system for prefabricating and installing rebar in span units, a system for moving external formwork (1) and internal formwork (2) simultaneously, and a system for automating tasks that depended on conventional heavy equipment when assembling and installing formwork. The purpose is to provide construction methods that can improve construction performance and shorten construction period.

A system for pre-assembling reinforcing bar by span unit includes assembling reinforcing bar and sheath pipe in span unit in reinforcing bar fabrication of other bridges; Next, after lifting the reinforcing bar using the hoist (Hoist, 10) of the door-shaped crane (11) installed on the bridge to the scaffold that is installed for the concrete placing, characterized in that the step consisting of moving and installing.

The system that moves the external formwork (1) and the internal formwork (2) at the same time and the construction automation system by the mechanical equipment when assembling and disassembling the formwork moves the entire equipment downward by using the main jack after the concrete is placed. ) And lowering the inner formwork (2); Removing braces 12 / turn buckle 13 / pins 14, etc. fixed to the formwork to dismantle the inner formwork 2; Automatically demolding the internal formwork (2) using a hydraulic jack and mounting the demolded internal formwork (2) on the crossbeam (4); Removing the steel bar fixed to the crossbeam 4 and then moving the formwork whole to the left and right by using a hydraulic jack attached to the crossbeam 4; Automatically spreading the scaffold 5 and the formwork to the left and the right by using a hydraulic jack attached to the bridge bracket 7 to complete the preparation for moving the scaffolding equipment; The outer formwork 1 and the inner formwork 2 are simultaneously moved to the next span by using the moving device 6 installed on the bridge bracket 7.

1 is a cross-sectional bottom support mobile scaffolding of the present invention

Figure 2 is a bottom support type mobile scaffold configuration according to the present invention

Figure 3 is a flow chart for automatically dismantling the external formwork and the internal formwork according to the present invention

4 is a front view and a side view of a reinforcing jig seat according to the present invention;

5 is a flow chart of the transportation and installation of the reinforcing jig according to the present invention.

Figure 6 is a transport, installation cross section of the reinforcing jig according to the present invention

Figure 7 is a cross-sectional view of a conventional lower support mobile scaffold

Explanation of symbols on the main parts of the drawings

1. Outer Form

2. Inner Form

3. Bottom Form

4. Cross Beam

5. Box Girder, Truss Girder

6. Moving Unit

7. Pier Bracket

8. Reinforcement Jig

9. Spreader Beam

10. Hoist

11.Gantry Crane

4 is a front view and a side view of a reinforcing jig seat according to the present invention, FIG. 5 is a flow chart of a rebar jig 8 according to the present invention, and FIG. 6 is a rebar jig 8 according to the present invention. ) Transport and installation cross section.

The present invention is to install a reinforcing jig seat on the rail 22, as shown in the drawings, to assemble the reinforcement in the span unit, and then to cast the concrete in the form of transporting and installing the reinforcing jig 8 to the door-shaped crane (11) During the dismantling and movement of strand strands, scaffolds (5), and piercing brackets (7), the rebars of the next span are preassembled. The detailed construction method is as follows.

First, the reinforcing jig movement rail 22 is installed on the other bridge 23, and then the reinforcing jig field is installed in the center of the other bridge. This reinforcing jig is installed door-type crane (11) for transporting the assembled reinforcing bar, and reinforce the bar by the span unit in accordance with the installed reinforcing jig to assemble the case pipe.

When the rebar and sheath pipe are assembled, the inspection is performed and the jig is prepared for transportation. At this time, there should not be any interference in the moving path from the upper rail 22 to the upper height of the reinforcing jig 8, it should be able to maintain a constant interval between the rail 22 and the rail surface evenly. In addition, when the reinforcing jig 8 is moved, a derailment preventing device and a fixing stopper may be installed at the rail end to prevent the rail from falling off when the rebar jig 8 breaks.

When the preparation for transportation is completed, the reinforcing jig 8 is fastened to the spreader beam 9 in the reinforcing jig by the hoist 10 of the door-shaped crane 11 installed on the bridge 23 and lifted. The lifted reinforcing jig 8 is installed in the set movable non-pore formwork 100. By repeating the above process, construction and construction period can be shortened considerably compared with the existing method, and the construction of reinforcing bars can be minimized by improving the construction quality of bridges. It also contributes to increased durability.

The configuration of the system for simultaneously moving the external formwork 1 and the internal formwork 2 and the system for automating the assembly and installation work of the formwork is as follows. Detailed features of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings. 7 is a cross-sectional view of a conventional lower support mobile scaffold, FIG. 1 is a cross-sectional view of a lower support movable scaffold according to the present invention, FIG. 2 is a configuration diagram of a lower support movable scaffold according to the present invention, and FIG. It is a flow chart which automatically dismantles the external formwork 1 and the internal formwork 2 according to the present invention.

The present invention is installed in the form of the bottom formwork (3) on the horizontal beam (4) installed on the upper side of the scaffolding as shown in the figure consists of a double formwork including up to the inner formwork (2) to the outside when moving the mobile scaffolding equipment The formwork (1) and the internal formwork (2) can be moved at the same time, and the detailed construction method is described in time series as an automated system by mechanical equipment when assembling and disassembling the formwork. First, after placing concrete, the entire jack is moved downward by using the main jack to lower the external formwork (1) and the internal formwork (2). In order to dismantle the internal formwork (2), remove the brace (12) / turn buckle (13) / pin (14) fixed to the formwork. Then, the inner die 2 is automatically demolded using a hydraulic jack, and the demolded inner die 2 is mounted on the cross beam. After removing the steel bar fixed to the cross beam (4) connection portion, using the hydraulic jack attached to the cross beam (4) to move the entire inner, outer and bottom formwork (1) (2) (3) to the left and right. Using the hydraulic jack attached to the pier bracket (7) to open the scaffold (5) and the formwork whole automatically left and right to finish the movement of the mobile scaffolding equipment. The outer formwork 1 and the inner formwork 2 are simultaneously moved to the next span by using the moving device 6 installed on the bridge bracket 7. When the mobile non-pore equipment is moved, the repeatability process as described above can improve workability and significantly shorten the air compared to the conventional method.

As described above, in the construction of a mobile non-porous double-tee bridge according to the present invention, a system for pre-assembling and installing reinforcing bars in the span unit of a bridge, and simultaneously moving and removing external formwork and internal formwork to mechanical equipment during assembly and disassembly of formwork The introduction of an automated system can reduce the number of workers and heavy equipment through efficient use of mobile non-machinery equipment, and also shorten the construction period, thereby improving construction and economic efficiency.

Claims (1)

1. In constructing double-tee bridges by mobile scaffolding,

   First installing the reinforcing jig moving rails 22 on the top of the other bridge 23, and installing the reinforcing jig field in the center of the top of the other bridge;

   Assembling the sheath pipe after reinforcing the bars in the unit of span in accordance with the installed reinforcing jig 18;

   Performing the inspection when the reinforcing bars and the sheath pipe are assembled;

   After the preparation for transporting the reinforcing jig (8) to lift the reinforcement using the hoist (10) of the door-shaped crane (11) installed on the bridge to the scaffold that is installed for the next span concrete pouring, and then moving;

   A step of installing the lifted reinforcing jig (8) to a movable non-pore formwork set using the hoist (10),

   After pouring concrete, move the whole equipment downward by using the main jack to lower the external formwork (1) and the internal formwork (2) and

   Removing braces 12 / turn buckle 13 / pins 14, etc. fixed to the formwork to dismantle the inner formwork 2;

   Automatically demolding the internal formwork using a hydraulic jack and placing the demolded internal formwork 2 on the cross beam;

   Removing the steel bar fixed to the crossbeam 4 and then moving the formwork whole to the left and right by using a hydraulic jack attached to the crossbeam 4;

   Using the hydraulic jacks attached to the bridge brackets 7 to automatically open the scaffold 5 and the formwork to the left and right to complete the preparation of the moving scaffolding equipment;

   Double-tees by a bottom-supported mobile scaffolding method, comprising the steps of simultaneously moving the outer formwork 1 and the inner formwork 2 to the next span by using the moving device 6 installed on the bridge bracket 7. How to construct