KR20060040997A - Bridge slab construction method and lattice bar deck-shaped precast concrete plate applied therein - Google Patents

Abstract

The present invention relates to a method of constructing a bridge slab and a lattice bar deck type PC plate to be applied to the method. The PC plate includes a plate body which is manufactured so as to maintain its own compressive strength not less than the compressive strength of the slab, And a truss frame partially formed on the upper surface of the plate body. The method includes applying a plurality of girders in parallel between the upper surfaces of the bridge piers, A plurality of cross beams are formed at a predetermined interval therebetween, and then the PC plates are pulled and carried by the work platform car and are installed adjacent to and in parallel to the upper part. Reinforcement is placed on the upper part of the cross beams, And according to the present invention, when the construction is performed, It is possible to improve the work efficiency and to improve the work efficiency by eliminating the troubles in the process and risk of safety accidents due to the installation and removal of the fountain and the operation platform, So that the strength of the bridge can be further improved, but the advantage of being able to visually identify the broken state of the bridge immediately as in the conventional case can be exhibited as it is.

Bridges, slabs, bridge overhead work, precast, PC plate, lattice bar deck

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a bridge slab construction method and a lattice bar-

1 is a perspective view showing an example of a bridge structure by the construction method of the present invention.

FIGS. 2A to 2D are views sequentially showing respective processes according to an exemplary method of constructing a bridge slab of the present invention,

FIG. 2A is a first process in a state in which a plurality of girders are mounted on an upper portion of a pier,

FIG. 2B is a second process diagram showing a process for installing a crossbeam by installing a work truck on an upper portion of the girder, pulling a cross beam form therebetween, and installing concrete thereon. FIG.

FIG. 2C is a third process showing the process of installing the PC plate (Precast Concrete Plate) of the present invention in the upper opening formed by the girder and the cross beam,

FIG. 2D is a fourth process diagram showing a state in which a work truck installed above the girder is disassembled, a reinforcing bar is laid, and concrete is installed to cure the slab integrally with the PC plate.

3 is a longitudinal sectional view of a bridge showing a structure of a composite slab completed by the construction method of the present invention.

4 is a perspective view illustrating a structure of a PC plate applied to a method of constructing a bridge slab of the present invention.

FIG. 5 is a cross-sectional view showing the internal structure of the PC plate according to the present invention cut in the plane direction.

FIG. 6 is a cross-sectional view taken along line A-A of the PC plate according to the present invention as shown in FIG.

FIG. 7 is a cross-sectional view taken along the line B-B of FIG. 4 showing the PC plate according to the present invention.

8 is a schematic longitudinal cross-sectional view illustrating the structure of a conventional artificial concrete specimen produced to perform a performance comparison test for a PC plate composite slab of the present invention and a PC plate synthetic concrete specimen of the present invention, respectively.

9 is a composite graph showing the load-displacement relationship according to the results of static fracture tests for the conventional spot-buried concrete specimens and the PC-plate composite concrete specimens of the present invention, respectively.

Description of the Related Art

a; The spacing b of the pair of bottom roots; Spacing between lower muscle and main muscle

D; Total thickness of composite slab D1; Plate body thickness

P; PC plate 1; pier

2 ; Girder 3; Cross beam

3a; Cross beam form 4; Slab

10; Work Balance 11; support fixture

12; Crane 13; wire

20; Truss frame 21; Plate body

22; A main muscle 22a; Lower extremity

23; Lattice bar (exposed bars) 24; Kang Hyun

25; Bracing reinforcing bars 30; Adhesive mortar

The present invention relates to a method of constructing a bridge slab and a lattice bar deck-shaped precast concrete plate applied thereto. More particularly, the present invention relates to a method of constructing a concrete slab, It is possible to minimize the number of safety accidents such as falling due to a failure due to no need to work on the operation scaffold and to improve the efficiency of work by shortening the process In addition, it is possible to improve the performance of bridges by applying high-strength PC plates according to the proven design criteria through experiments, and to realize a bridge slab construction method And a lattice bar deck type PC plate applied thereto.

The structure of a general bridge includes a plurality of piers which are arranged on a ground at regular intervals, a girder which is arranged in parallel in a horizontal direction at regular intervals between the upper surfaces of the adjacent piers, A cross beam formed orthogonally at regular intervals between adjacent girders for reinforcing the deflection of the girder and a slab cured by being placed on the girder.

The girder is a prestressed concrete beam or a steel box which is constructed to withstand the lateral force (bending stress) due to the vertical pressure such as the weight and the weight of the slab, (Steel box) type beam structures. In the case of the concrete beam, a cross beam formwork is installed in an orthogonal direction at predetermined intervals therebetween, and then reinforced by curing the cross beam by pouring concrete. In addition, in order to construct a slab corresponding to the upper construction of a bridge, a deck plate as a temporary bottom plate capable of placing concrete on the upper surface of the girder is to be installed.

The former is constructed by using slabs and plywood, but recently it has been used as a part of a precast concrete plate, which is a part of the slab placed on the site and does not need to be removed after completion. Is a trend that is being implemented.

Furthermore, when the cracks are generated in the aesthetic pipe after the construction or the concrete structure itself, the mold is troublesome in the process of dismantling and removing it in order to facilitate maintenance after being visually identified, The worker can move and work on the line by connecting the line. In consideration of the surrounding conditions, the worker can not use the footrest with a limited size (width). There was also a case where it would not be possible to provide a stable working environment that would protect valuable people.

Accordingly, various new technologies related to the above-mentioned PC plate synthesis have been proposed and disseminated in order to solve the above-mentioned problems of the slab construction method by such a mold installation. The term "precast" as used herein refers to a method of prefabricating a facility using a fixed facility and can be manufactured under optimal conditions, so that the accuracy (accuracy) and strength (strength) of a concrete product There is an advantage to be improved.

As an example of such a technique, Patent Application No. 2157, 1996, is available.

In the case of a steel box girder, in the case of a steel box girder, there are a plurality of rows of crown portions to be combined with the claw portions and anchor reinforcing bars to be described later, A plurality of stud bolts are fixedly formed on the upper surface of the girder, a plurality of stud bolts are provided on the upper and lower surfaces of the girder, A half slab (a lattice bar deck type PC plate) having pegs protruding in the horizontal direction at both ends thereof, and an anchor reinforcing bars inserted in the pegs, and a lattice bar (upper reinforcing bar) And a slab that is cured by being placed on the half slab. Other components include a non-slip stopper for the half slab, a packing for preventing penetration of the mortar into the main portion, a girder finishing plate, and a fastening bolt.

According to the above-described construction, the half slab having the claw portion manufactured in the field or factory is directly mounted on the girder, the upper connecting rope and the reinforcing bar are appropriately laid, After inserting reinforcing bars for anchors, concrete is placed in the upper part. That is, when the upper slab is cured, the claw portions and the anchor reinforcing bars are embedded in the interior of the slabs, and the reinforcing bars are integrally combined with each other.

However, the above-mentioned prior art has a disadvantage that the shape of the girder itself needs to be separately manufactured, and that the PC plate is required to have a complicated structure, shape and additional configuration for full synthesis with the slab, Particularly, there has been a serious problem that the PC plate is structurally fragile due to the formation of the recess to eliminate the installation interference.

In view of the above problems of the prior art, the applicant of the present invention has already been recognized as a patented technology by proposing a 'method of constructing a bridge slab and a PC plate applied thereto' in 2000 Patent Application No. 56002.

The registered patent of the applicant of the present application is a lattice bar deck type PC plate of a simple structure by a new arrangement design, which is not structurally weaker than the prior art and can be easily constructed using the existing structure as it is Method and structure. In addition, since the PC plate is designed to be broken before the slab by maintaining a compressive strength lower than the allowable compressive strength of the slab cured on the upper side, it is possible to visually identify and predict the cracks of the slab before the maintenance, It has an advantage that can be performed.

However, the present applicant's method of constructing a bridge slab according to the patent application and the PC plate applied thereto maintain a compressive strength lower than that of the slab in order to ensure visibility at the time of slab fatigue failure, There is a limit to strengthening to have greater strength.

SUMMARY OF THE INVENTION The present invention has been made in order to solve all of the above problems, and it is an object of the present invention to provide a method of manufacturing a concrete slab, It is possible to minimize the number of safety accidents such as a fall due to a failure due to the fact that work on the scaffold is unnecessary and it is possible to improve the efficiency of the work by shortening the process, It is possible to further improve the performance and stability of the bridge by applying the high strength PC plate according to the design standard, and in the case where fatigue breakage of the slab proceeds, cracking starts from the lower PC plate, It is possible to take prompt action such as maintenance work for large-scale accident such as bridge collapse And a lattice bar deck type PC plate applied to the slab construction method.

According to another aspect of the present invention, there is provided a method of constructing a bridge slab, comprising: placing a plurality of girders at equal intervals in parallel between upper surfaces of adjacent bridge piers installed at predetermined intervals, After the beam is formed, a plurality of lattice bar-type PC plates separately pre-cast to a predetermined size and number are towed and transported by a work platform car, The method of claim 1, wherein the pre-casting of the lattice bar-deck type PC plate is performed by placing a plurality of reinforcing bars in a rectangular frame having a predetermined depth, The reinforcing bars are arranged so as to be orthogonal to each other at a predetermined interval in the longitudinal direction and the width direction, A plurality of truss frameworks are installed so as to be protruded by a predetermined height to the upper portion of the rectangular frame at positions symmetrical with respect to the center of the diagonal direction, and concrete is laid in the rectangular frame to cure. The PC plate is manufactured so as to maintain a high strength higher than the compressive strength of the slab by the proven design standard.

In addition, as a preceding step before the installation of the PC plate, it is preferable that the contact between the girder and the PC plate is performed so that the PC plate can be stuck to each other while maintaining a sufficient contact area for stably installing the PC plate from the upper surface of the girder It is preferable that the method further comprises a step of coating and interposing the mortar to an appropriate thickness on the surface.

In order to achieve the above object, a lattice bar deck type PC plate for constructing a bridge slab according to the present invention is designed so as to maintain its own compressive strength not less than the compressive strength of a slab, and is manufactured in a pre- A plurality of main rods and a plurality of reinforcing bars embedded in the plate body so as to be orthogonal to each other at a predetermined interval in the longitudinal direction and the width direction; And a plurality of truss frames formed by partially embedding and partially protruding from the upper surface of the plate body.

Here, the compressive strength of the plate body is preferably formed so as to maintain the compressive strength of the slab greater than or equal to the compressive strength of the slab when forming a specific numerical value within a range of 270 to 400 kgf / cm ² .

The thickness of the plate body is preferably at least 50 mm, but not more than 60% of the composite slab thickness.

The truss structure may include two lower end roots arranged at predetermined intervals on both sides of the main roots laid out at the center thereof and spaced apart at a predetermined height from a central upper portion between the pair of lower roots, And a lattice bar which is exposed to the outside of the upper surface of the body along the longitudinal direction of the body, and the lower and upper lattice bars and the triangular structure formed by the pair of lower lattice bars, And the lattice bar are formed so as to form an integral truss structure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method of constructing a bridge slab according to a preferred embodiment of the present invention and a lattice bar deck type PC plate applied thereto will be described in detail with reference to the accompanying drawings.

1 to 9 illustrate a method of constructing a bridge slab according to the present invention and test specimens and experimental results for a performance comparison test of a lattice bar deck type PC plate P and a PC plate composite slab applied thereto, 2A to 2D are views sequentially showing respective processes according to an example of the method of constructing a bridge slab of the present invention. FIG. 2A is a cross-sectional view of the bridge bridge 1 FIG. 2B is a cross-sectional view of a girder 2 in which a work truck 10 is installed at an upper portion of the girder 2 and a cross beam form 3a is provided therebetween. And FIG. 2C is a sectional view of the cross beam 3, which is formed by the girder 2 and the cross beam 3, in a second step shown in FIG. The installation of the invention PC plate (P) 2 (d) is a view showing a third process of disassembling the work truck 10 installed on the girder 2, placing a reinforcing bar, and placing concrete on the girder 2 so as to integrally form a slab 4 is a cross-sectional view of the bridge showing the structure of the composite slab completed by the construction method of the present invention, and Fig. 4 is a cross-sectional view showing the structure of the PC plate P 6 is a cross-sectional view taken along line AA of FIG. 4 relative to the PC plate P, and FIG. 7 is a cross-sectional view of the PC plate P shown in FIG. 4 is a cross-sectional view taken along the line BB of Fig. 4, and Fig. 8 is a graph showing the results of the comparison between the conventional cast-in-place concrete specimen prepared for carrying out the performance comparison test for the concrete slab of the present invention, Respectively. And FIG. 9 is a composite graph showing the load-displacement relationship according to the results of the respective static fracture tests for the respective specimens.

The structure of the bridge completed by the construction method of the present invention is similar to that of a general bridge as shown in Fig. A plurality of girders 2 arranged in parallel in a horizontal direction at regular intervals between the upper surfaces of the adjacent piers 1 and a plurality of girders 2 arranged on the ground at regular intervals, A plurality of cross beams 3 formed in a direction orthogonal to each other at regular intervals between adjacent girders 2 to reinforce deflection of the girder 2; And a slab (4). It should be noted, however, that there is only a difference in the structure of the PC plate P synthesized with the slab 4 and the construction method using the same as in the above-mentioned registered patent.

The bridge slab construction method using the lattice bar deck type PC plate of the present invention is widely applied to all girder bridges such as prestressed concrete beam (PSC beam), PSC girder, and steel box girder can do. As described in the above-described prior arts, the protrusions on the upper surface of the girder (concrete beam) and the clamping jaws, the supporting jaws of the corresponding PC plate, the separate plates for fixing the PC plate, the stud bolts and the fastening bolts (For studs, stud bolts, fastening bolts, etc.), and for the hooks and anchors on both sides of the PC plate for firm coupling between the recesses and the connecting jaws and slabs on both sides of the bottom of the PC plate A reinforcing bar, a packing for preventing penetration of the mortar into the lumber, and a stopper for preventing slipping of the PC plate, and the like.

It should be noted that the most important point in the present invention is that the strength of the lattice bar deck type PC plate P should be equal to or more than the strength of the slab 4 cured on the top. This is to reinforce the formwork function of the PC plate P before slab combination and to further increase the strength of the composite slab after completion of the construction and has a view contrary to the prior art proposed by the applicant of the present invention, Even if the strength of the lower PC plate P is higher than that of the back slab 4 of the bridge structure, cracks start from the lower PC plate P. Therefore, it is possible to visually identify and predict the crack occurrence of the bridge structure, The fact that there is no problem is due to the fact that it has been proven through experimental results which will be described later. When the strength difference exists between the PC plate P and the slab 4, the gap between the PC plate P and the slab 4 is appropriately designed according to the interval, height, Full synthesis should be demonstrated experimentally.

The main design criteria of the lattice bar deck type PC plate P according to the present invention will be described in more detail with reference to FIGS. 3 to 7. FIG.

First, the height of the truss frame 20 of the PC plate, that is, the position of the lattice bar (exposed reinforcing bar) 23, is determined by the height of the upper or lower assembly reinforcing bar (not shown) It is designed to match the assembly height considering the position. The strength of the PC plate P is determined depending on whether the truss frame 20 has a cross-section of any size.

3, the thickness D1 of the plate body 21 of the PC plate P is designed to be at least 50 mm but not to exceed 60% of the composite slab thickness D, as shown in FIG. For example, when the total thickness of the composite slab combined with the PC plate and the slab is 250 mm, the thickness of the plate body should be 50-150 mm.

In order to realize the PC plate P with a minimum thickness, it is required to maintain a high strength and at least a strength equal to or higher than that of the slab 4 should be maintained. When a low-strength PC plate is used, there is a fear of self-damage during transportation after production and installation.

4 to 7, the PC plate P according to the present invention is designed so as to maintain its own compressive strength not less than the compressive strength of the slab 4, and is manufactured in a precast method A plurality of main ropes 22 and reinforcing reinforcing bars 25 which are embedded in the plate body 21 so as to be orthogonal to each other at a predetermined interval in the longitudinal direction and the width direction, A plurality of truss frameworks 20 are disposed between the main ropes 22 in parallel along the longitudinal direction thereof and partially embedded in the truss framework 20 and partially protruded from the upper surface of the plate body 21, .

In the above structure, the compressive strength of the plate body 21 can be maintained to be not less than the compressive strength for the slab 4 when the compressive strength of the slab 4 forms a specific value within the range of 270 to 400 kgf / cm ² It is more preferable that the compression strength of the plate body 21 is maintained at 400 kgf / cm ² or more when the compression strength of the slab 4 is 270 kgf / cm ² .

The truss framework 20 includes two lower end roots 22a arranged to be spaced apart from each other by a predetermined distance a on the basis of the main rope 22 laid at the center and the pair of lower roots 22a And a lattice bar 23 spaced apart at a predetermined height from the center of the plate body 21 and exposed to the outside of the upper surface of the plate body 21 along the longitudinal direction of the plate body 21. The pair of lower end roots 22a, And the lower end muscle 22a and the lattice bar 23 are formed so as to form an integral truss structure by welding a continuously repeatedly bent lid 24 to both side sloping sides of the triangular structure formed by the lower end fingers 23 .

The distance a between a pair of lower end roots 22a forming the truss frame 20 is about 1 in comparison with an interval b between the pair of lower end roots 22a and the adjacent main rope 22, : 2, which is only one example that may appear in design considering the surrounding conditions. In addition, the interval (a) between the pair of lower ends 22a and the distance between the lower end 22a and the main It is not necessary to be structurally limited since the interval b between the first and second electrodes 22 can be designed to be equal or varied.

Hereinafter, experiments for confirming the validity of the slab construction method using the lattice bar deck type PC plate according to the present invention and results derived therefrom will be described. This experiment was conducted by Chonnam National University and Honam University after constructing Task Task Team. This experiment was conducted to verify that the bridge slab constructed using the lattice bar deck type PC plate of the present invention has superior performance to that of the existing slant concrete slabs. Under the same conditions, four cast concrete specimens and five Static fracture experiments on PC - plate composite concrete specimens and dynamic fracture tests by cyclic loading on these specimens were carried out, respectively, and the performance differences between the existing slabs and the composite slabs were compared.

As a result of these tests, the composite slabs according to the present invention were found to have superior stiffness (yield strength) with respect to yield load, fracture load and dynamic load.

All the static and dynamic fracture tests related to the present invention were carried out using a two-point loading method after a specimen having a ratio of inter-leaflet to effective height ratio of 6 was produced. The support points were located 150 mm inside from both ends of the specimen, and the two load points were loaded at the center of the specimen at intervals of 300 mm. The displacement was measured at the center of each specimen. As shown in FIG. 8, three specimens of Field Concrete (FC) specimens of length 3000 mm, width 600 mm, thickness (height) 250 mm, (PCP) composite concrete specimen is a structure in which three reinforcing bars are embedded at regular intervals in the longitudinal direction of the specimen at a position of a length of 3000 mm, a width of 600 mm, a thickness (height) of 250 mm, Respectively. H16 and H22 were used for the compression reinforcement (upper reinforcing bars) and tensile reinforcing bars (lower reinforcing bars) respectively, and the compression ratio and tensile reinforcing ratio of the FC specimens were 0.5% and 1.0%, respectively.

(1) Static fracture experiment of each specimen

First, the destruction experiments on the lattice bar deck type PC plate itself were preceded. As a result of the test of the breaking load applying the load of 460 kg to the above-mentioned PC plate, the PC plate was destroyed at 1,596 kg. Therefore, it is considered that there is no risk of cracking of the plate body when the floor plate is used by using the PC plate, and when an unexpected ultimate load is applied, the compression side steel wire Lattice bar) in addition to the serious damage of the plate body including the buckling of the plate body.

In addition, this experiment was carried out up to the point of destruction as a 2-point static load of 4 FC specimens and 5 PCP specimens, and the results of each experiment are summarized in Table 1 below. The static load-displacement curve between the concrete specimens is shown in Fig.

According to the above Table 1, the PCP composite specimen of the present invention showed an average 2.1 times increase in crack load and 1.42 times increase in yield load as compared with FC specimen. This phenomenon can be attributed to the use of lattice bars and high-strength concrete (plate body) of PCP composite specimens.

Further, in the static load-displacement curve of FIG. 9, the slope of the curve indicates the stiffness of each specimen. From the above graph, the stiffness estimated by each load step of each FC and PCP composite specimen is numerically represented as shown in Table 2 below. Here, the slope of each curve is estimated by selecting four intervals between the crack load and the yield load.

As a result, the stiffness of the PCP composite specimen increases by 14.5% on average compared with the FC specimen, which is also attributable to the use of the lattice bar and high strength concrete of the PCP composite specimen. That is, from the structural point of view, the lattice bar functions to increase resistance to compression, bending, shearing force, etc. due to a hypothetical load.

In addition, as an example of experimental results for an optimized compression strength between the upper slab and the lower precast concrete plate, the compression strength of a slab compression strength of the precast concrete plate when 270kgf / cm ² was found adequate to keep the 400kgf / cm ^2.

(2) Dynamic fracture test by repeated load of each specimen

In this experiment, the dynamic stiffness of each specimen can be evaluated by repeatedly loading the same size loads up to the time of destruction for four FC specimens and five PCP specimen specimens.

According to a paper by Park Young-hoon, presented at the 1994 conference, it was concluded that the repetition frequency of fatigue fracture exceeded 300,000 times when repeatedly applying the fatigue load corresponding to 60% of the static fracture load in the concrete beam . Therefore, in the present experiment, it was confirmed that the PCP composite specimen was able to maintain a cyclic fatigue limit of 300,000 times or more (equivalent to 60% of the static fracture load value of the PCP synthetic specimen) to each FC and PCP synthetic specimen The performance evaluation is made possible by comparing the number of repeated load loads up to the time of each fatigue failure.

Table 3 below shows the static failure loads and their mean values for each FC and PCP composite specimen. Since the cyclic fatigue load corresponding to 60% of the static fracture load of the PCP composite specimen according to the data in the above [Table 3] is 17 tons, when the ratio of the cyclic fatigue load to the average static fracture load of the PCP synthetic specimen is 60% The ratio of the cyclic fatigue load to the average static fracture load of the FC specimen corresponds to 77.5%.

As a result of this dynamic fracture test, the FC specimens were destroyed at an average of 61,222 times, and the PCP synthetic specimens were destroyed at an average of 323,685 times, respectively. As a result, the PCP synthetic specimens showed much better performance than the FC specimens for repeated fatigue loads. This is due to the decrease in the tensile stress occurring in the main bars (tensile bars) 22 inside the PC plate, as mentioned in the static fracture test results. According to this experiment, since the PCP composite specimen exhibits a typical flexural fracture progress due to the dynamic cyclic loading, the fracture (slip phenomenon) due to fatigue accumulation at the interface between the PC plate (P) and the slab (4) There was no fear of the problem.

The results of the static and dynamic fracture tests of PCP composite specimens as described above are summarized as follows.

First, in comparison of static loading test results, PCC composite concrete specimens showed significantly higher flexural strength (stiffness) compared with the specimens placed in the field, and the tensile reinforcement (lower reinforcing steel) The tensile strength was also significantly smaller than that of the concrete specimens. This can be seen as an effect of the additional reinforcement of reinforced concrete and reinforced concrete of the PC plate.

Secondly, in the dynamic fracture experiment by repeated loading of the same load, PC plate synthetic concrete specimens were destroyed on average 323,685 times, whereas specimens placed in the field were destroyed on average 61,222 times. This fatigue test result suggests that the PC plate synthetic concrete slab has far superior performance to the on-site concrete slab.

Third, unlike the initial concern that the PC-plate composite concrete slab will reveal its weakness at the interface between the PC plate and the slab, no cracks occurred at the interface as shown in the static and dynamic fracture test results . This means that the slip phenomenon does not occur at the interface between the PC plate and the slab and the complete synthetic behavior is being performed.

Fourth, according to the results of the actual construction and the results of this experiment, even if the lower PC plates maintaining a higher compressive strength than the upper slab are integrally formed, cracks are generated from the PC plate at the time of fatigue failure, Visual identification was possible.

An example of a method of constructing a bridge slab according to the present invention using a PC plate P having a structure as shown in the above experiments will now be described with reference to the respective process views of FIGS. 2A to 2D.

First, in a factory, a pre-casting step (pre-casting step) of pre-casting a PC plate (P) of concrete material to be installed on a girder (2) . That is, in the pre-casting step, a plurality of reinforcing bars 22 and 25 are arranged in a longitudinal direction and an orthogonal direction within a rectangular frame having a predetermined depth, and protruded to the upper portion of the rectangular frame at positions symmetrical with respect to the longitudinal direction center After the truss frame 23 is laid, the concrete is laid in the rectangular frame and cured.

On the other hand, as shown in Fig. 2A, a plurality of girders 2 are equally spaced and parallel to each other on upper portions of two adjacent bridge piers 1, which are arranged at predetermined intervals. Next, as shown in Fig. 2B, a work carriage 10 constituted by a rail and a supporting stand 11 and a crane 12 is installed on the upper side of the adjacent girders 2, Is used to move the work carriage (10) in the longitudinal direction of the girder (2) while the cross beam formwork (3a) is fixed to the crane (12) of the work carriage (10) Concrete is placed in each of the cross beam formers 3a so as to form a cross beam 3 at regular intervals between the girder 2 and the concrete is cured After that, the cross beam form 3a is disassembled and removed to complete the construction. At this time, the structures such as the rails and supports for installing the work carriage 10 may be unnecessary depending on the type of the work carriage 10 to be applied.

After the cross beam 3 is formed as described above, the adhesive mortar 30 is applied to an entire surface of the girder 2 and the contacted plate P with an appropriate thickness, as shown in Fig. 1, So that the PC plate P can be stably installed without slippage. The mortar application step can be completed by simply curing the mortar layer with an appropriate thickness by a predetermined area so that structural weakness of the PC plate due to the formation of the recesses as in the conventional case can be prevented.

After all of the plurality of cross beams 3 have been installed, as shown in FIG. 2C, the worker truck P is pulled and fixed to the wire 13 of the crane 12, 10 in the longitudinal direction of the girder 2 while being closely arranged one by one at a proper position of the upper opening formed by the girder 2 and the cross beam 3. [ 1, the truss frame 20 is installed orthogonally to the girder 2, and the PC plate P is installed in the adhesive mortar 30 After the fixing of the PC plate P on the girder 2 and the cross beam 3 after the proper time has elapsed, So as to prevent the leakage of the mortar when the concrete is poured, and to prevent the separation of the concrete material.

As shown in FIG. 2d, the work truck 10 installed on the girders 2 is disassembled and the reinforcing bars are fastened to the upper portion of the PC plate P, The slab 4 is cured by pouring concrete from the upper part of the slab 4. After a proper time, the PC plate P and the slab 4 are integrally combined to form a composite slab structure, All the operations according to the construction method of FIG.

As described above, according to the method of constructing the bridge slab to which the PC plate according to the present invention is applied, the formwork and the operation footplate are installed at the time of constructing the slab at the upper part of the bridge to cure the concrete, Since it is unnecessary to work on the scaffolding, it is possible to minimize the safety accidents such as falling due to the scuffle, and the construction period is shortened by about 50 to 70% as compared with the conventional method using the formwork, As a result, the efficiency of the work can be improved, and the construction cost can be reduced by 15% or more.

In addition, according to the present invention, it is possible to improve the performance and stability of a bridge by applying a high-strength PC plate according to a proven design standard through experiments, and to improve the performance and stability of a bridge, when fatigue failure of the slab progresses, Since cracks can be recognized and visually recognized, there is a variety of advantages such that maintenance work such as maintenance work can be performed quickly, thereby preventing large accidents such as collapse of bridges.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. It is to be understood that such equivalent embodiments are also intended to be included within the scope of the appended claims. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

Claims (7)

A plurality of girders are equally spaced in parallel between the upper surfaces of adjacent piers installed at predetermined intervals, a plurality of cross beams are formed at predetermined intervals therebetween, and a plurality of lattices The bar-deck type PC plates are trained and transported by a work platform car, and are installed adjacent to and in parallel with the required amount. The reinforcing bars are placed on the top of the PC plate forming the bottom plate, A method of constructing a slab for a bridge slab, The precasting step of the lattice bar deck type PC plate is characterized in that a plurality of reinforcing bars are arranged in a rectangular frame having a predetermined depth so as to be orthogonal to each other at a predetermined interval in the longitudinal direction and the width direction, The method comprising the steps of placing a plurality of truss frames so as to be protruded by a predetermined height to the upper portion of the frame and then curing the concrete by placing the concrete in the rectangular frame. Wherein the slab is constructed so as to maintain a high strength higher than a compressive strength of the slab. The method according to claim 1, Wherein the compressive strength of the PC plate is designed to maintain a value greater than or equal to the compressive strength of the slab when the compression strength of the slab is in a range of 270 to 400 kgf / cm ² . The method according to claim 1, Wherein the pre-process of installing the PC plate is such that the PC plate is held on the entire contact surface between the girder and the PC plate so that the PC plate can be stuck to each other while maintaining a sufficient contact area for stably installing the PC plate from the upper surface of the girder Wherein the mortar is applied and interposed at an appropriate thickness with respect to the slab. A rectangular plate body which is designed to maintain its own compressive strength equal to or higher than the compressive strength of the slab and is manufactured in a precast manner in accordance with the design standard; A plurality of main bars and a plurality of reinforcing bars embedded in the plate body so as to be orthogonal to each other at a predetermined interval in a longitudinal direction and a width direction; And And a plurality of truss bone bars arranged in parallel between the main rods along the longitudinal direction thereof, the truss bone bars being partially buried while the remaining part of the truss bone bars protruding from the upper surface of the plate body. Deck type PC plate. 5. The method of claim 4, Wherein the compression strength of the plate body is formed so as to maintain a compression strength of the slab when the compression strength of the slab is in a range of 270 to 400 kgf / cm ^2. PC plate. 5. The method of claim 4, Wherein the thickness of the plate body is at least 50 mm and not more than 60% of the thickness of the composite slab. 5. The method of claim 4, Wherein the truss frame comprises two lower end roots arranged at predetermined intervals on both sides of a main rope laid out at a center thereof and spaced apart at a predetermined height from a central upper portion between the pair of lower roots, And a lattice bar each of which is exposed to the outside of the upper surface along the longitudinal direction and which is continuously and repeatedly bent at both side sloping sides of the triangular structure formed by the pair of lower end muscles and the lattice bar, Wherein the lattice bar and the lattice bar are formed to form an integral truss structure.

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