KR101643325B1 - Cable fixing apparatus with the means of stress distribution and the manufacturing steel composite girder using the same - Google Patents

Abstract

The present invention relates to a fixed stage fixing part which can prevent generation of crack on a concrete around a fixed stage fixing part by expanding a distribution range of stress generated in a fixed stage of a strand, and also can prevent unnecessary increase of the concrete cross section, and a manufacturing method of a composite girder using the same. The fixed stage fixing part has a number of stress distribution plates installed at a web of a steel material. Each stress distribution plate is arranged to be separated from each other as to an up/down and left/right direction. A penetration groove penetrated by the strand is comprised at each stress distribution plate so that one side is opened. An end part of the strand penetrating the penetration groove of the stress distribution plate constitutes a bulb wherein wires are released and spread.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a stress-dispersed fixed stage fusing unit for manufacturing a composite steel girder, and a method of manufacturing a steel composite girder using the same.

The present invention relates to a structure of a fixing unit for fixing an end portion of a strand of a steel cord to introduce a prestress into a steel composite girder. More specifically, The present invention relates to a method for manufacturing a composite composite girder, and more particularly, to a method for manufacturing a composite composite girder which is capable of preventing a crack from occurring in a concrete and preventing a concrete cross section from being unnecessarily increased.

PSC composite girders supporting the loads of bridges, which are composite sections in which the girder and bottom plate are integrated by connecting the reinforced concrete and the steel girder with the shear connection, have been widely applied since they can vary the bridge or the plane linearity. However, the concrete abdomen of the composite girder does not play a large structural role, but its own weight occupies 30% of the total weight.

To solve the above-mentioned problem of the PSC composite girder, it is a steel composite PSC composite girder as in the present invention. In other words, the synthetic composite PSC composite girder has the effect of reducing the self weight and improving the workability by replacing the abdomen of the girder with the steel sheet, and installing the concrete casing in the lower part and installing the tension material therein, .

However, since the cross section of the concrete casing installed at the lower part of the composite synthetic PSC composite girder is relatively small in size, the fusing part for fixing and fixing the tensed strand for the introduction of the prestress generates concentrated stress at the end of the concrete casing, In order to prevent this, there is a problem that the cross section of the concrete is unnecessarily enlarged.

One of the proposals for solving such a problem is the arrangement of the PC strand of the prestressed steel composite girder of the registered patent publication No. 10-0547619 shown in Figs.

The arrangement of the PC strand of the prestressed steel composite girder of the above registration No. 10-0547619 is a steel composite girder in which concrete is placed so as to enclose a part of the steel as shown in Fig. A first PC strand fixed to an end of the girder and fixed to the inside of the concrete at a position spaced from the other end of the girder by a fixed fixing unit; A second PC strand fixed to the other end of the girder by a movable fixing unit and fixed to the concrete at a position spaced from the one end of the girder by a fixed fixing unit; . 2, a rectangular fixing plate is attached to the abdomen of the I-shaped steel, and the strand is fixedly fixed using a wedge.

The above-mentioned prior art struc- ture line arrangement structure has a positive effect of preventing the cracks of the ends of the concrete casing to some extent by avoiding the concentrated placement of the fixing ports at both ends.

However, since the fixed fixing port provided in the concrete casing is concentratedly installed on the fixing plate, there is a limit in that concrete cracking on the end face can not be sufficiently prevented due to the concentrated load acting on the fixing plate, The stress is concentrated on the corner portion due to the angular shape.

In addition, each of the divided pieces of the wedge to be inserted into the fixed fixing hole must be integrally inserted into the wedge hole so that the wedge pressure is uniformly applied to each outer surface of the stranded wire. The wedge is inserted into the wedge hole The wedge is inserted into the wedge hole and tightly engaged with the wedge hole so that the degree of insertion of each divided segment of the wedge into the wedge hole in the tension of the stranded wire It is not possible to reset each of the divided pieces of the wedge and to check the rigidity of the wedge in a state of being locked, so that there is a problem that the structural stability can not be assured.

KR 10-0547619 B1

The present invention extends the range of dispersion of the stress applied to the fixed end embedded in the concrete casing to improve the fixing performance at the fixed end while preventing cracks caused by the prestress tensile force in the concrete casing, The present invention provides a structure of a stress distribution type fixed-end fusing unit for manufacturing a steel composite girder which can secure stability.

Another object of the present invention is to provide a structure of a stress-dispersion type fixed-end fusing unit for manufacturing a steel composite girder which can improve workability of arrangement of stranded wires and shorten the length of air and improve economy.

It is another object of the present invention to provide a structure of a stress distribution type fixed fusing unit for manufacturing a composite steel girder having general versatility, which can be applied to various standards of steel composite girders.

According to a most preferred embodiment of the present invention for solving the above problems, one end of a strand for introducing a prestress into a steel composite girder, whose abdomen is made of steel and has a concrete casing at the bottom, is fixedly fixed to the concrete casing In the fixed-end fusing unit, a plurality of stress dispersing units are provided in the abdomen of the steel material, and the respective stress dispersing units are disposed so as to be spaced apart from each other with respect to the vertical and horizontal directions. Is provided so as to be open to any one side thereof and the end portion of the strand through the through groove of the stress dispersing device constitutes a bulb which is loosened by breaking the stranded wire to provide a stress dispersed type fixed end fixing portion for manufacturing a steel composite girder .

Further, the stress dispersing apparatus further includes a float preventing means for preventing the strand inserted in the through groove from rising due to buoyancy of the unhardened concrete, and a bulb retaining means for retaining the stranded state at the end of the strand is further provided .

According to another embodiment of the present invention, a stress distribution device installed on the abdomen of a steel material is installed via an angle adjusting plate, and the angle adjusting plate may adjust the position of the stress dispersing device so that the angle between the respective strands is changed The present invention relates to a stress-dispersed type fixed-end fixing unit for manufacturing a composite steel girder.

According to another embodiment of the present invention, there is provided a method of manufacturing a steel material, comprising the steps of: installing the stress dispersing device at a position spaced inwardly from an end of a steel material; Installing a stranded wire so as to fit one end of a strand with a bulb formed in a through groove of the stress dispersing device so that an inner end of the bulb is in contact with the stress dispersing device; Constructing a concrete casing in a lower portion of the steel so that the stress dispersing device is embedded; And a step of pulling the other end of the strand at the outer end of the concrete casing to introduce a prestress into the concrete casing. The method of manufacturing a composite composite girder using the stress-dispersed fixed end fixing unit is also provided.

Since the positions where the respective strands dispersed from the tendon are fixed are disposed to be effectively spaced apart from each other in the front, rear, left and right directions in the concrete casing, the stress generated in the fixed end is widely dispersed by the tension of the tendon, It is possible to prevent cracks from being generated in the casing, and there is no need to unnecessarily increase the cross section of the concrete casing in order to prevent cracking.

In addition, since the fixing means is formed by the bulb, the fixing state can be clearly known even in the state where the concrete is embedded, and the bulb is supported by the stress dispersing device in addition to the anchoring action by the formation of the bulb, And furthermore, the bulb caused by the tension of the tendon and the stress dispersing device by the bulb jointly share the expectation of a very large fixing performance.

Further, according to the present invention, it is prevented that the bulb is reduced or the strand is floated due to the concrete insertion pressure and the buoyant force, and the precise arrangement of the strand is completed only by inserting the strand in the through groove formed in the stress distributor, Since the error can be corrected, it is possible to construct a high quality steel composite girder very easily, and it can be universally used in various standards of steel composite girders by adjusting the position of the stress distribution plate.

1 is a cross-sectional view showing an arrangement structure of a PC strand of a prestressed steel composite girder according to the prior art.
FIG. 2 is a cross-sectional view illustrating a fixing method of a fixed end fixing port applied to the conventional technique of FIG. 1;
3 is a cross-sectional view of a steel composite girder to which a structure of a fixed-end fixing unit according to an embodiment of the present invention is applied.
4 is an enlarged view of an enlarged structure of an embodiment of the fixed-stage fixing unit.
5 is a perspective view showing the structure of another embodiment of the fixed-stage fixing unit.
6 is a perspective view of an example in which a plurality of stress distribution plates are provided on the abdomen of a steel material to constitute the fixed stage fusing unit of the present invention.
Figs. 7 and 8 are a perspective view, a front view, and a side view showing each example of the floating prevention means applied to the fixed-end fusing unit of the present invention.
Fig. 9 is a perspective view and a state of use of the bulb holding means applied to the fixed stage fusing unit of the present invention.
10 is a perspective view of an angle adjusting plate applied to a structure of a fixed stage fixing unit according to another embodiment of the present invention.
11 is a front view of each embodiment of a slit combination provided in the angle adjusting plate applied to the embodiment of FIG.
12 is an explanatory view of a process of changing the position of the stress distributor in the embodiment of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in order to obscure or obscure the technical idea of the present invention due to the detailed description of the known structure in describing the present invention, the description of the structure of the above known structure will be omitted.

3 is a cross-sectional view of a structure of a strand 221 of a steel composite girder constructed using the structure of a fixed stage fixing unit 300 according to an embodiment of the present invention and a girder for explaining the fixing unit 300 And FIG. 4 is an enlarged view of the configuration of the fixed-stage fixing unit 300 according to one embodiment.

3, the fixed stage fusing unit 300 of the present invention includes a stiffener 221 having a stomach 100 and a concrete casing 200 at a lower portion thereof, And one end of the strand 221 is embedded and fixed in the concrete casing 200 in order to tense the strand 221 at the exposed end of the concrete casing 200 Structure.

The steel material 100 may be an I-shaped steel having upper and lower flanges, but may be a T-shaped steel having only a part of a flange or a steel sheet having no flange itself.

A concrete casing 200 is constructed by placing a sheath pipe 210 in which a reinforcing bar (not shown) is inserted and a strand 221 is inserted into a lower portion of a steel material 100, And the other end of the strand 221 is fixed and fixed to a tensile fixing member 400 which is exposed at an end of the concrete casing 200. The tensile fixing member 400 is fixed at one end thereof by a predetermined distance from the end of the concrete casing 200,

As shown in FIG. 4, the fixed stage fusing unit 300 for fixing one end of the strand 221 to the inside of the concrete casing 200, as described above, And a bulb 310 (BULB) constituted by a stress dispersing device 320 and a strand 221a of a strand 221. [

At this time, the stress distributor plate 320 may be directly attached to the abdomen of the steel material 100, or may be installed via an angle adjusting plate 350, which will be described later.

The stress dispersing apparatus 320 may be constituted by a plate-shaped stress dispersing plate 321 as shown in FIG. 4 or a rod-shaped stress dispersing plate 322 as shown in FIG.

In the case where the stress dispersing device 320 directly or indirectly installed on the steel material 100 is composed of the plate-like stress dispersing plate 321, it is preferable that the frame has a curved shape like an ellipse . This shape of the curve makes it possible to solve the problem that the stress is concentrated on the square corner portion of the fixing plate in the prior art.

In the case where the stress dispersing device 320 is constituted by a rod-shaped stress dispersing member 322, it is very economical to use an easily available long bolt in the market. Particularly, each strand 221, which is placed on one stress dispersing member 322, Can be adjusted very precisely. The stress dispersing member 322 is provided with a screw thread 322a having one end fixed to the steel material 100 and a washer 322b and a fixing bolt 322c fastened to the screw rod 322a .

The bulb 310 functions as a main fixed fixture by forming a bulb at the end of the strand 221 and the stress dispersing device 320 contacting the bulb 310 can adjust the position of the strand 221, So that the fixation stage fixing unit 300 has a high fixation force. Therefore, the stress dispersing device 320 is installed in contact with the inner end of the bulb 310 so that stress can be easily transmitted between the bulb and the stress dispersing device 320.

Meanwhile, the tendon 220 inserted into the sheath tube 210 is composed of a plurality of stranded strands 221. The stranded strands 221 in the present invention are individually fixed and fixed, So that the stress generated by the tension of the tendon 220 is uniformly dispersed in a wide range of the concrete casing 200. In addition,

Therefore, the bulb 310, which is formed so that the strand 221a is loosened at the end of the strand 221, is different in the upper, lower, left, and right positions for each strand 221, A plurality of stress dispersing apparatuses 320 are also disposed so as to be spaced apart from each other in the up, down, left, and right directions. 6 shows a state in which a plurality of stress dispersing apparatuses 320 are spaced apart from each other as described above using the stress dispersing plate 321 as an example.

As described above, the stress dispersing device 320 has a function of setting the installation position of the strand 221. In the stress dispersing device 320, the strand 221 is passed through and the position of the strand 221 is fixed And the through holes 323 provided in the respective stress dispersing apparatuses 320 are spaced apart from each other by a distance from the steel material 100 (a1? A2? A3? A4) 310) may be placed differently back and forth

At this time, the through-hole 323 is configured such that one side of the stress dispersing device 321 is opened. If the strand 221 is inserted into the through-hole 323, Not only the required spacing between the adjacent strands 221 is maintained but also the installation work of the strand 221 is completed only by the above-described fitting operation, so that the precision and workability are improved. In addition, It is possible to omit the work of installing spacers, which has been conventionally performed to maintain the interval between the first and second plates 221, 221, 221, and 221, thereby reducing the air shortening effect.

On the other hand, the unhardened concrete poured in order to construct the concrete casing 200 generates buoyancy, and the end of the strand 221 placed in the through hole 323 with the open upper part can float up by the buoyancy. Therefore, the stress dispersing device 320 may further include floating preventing means for preventing the strand 221 inserted in the through hole 323 from rising as described above.

Figs. 7 and 8 illustrate each of the embodiments of the floating preventing means with the stress distributor 321 as an example.

7, the strand 221 inserted into the through hole 323 is prevented from moving upward by using a fixing table 330 manufactured separately from the stress dispersing plate 321, And the fixing table 330 includes an engaging portion 331 and an engaging portion 332. 7 (a) is a perspective view showing the structure of the fixing table 330, and FIGS. 7 (b) and (c) are a front view and a side view in a state where the fixing table 330 is applied.

The hooking part 331 located on the upper part of the fixing table 330 can be formed in various shapes by pressing the strand 221 inserted in the through groove 323, And it is preferably formed in an inverted U shape to enclose the upper part of the strand 221. The engaging portion 332 has a shape bent in a direction perpendicular to the engaging portion 331 so as to be caught and fixed to the lower end of the stress dispersing plate 321 while being connected to the grip portion 331 pressing the strand 221 .

7 (b) and 7 (c), when the upper portion of the strand 221 to be fixed is enclosed by the engaging portion 331, the engaging portion 332 located at the lower portion thereof is subjected to stress dispersion The strand 221 inserted into the through hole 323 does not float upward even if buoyancy is generated by the unhardened concrete.

The engaging portion 332 may have an elastic force so that the state of being caught by the lower end of the stress dispersing plate 321 may not be easily released by an external force.

8, the shape of the passage groove 323 provided in the stress dispersing plate 321 is changed so that the passage groove 323 is formed in the passage groove 323. In this embodiment, So that the strand 221 can be prevented from moving upward.

That is, the shape of the vertically formed passage groove 323 is formed to be longer in the horizontal direction at the lower end, so that the shape of the entire passage groove 323 is formed in the shape of b < . Therefore, if the strand 221 is vertically inserted as shown in FIG. 8 (b) and then moved to the left or right, it is possible to prevent the strand 221 from rising due to buoyancy of the unreinforced concrete, do.

The bulb 310 formed at the end of the strand 221 has a bulb shape to function as a fixed anchor, that is, an anchoring function. In order to efficiently anchor the bulb 310, It is necessary that the bulb 310 having a wide opening is buried in the concrete while being held.

Therefore, the fixed stage fixing unit 300 of the present invention may further include a bulb retaining unit 340 that can maintain the state that the strand 221a is open at the end of the strand 221 even if it acts on the insertion pressure of the concrete .

9 (a) is a perspective view of an embodiment of the bulb holding means 340, and FIG. 9 (b) is a perspective view of the bulb holding means 340 300) structure in a perspective view.

The bulb holding means 340 includes a bulging plate 341 inserted between the twisted wire 221a and a plurality of leg portions 342 formed at a predetermined distance outside the bulging plate 341, And a fixing band 343 for fixing the portion 342 to the strand 221.

Each of the element wires 221a has a sectional size difference between the protruding plate 341 and the strand 221 and a difference in size between the protruding wires 341 and the strand 221. [ As shown in Fig.

A strand insertion groove 341a may be further formed around the protrusion 341 at regular intervals.

The structure of the fixed stage fusing unit 300 of the present invention described above is configured such that the stress dispersing apparatus 320 is fixedly attached directly to the abdomen of the steel material. In yet another embodiment of the present invention, (320) is changed.

9 to 11 are views for explaining the above-described variable embodiment of the present invention taking the stress dispersive plate 321 as an example, and Fig. 9 is a diagram showing the stress distribution plate 321, which is located between the stress distributor 321 and the steel material 100, 10 is a front view for explaining various embodiments of the angle adjusting plate 350 and FIG. 11 is a perspective view illustrating the angle adjusting plate 350 Is applied to move the stress dispersing plate 321. As shown in Fig.

The present embodiment differs from the above-described embodiment in that the stress distribution plate 321 provided on the abdomen of the steel material 100 is installed via the angle adjusting plate 350. [

The angle adjusting plate 350 can adjust the position of the stress distributing plate 321 for setting the arrangement state of the strand 221 so that the respective strand 221 dispersed from the tendon 220 in the sheath tube 210 can be adjusted, Or the distance between the bulbs formed by the bulb 310 can be adjusted.

 To this end, the angle adjusting plate 350 is provided with a plurality of slits 351, and the stress dispersing plate 321 is fixed to a moving base 352 moving along the slits 351. The angle adjusting plate 350 is spaced apart from the abdomen of the steel material 100 by a predetermined distance, for example, a thickness of a fixing nut 353 fastened to an end of the moving base 352, And is fixedly installed.

Fig. 10 shows each embodiment relating to the combination of the plurality of slits 351. Fig.

As shown in FIG. 10, at least the slit 351 located at the uppermost or lowermost portion of the plurality of slits 351 provided in the angle adjusting plate 350 is installed to be inclined downward or upward. This makes it possible to efficiently cope with the thickness of the concrete casing 200 which is changed according to the standard of the steel composite girder by increasing or decreasing the vertical distance between the fixing ends of the respective strand 221.

11, the stress distributor plate 321 is moved along the slit 351, and a force is applied to the movable plate 352, which is integrated with the stress distributor plate 321, on the back surface of the angle adjusting plate 350 The steel strand 221 disposed in correspondence with the size of the steel composite girder or the cross-sectional size of the concrete casing 200 can be placed at the correct position by fastening the fixing nut 353 to the end portion.

The structure of the fixed stage fixing unit 300 of the present embodiment having the angle adjusting plate 350 can be applied to various standards of the steel composite girder, so that it is versatile. In addition, the construction error of the fixing fixture, It is possible to utilize it as a means for correcting the workability and also as another factor for improving the workability.

Although the angle adjusting plate 350 may be formed in a rectangular shape, it is preferable that the angle adjusting plate 350 has a shape of an inclined trapezoid so as to correspond to the arrangement of the stress distributing plate 321, And prevents the occurrence of fragments, thereby eliminating unnecessary waste of the steel material 100.

The girder using the fixed stage fusing unit 300 of the present invention includes the steps of installing the stress dispersing apparatus 320 described above at a position inwardly spaced from the end of the steel material 100; One end of a strand 221 in which a bulb 310 is formed is inserted into a through groove 321 of the stress dispersing device 320 so that the inner end of the bulb 310 contacts the stress dispersing device 320, 221); Constructing a concrete casing (200) below the steel (100) so that the stress dispersing device (320) is embedded; And a step of pulling the other end of the strand 221 at the outer end of the concrete casing 200 and introducing a prestress into the strand 221. The manufacturing is thus completed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the invention is not limited to the disclosed embodiments, but, on the contrary, It is obvious that it will be possible to carry out various modifications thereof. It is therefore intended that such modifications are within the scope of the invention as set forth in the claims.

100; Steel material 200; Concrete casing
210; Sheath tube 220; Tendon
221; Strand 221a; glandule
300; A fixed-stage fixing unit 310; Bulb
320; A stress dispersing device 321; Stress distribution plate
322; Stress distribution band 323; Pass Home
330; A fixing table 331; Hook
332; A locking part 340; Bulb retaining means
341; A protruding plate 341a; Wire insertion groove
342; Leg portion 343; Fixed band
350; Angle adjusting plate 351; Slit
352; Mobile station 353; Fixed nut
400; Tension anchor

Claims (11)

The one end of a strand 221 for introducing a prestress into a steel composite girder in which the abdomen is made of a steel material 100 and a concrete casing 200 provided at the bottom is fixedly fixed and fixed to the concrete casing 200 In the unit 300,
A plurality of stress dispersing apparatuses 320 are provided on the abdomen of the steel material 100. The respective stress dispersing apparatuses 320 are arranged to be spaced apart from each other in the up and down and left and right directions, The through-hole 323 is formed so as to be open to one side surface,
An end of the strand 221 passing through the through groove 323 of the stress dispersing device 320 constitutes a bulb 310 in which a strand 221a is loosened,
The stress dispersing device 320 is composed of a rod-shaped stress distribution plate 322. The stress distribution plate 322 includes a screw rod 322a having one end fixed to the steel member 100 and the screw rod 322a , And a fixing bolt (322c) which is fastened to the washer (322b). delete delete delete delete delete 3. The composite composite girder according to claim 1, wherein the strand 221 is further provided with bulb retaining means 340 for retaining the strand 221a at the open end thereof. . The bulb holding apparatus according to claim 7, wherein the bulb holding means (340) comprises a bulging plate (341) inserted between the twisted wires (221a), and a plurality of legs And a fixing band (343) for fixing the leg portion (342) to the stranded wire (221). The apparatus according to claim 1, wherein the stress dispersing device (320) installed on the abdomen of the steel material (100) is installed via an angle adjusting plate (350) alpha) of the stress dispersing device (320) is changed so that the position of the stress dispersing device (320) can be adjusted. The slider according to claim 9, wherein the angle adjusting plate (350) is provided with a slit (351), and the stress dispersing device (320) is fixed to a moving base (352) Stress - Dispersed Fixed - End Fixation for Composite Girder Fabrication. A manufacturing method of a composite steel girder according to any one of claims 1 to 10,
Providing a stress disperser (320) at a location spaced inwardly from an end of the steel (100); One end of a strand 221 in which a bulb 310 is formed is inserted into a through hole 323 of the stress dispersing device 320 so that the inner end of the bulb 310 contacts the stress dispersing device 320, 221); Constructing a concrete casing (200) below the steel (100) so that the stress dispersing device (320) is embedded; And a step of pulling the other end of the strand 221 at the outer end of the concrete casing 200 to introduce a prestress into the concrete casing 200. [ How to make a girder.

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