KR102341972B1 - Strand distribution apparatus and psc girder in which the strand distribution apparatus applited t0 - Google Patents

Abstract

Disclosed is a strand distribution apparatus. The strand distribution apparatus according to an embodiment of the present invention comprises: a steel pipe unit wherein a height thereof is lowed as going to an end, the same is cut to provide a plurality of floors in a stepped shape, and then an upper part thereof is covered by a cover unit; a discharge unit which is provided to discharge strands from each floor of the steel pipe unit; and guide frames which are provided in a pair in front of the discharge unit on each floor and guide the strands extended from the discharge unit. According to the present invention, number of PSC strands is reduced, efficiency of tension force is improved, and weight of a girder is reduced.

Description

STRAND DISTRIBUTION APPARATUS AND PSC GIRDER IN WHICH THE STRAND DISTRIBUTION APPARATUS APPLITED T0

The present invention relates to a strand distribution device and a PSC girder to which a strand distribution device is applied, and more particularly, a distribution device capable of dividing and fixing strands in multiple positions inside the PSC girder is applied, thereby reducing the number of PSC strands arranged, It is an invention related to a PSC girder to which a strand distribution device and a strand distribution device are applied, which improves the efficiency of introducing tension and can realize weight reduction of the girder.

Post-tensioning Tendons of Prestressed Concrete (PSC) girder are arranged in a parabolic shape. Since the tension bending moment corresponding to the external force bending moment occurring in the parabolic shape is generated in the girder section, the parabolic arrangement of the tendon can be viewed as an ideal arrangement in terms of structural mechanics.

However, this parabolic arrangement of tendons has several problems in terms of design of the girder. First, the parabolic arrangement of the tendon reduces the tension force introduction efficiency because curvature friction occurs in the strand. Second, in the case of a long girder extension, the friction loss of the strand increases and tension work at both ends is required. Third, the parabolicly arranged tendons pass through the girder abdomen, and there is a need to thicken the girder abdomen. Lastly, when installing the tendon, it is difficult to accurately arrange the shape, so an error may occur when introducing tension force.

Alternatively, the method of arranging the tendons in a straight line under the girder can solve the problem of parabolic arrangement, but as described first, it is disadvantageous in terms of structural mechanics. If a tension force is introduced in accordance with the bending moment of the external force generated at the center of the girder, an excessive resistance moment is generated at the end of the girder.

While arranging the tendons in a straight line, in some cases, one of the anchoring ends of the two ends is provided inside the girder to prevent overdesign on the end of the girder. More specifically, in the case of arranging a tension end anchorage capable of introducing a tension force at the end of the existing girder, and disposing a fixed anchor type anchorage embedded in the concrete inside the girder. Tendons arranged in this way can exhibit more effective resistance because all quantities overlap in the central section of the girder.

However, there are also restrictions on the method of arranging the tendons in a straight line by applying a fixed anchor type anchorage. The point is that there is a limit to improving the structural mechanical efficiency because the existing fixed anchor type anchorage can be fixed only at one point. In addition, due to the nature of the anchorage type anchorage in which a plurality of strands arranged on one tendon must be fixed to the concrete in a dispersed form, there is a disadvantage that the concrete cross section of the anchoring portion must be enlarged.

On the other hand, if the strands are pulled out from the anchorage anchorage during tension or a problem occurs inside the anchorage, there may be a problem that the entire girder needs to be reconstructed. Therefore, rather than general post-tensioning external anchorage, fixed anchorage anchorage that is embedded in concrete and cannot be re-constructed needs to exhibit high anchoring reliability above all else.

The present invention has been devised to solve the problems of the prior art described above, and by applying a strand distribution device that can divide and fix strands in multiple positions on a PSC girder, reduce the number of PSC strands placed and improve the efficiency of introducing tension and to provide a PSC girder to which a strand distribution device and a strand distribution device capable of realizing weight reduction of the girder.

Another object of the present invention is to provide a PSC girder to which a strand distribution device and a strand distribution device are applied for providing a stable fixed anchor type anchorage end by improving the interlocking and anchoring performance of a strand through a strand anchoring coupler.

A strand distribution device according to the present invention for solving the above-mentioned technical problem, the height is lowered toward the end, the steel pipe portion is cut to provide a plurality of layers in a step shape, and then the upper portion is covered by the cover portion; a discharge unit provided to discharge the strands from each layer of the steel pipe unit; and a guide frame provided as a pair in front of the discharge unit in each layer to guide the strands extending from the discharge unit.

The discharge part is provided in a semi-circular or rectangular shape to correspond to the shape of the end of each layer of the steel pipe part, and a passage hole is provided to allow each strand to pass therethrough.

The guide frame is provided in a grating shape to have a plurality of grids, and includes a pair of pillars, a transverse connection connecting the pair of pillars in the transverse direction, and a division provided to be perpendicular between the pillars. characterized in that

The guide frame may include a first guide frame provided adjacent to the discharge unit and a second guide frame provided to be spaced apart from the first guide frame by a preset interval.

The first guide frame guides the strands extending from the discharge unit to correspond to the height at the discharge unit,

The second guide frame is characterized in that it guides the strands disposed on the first guide frame to be dispersed in the vertical or horizontal direction.

It characterized in that it further comprises a strand anchoring coupler provided to fix the strands at the ends of the strands.

The stranded wire fixing coupler includes: a main body provided in a circular shape; a strand fastening hole provided in the body part; a fixing socket partly inserted into the body part; and a resistance key provided on the outer surface of the main body.

The PSC girder to which the strand distribution device according to another embodiment of the present invention is applied for solving the above-described technical problem is characterized in that the strand provided at the end of the strand distribution device is applied.

The stranded wire is provided symmetrically to the left and right of the girder, characterized in that it is provided in a straight line at the lower part of the girder.

One strand of the strands provided symmetrically is fixed at one end of the girder and spaced apart from the other end by a preset distance to apply a strand distribution device, and the strand of the other side is fixed at the other end of the girder, but one end It is characterized in that it is spaced apart by a preset distance from the stranded wire distribution device is applied.

According to the present invention, strands can be arranged according to the required moment when designing a girder, and the quantity of strands can be reduced by 20-25% due to cross tension, and the cost of girder manufacturing is reduced by reducing the number of anchorages.

In addition, according to the present invention, since there is no need to arrange tendons on the abdomen, the thickness of the abdomen can be reduced to lighten the girder. can do.

1 is a perspective view showing a strand distribution device according to an embodiment of the present invention;
2A and 2B are schematic views showing that a strand is distributed by a strand distribution device according to an embodiment of the present invention;
3A is a cross-sectional view showing a stranded wire fixing coupler according to an embodiment of the present invention;
Figure 3b is a schematic view showing that the strand anchoring coupler according to an embodiment of the present invention is provided on the strand;
4a to 4c are schematic views showing that a strand distribution device according to an embodiment of the present invention is provided on a PSC girder;
5 is a schematic diagram showing that the strand distribution device according to an embodiment of the present invention is provided on the PSC girder and the moment is optimized.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

Hereinafter, a strand distribution device according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 is a perspective view showing a strand distribution apparatus according to an embodiment of the present invention, FIGS. 2A and 2B are schematic views showing that a strand is distributed by the strand distribution apparatus according to an embodiment of the present invention, and FIG. 3A is the present invention It is a cross-sectional view showing a strand anchoring coupler according to an embodiment, and Figure 3b is a schematic view showing that the strand anchoring coupler according to an embodiment of the present invention is provided on the strand.

1, the strand distribution device according to an embodiment of the present invention includes a steel pipe part 110, a cover part 120, a discharge part 130, a strand fixing coupler 140, and guide frames G1 and G2. include

The height of the steel pipe part 110 is lowered toward the end, and the upper part is covered by the cover part 120 after it is cut in a step shape to provide a plurality of layers, and a plurality of strands S are provided therein. It is to guide the stranded wire (S) to be discharged step by step.

The steel pipe unit 110 is provided as an example in three layers, and the number of layers is not limited to three layers. Although the steel pipe part 110 is exemplified to be provided to cut a round steel pipe in a stepwise manner, the steel pipe part 110 is not limited to a round steel pipe, and it is also possible to provide a polygonal cross section.

The steel pipe part 110 according to an exemplary embodiment of the present invention has a main body steel pipe 111 that is an uncut portion, and an upper part of the body steel pipe 111 is cut in the longitudinal direction of the body steel pipe 111. The first cut steel pipe 113 cut in cross section by a height corresponding to 1/3 of the diameter, is connected from the first cut steel pipe 113, and the upper part of the first cut steel pipe 113 is in the longitudinal direction of the steel pipe part 110 It includes a second cut-off steel pipe 115 in which the cross section is cut by a height corresponding to 2/3 of the diameter of the main body steel pipe 111.

The upper portion of the first cut steel pipe 113 is covered by the first cover part 121 provided in a plate shape, and the upper part of the second cut steel pipe 115 is covered by the second cover part 123 provided in the plate shape. do.

The cutout space provided between the first cover part 121 and the body steel pipe 111 is covered by the first discharge part 131 , and the cutout provided between the second cover part 123 and the first cover part 121 . The space is covered by the second discharge part 133 , and the cut space provided at the ends of the second cut-off steel pipe 115 and the second cover part 123 is covered by the third discharge part 135 .

The highest layer (three layers) is provided by the first cut steel pipe 113 , the first cover part 121 , and the first discharge part 131 , and the second cut steel pipe 115 and the second cover part 123 . ) and a portion of the PSC girder that is provided at a height corresponding to the third discharge unit 135 and the third discharge unit 135, and the next highest layer (two layers) is formed by the second discharge unit 133. The lowest floor (1st floor) is provided by these.

The discharge unit 130 is provided to discharge the strands S from each layer of the steel pipe unit 110 . The discharge unit 130 is provided in a semicircular or rectangular shape to correspond to the shape of the end of each layer of the steel pipe unit 110 , and a through hole H is provided to allow each strand S to pass therethrough.

The first discharge part 131 and the third discharge part 135 are provided in a semicircular shape, and the second discharge part 133 is provided in a rectangular shape.

The guide frames G1 and G2 are provided as a pair in front of the discharge unit 130 in each layer to guide the strands S extending from the discharge unit 130 .

Guide frames (G1, G2) are provided in a grating shape to have a plurality of grids, a pair of pillars (P), a pair of pillars (P) in the transverse direction for connecting the transverse connection (L), And it includes a division (M) provided to be perpendicular between the pillar (P).

The pair of pillar parts P may be respectively coupled to the sides of the first cut steel pipe 113 and the second cut steel pipe 115, and are provided at preset positions of the PSC girder to set the guide frames G1 and G2. do. A lower lateral connection part L2 of the lateral connection parts L may be respectively connected to the first cover part 121 and the second cover part 123 .

The guide frames G1 and G2 include a first guide frame G1 provided adjacent to the discharge unit 130 and a second guide frame G2 provided to be spaced apart from the first guide frame G1 by a preset interval. .

2A and 2B, the first guide frame (G1) guides the strands (S) extending from the discharge part 130 to correspond to the height at the discharge part, and the second guide frame (G2) is the second guide frame (G2). 1 Guide the strands (S) disposed on the guide frame (G1) to be dispersed in the vertical or left and right directions.

For example, in FIG. 2B , the first strand s1 is guided in the same height and the same direction in the first and second guide frames G1 and G2, and the second strand s2 is the first guide frame G1. The second guide frame G2 is guided to be distributed in the upper left direction, and the third strand s3 is arranged to be dispersed in the left direction in the second guide frame G2 than in the first guide frame G1. .

The remaining strands s4, s5, s6, and s7 are also arranged to be distributed upwardly or to the right in the second guide frame G2 than in the first guide frame G1.

In each layer, the strands (S) are guided by the guide frames (G1, G2) to be dispersed in the vertical or left and right directions as shown in Figure 2a, and a strand fixing coupler (S) provided to fix the strands (S) at the ends of the strands 140) is settled by

The strand fixing coupler 140 includes a main body 141 provided in a circular shape, a strand fastening hole 143 provided inside the main body 141, a fixing socket 147 partially inserted into the main body 141, and the main body. It includes a resistance key 145 provided on the outer surface of the portion (141).

The fastening hole 143 is provided to enable rotational fastening along the strand cross-section pattern, the fixing socket 147 is a wedge socket that can fix the passed strand s with a wedge, and the strand S is a fastening hole ( 143) is first bitten, and the fixed socket 147 is secondarily bitten and fixed. Accordingly, by providing a resistance key 145 protruding in the opposite direction to the twist of the strand S through the strand fixing coupler 140 of the present invention on the outside of the main body 141, the strand S into which tension is introduced is fixed by the strand It is possible to increase the fixing strength by resisting the property of rotation like the coupler 140 .

4A to 4C are schematic views showing that the strand distribution device according to an embodiment of the present invention is provided on a PSC girder, and FIG. to be.

The PSC girder, for example, was applied as a wide type with a wide upper flange, but if the strand distribution device according to the embodiment of the present invention can be applied, the shape of the cross-section of the PSC girder is not limited to the wide type.

The strand (S) may be symmetrically provided on the lower flange of the PSC girder.

Section aa shows the anchoring part (J1) at the end of the PSC girder, section bb shows the end of the strand distribution device (SP), section cc shows the second floor end of the strand distribution device (SP), and section dd shows the strand The third floor end of the distribution device SP is shown. The e-e section shows the area where the strand distribution device (SP) is not applied as the central part of the PSC girder.

The stranded wire is provided symmetrically to the left and right of the PSC girder, but is provided in a straight line at the bottom of the PSC girder. Among the strands (S) provided symmetrically, one strand (SL) is fixed (J1) at one end of the PSC girder, and spaced apart from the other end by a preset distance to apply the strand distribution device (SP2), and the other strand (SR) is fixed (J2) at the other end of the PSC girder, spaced apart from one end by a preset distance, the strand distribution device (SP1) is applied. Here, one end refers to the left end of the PSC girder, and the other end refers to the right end of the PSC girder.

5, in the PSC girder according to the embodiment of the present invention, it is fixed by the fixing end (J1) at the left end, and dispersedly fixed by the strand distribution device (SP2) at a distance spaced apart by a preset interval from the right end It is possible to check the tension moment by the tendon including the strand (S). That is, the tension moment by the (1) tendon is provided in a rectangular shape as a whole, and becomes smaller in a step shape toward the end of the strand distribution device SP2.

In addition, in the PSC girder according to the embodiment of the present invention, the strand is fixed by the fixing end (J2) at the right end and dispersedly fixed by the strand distribution device (SP1) at a distance spaced apart from the left end by a preset interval (S) It is possible to confirm the tension moment due to the tendon including That is, the tension moment due to the ② no. tendon is provided in a rectangular shape as a whole, and becomes smaller in a step shape toward the end of the strand distribution device SP1.

When the tension moments by the ① and ② tendons are added, the tension moment is provided in a rectangular shape in the center, but becomes smaller in a stepwise shape toward the left and right ends. will be prepared

Accordingly, according to the present invention, strands can be arranged according to the required moment when designing the girder, and the quantity of strands can be reduced by 20 to 25% due to cross tension, and the cost of manufacturing the girder is reduced by reducing the number of anchorages.

In addition, according to the present invention, there is no need to arrange the tendons in the abdomen, the thickness of the abdomen can be reduced and the weight of the girder can be reduced.

The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

SP: strand distribution device
110: steel pipe part
120: cover part
130: discharge unit
140: strand anchoring coupler
G1: guide frame
G2: guide frame

Claims (10)

a steel pipe part whose height is lowered toward the end and the upper part is covered by a cover part after it is cut to provide a plurality of layers in a step shape;
a discharge unit provided to discharge the strands from each layer of the steel pipe unit; and
In each layer, a pair of guide frames are provided in front of the discharge unit to guide the strands extending from the discharge unit.
The guide frame is provided in a grating shape to have a plurality of grids, and includes a pair of pillars, a transverse connection connecting the pair of pillars in the transverse direction, and a division provided to be perpendicular between the pillars. ,
The guide frame includes a first guide frame provided adjacent to the discharge unit and a second guide frame provided to be spaced apart from the first guide frame by a preset interval,
The first guide frame guides the strands extending from the discharge unit to correspond to the height at the discharge unit, and the second guide frame guides the strands disposed on the first guide frame to be dispersed in vertical or horizontal directions. Stranded wire distribution device, characterized in that. According to claim 1,
The discharge part is provided in a semi-circular or rectangular shape to correspond to the shape of the end of each layer of the steel pipe part, and a through hole is provided so that each strand can pass through. delete delete delete According to claim 1,
The strand distribution device further comprising a strand fixing coupler provided to fix the strands at the ends of the strands. 7. The method of claim 6,
The stranded wire fixing coupler,
a body portion provided in a circular shape;
a strand fastening hole provided in the body part;
a fixing socket partly inserted into the body part; and
A strand distribution device comprising a; resistance key provided on the outer surface of the main body. A PSC girder to which a strand distribution device is applied, characterized in that the strand provided with the strand distribution device according to any one of claims 1, 2, and 6 to 7 is applied. 9. The method of claim 8,
The strand is a PSC girder to which a strand distribution device is applied, characterized in that it is provided symmetrically to the left and right of the girder and is provided in a straight line at the lower part of the girder. 10. The method of claim 9,
One strand of the strands provided symmetrically is fixed at one end of the girder and spaced apart from the other end by a preset distance to apply a strand distribution device, and the strand of the other side is fixed at the other end of the girder, but one end A PSC girder with a strand distribution device, characterized in that the strand distribution device is applied by being spaced apart by a preset distance from the PSC girder.

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