KR101520034B1 - Prestressed concrete triangle box girder - Google Patents

Abstract

The present invention is a prestressed concrete triangular box girder, which may have a superior sectional stability even when a separation wall is not installed or a minimum number of separation wall is installed, reduce its weight and a required amount of material thanks to a triangular section, and has an advantage to a long span by introducing a compressive force through steel wires. A prestessed concrete triangular box girder according to an embodiment of the present invention includes a girder, which includes a lower flange, a slanted web extended from the center of the lower flange to the upper side while having a V-shape, and an upper flange connecting both upper parts of the slanted web with each other and; an end part reinforcing rib included in the inner surface of the slanted web at a point part of the girder, wherein the lower flange, the slanted web, the upper flange, and the end part reinforcing rib are formed by concrete, and interior angels of a triangle formed by the slanted web and the upper flange are in a range from 55 to 65 degrees, respectively.

Description

Prestressed concrete triangle box girder}

The present invention relates to a box girder which is installed in a bridge, and in particular, even if a girder is not provided with a bulkhead or installed at a minimum, safety of the section is excellent and the sectional shape can be maintained. To a prestressed concrete triangular box girder which is made to be made between a long diameter and a long diameter.

The conventional PSC box girder or the steel composite PSC box girder has a box-like cross-sectional shape or a box-shaped form. Such cross-sectional structures are to be provided with diaphragms or vertical crossing bracing at regular intervals inside the girders to maintain the cross-sectional shape. This is to prevent the shape in which the girder is collapsed in correspondence with twisting, warping or the like in the cross-sectional shape of a box or a forming structure. In this case, since the cross-sectional shape of the PSC box-shaped girder is not an optimal cross-sectional shape, it is uneconomical due to a large amount of material, and the girder weight is increased.

Therefore, it is required to improve the technology of PSC box girder which increases stability and economical efficiency by increasing the torsion and bending resistance while optimizing the PSC box girder or steel composite PSC box girder, and reducing the material requirement.

BACKGROUND OF THE INVENTION [0002] U.S. Patent No. 4,912,794 discloses a girder having a triangular cross-section of a girdle, an abdomen formed of a steel sheet, a lower end of a steel sheet connected to a lower cord, and an upper end connected to a concrete upper cord The bridge is proposed.

As another background art of the present invention, US Pat. No. 4,993,094 proposes a long span bridge using a slanting line girder having a lower end connected to a lower boom and an upper end connected to an upper boom.

As another background art of the present invention, U.S. Patent No. 5,052,309 discloses a magnetic levitation transportation track having a structure in which a lower end of a steel strut constituting the abdomen is connected to a steel tube and an upper end thereof is connected to a rib side of the upper member. Carrier has been proposed.

However, the above background arts do not have a means to cope with the tensile resistance generated in the momentum section when applied to a bridge between the dogs, and it is difficult to resist the bending stress that becomes increasingly inward from the fulcrum portion, There is a problem that it is difficult to introduce a compressive force.

U.S. Patent No. 4,912,794 U.S. Patent No. 4,993,094 U.S. Patent No. 5,052,309

The present invention is characterized in that, even if a girder is not provided with a partition wall or a girder is installed at a minimum, safety of the cross section is excellent and the cross-sectional shape can be maintained. The present invention is directed to a prestressed concrete triangular box girder which is made to be slidable.

A prestressed concrete triangular box girder according to an exemplary embodiment of the present invention includes:

A girder including a lower flange, an oblique abdomen extending upward in a V-shape at the center of the lower flange, and an upper flange connecting upper portions of the oblique abdomen; And an end reinforcing rib provided at an inner side surface of the incline at a position of a fulcrum of the girder, wherein the lower flange, the oblique flank, the upper flange, and the end reinforcing rib are made of concrete, The inner angles of the triangles formed by the triangles may be in the range of 55 to 65 degrees, respectively.

The intersection of the inner side lines of the end reinforcing ribs is located at the center of the upper surface of the lower flange. The intersection point of the inner side lines of the inclined belly portion is located at the center of the lower surface of the lower flange, As shown in FIG.

Further, the upper flange in the moment section of the inner flank of the girder may further include a steel plate.

In addition, the upper flange in the moment section of the inner flank of the girder may further include a PS strand.

An internal reinforcing rib provided on the inner side surface of the inclined belly spaced inward from a fulcrum portion of the girder, an inner tension PS wire fixing portion provided at both ends of the lower flange and both ends of the oblique belly portion, An outer tension PS steel wire fixing portion provided at an upper outer side of an end reinforcing rib of an outer flank of the girder, a reinforcing rib saddle inside the PS steel wire provided at the lower portion of the inner reinforcing rib of the girder, A PS strand inner side fulcrum portion provided on the upper portion, an inner tensional PS stranded portion provided inside the inclined belly portion and the lower flange of each of the girders, and an outer tension PS strand disposed in the inner space portion of the girder, The tension PS strand is tensioned between both ends of each girder after each girder is manufactured, and the outer tension PS strand is connected to the girder by alternately or rigidly connecting the girder, It may be collectively tension between the two outer ends of the girder.

A girder including a lower flange, an oblique abdomen extending upward in a V-shape at the center of the lower flange, and an upper flange connecting the upper portions of the oblique abdomen; And an end reinforcing rib provided at an inner side surface of the incline at a fulcrum position of the girder, wherein the lower flange, the upper flange, and the end reinforcing rib are made of concrete, and the oblique belly is formed of a corrugated steel sheet or a steel truss Wherein the internal angles of the triangular shape formed by the oblique abdomen and the upper flange are in the range of 55 to 65 degrees, the intersection of the inner side lines of the end reinforcing ribs is located at the center of the upper surface of the lower flange, The intersection of the side lines may be located at the center of the lower surface of the lower flange, and may be located on the upper surface of the coplanar device installed below the girder.

The lower flange may further include a U-shaped steel plate surrounding the lower surface and the side surface of the lower flange.

According to the prestressed concrete triangular box girder of the present invention, since the sectional safety is excellent, it is possible to maintain the sectional shape even if the diaphragm is not installed in the girder or the girder is installed at the minimum. In addition, the girder shape is triangular and the material requirement is reduced, which is very economical. In addition, the weight of the girder is smaller than that of the existing PSC box type girder, making it very easy to manufacture and install. In addition, by introducing the compressive force with the PS steel wire, it is possible to reduce the diameter of the PSC box.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention, Shall not be construed as limiting.
1 is a perspective view of a prestressed concrete triangular box girder according to the present invention.
FIG. 2A is an enlarged view of a portion "X" in FIG.
2B is an enlarged view of the "Y" part of FIG.
3 is a perspective view of an outer span PSC triangular box girder included in FIG.
Figure 4 is a perspective view of the inner cross-sectional PSC triangular box girder included in Figure 1;
FIGS. 5A to 5E are cross-sectional views taken along the lines AA, BB, CC, DD, and EE of FIG. 1, respectively.
6 is a sectional view of a prestressed concrete triangular box girder according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto.

The triangular cross-section of the cross-sectional shape constitutes the most stable cross-sectional shape. When the bridge is closed at the girder, if it is not a triangle shape, when it receives a torsion or warpage, the cross-sectional shape is distorted. Therefore, vertical crossing bracing or concrete or steel diaphragm Should be. However, in the case where the cross-sectional shape of the girder according to the present invention is a triangle, the cross section of the girder is not distorted due to twisting, warping or the like without the diaphragm.

The present invention is characterized in that the shape of the girder is similar to a regular triangle or an equilateral triangle when constructing a closed cross-section with concrete or steel, thereby increasing the warping resistance capability and reducing the resistance of the concrete slope abdomen A concrete reinforcing rib is additionally formed on the side surface so that the inner side line of the upper portion of the concrete girder and the inner side line of the inclined belly portion including the concrete reinforcing ribs formed on the inclined belly portion are formed in a triangular shape.

At this time, the virtual vertex of the lower end of the inner side line of the triangle is located on the upper surface of the lower flange, and the lower surface of the lower flange corresponding to the lower vertex at the virtual vertex position of the lower flange is set as the point reaction force point. That is, the point reaction force point is the vertex of the lower side of the inner side line of the virtual triangle having no reinforcing ribs, which corresponds to the vertex of the lower side of the inner side line of the triangle composed only of the oblique abdomen, so that no warpage occurs in the reinforcing ribs of the concrete and the incline, The shape becomes a stable triangular shape.

Therefore, the girder according to the present invention can eliminate the need for a separate concrete partition wall (diaphragm) in the sloping portion of the concrete or minimize the thickness of the concrete partition wall. Further, according to the above-mentioned shape structure, the side line of the concrete sloped portion of the concrete of the triangular girder and the concrete upper cover meet with each other at the center section of the girder without the concrete reinforcing ribs. The lower flange lower portion of the triangle forming the triangle close to the equilateral triangle or the equilateral triangle The point at the vertex position becomes a point reaction force point at the inner and outer fulcrum positions, and the coordinate system is installed at that point.

The present invention relates to a concrete reinforcing rib disposed inside a triangular box girder and a reinforced concrete reinforcing rib provided inside a triangular box girder at a position where a concrete saddle or a concrete beam is disposed inside a PSC triangular box girder, (Diaphragm) function to maintain a triangular cross-sectional shape.

Therefore, the PSC triangular box girder according to the present invention is the most economical since it has the largest stiffness of the girder cross-section and is the most stable than any cross-sectional shape and can eliminate or minimize the concrete partition wall (diaphragm) inside the girder. In addition, the cross-sectional shape as described above can be equally applied to a steel composite PSC box-shaped girder using a corrugated steel plate or a steel truss.

<Examples>

As shown in FIGS. 1, 3 and 4, the PSC triangular box girder 10 (hereinafter referred to as "girder 10") is divided into three parts by a PSC triangular box girder 10a and an outer PSC triangular box girder 10b Construction.

The inter-sideways PSC triangular box girder 10a is installed between adjacent piers 2 and 2 and the outer pivot PSC triangular box girder 10b is installed between the alternation 1 and the pier 2. [

The girder 10 has a lower flange 101 as shown in Figs. 3 to 5E, oblique wraps 102 and 102 extending upward in a V-shape from the center of the lower flange 101 and upper portions of both oblique wraps 102 and 102 And an upper flange 103 connected to the upper flange 103.

At this time, the girder 10 includes end reinforcing ribs 104 provided on inner side surfaces of the oblique abdominal portions 102 and 102 at the fulcrums.

The lower flange 101, the oblique wraps 102 and 102, the upper flange 103 and the end reinforcing ribs 104 are made of concrete.

The internal angles P1 and P2 of the triangle formed by the oblique abdomen portions 102 and 102 and the upper flange 103 are determined in the range of 55 to 65 degrees, respectively. Therefore, as shown in the sectional views of FIGS. 5A to 5E, the girder 10 of the present invention has a triangular cross section in the longitudinal direction. Therefore, the girder 10 has a triangular cross-section with a large resistance against twisting, so that the cross-section of the girder 10 is not distorted due to twisting, warping or the like without the diaphragm.

At this time, the intersection point O1 of the inner side line 104a of the end reinforcing rib 104 is located at the center of the upper surface of the lower flange 101. The intersection O2 of the inner side line 104b of the oblique abdomen portions 102 and 102 is located at the center of the lower surface of the lower flange 101 and at the same time the upper surface of the coplanar device 5 installed at the lower portion of the girder 10 As shown in FIG.

Therefore, the point reaction force point of the calibration apparatus 5 corresponds to the vertex of the lower end of the inner side line 104b of the virtual triangle having no reinforcing ribs, which corresponds to the lower end vertex of the triangular inner side line 104b composed of only the oblique abdominal portions 102 and 102, No warpage occurs in the ribs and the warp belly 102 or 102, so that the cross-sectional shape of the girder 10 becomes a stable triangular shape.

The upper flange 103 in the moment section of the inner flank of the girder 10 may further include a steel plate 105 as shown in FIG. 5E. That is, the upper flange 103 in the moment of the moment may be formed by combining the steel plate 105 with concrete. As a result, the steel plate 105 is synthesized in the moment portion of the inner flank of the girder 10, thereby increasing the tensile resistance.

In addition, the upper flange 103 in the momentum section of the inner flank of the girder 10 may further include a PS steel wire W3. In this embodiment, the PS steel wire W3 passes through the upper flange 103 and passes through the fixing device at one end to the lower side of the upper flange 103 of the inner side interstices PSC triangular box girder 10a and at the other end to the outer side PSC triangle box girder And is fixed under the upper flange 103 of the flange 10b.

On the other hand, the inner reinforcing ribs 106 may be provided on the inner surfaces of the inclined wraps 102 and 102 to be spaced inward from the fulcrum of the girder 10. Also, an internal tension PS wire fixing unit 107 is provided at both ends of the lower flange 101 and at both lower ends of the oblique abdomen 102, 102. Also, an outer tension PS steel wire fusing unit 109 is provided on the outer side of the upper end of the end reinforcing rib 104 at the outer flank of the girder 10. [ The reinforcing rib saddle portion 110 inside the PS steel wire is provided at the lower portion of the inner reinforcing rib 106 of the girder 10 and the reinforcing rib saddle portion 110 of the inner side of the PS steel wire inside the upper end reinforcing rib 108 A fulcrum portion saddle portion 112 is provided.

An inner tension PS steel wire W1 is provided inside the warp belly 102 and a lower flange 101 of each girder 10 and an outer tension PS steel wire W2 is installed in the inner space of the girder 10 . A part of the inner tension PS wire W1 is installed in the lower flange 101 and the other part is installed in the lower flange 101 starting from the inclined wraps 102 and 102 and going to the center of each girder 10. [ At this time, the inner tension PS wire W1 is tensioned between both ends of each girder 10 after manufacture of each girder 10, and is fixed to the inner tension PS wire fixing portion 107. [ The outer tension PS wire W2 is also tensioned at both outer ends of the outer span girder 10b after the girder 10 is mounted on the alternating bridge 1 or the bridge bridge 2, As shown in Fig.

6, the inclined wraps 102 and 102 may be formed of a corrugated steel plate or a steel truss, and the lower flange 101 may further include a U-shaped steel plate 115 surrounding the lower and side surfaces thereof.

As described above, the girder 10 of the present invention has the shape of a cross section most optimized as a triangle and resists the bending stress of the single segment girder by the inner tension PS wire W1, and at the same time, The PSC triangular box girder 10a and the outer span PSC triangular box girder 10b are collectively connected together and the PS steel wire W3 installed on the upper flange 103 in the momentum section of the inner flank of the girder 10 ), The structural stability, the workability and the economical efficiency are increased, the long span can be achieved, and the cross-section can be said to have an excellent aesthetic appearance.

In addition, the upper portion of the concrete of the girder 10 can increase the tensile resistance by synthesizing the steel plate 105 in the section of the upper part of the inner flank in the continuous bridge.

Further, in the case of the steel composite PSC triangular box girder 10 constituted by the corrugated steel sheet or the steel truss, the upper part of the concrete may be replaced with the steel horizontal bracing to improve the workability.

In addition, the PSC triangular box girder 10 of the present invention can be divided into two segments, that is, a positive moment segment and a parent segment, and can be alternately assembled (1) and assembled when installed on the bridge pier (2). In this case, there is an advantage that the girder 10 can be made longer.

In addition, since the lower flange 101 is wrapped with the U-shaped steel plate 115, the strength of the concrete of the lower flange 101 is increased and the concrete of the lower flange 101 is exposed to the outside The durability of the lower flange 101 is increased, which can reduce the construction cost in the long span and low-height bridges. Since the U-shaped steel plate 115 serves also as a formwork of the lower flange 101, it is possible to easily construct the lower flange 101 without using a separate formwork in the manufacturing site, When the U-shaped steel plate 115 and the incline portions 102 and 102 are connected to each other by forming a connecting member at appropriate intervals, the girder 10 composed of only the steel material not poured concrete in the lower flange 101 is alternately (1) It is also possible to apply a construction method in which concrete is laid on a portion of the lower flange 101 after being mounted on the lower flange 101 to tense with a PS steel wire. In this case, since the weight of the girder 10 is small, it is very easy to mount and fix the girder 10 even when it is long. Therefore, after the concrete in the lower flange 101 is preliminarily laid, the girder 10 is first placed in the alternation 1 or the pier 2 and the lower flange 101 ) Part of concrete can be selectively applied according to site conditions.

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 in light of the above teachings. will be. The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

101: Lower flange
102: oblique abdomen
104, 108: End reinforcing rib
105: steel plate
106: Inner reinforcing rib
110: inner reinforcing rib saddle portion
112: PS wire inner side point saddle portion
W1: Internal tension PS liner
W2: External tension PS liner

Claims (7)

And an upper flange 103 connecting the upper portions of the oblique abdomen portions 102 and 102. The lower flange 101 includes a lower flange 101, a lower flange 101, A girder 10; And
And an end reinforcing rib (104) provided on an inner surface of the oblique abdomen (102, 102) at a fulcrum position of the girder (10)
The lower flange 101, the incline portions 102 and 102, the upper flange 103 and the end reinforcing ribs 104 are made of concrete,
The internal angles P1 and P2 of the triangle formed by the oblique wraps 102 and 102 and the upper flange 103 are in the range of 55 to 65 degrees,
An inner reinforcing rib 106 spaced inwardly from a fulcrum portion of the girder 10 and provided on the inner surface of the oblique abdominal portion 102 and 102 and a pair of inner reinforcing ribs 106 disposed on both ends of the lower flange 101 and both ends of the oblique abdominal portion 102, An outer tension PS steel wire fusing unit 107 provided at the upper portion of the upper end of the end reinforcing rib 104 at the outer flank of the girder 10, A PS steel wire inner reinforcing rib saddle 110 provided at the lower portion of the inner reinforcing rib 106 of the girder 10 and a PS steel wire inner saddle portion saddle 110 provided at an upper portion of the end reinforcing rib 108 of the inner fringe of the girder 10, An inner tensional PS steel wire W1 installed inside the lower flange 101 of the girder 10 and the outer tread installed in the inner space of the girder 10; PS wire W2,
The inner tension PS wire W1 is tensioned between both ends of each girder 10 after fabrication of each girder 10,
Wherein the outer tension PS steel wire W2 is tensioned collectively between both outer ends of the outer span girder after the girder 10 is mounted on alternating 1 or bridge 2. [ .
The method according to claim 1,
The intersection O1 of the inner side line 104a of the end reinforcing rib 104 is positioned at the center of the upper surface of the lower flange 101,
The intersection point O2 of the inner side line 104b of the oblique wads 102 and 102 is located at the center of the lower surface of the lower flange 101 and is located on the upper surface of the coordinate device 5 provided below the girder 10. [ Of the prestressed concrete triangular box girder.
The method according to claim 1,
Characterized in that the upper flange (103) in the momentum section of the inner flank of the girder (10) further comprises a steel plate (105).
The method according to claim 1,
Characterized in that the upper flange (103) in the momentum section of the inner flank of the girder (10) further comprises a PS steel wire (W3).
delete And an upper flange 103 connecting the upper portions of the oblique abdomen portions 102 and 102. The lower flange 101 includes a lower flange 101, a lower flange 101, A girder 10; And
And an end reinforcing rib (104) provided on an inner surface of the oblique abdomen (102, 102) at a fulcrum position of the girder (10)
The lower flange 101, the upper flange 103 and the end reinforcing ribs 104 are made of concrete,
The warp belly 102 or 102 is composed of a corrugated steel sheet or a steel truss,
The internal angles P1 and P2 of the triangle formed by the oblique wraps 102 and 102 and the upper flange 103 are in the range of 55 to 65 degrees,
The intersection O1 of the inner side line 104a of the end reinforcing rib 104 is positioned at the center of the upper surface of the lower flange 101,
The intersection point O2 of the inner side line 104b of the oblique wads 102 and 102 is located at the center of the lower surface of the lower flange 101 and is located on the upper surface of the coordinate device 5 provided below the girder 10. [ Lt; / RTI &gt;
An inner reinforcing rib 106 spaced inwardly from a fulcrum portion of the girder 10 and provided on the inner surface of the oblique abdominal portion 102 and 102 and a pair of inner reinforcing ribs 106 disposed on both ends of the lower flange 101 and both ends of the oblique abdominal portion 102, An outer tension PS steel wire fusing unit 107 provided at the upper portion of the upper end of the end reinforcing rib 104 at the outer flank of the girder 10, A PS steel wire inner reinforcing rib saddle 110 provided at the lower portion of the inner reinforcing rib 106 of the girder 10 and a PS steel wire inner saddle portion saddle 110 provided at an upper portion of the end reinforcing rib 108 of the inner fringe of the girder 10, An inner tensional PS steel wire W1 installed inside the lower flange 101 of the girder 10 and the outer tread installed in the inner space of the girder 10; PS wire W2,
The inner tension PS wire W1 is tensioned between both ends of each girder 10 after fabrication of each girder 10,
Wherein the outer tension PS steel wire W2 is tensioned collectively between both outer ends of the outer span girder after the girder 10 is mounted on alternating 1 or bridge 2. [ .
The method of claim 6,
Wherein the lower flange (101) further comprises a U-shaped steel plate (115) surrounding the lower surface and the side surface of the lower flange (101).

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