WO2007100226A1

WO2007100226A1 - Composite beam for girder

Info

Publication number: WO2007100226A1
Application number: PCT/KR2007/001051
Authority: WO
Inventors: Tae Young Sim; Jun Gi Sim
Original assignee: Tae Young Sim; Jun Gi Sim
Priority date: 2006-03-02
Filing date: 2007-03-02
Publication date: 2007-09-07

Abstract

There is provided a composite girder having a box-shaped steel member filled with concrete, including: an outer steel member having a blocked-out empty space in a lower portion of the composite girder by forming a hollow penetrating portion penetrating in a transverse direction between both ends; and inner-side concrete filling an inner space of the outer steel member excluding the hollow penetrating portion without using reinforcing rods. Accordingly, it is possible to effectively resist tensile stress in a DD of the girder and to efficiently cope with vibration and drooping. Since a space occupied by objects such as facility pipes disposed under the girder can be removed, an inter-floor height of a building can be optimally used, and thus, usability can be improved. In addition, the composite girder can be used as a bridge girder capable of optimizing the bridge height.

Description

Description COMPOSITE BEAM FOR GIRDER

Technical Field

[1] The present invention relates to a composite girder and, more particularly, to a composite girder formed by composing a steel member with concrete and used as a beam disposed between upper surfaces of indoor columns or a bridge girder. Background Art

[2] Conventionally, in a reinforced concrete (RC) beam 10 or a prestressed concrete

(PSC) beam 20 used as a building beam or a bridge girder shown in FIGS. 1 and 2, a large amount of concrete is used. Therefore, reinforcing rods 11 and 21 need to be provided, and a concrete form needs to be installed and dissembled.

[3] Accordingly, much personnel and time are required. Due to a weight thereof and environments, there is a problem of deterioration such as crack of the concrete and corrosion of the reinforcing rods. Therefore, maintenance is difficult, and life time is reduced. Particularly, since the weight thereof is large, construction thereof is very difficult.

[4] In addition, due to the piled load of the RC beam 10 and the PSC beam 20, tensile stress and compression stress are exerted to a cross section of the beam. However, the cross section of the girder in the vicinity of a neutral axis has no function of supporting the tensile stress and the compression stress. Accordingly, there is a problem of inefficiency of supporting of the piled load.

[5] In order to compensate for the shortcomings of the RC beam and the PSC beam, there has been developed a composite beam 30 where the RC girder formed in an inner portion shown in FIG. 3 is surrounded by a concrete-form/reinforcing member 30.

[6] However, since the composite beam 30 has a structure where the RC beam provided with reinforcing rods 32 is simply surrounded by the steel member (reinforced member), inner concrete cannot resist tensile stress. Therefore, unnecessary concrete for resisting tensile stress is used, so that a weight thereof is increased. Since the reinforcing rods need to be provided for the purpose of inner tensile reinforcement, the composite beam is not suitable for a long span girder for supporting a large upper load. In addition, in a case where a venting duct or a cable tube is installed in the composite beam, the RC beam, and the PSC beam in the building, the duct or the cable tube are suspended under the beam. Therefore, there is a limitation to a ceiling height between the base plates. Accordingly, there is a need to more efficiently ensure the ceiling height. Disclosure of Invention Technical Problem

[7] An object of the present invention is to provide a composite girder capable of removing unnecessary tasks for providing a concrete form and reinforcing rods for concrete in a building RC beam or PSC beam and not requiring maintenance of the concrete unlike a conventional one.

[8] Another object of the present invention is to provide a composite girder as a bridge girder capable of sufficiently ensuring a low ratio of span length to bridge height and ensuring an inter-floor height or a bridge height as high as possible. Technical Solution

[9] According to an aspect of the present invention, there is provided a composite girder 100 having a box-shaped steel member filled with concrete, comprising: an outer steel member 110 having a blocked-out empty space in a lower portion of the composite girder by forming a hollow penetrating portion 200 penetrating in a transverse direction between both ends; and inner-side concrete 130 filling an inner space of the outer steel member excluding the hollow penetrating portion 200.

[10] A plurality of the hollow penetrating portions 200 may be partitioned by belly- portion columns 150 disposed between the hollow penetrating portions.

[11] In an upper section of the composite girder 100, an upper flange 111, that is, a steel member, and inner-side concrete 130 are composed so as to support the compression stress caused from a load.

[12] The hollow penetrating portion 200 is provided to a lower portion of a belly portion

112, so that the concrete vulnerable to the tensile stress is removed. A facility duct or the like is formed to penetrate the hollow penetrating portion 200, so that it can be used in various applications.

[13] In a lower section of the composite girder 100, the lower flange 113, that is, a steel member is formed to sufficiently resist the tensile stress caused from the load. Particularly, the lower flange 113 is formed in various shapes such as an I- type, a tube, and a circular tube, so that it can more effectively resist the load.

[14] In addition, the composite girder 100 may be formed to have an I-shaped cross section or a rectangular cross section in terms of reduction of steel member and weight thereof.

Advantageous Effects

[15] According to the present invention, in the composite girder which is constructed with a steel member in the outer portion and an inner-side concrete filled in the inner portion, a compressed steel plate disposed over a neutral axis shares a compression force, and a tensile member disposed under the neutral axis shares a tensile force.

[16] Therefore, it is possible to implement a composite girder capable of maximally using advantages of elements such as the concrete, the steel member, and the tensile member. The load caused from the weight occurring at the time of producing the outer steel member can be cancelled step-by-step by using the tensile member disposed under the composite girder. Therefore, the composite girder can be used for a long span by the same cross section.

[17] In addition, in comparison with a steel box girder constructed with only the steel member, the inner portion thereof is filled with the concrete, noise, vibration, and welding amount can be reduced, and performance of resisting fatigue can be excellent. In addition, rigidity thereof is large, and a danger of local buckling can be lowered. In addition, other reinforcing members are not needed, and a danger of corrosion can be lowered.

[18] Since the inner-side concrete is surrounded by the outer steel member, the reinforcing rods needs not to be provided to the inner concrete, and maintenance related to the crack is unnecessary. Since a facility pipe including a duct and a cable tube are formed to penetrate the belly portion of the composite girder, an inter- floor space of a building can be maximally used. Therefore, it is possible to produce and construct a building composite girder, an engineering composite girder, particularly, a bridge composite girder with a high constructional performance and a high economical efficiency. Brief Description of the Drawings

[19] FIGS. 1 to 3 are cross-sectional views of a conventional beam and composite girder.

[20] FIGS. 4 to 7 are views showing assembled states of anouter steel member and examples of a composite girder according to an embodiment of the present invention.

[21] FIGS. 8 to 11 are views showing lower flanges of the composite girder as modified examples of FIG. 7.

[22] FIG. 12 is a view showing a composite girder according to another embodiment of the present invention.

[23] FIGS. 13 to 16 are views showing lower flanges of the composite girder as modified examples of FIG. 12.

[24] FIGS. 17 and 18 are views showing installed states of the composite girder of FIG.

5 in a column or a bridge lower structural object according to the present invention.

[25] <Reference Numerals>

[26] 100: composite girder

[27] 110: outer steel plate

[28] 111: upper flange

[29] 112: belly portion [30] 113: lower flange

[31] 120: hollow penetrating portion plate

[32] 130: inner-side concrete

[33] 140: compressed steel plate

[34] 150: belly -portion column

[35] 200: hollow penetrating portion

[36] 300: inner-side reinforcing member

[37] 400: cable tube

[38] 500: duct

[39] 600: column/bridge lower structural object

Mode for the Invention

[40] Now, a composite girder 100 according to embodiments of the present invention is described in detail with reference to the accompanying drawings.

[41] FIG. 4 shows an assembled state of an outer steel member 110 constituting a composite girder 100 according to the present invention. FIGS. 5 to 7 show completed states of the composite girder and upper surface thereof.

[42] FIGS. 8 to 11 show examples of the composite girders 100 having lower flanges

113 in different shapes.

[43] FIG. 12 shows a composite girder according to another embodiment of the present invention.

[44] FIGS. 13 to 16 show examples of the composite girder 100 of FIG. 12 having lower flanges 113 in different shapes.

[45] FIGS. 17 and 18 show embodiments of a composite girder.

[46] As shown in FIG. 4, the outer steel member 110 according to the present invention includes: a lower flange 113; a belly portion 120 which protrudes upwardly from an upper surface of the lower flange 113 to face each other so as to form a belly-portion inner space, wherein hollow penetrating portion plates 121, 122, and 123 are disposed in a lower portion of the belly -portion inner space to form a hollow penetrating portion 200; and the upper flange 111.

[47] Basically, the outer steel reinforcing member 110 serves as a concrete form. The outer steel member is filled with concrete 130, so that a structural member without requiring separate reinforcing rods can be designed. The outer steel member 110 is different from that of FIG. 3 where separate reinforcing rods are provided. Since the outer steel member can be manufacturing integrally in a factory, quality control can be easily performed.

[48] In addition, the concrete 130 can be confined by the outer steel reinforcing member

110. Therefore, an efficient strength of the composite girder 100 can be obtained. [49] In the lower flanges 113 according to the embodiments shown in FIGS. 4 and 12, a steel plate having a predetermined width is extended in the longitudinal direction. The width and length thereof can be modified. Preferably, the width of the lower flange is substantially equal to that of the upper flange.

[50] The lower flange 113 has a function of stably supporting the composite girder 100 according to the present invention on a ground or a top of the column and afunction of effectively resisting a tensile stress caused from a load. The lower flange may be constructed in various shapes shown in FIGS. 8 to 11 and FIGS. 13 to 16.

[51] As described above, the lower flange 113 has a structure for resisting the tensile stress caused from the load. As described later, the lower flange constructed with the steel plate has a hollow penetrating portion where the concrete is not provided. Therefore, the belly portion having the hollow penetrating portion can resist the tensile stress, so that a crack of the concrete caused from the tensile stress can be prevented.

[52] The belly portion 112 is formed to protrude vertically from an upper surface of the lower flange 113, so that the belly-portion inner space is formed. The belly portion is constructed with two steel plates facing each other.

[53] In the embodiments shown in FIGS. 4 and 12, the belly portion 112 hasthe hollow penetrating portion 200 which is constructed by cutting two side plates 121 and 122 in a predetermined shape, welding cut sides of the two side plates 121 and 122, and welding the upper plate 123 to upper portions of the side plates 121 and 122.

[54] The two side plates 121 and 122 and the upper plate 123 constituting the hollow penetrating portion 200 are collectively referred to as hollow penetrating portion plates 120.

[55] The hollow penetrating portion 200 serves as a transverse channel though which a cable tube 500 and/or a venting duct 400 shown in FIGS. 17 and 18 penetrate.

[56] Conventionally, the cable tube 500 and/or the venting duct 400 are suspended under a girder or a beam by using wires. Therefore, there is a problem in that a volume thereof reduces a ceiling distance, so that an inter- floor space cannot be efficiently used. However, according to the present invention, the cable tube and/or the venting duct are inserted into the hollow penetrating portion 200 of the belly portion of the composite girder, so that the inter-floor height can be increased and the inner- floor space can be efficiently used.

[57] In a case where the duct or the like is not inserted into the hollow penetrating portion 200, an inner space thereof may be filled with an inner-side reinforcing member 300 including a bracing member or a spacer as shown in FIGS. 17 and 18.

[58] Although the hollow penetrating portion 400 may be formed as one space in various shapes, a plurality of the hollow penetrating portions may be formed to be separated from each other. In this case, portions between the hollow penetrating portions 400 become belly -portion columns 150. As result, the plurality of the hollow penetrating portions can be partitioned by the belly-portion columns.

[59] The number, interval, volume, and shape of the hollow penetrating portions 200 may be optimized according to use of the composite girder and production and construction costs thereof.

[60] The belly-portion inner space formed by the belly portion 112 is filled with inner- side concrete 130.

[61] At this time, although the belly -portion inner spaceprovided with belly-portion columns 150 may be filled with inner-side concrete 300, the hollow portion may be formed instead of the inner-side concrete.

[62] In this case, an upper plate 124 may be formed on the upper surface of the belly- portion column 150.

[63] In a case where the upper plate 124is provided, a non-concrete material such as urethane and epoxy resin may be used as a material for filling the belly-portion inner space. As shown in FIGS. 4, 12, 17, and 18, an inner reinforcing member 300 may be provided.

[64] In this manner, the inner space of the belly portion 112 is filled with the concrete

130, and the hollow penetrating portions 200 are formed in a lower portion thereof, so that a blocked-out space is formed as it is. Therefore, the concrete vulnerable to the tensile stress can be removed, and a transverse channel through which the cable tube, the duct, or the like penetrate can be formed.

[65] The upper flange 113 is formed by bending the upper portion of the belly portion

112 outwardly. Next, an upper central opening Sl is formed by bending the two ends thereof inwardly as shown in FIG. 5. As a result, a portion of the upper surface of the outer steel member 110 may be exposed.

[66] The upper central opening Sl can be used as a space where the inner-side concrete

130 is provided and a space where a compressed steel plate 140 is buried in the upper portion of the inner-side concrete 300.

[67] The compressed steel plate 140 can resist the compression stress caused from an external force exerted on the upper portion of the composite girder, so that a member having more efficient cross-sectional force can be produced.

[68] Although the compressed steel plate 140 may be formed to extend in the longitudinal direction in a shape of an integrated plate 141, the compressed steel plate may be formed in a partitioned shape in terms of easiness of conveying and installation.

[69] In addition to a basic function of the outer steel member 110 which is used as a concrete form for the inner-side concrete 130, the outer steel member 110 in composition with the inner-side concrete 130 has a function of resisting an external load.

[70] Due to these functions, vibration and drooping of the composite girder can be reduced, and fatigue resistance thereof can be increased. Therefore, the outer steel member according to the prevent invention can be referred as an outer concrete form and an outer reinforcing member.

[71] A plurality of studs (not shown) are formed on the inner surface of the outer steel member 110 by using a welding method, so that a performance of composition of the outer steel member to the inner-side concrete can be increased.

[72] In addition, for the composition ofthe outer steel member with a base plate concrete, a plurality of studs are also formed on the upper surface of the upper flange 111 of the outer steel member 110.

[73] FIG. 6 shows an example of the outer steel member 100 according to the present invention, where the upper surface of the outer steel member is entirely opened.

[74] Namely, the upper flange 111 is bent, but the upper central opening Sl are not formed, so that the upper surface of the outer steel member 110 can be maintained in a completely opened state.

[75] FIG. 7 shows an example of the outer steel member 100 according to the present invention, where the upper surface of the outer steel member is closed.

[76] Namely, the lower flange 113, the belly portion 112, and the upper flange 111 are formed to constitute a closed box. Accordingly, the upper surface of the outer steel reinforcing member is closed. In this case, a penetrating hole used for providing the inner- side concrete is formed.

[77] As shown in FIGS. 8 to 11, the lower flanges 113 of FIG. 6 may be formed in other shapes instead of a plate shape.

[78] In FIG. 8, the lower flange 13 is formed in a shape of I-type or H-type beam. A height of the beam may be adjusted to a predetermined height according to the design of the composite girder. Due to these shapes, it is possible to more effectively cope with the tensile stress in the DD of the composite girder

[79] In FIGS. 9 and 10, the lower flange 113 is formed in a shape of a quadrangular tube. FIG. 9 shows a square tube, and FIG. 10 shows a thin rectangular tube. Due to the tube-shaped lower flange 113, it is possible to more effectively cope with the tensile stress in the underpart of the composite girder andto further increase distortion resistance.

[80] In FIG. 11, the lower flange 113 is formed in a shape of a circular tube. The technical effects thereof are basically the same as those of the quadrangular- tube-shaped lower flange.

[81] As shown in FIG. 12, in theupper flange 111 of the composite girder 100, the upper surface of the outer steel member 110 is closed to form the penetrating hole by bending both end portions inwardly instead of bending the upper end portion of the belly portion 112 outwardly. As a result, the composite girder 100 is formed to have a rectangular cross section.

[82] Although not shown in FIGS. 5 and 6, the upper surface of the composite girder may be partially opened to form the upper central opening Sl. Alternatively, the upper surface thereof may be entirely opened.

[83] FIGS. 13 to 16 show various shapes of the lower flange 113 used for the composite girder 100 having such a rectangular cross section.

[84] In FIG. 13, the lower flange 113 is formed to be an I-type beam or an H-type beam.

[85] In FIGS. 14 and 15, the lower flange 113 is formed in a shape of a quadrangular tube. FIG. 14 shows the lower flange formed in a square tube. FIG. 15 shows the lower flange formed in a thin rectangular tube. In FIG. 16, the lower flange 113 is formed in a shape of a circular tube.

[86] In the composite girder 100, the upper flange having a shape of a hunch may be removed, and only the belly portion may be provided. In this case, the steel member corresponding to the upper flange having a shape of a hunch and an amount of concrete corroding to the upper flange can be reduced. A weight of portions of the composite girder which are unnecessary according to some designs can be removed. Accordingly, an amount of the expensive steel plate can be reduced.

[87] Although the composite girder having an I-type cross section is described, the present invention is not limited thereto, but a circular cross section or others may be used

[88] FIGS. 17 and 18 show installed states of the composite girder of FIGS. 7 and 12 which is mounted on the upper surface of a column or a pier/abutment 600 which is a structural element of a bridge.

[89] A cable tube 400 or a duct 500 is formed to penetrate through the hollow penetrating portion 200 which is formed in the belly portion 112 of the composite girder 100. In this case, any obstacle is not provided under the composite girder. The hollow penetrating portion 200 may be empty. Otherwise, an inner-side reinforcing member 300 such as a bracing member may be inserted into the hollow penetrating portion.

[90] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims. Industrial Applicability

[91] According to the present invention, by compensating for shortcomings of a con- ventional girder and improving advantages thereof, so that it is possible to implement a long span at a low bridge height. Since initial construction cost and maintenance cost can be reduced, it is possible to implement an economical girder in terms of a life- cycle cost. In addition to advantages of materials and mechanical structure, a girder having a good appearance can be obtained.

Claims

[1] A composite girder having a box-shaped steel member filled with concrete, comprising: an outer steel member having a blocked-out empty space in a lower portion of the composite girder by forming a hollow penetrating portion penetrating in a transverse direction between both ends; and inner-side concrete filling an inner space of the outer steel member excluding the hollow penetrating portion without using reinforcing rods.

[2] The composite girder according to Claim 1, wherein a plurality of the hollow penetrating portions are partitioned by belly-portion columns disposed between the hollow penetrating portions.

[3] The composite girder according to Claim 2, wherein the outer steel reinforcing member is formed to be a box having an I- type cross section or a rectangular cross section, wherein the composite girder comprises: a lower flange; a belly portion having a belly-portion inner spacewhich is formed to protrude upwardly from an upper surface of the lower flange to face each other and hollow penetrating portion plates which is formed in a lower portion of the belly- portion inner space so as to form a hollow penetrating portion; and an upper flange which is formed in a bent shape to extend from a belly-portion plate member in a longitudinal direction of an upper inner space.

[4] The composite girder according to Claim 3, wherein the upper surface of the upper flange is one of an opened upper surface, a partially opened upper surface which is formed by inwardly bending an upper end portion of the belly portion so as to form an upper central opening, and a cross-section-closed upper surface where a concrete filling hole is formed.

[5] The composite girder according to Claim 3 or 4, wherein the lower flange is formed with at least one of an I-type beam, a quadrangular tube, and a circular tube.

[6] The composite girder according to any one of Claims 1 to 4, wherein a compressed steel plate is further buried in the upper flange in the longitudinal direction.

[7] The composite girder according to any one of Claims 1 to 4, wherein a transverse penetrating member including indoor pipes is further provided to the hollow penetrating portion.

[8] The composite girder according to any one of Claims 1 to 4, wherein inner portions of the belly -portion columns disposed between the penetrating portions is filled with belly-portion column filling material including empty spaces or inner-side concrete, and wherein an upper plate is further formed on an upper end of the belly-portion column to close the belly-portion column so as to form the empty space. [9] The composite girder according to Claim 8, wherein an inner-side reinforcing member including a bracing member or a spacer is further provided to an inner portion of the hollow penetrating portion or the belly-portion column where the transverse penetrating member is not provided.