KR20170029714A - Method of manufacturing bridge girder and tensioning apparatus used therein - Google Patents

Method of manufacturing bridge girder and tensioning apparatus used therein Download PDF

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KR20170029714A
KR20170029714A KR1020150126514A KR20150126514A KR20170029714A KR 20170029714 A KR20170029714 A KR 20170029714A KR 1020150126514 A KR1020150126514 A KR 1020150126514A KR 20150126514 A KR20150126514 A KR 20150126514A KR 20170029714 A KR20170029714 A KR 20170029714A
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girder
force
tensional
tension
lateral displacement
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KR1020150126514A
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Korean (ko)
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KR101765654B1 (en
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박영하
박기원
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주식회사 대련건설
박기원
박영하
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    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
    • E01D2/00—Bridges characterised by the cross-section of their bearing spanning structure
    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
    • E01D21/00—Methods or apparatus specially adapted for erecting or assembling bridges
    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
    • E01D2101/00—Material constitution of bridges
    • E01D2101/20—Concrete, stone or stone-like material
    • E01D2101/24—Concrete
    • E01D2101/26—Concrete reinforced
    • E01D2101/28—Concrete reinforced prestressed
    • E01D2101/285—Composite prestressed concrete-metal

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Bridges Or Land Bridges (AREA)

Abstract

The present invention relates to a method to manufacture a bridge girder and a device to apply tensile force to the girder. The method includes: a tendon installation step of installing at least two tendons including a first tendon inserted into a sheath tube around a transverse neutral axis from the center of a span of a girder, and a second tendon inserted into the other sheath tube around the transverse neutral axis from the center of the span of the girder; and a tensile force applying step of performing settlement after applying first tensile force to the fist tendon and applying second tensile force to the second tendon at the same time. As the first tensile force and the second tensile force are applied at the same time to the first and second tendons placed at a distance from each other around the transverse neutral axis from the center of the span of the girder, the present invention is capable of accurately applying fixed tensile force while suppressing the transverse displacement of the girder.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing a bridge girder,

The present invention relates to a method of making a girder for a bridge and a tensional force introducing apparatus for the girder used therefor, and more particularly, to a method for preventing a lateral displacement of a girder in a process of introducing a prestress using a tie- The present invention relates to a method of manufacturing a girder for a bridge and a tensional force introduction device for the girder used in the method.

Generally, the bridge supports the load acting on the upper plate by the girder mounted on the lower structure, so that the bridge girder is made to have a larger supporting ability. The bridge girder is composed of a reinforced concrete structure. However, a tension material is embedded in the bridge so as to support the bridge over a longer span, or a composite of a high-strength steel girder and a casing concrete is constituted.

For example, as shown in Fig. 1, a girder 1 for a bridge has a structure in which a tension member 20 is embedded in a parabolic shape in a concrete structure 10 in which reinforcing bars and concrete are combined, A tensile force P for pulling the tensile member 20 is applied so that the force Fz that upwardly lifts the concrete structure 10 at the lower edge of the neutral shaft at the center of the span is introduced. As a result, the girder 1 for a bridge is manufactured in a state in which a compressive stress for canceling the tensile stress of the lower shaft of the neutral shaft acting on the joint is introduced, so that the girder 1 has a higher supporting ability.

At this time, in order to arrange the tension member 20 in the inside of the girder 1 in a parabolic shape, the tension member 21, 22, 23, 24, 20 is attached to the end portion of the girder 1, 88 and the tension members 21, 22, 23, and 24 are distributed and disposed on one side and the other side, respectively, with respect to the neutral axis 88 in the transverse direction at the center of the span of the girder 1. That is, it is possible to arrange the tension members 21, 22, 23, 24 along the transverse neutral axis 88 at both ends as shown in FIG. 2A, but at the middle of the span, (88).

Accordingly, when the first tensile force P1 pulling the first tensile member 21 indicated by reference numeral 21 as shown in FIG. 3A is introduced into the first tensile member 21 as much as the design value, the first tensile force P1 21 is eccentrically disposed at one side with respect to the transverse neutral axis 88 at the center of the span of the girder so that the force F1 in the transverse direction acts on the other side of the transverse neutral axis 88 to generate the first tensile force P1 The transverse displacement d1 to the other side is generated at the span center portion compared to the state 10p before the introduction of the shear force. In the drawing, the unexplained reference numeral 10x indicates the state of the side of the girder in the state in which the first tensional force P1 is introduced.

Then, as shown in FIG. 3B, when the second tension force P2 pulling the second tension member 22 indicated by 22 is introduced into the second tension member 22 corresponding to the design value, the second tension member 22 The force F2 in the transverse direction acts on one side of the transverse neutral shaft 88 so that the second tension force acts on the center of the span of the girder, The transverse displacement dy to one side is generated at the span center portion compared to the state 10x before introduction of the pivotal members P2 and P2. In the figure, the reference numeral 10y denotes a deflection displacement state of the side surface of the girder 1 in a state in which the first tensional force P1 is introduced and the second tensional force P2 is introduced.

However, as the first tensile force P1 is introduced, the length of the concrete girder 1 is shrunk by L1 and the second tensile force P2 is introduced, so that the length of the concrete girder 1 is again shrunk by L2 A part of the first tensional force P1 introduced into the first tensional material P1 is lost as much as the shrinkage length L2 of the concrete girder 1 while the second tensional force P2 is introduced.

The first tension member 21 and the second tension member 22 are spaced apart from each other by the same length with respect to the transverse neutral axis 88 at the center of the girder span and the first tension force P1 and the second tension force P2, The tensile forces P1 and P2 introduced into the first torsion material 21 and the second tensile material 22 are different from each other so that the lateral displacement of the length indicated by y in Fig. Causing permanent problems.

This phenomenon occurs in the same way when the third and fourth tensions 23 and 24 are introduced into the third and fourth tensions.

On the other hand, the shrinking lengths L1 and L2 of the girder 1 and the tensile strength P2 of the second torsion bar 22 are determined by the tension forces P1 and P2 introduced into the first torsion coil 21 and the second torsion coil 22, The second tension member 22 is smaller than the first tension force P1 introduced into the first tension member 21 in consideration of the fact that the center axis moves toward the first tension member 21 when introducing the first tension member 21 The concrete elastic modulus E of the concrete structure 10 is not always constant but also depends on the mixing ratio with the sand, gravel and the like forming the concrete structure 10, the curing time, etc. Even when the second tensional force P2 is introduced, The lateral displacement (y) at the center of the span of the girder 1 can not be avoided because there is a large variation in the elastic modulus Eo of the designed value from 0.7 times to 1.4 times.

When the transverse displacement y is generated in the bridge girder 1 as described above, the stability of the bridge girder 1 at the time of conveyance, lifting and mounting is lowered and the workability of the bottom plate is poor There arises a problem that the supporting ability of the girder is lowered due to the lateral deviation (gradient) of the longitudinal stress in the girder. Therefore, in the course of introducing the tension forces P1, P2, ... into the tension members 20 during the manufacture of the bridge girder 1, There is a great need to prevent the displacement (y) from being generated.

In order to solve the above-mentioned problems, the present invention provides a method of manufacturing a bridge girder for preventing lateral displacement of a girder in a process of introducing a prestress by using a tension member installed in the girder for a bridge, And an object of the present invention is to provide a tension force introduction device for a girder.

That is, even if the tension members are spaced apart from the transverse neutral axis at the middle of the span of the bridge girder, the distribution of the tension force introduced by the tension member is uniformly adjusted so that the lateral displacement is not generated in the finished bridge girder The problem of lowering the stability during transportation, lifting and mounting of the bridge girder is solved, the workability of the bottom plate is improved, the lateral deviation of the longitudinal stress in the girder is reduced, .

In order to achieve the above-mentioned object, the present invention is characterized in that, in order to achieve the above-mentioned object, the present invention is characterized in that a first tensional element inserted in a sheath tube at one side with respect to a transverse neutral axis at the center of a span of the girder, A tension member mounting step of installing two or more tension members including a second tension member inserted into the sheath pipe at the other side; Introducing a first tensional force into the first tensional element and introducing a second tensional force into the second tensional element at the same time and then fixing the same; The present invention also provides a method of manufacturing a girder.

That is, by introducing the first tensile force and the second tensile force simultaneously to the first torsion material and the second torsion material spaced apart from each other with respect to the transverse neutral axis at the center of the span of the girder, the first tensile force is introduced into the first tensile material, It is possible to control the tension applied to the first tension member and the second tension member located on the opposite sides of the transverse neutral axis due to no tension loss caused by the amount of shrinkage in the longitudinal direction of the girder generated when the second tension force is introduced to the tension member. It is possible to accurately introduce the predetermined tension force while suppressing the occurrence of the lateral displacement of the girder.

For example, in a state where the first torsion material and the second torsion material are spaced apart by the same distance from the transverse neutral axis of the girder, the first torsion force introduced into the first torsion material and the second torsion force introduced into the second torsion material are made equal The first tension applied to the first tension member and the second tension force applied to the second tension member are set so that the transverse displacement does not occur regardless of the difference between the elastic modulus E of the concrete and the design elastic modulus Eo The tension force can be accurately introduced.

However, since the cross section of the girder for a bridge may not be formed symmetrically with respect to the transverse neutral axis along the longitudinal direction, the deviation of the magnitude of the first tension and the second tension may be within an appropriate deviation (for example, 20% Or less), it is possible to introduce a predetermined tension force into the tensile material while suppressing the displacement in the lateral direction.

In addition, even when the first torsion material and the second torsion material are spaced apart from each other by a distance different from the transverse neutral axis of the girder, the momentum in the transverse direction due to the tension introduced into the first torsion material by the first torsion force The size of the first tensional force and the second tensional force is determined so that the area and the area of the lateral moment diagram due to the tension introduced into the second tensional element by the second tensional force become equal. This makes it possible to prevent lateral displacement from occurring in the state where the fabrication of the girder is completed. Thus, regardless of whether the elastic modulus of the concrete is different from the design elastic modulus (Eo), the transverse forces acting on the girder due to the tensional forces introduced into the first and second tensions cancel each other, Can be prevented.

The construction of the present invention can be applied not only to a PSC girder having a reinforced concrete structure but also to a composite girder in which a casing concrete is combined with a steel girder. That is, the present invention can be applied to a tensioner installed in a girder and to introduce a tension force in a post-tensioning manner to a girder provided with a tension member spaced from a transverse neutral axis of the girder in the middle of the span.

On the other hand, the first tensional element may introduce the first tensional force at one end of the girder, and the second tensional element may introduce the second tensional force at the other end of the girder. That is, the first tensional material is introduced from the one end of the girder by the movable fastening means and pulled by the hydraulic jack or the like, and acts as a fixed fastening means at the other end of the girder. The second tensional material is introduced from the other end of the girder by the movable fastening means into the second tensional force pulled by the hydraulic jack or the like, and serves as a fixed fastening means at one end of the girder.

Thus, by introducing the first tensioning force and the second tensioning force simultaneously to the first tensioning material and the second tensioning material at the ends of the different girders, the hydraulic jack for introducing the first tensioning force and the hydraulic jack for introducing the second tensioning force The tension force can be introduced smoothly without interference.

On the other hand, the tension introduced into the first torsion member by the first torsion force introduced from one end of the girder and the tension introduced into the second torsion member by the second torsion force introduced from the other end of the girder cause friction The deviation caused by the friction of the tensile force introduced into the tensile member due to the first tensile force and the second tensile force is smaller than the deviation of the center of the span of the girder The tension deviations due to friction along the longitudinal direction cancel each other out. Accordingly, the first tension members and the tension introduced into the first and second tension members along the longitudinal direction of the girder can be advantageously introduced symmetrically with respect to the girder portion.

On the other hand, the tensile force introduced into the tensile material is introduced symmetrically along the longitudinal direction with respect to the center of the span, but there may also be a case where it is desired to introduce a tensile force into the tensile material. In this case, when the length of the girder is short (for example, 15 m or less), the elongation length of the tension member is short due to the re-tension force introduced after the tension member is fixed, Therefore, it is not easy to obtain a re-tension effect.

However, when the length of the girder is sufficiently long (for example, 20 m or more), it is easy to change the wedge fixing position of the fixing port because the length stretched to the first torsion material and the second torsion material by the re- The re-tension effect can be easily obtained. That is, when the length of the girder is sufficiently long, it can be utilized for the purpose of re-tensioning.

On the other hand, in the bridge girder, in addition to the first tensional element and the second tensional element described above, a third tensional element inserted in the sheath tube at one side relative to the transverse neutral axis of the girder and a third tensional element inserted in the sheath tube at the other side with respect to the transverse neutral axis And may further include an inserted fourth tensional element. In this case as well, it is possible to suppress the occurrence of lateral displacement of the girder by simultaneously introducing the third tensional force to the third tensional element and introducing the fourth tensional force to the fourth tensional element and then fixing them.

Above all, in the present invention, the step of introducing the tensional force includes a step of measuring a lateral displacement of the girder; A tensional force adjusting step of adjusting a first tensional force introduced into the first tensional material and a second tensional force introduced into the second tensional material based on the lateral displacement of the girder obtained in the lateral displacement measuring step; And a taut material fixing step of fixing the first tensional material and the second taut material when the transverse displacement is within an allowable range.

In this way, the tensional force is introduced simultaneously to the first torsion material and the second torsion material embedded in the concrete of the bridge girder. In this process, the lateral displacement is detected in real time, and the first torsion force and the second torsion force 2 By controlling the tension, it is possible to suppress the occurrence of lateral displacement while introducing the designed first and second tensions into the first and second tensions.

On the other hand, according to the present invention, there are provided two tension members including a first tension member inserted into a sheath pipe at one side relative to a transverse neutral axis of the girder, and a second tension member inserted and disposed at the other side sheath pipe with respect to the lateral neutral axis A first tensioning means for introducing a first tensioning force to the first tensioning member; Second tensioning means for introducing a second tensioning force to said second tensions; A lateral displacement measuring means for measuring a lateral displacement of the girder while introducing a first tensional force into the first tensional element and introducing a second tensional force into the second tensional element; The first tensioning force introduced by the first tensioning means and the second tensioning force introduced by the second tensioning means so that the lateral displacement value of the girder obtained by the lateral displacement measuring means is within the permissible range A control unit; The tension force introduction device of the present invention is characterized in that the tension force introduction device of the girder is provided.

At this time, the lateral displacement measuring means is provided at the center of the span of the girder in which the lateral displacement is most generated, and accurately detects the small lateral displacement.

In this case, the transverse displacement measuring means may be formed of a non-contact sensor that receives light after receiving light, and may be a contactless sensor that is held in contact with the abdomen of the girder, It may be an expression displacement gauge. Whether the transverse displacement measurement means is formed by contact or non-contact, the transverse displacement value measured by the transverse displacement measurement means can be automatically transmitted to the control unit.

The first tension means and the second tension means are formed as a hydraulic jack whose hydraulic pressure is controlled remotely so that the magnitude of the hydraulic pressure is automatically adjusted on the basis of the lateral displacement value received in real time by the lateral displacement measuring means , The lateral displacement is not always generated during the introduction of the tension to the tension of the girder.

The term "transverse neutral axis" in this specification and claims refers to a neutral axis in the lateral direction perpendicular to the gravity (relative to the center axis of the girder if the material distribution of the girder is uniform) define. That is, in the present specification and claims, 'transverse direction' refers to a lateral direction perpendicular to gravity, and in this specification and claims, 'longitudinal direction' refers to the longitudinal direction of the girder.

As described above, according to the present invention, a first tensile force and a second tensile force are simultaneously applied to a first tensile material and a second tensile material spaced apart from each other with respect to a transverse neutral axis at the center of the span of the girder, There is no loss of tension due to the amount of shrinkage in the longitudinal direction of the girder, which is generated when the second tensional force is introduced into the second tensional element in the state where the second tensional element is introduced. Therefore, the first tensional element located on the opposite side to the transverse neutral axis and the second tensional element It is possible to obtain an advantageous effect of suppressing lateral displacement of the girder in the process of introducing a tension force to the tension member of the girder and fixing the tension member to the tension member in real time.

In addition, in the present invention, even if the elastic modulus E of the concrete is different from the modulus of elasticity Eo of the design, the first and second tensions disposed on the opposite sides with respect to the lateral neutral axis are introduced with a tensile force The effect of suppressing the occurrence of lateral displacement of the girder can be obtained.

In addition, the present invention is characterized in that, when a tensile force is simultaneously introduced into two or more tensile members disposed on opposite sides with respect to a transverse neutral axis, and when a tensile force is introduced at one end by friction between the tensile member and the sheath tube, It is possible to automatically resolve the loss due to the friction between the sheath tube and the tension member, by automatically canceling the deviation of the tension generated along the longitudinal direction of the sheath tube.

The present invention relates to a method of measuring a lateral displacement of a girder in a process of introducing a tension force and measuring a lateral displacement of the girder in real time based on the measured first lateral force and the first tension applied to the first prism located on the opposite side to the lateral neutral axis , The second tensional force introduced into the second tensional material is automatically adjusted so that the occurrence of the lateral displacement of the girder can be always maintained within a certain range regardless of the skill of the operator.

Accordingly, by adjusting the transverse displacement of the manufactured concrete girder or synthetic girder to substantially 0, it is possible to improve the stability in transportation, lifting, and mounting of the girder for a bridge, improve the workability of the bottom plate and the like , It is possible to obtain an advantageous effect of improving the supportability of the girder by maintaining the lateral gradient of the longitudinal stress in the girder symmetrically.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical cross-sectional view showing a general prestressed concrete (PSC)
FIG. 2A is a cross-sectional view along the cutting line AA in FIG. 1,
FIG. 2B is a cross-sectional view along the cutting line BB in FIG. 1,
FIG. 3A is a plan view showing the construction of a girder for introducing a first tension to a first tension member of the girder of FIG. 1;
FIG. 3B is a plan view showing a configuration of a girder for introducing a second tension force to the second tension member of the girder of FIG. 1;
4 is an enlarged view of a portion 'A' in FIG. 3B,
5 is a view showing the construction of a prestressed concrete (PSC) girder according to an embodiment of the present invention,
Fig. 6 is a sectional view taken along the cutting line CC of Fig. 5,
Fig. 7 is a flowchart sequentially showing the manufacturing method of Fig. 4,
Fig. 8A is a plan view showing the construction of a girder simultaneously introducing a first tensional force and a second tensional force to the first tensional element and the second tensional element at each end of the girder of Fig. 5;
FIG. 8B is a plan view showing a configuration of a girder which simultaneously introduces first and second tensile forces and second 2-tensile forces to the first and second tensions at opposite ends of the girder of FIG. 5;
Fig. 9 is a plan view showing the construction of a girder simultaneously introducing third and fourth tensions to the third torsion material and the fourth torsion material at each end of the girder of Fig. 5;
10 is a cross-sectional view of a composite girder to which the present invention may be applied.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the subject matter of the present invention.

7, a manufacturing method (S100) of a girder 1 for a bridge according to an embodiment of the present invention is a method of manufacturing a bridge girder 1 according to an embodiment of the present invention, A tension member mounting step S110 of installing a tension member 20 including a first torsion member 21 and a second tension member 22 disposed on the opposite side and a second tension member mounting step S110 of mounting the first torsion member 21 and the second torsion member 22 A tension jack installation step S120 for installing a first tension jack 110 and a second tension jack 120 for introducing a first tension P1 and a second tension P2; A tensional force introduction step S130 for simultaneously introducing the first torsional force P1 and the second torsional force P2 to the first torsion 21 and the second torsion 22 with the second tension jack 120, A lateral displacement measuring step S140 of measuring the lateral displacement y of the girder 1 by using the lateral displacement sensor 130 in the course of the step S130, 0 < / RTI > so that the first pull-up jack 110 and the second pull- It is configured to include a jack tension adjusting step for adjusting the amount of tensile force that is being introduced in the (120) (S150).

The bridge girders 1 and 2 may be a prestressed concrete (PSC) girder in which a tensile material 20 is embedded in a reinforced concrete girder 10 as shown in FIG. 5, Or a composite girder in which a casing concrete 60 is combined with a girder 50. In other words, tensile forces (P1, P2, P3, P4) are introduced into the concrete (10, 60) in order to introduce a compressive prestress into the tensile material (20) The girders 1 and 2 can be applied to the method and apparatus according to the present invention.

In the method of manufacturing a girder (S100) according to the present invention, a tension force introduction apparatus 100 of a girder for automatically suppressing and controlling the occurrence of lateral displacement of the girders 1, 2 can be applied. That is, the apparatus 100 for introducing a tensional force of a girder according to an embodiment of the present invention is a device for introducing a first tensional force P1 into a first tensional element 21 installed in the girders 1, A first tensioning means (or first tensioning jacks) 110 and 210 and a second tensioning means formed by a hydraulic jack or the like to introduce a second tensioning force P2 into the second tensioning material 22 in the girders 1,2. (Or second tension jacks) 120 and 220 and a transverse displacement sensor (not shown) for measuring the lateral displacement y in a state in which the tension forces P1, P2, ... are introduced into the girders 1 and 2 And a first tension force P1 and a second tension force P1 introduced from the first tension means 110 and the second tension means 120 based on the lateral displacement values received from the lateral displacement sensor 130. [ And a control unit 140 for controlling the operation unit P2.

The first tension devices 110 and 210 and the second tension devices 120 and 220 are connected to the hydraulic pressure supply pipe from the control part 140 so that hydraulic pressure is supplied to the first tension devices 110 and 210 and the second tension devices 120 and 220 in accordance with the control signals S1 and S2, The magnitudes of the tension forces P1 and P2 pulling the connected tension members 21 and 22 are controlled in real time.

The transverse displacement sensor 130 may be provided as a contact type sensor for measuring in a state in contact with at least one of the abdomen of the girder 1 and the upper and lower flanges, And may be installed as a non-contact type sensor that receives the reflected light and senses the lateral displacement y of the girder 1. When the transverse displacement sensor 130 is provided as a contact type sensor, it can be formed as a contact type displacement gauge that measures the displacement of the probe elastically supported in contact with the abdomen of the girder or the upper and lower flanges.

8A, it is preferable that the lateral displacement sensor 130 is installed at the center of the span of the girders 1, 2 having the greatest transverse displacement, and the lateral displacement of the girders 1, It is preferable to measure both the sensors 131 and 132 disposed on the upper and lower sides with reference to Fig. 8A to compensate for the non-contact state with the girders 1 and 2 and the measurement error. However, the transverse displacement sensor 130 may be installed only on one side of the girders 1, 2 to measure the transverse displacement values of the girders 1, 2.

The control unit 140 receives the lateral displacement value y measured by the lateral displacement sensor 130 and detects the lateral displacement value y by using the first tension means 110 and 210 and the second tension means 120 and 220, (P1, P2, P3, and P4) that pull the pulling members 21, 22, 23, 24; 20 in real time.

The tensioning force introducing apparatus 100 of the girder according to the present invention includes the first tension member 21 inserted into the sheath tube 30 at one side with respect to the transverse neutral axis 88 of the girders 1, And a second tension member 22 inserted in the other sheath pipe with respect to the transverse neutral axis 88 to introduce the tensile force P into the at least two tension members 20, The first tensioning means 110 and 210 and the second tensioning means 210 and 220 (or 210 and 220) are arranged such that the transverse displacement value y measured at the device transverse displacement sensors 131 and 132, The material and the cross section of the girders 1 and 2 are arranged asymmetrically with respect to the transverse neutral axis 88 along the longitudinal direction by adjusting the first and second tensional forces P1 and P2 introduced by the transverse neutral axis 88 The lateral displacement can be limited within the permissible range by the first tension force P1 and the second tension force P2 which are finally introduced into the first torsion coil 21 and the second tension coil 22 You may be adjusted to a value of lateral displacement to zero).

For the sake of convenience, the prestressed concrete (PSC) girder shown in FIG. 5 will be described in detail below.

Step 1 : The reinforced concrete structure (10) of the girder (1) is made by curing the concrete by making the formwork and placing the unreinforced concrete under the condition of reinforcing steel. At this time, the sheath pipe 30 is arranged in a parabolic shape in the longitudinal direction of the girder 1 before the unhardened concrete is poured.

When the poured concrete is cured, tensile members 21, 22, 23, 24, 20 are inserted into the sheath pipe 30 previously installed (S110). 2A and 6, the tension members 21, 22, 23, and 24 are vertically disposed on the transverse neutral axis 88 at the ends of the concrete girder 1, and the concrete girders 1, In the middle of the span of the horizontal neutral axis 88. [

2A and 2B, the curvature of the first tensional element 21 arranged in the longitudinal direction is smaller than the curvature of the second tensional element 22 arranged in the longitudinal direction. Therefore, when introducing the tensional force, The separation distance y1 of the first tautness 21 with greater friction with the first tension member 30 can be determined to be slightly smaller than the separation distance y2 from the transverse neutral axis 88 relative to the second tension member 22. [ have. Likewise, since the curvature of the third tensile member 23 is smaller than that of the fourth tensile member 24, friction with the sheath tube 30 is slightly larger, so that the distance from the transverse neutral axis 88 to the third tensile member 23 (y3) may be set slightly smaller than the separation distance (y4) of the fourth tensional material (24). However, since the frictional loss of the tension due to the difference in curvature of the tensile material is not large, these tensile materials 20 are disposed symmetrically with respect to each other. On the other hand, it is possible to compensate for the difference in the separation distance of the tensions due to the difference in the fine tensions introduced into the tensions.

Step 2 : Then, as shown in Fig. 8A, a first tension jack 110 is installed at the end of the first tensional element 21 at one end of the girder 1, and a second tension jack 110 at the other end of the girder 2, A second tension jack 120 is installed at the end of the tension member 22 (S120).

At this time, since the first tension member 21 at the other end of the girder 1 and the second tension member 22 at one end of the girder 1 serve as a fixed fixing member, no tension jack is provided. As described above, the first tensile jack 110 for introducing the tensile force to the first tensile member 21 at one end and the other end of the girder 1, the second tensile jack 120 for introducing the tensile force to the second tensile member 22, The first tension jack 110 and the second tension jack 120 are smoothly installed at both ends of the girder without interfering with each other.

According to another embodiment of the present invention, when the first tension jack 110 and the second tension jack 120 provided on the first torsion coil 21 and the second tension coil 22 do not interfere with each other, The first tension jack 110 and the second tension jack 120 may be installed at one end of the girder. However, when a tensile force is applied to the tensile member 20, the friction between the tensile member 20 and the sheath tube 30 tends to become larger as the distance from the tensile jacks 110 and 120 increases. Therefore, It is more preferable that the first tension jack 110 and the second tension jack 120 are installed at different ends of the girder 1. [

Step 3 : Then, a tensile force P is introduced simultaneously to the first tension jack 110 and the second tension jack 120 (S130).

Since the cross sections of the girder 1 are generally symmetrical to each other with respect to the transverse neutral axis 88, the first and second tensions 21, (Y1, y2) are substantially the same. The first tension P1 and the second tension P2 introduced into the first tension member 21 and the second tension member 22 by the first tension jack 110 and the second tension jack 120 are set at the initial As shown in FIG.

On the other hand, when the distances y1 and y2 at which the first tensional element 21 and the second tensional element 22 are spaced from each other with respect to the transverse neutral axis 88 are different from each other with respect to the transverse neutral axis 88, The first tension P1 and the second tension P2 are set so that the initial stress P1 and the second tension P2 are equal to each other so that the distances y1 and y2 spaced from the neutral axis 88 are multiplied by the tensile forces P1 and P2 introduced into the respective tensile members 21 and 22. [ . Thereby, the lateral displacement (y) is not generated when the cross section is constant along the longitudinal direction of the girder 1 and the material distribution is uniform.

In the figure, the tension force is simultaneously applied to the tension members 21, 22 (23, 24) spaced from the lateral neutral axis 88 of the girder 1 by a similar distance. However, in another embodiment of the present invention The first tension member 21 and the fourth tension member 24, the second tension member 22 and the third tension member 22 spaced apart from each other by a distance from the transverse neutral axis 88 of the girder 1 A tension force may be simultaneously introduced into the elastic member 23.

For example, if the first tensional force P1 to be introduced into the first tensional element 21 is 100 and the second tractive force P2 to be introduced into the second tractive element 22 is 100, The tensile forces P1 and P2 of 100 respectively are introduced into the tensile members 21 and 22 by means 110 and 120, respectively.

As described above, by simultaneously introducing the tensile forces P1 and P2 to the tensile members 21 and 22 located on opposite sides of the lateral neutral axis 88 of the span of the girder 1, P2 in the transverse direction of the girder 1 in the process of introducing the tensile forces P1, P2 to the tensile members 21, 22, because the moments due to the tensile forces P1, P2 introduced on the left and right sides of the cross- The displacement y can be prevented from being generated.

Step 4 : During the process of step 3, the transverse displacement sensor 130 of the tensioning force introducing apparatus 100 of the girder has a displacement y at which the abdomen of the girder 1 and the upper and lower flanges are deformed in the transverse direction And detects it in real time (S140).

It is preferable that the transverse displacement sensor 130 is installed at the center portion of the span of the girder having the largest transverse displacement of the girder. However, according to another embodiment of the present invention, the transverse displacement sensor 130 may be provided at a position other than the center portion of the span of the girder. Although the lateral displacement sensors 131 and 132 are provided on both sides of the girder 1, the lateral displacement sensors 131 and 132 may be provided only on one side of the girder 1. [

The transverse neutral axis 88 of the girders 1 and 2 is set to be equal to the distance y1 and y2 between the first tensional element 21 and the second tensional element 22 on the basis of the transverse neutral axis 88, Even if the first torsional force P1 and the second torsional force P2 are introduced to the first torsion member 21 and the second torsion member 22 arranged at the opposite sides of the span at the center of the span with the same magnitude (for example, 100) The moment values are different from each other with respect to the transverse neutral axis 22 due to the asymmetric cross-sectional asymmetry in the longitudinal direction of the girders 1 and 2 or the difference in friction between the tension members 21 and 22 and the sheath pipe, 1, 2) can be generated.

The transverse displacement value y measured by the transverse displacement sensor 130 at the center of the span of the girder 1 is automatically transmitted to the controller 140.

Instead of measuring the transverse displacement value y in real time by the transverse displacement sensor 130 and transmitting it to the control unit 140, according to a less preferred embodiment of the present invention, The operator may manually measure the lateral displacement value y during the introduction of the tension forces P1, P2, ....

Step 5 : The control unit 140 of the tensional force introduction apparatus 100 of the girder automatically receives the lateral displacement value y measured at the center of the girder span by the lateral displacement sensor 130, and calculates the received lateral displacement value (S1, S2) for adjusting the hydraulic pressure in the first tensioning means (110) and the second tensioning means (120) so that the lateral displacement value (y) becomes 0 1 tensile means 110 and second tensile means 120, respectively.

For example, if the lateral displacement of the girder 1 is generated on the basis of Fig. 8A, the first tensional force P1 is introduced by the first tensional element 21, 2 tensile force P2 is larger than the lateral force L2 generated by the second tensile member 22 so that the magnitude of the first tensile force P1 introduced into the first tensile member 21 gradually increases And gradually increases the magnitude of the second tension force P2 that has been introduced into the second torsion springs 22. For example, the magnitude of the first tensional force P1 is reduced from 100 to 99, and the magnitude of the second tensional force P2 is increased from 100 to 101.

The first tensioning force P1 and the second tensioning force P2 introduced to the first torsion coil 21 and the second torsion coil 22 are maintained in a state in which the sum (99 + 101) , The lateral displacement y at the center of the span of the girder can be adjusted to be 0 or less than an allowable range (for example, 1 cm) (S150). Thereby, the pulling force Lz predetermined at the time of designing can be accurately introduced into the girder 1. [

In this state, one end of the first tension member 21 provided with the first tension jack 110 and the other end of the second tension member 22 provided with the second tension jack 120 are fixed, 21 and the second tensions 22, respectively.

As described above, according to the present invention, the first and second tensions (P1 and P2) and the first and second tensions (P2 and P2) are applied to the first and second tensions (21 and 22) (Y) of the girder is maintained at a very low level by adjusting the transverse displacement y at the center portion of the span to 0 or within the permissible range by the control unit 140, It is possible to obtain an advantageous effect that the tensile forces P1 and P2 of the design values to be introduced into the tensile member 21 and the second tensile member 22 can be accurately introduced.

Further, since the first tensioning force P1 and the second tensioning force P2 are introduced at the same time, the tension of the girder 1 due to the introduction of the tension force P1 of either the first tensioning member 21 or the second tensioning member 22 The length reduction dx does not affect the length reduction of the girder 1 due to the introduction of the other tension force P2. Therefore, by introducing the first tensional force P1 and the second tractive force P2 at the same time, it is possible to eliminate the influence on the shrinkage of the girder 1, so that the tension force to be introduced into the girder 1 can be more accurately It is possible to obtain an advantage that can be introduced.

In addition, as the length of the girders 1, 2 becomes longer, the tension members 21, 22, ... placed on the girders 1, 2, ... place one end of the girder at the fixed fixing ports 21f, 22f The tensile force introduced into each of the tension members 21, 22, ... is applied to the sheath tube 21, 22, ... in a state where the other end of the girder is used as the movable fixation holes 21a, 22a and the tension forces P1, A phenomenon that the distance from the movable fixing holes 21a, 22a, ... becomes smaller due to the friction with the tension members 21, 22,.

However, in the method of manufacturing a girder according to the present invention (S100), even if a tension is applied by using one end of the tension members (21, 22, ...) as a movable fixture, The tensile force is simultaneously introduced into the girders 21, 22, 23, 24, and the frictional losses in the longitudinal direction of the girders are canceled to be equal to each other to cancel out the tension distribution symmetrical in the longitudinal direction about the center of the span Can be obtained.

The measured values of the lateral displacement sensor 130 are transmitted to the control unit 140 so that the values of the tension forces P1 and P2 introduced by the first tension jack 110 and the second tension jack 120 According to another embodiment of the present invention, the first tension force P1, which is manually introduced by the first tension jack 110 and the second tension jack 120, And the second tension force P2.

On the other hand, when the girder is a short-span girder having a length of 15 m or less, even if an additional tension force is to be introduced to the tension members 21 and 22 into which the tension is already introduced, the extension length generated in the tension member due to the re- It is not easy to obtain a re-tension effect due to the property that the wedge of the wedge tends to be fixed at the original position.

However, when the length of the girder is sufficiently long (for example, 20 m or more), the first and second tensile forces P1 'and P1' applied to the first and second tensions 21 and 22, 2 stretching length of the first tensile member 21 and the second tensile member 22 is sufficiently long due to the tensile force P2 ', it becomes easy to change the fixation position of the fixture. Therefore, when the length of the girder is sufficiently long, the tensile members 21 and 22 to which the tensile force has already been introduced may be re-tensioned as required.

On the other hand, after the first tensile force P1 and the second tensile force P2 are introduced into the first tensile member 21 and the second tensile member 22 of the tensile member 20 disposed on the girder 1 , The third tension force P3 and the fourth tension force P4 may be introduced in the same manner for the remaining third tensions 23 and the fourth tensions 24 as shown in Fig.

A first tension jack 210 for introducing a third tension force P3 to the third tension member 23 is provided at one end of the girder 1 and a fourth tension member 24 is provided at the other end of the girder 1. [ A second tension jack 220 for introducing the fourth tension force P4 is provided. The third tension jack 210 and the fourth tension jack 220 introduce the tension forces P3 and P4 of a magnitude not affecting the moment on the transverse neutral axis 88. [ That is, in the case where the third tensional material 23 and the fourth tensional material 24 are spaced apart from each other by the same distance y3, y4 from the transverse neutral axis 88 at the center of the span of the girder, the third tensional force P3, 4 The tension force (P4) is determined the same.

Then, the transverse displacement at the center of the girder span is measured by the transverse displacement sensors 131 and 132, and the third tensional element 23 and the fourth tensional element 23 are adjusted so that the transverse displacement value at the span center portion is within the predetermined allowable range. And adjusts the tension forces P3 and P4 introduced into the tensile member 24. At this time, while the sum of the tensile forces P3 and P4 of the designed values to be introduced into the third tensile material 23 and the fourth tensile material 24 remains the same, the third tensile force P3 and the fourth tensile force P4, And then settled.

The third tension member 23 is arranged on the side of the first tension member 21 with respect to the transverse neutral axis 88 and the fourth tension member 24 is arranged on the side of the second tension member 22 The third tension member 23 is disposed on the second tension member 22 side with respect to the transverse neutral axis 88 and the fourth tension member 24 is disposed on the second tension member 22 side, But may be disposed on the first tensional material 21 side with respect to the transverse neutral axis 88. [

On the other hand, in the case of the tensile members 20 disposed on the girders 1 and 2, when there is a tensile material passing through the transverse neutral axis 88 at the middle of the spiral, only the tensile material passing through the transverse neutral axis 88 A tension may be introduced or a tension may be introduced with two or more tension members disposed on both sides of the transverse neutral axis 88 at the center of the span.

Although an even number of tensile members 20 are illustrated in the drawings, an odd number of tensile members 20 including the fifth tensile members may be disposed on the end faces of the girders 1 and 2. When an odd number of tensile members 20 are disposed on the end face of the girder 1, a fifth tension member (not shown) is generally disposed on the transverse neutral shaft 88. In this case, a fifth tensional force may be introduced singly into the fifth tensional element, and a first tensional element 21 and a second tensional element 22 introduced into the second tensional element 22, which are opposite to each other with respect to the transverse neutral axis 88, May be introduced together with the tension force P1 and the second tension force P2. Even though the fifth taut is not disposed on the transverse neutral axis 88, the fifth taut is positioned closest to the lateral neutral axis 88 relative to the other tensions 21, 22, 23, 24 The first tension member 21 and the second tension member 22 which are disposed on the opposite sides of the transverse neutral axis 88 are introduced together with the first tension force P1 and the second tension force P2 introduced into the first tension member 21 and the second tension member 22, do.

The present invention having the above-described structure simultaneously applies tension forces P1 and P2 to two or more tension members 21 and 22 spaced from each other with respect to the transverse neutral axis 88 at the center of the span of the girder, A tension loss due to a shrinkage amount dx in the longitudinal direction of the girder which occurs when the second tensioning force P2 is introduced into the second tensioning material 22 in a state in which the first tensioning force P1 is introduced into the second tensioning material 21 It is possible to obtain an advantageous effect that it is possible to introduce the correct tensioning force into the tension members 21, 22, .. and to suppress the displacement in the lateral direction within the allowable range.

In addition, according to the present invention, in introducing a tensile force simultaneously to the first torsion material and the second torsion material which are located on opposite sides of the transverse neutral axis, the tension force P1 The girders 1 and 2 are automatically controlled by the tension jacks 110 and 120 to introduce the prestresses into the girders 1 and 2. The girders 1 and 2 can be easily moved in the horizontal direction, The tension forces P1, P2, ... defined in the design stage can be accurately introduced into the tensile members 20 of the first and second tires 20,

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

1: PSC girder 2: composite girder
21: first tension member 22: second tension member
23: third tension member 24: fourth tension member
30: Sheath tube 40: Fusing unit
100: tensioner introduction device of the girder 110, 210: first tension jack
120, 220: second tension jack 130: transverse displacement sensor
140: control part P1: first tension
P2: second tensile force P3: third tensile force
P4: fourth tension

Claims (13)

A first tensional element inserted into the sheath tube at one side relative to the transverse neutral axis at the center of the span of the girder and a second tensional element inserted into the sheath tube at the other side with respect to the transverse neutral axis at the center of the span of the girder A tension member mounting step of installing two or more tension members to be provided;
Introducing a first tensional force into the first tensional element and introducing a second tensional force into the second tensional element at the same time and then fixing the same;
And a plurality of girders are formed on the outer circumference of the girder.
The method according to claim 1,
Wherein the first tensional element introduces the first tensional force at one end of the girder and the second tensional element introduces the second tensional force at the other end of the girder.
3. The method of claim 2,
Wherein the first tensional material is further introduced with a first 1-2 tension force and the second tension material is further introduced with a second 2-2 tension force.
The method according to claim 1,
The area of the moment diagram in the lateral direction due to the tension introduced into the first tensional element by the first tensional force and the area of the lateral moment diagram due to the tension introduced into the second tensional element by the second tension force are the same Wherein the first tensioning force and the second tensioning force are determined so that the first tension force and the second tension force are generated.
5. The method of claim 4,
Wherein the first tensioning force and the second tensioning force have a deviation of 20% or less.
The method according to claim 1,
Wherein the girder is one of a concrete girder and a steel composite girder, and the first tensional material and the second tensional material are inserted into a sheath pipe embedded in concrete.
The method according to claim 1,
Wherein the girder is provided with an odd number of tensile members including a fifth tensile member closest to the transverse neutral axis,
Wherein the fifth tensional force introduced into the fifth tensional element is introduced together with the first tensional force introduced into the first tensional element and the second tensional force introduced into the second tensional element.
8. The method according to any one of claims 1 to 7,
A third tensional element inserted into the sheath tube at one side with respect to the transverse neutral axis of the girder and a fourth tensional element inserted into the sheath tube at the other side with respect to the transverse neutral axis,
Introducing a third tensional force into said third tensional element and introducing a fourth tensional force into said fourth tensional element, and then fixing the same.
8. The method according to any one of claims 1 to 7,
A lateral displacement measurement step of measuring a lateral displacement of the girder;
A tensional force adjusting step of adjusting a first tensional force introduced into the first tensional element and a second tensional force introduced into the second tensional element based on the lateral displacement of the girder obtained in the lateral displacement measuring step;
Fixing the first torsion material and the second torsion material when the transverse displacement is within an allowable range;
And a plurality of girders are formed on the outer circumference of the girder.
Two or more tension members including a first tension member inserted into a sheath pipe at one side relative to a transverse neutral axis of the girder and a second tension member inserted and disposed at the other side of the sheath pipe with respect to the transverse neutral axis, As a device to be used,
First tensional means for introducing a first tensional force to said first tensional material;
Second tensioning means for introducing a second tensioning force to said second tensions;
A lateral displacement measuring means for measuring a lateral displacement of the girder while introducing a first tensional force into the first tensional element and introducing a second tensional force into the second tensional element;
The first tensioning force introduced by the first tensioning means and the second tensioning force introduced by the second tensioning means so that the lateral displacement value of the girder obtained by the lateral displacement measuring means is within the permissible range A control unit;
And the tension force introduction device of the girder.
11. The method of claim 10,
Wherein the lateral displacement measuring means is provided at the center of the span of the girder.
11. The method of claim 10,
Wherein the measured value in the lateral displacement measuring means is transmitted to the control unit.
13. The method of claim 12,
Wherein the first tension means and the second tension means are hydraulic jacks that are remotely controlled hydraulic pressure so that the tension force is automatically controlled from the control unit based on the measured value in the lateral displacement measurement means.
KR1020150126514A 2015-09-07 2015-09-07 Method of manufacturing bridge girder and tensioning apparatus used therein KR101765654B1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102167843B1 (en) * 2019-11-28 2020-10-20 (주)엠에스 Manufacturing method of prestressed girder for improvement of lateral curvature and construction method of girder bridge using same
KR102538558B1 (en) * 2021-12-22 2023-06-01 (주)지승씨앤아이 Prestressed concrete girder having end diaphragm

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102167843B1 (en) * 2019-11-28 2020-10-20 (주)엠에스 Manufacturing method of prestressed girder for improvement of lateral curvature and construction method of girder bridge using same
WO2021107249A1 (en) * 2019-11-28 2021-06-03 주식회사 엠에스 Method for manufacturing prestressed girder for improvement of transverse curvature, and method for constructing girder bridge thereby
KR102538558B1 (en) * 2021-12-22 2023-06-01 (주)지승씨앤아이 Prestressed concrete girder having end diaphragm

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