KR101550553B1 - Methods of Manufacturing A Prestressed Girder Using Steel Rib Plate - Google Patents

Abstract

The present invention relates to a method to manufacture a girder using a rib plate connection. A rib (101) having a predetermined height is installed in a longitudinal direction on a lower surface of a floor plate (100). An upper structure is formed to be in a same line with the rib (101) in the longitudinal direction, and has a second rib (102) expanded with a higher height than that of the rib (101) in a vertical direction of a lower surface. The expanded rib (102) is installed at a distance ranging from 2.5-5.0 m along the longitudinal direction of the rib (101). A lower end of the expanded rib (102) of the upper structure and an upper end of a lower structure such as a steel box, a hollow circular steel tube, or the like are mutually connected; thereby realizing a process wherein the upper and the lower structure is integrated.

Description

[0001] METHOD FOR MANUFACTURING PRESTRESSED GARDER USING RIB PLATE JOINTS [0002]

The present invention relates to a method of manufacturing a girder type structure (GD) using a beam such as a steel box or a hollow round steel pipe, The lower end of the enlarged rib 102 and the upper portion of the beam 200 are joined to each other to secure a load transmission path to integrate the beam 101, 200 and the prestressed prestressed prestressed prestressed prestressed prestressed prestressed prestressed prestressed prestressed prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prismatic prism The present invention relates to the production of a structure (GD) with improved member structure and member utilization efficiency.

Generally, when a girder structure is manufactured using beams such as a steel box or a hollow tube, the bending moment generated in the member increases sharply when the length of the span increases, In order to overcome this problem, it is necessary to increase the beam height (D) when applying a strong beam, or to increase the diameter of steel pipe (D ), Or increase the thickness of the applied member. This increases the number of members and decreases the utilization efficiency of the members, and increases the scale of the construction, thereby limiting the plan for the economic and efficient member construction.

 Because of the above reasons, there is a limitation in securing the member bending stiffness when planning a structure with a relatively low deformity. Therefore, in order to overcome the phenomenon of excessive compression and tensile stress of the beam generated by external force, Therefore, it is necessary to establish a proper member plan considering the span of the structure, the deformations, and the thickness of the members in order to plan the effective structure.

      In this case, the range of the formulas defined by the relatively low deformations (D) can range from about 1/20 to 1/30 in terms of the form ratio to the ground.

      As shown in Fig. 8, when the prestressing is introduced by installing a tension material inside the beam for the purpose of canceling the lower and upper stresses of the beams, The upper and lower stresses of the beams are generated by the magnitudes of fU1 and fL1 respectively due to the action of the bending moment M1 by the external force W1 and the upper and lower stresses of the beams after the introduction of the prestress are frU3 and frL3, Although the compressive stress is reduced sufficiently by the introduction of the prestress, the compression stress of the reinforcement is excessively generated.

      This is due to the bending moment generated by the external force acting on the beam in the relatively low beam behavior, which causes compression and tensile stresses in the member, and the bending moment and the compressive force act as the main load due to the prestress force , The bending moment generated during the introduction of the prestress acts as the magnitude of the product Pr (Pr xe) of the tensile force (Pr) of the tension member and the distance (e) of the load acting point to the neutral axis of the beam, In the case where the distance (e) is not sufficiently secured, sufficient bending moment is not generated compared to the magnitude of the tension Pr of the tensile material. Therefore, even if the effect of stress cancellation on the compressive stress generated in the up- , A phenomenon occurs in which the upward compressive stress frU3 of the beam is excessively generated.

Therefore, in order to improve the member utilization efficiency through effective control of the stress generated in the member in relatively low-profile beams, it is necessary to overcome the technical limitation of the conventional prestress introduction method and to search for a more effective member configuration and structural control method Is required.

In order to solve the above-mentioned problems, the present invention overcomes the sectional force characteristic of a conventional beam member in which a bending moment dominant member force is generated, and as shown in Fig. 5, occurs in the beam 200 The bending moment M2 is reduced and the tensile force P2 is generated.

According to the present invention, as shown in (A) of FIG. 5, a bending moment is generated by a vertical load W1 acting on a simple fixed beam, where + M1 occurs in a typical beam configuration And + M2 is a moment according to the beam configuration according to the present invention. As shown in the figure, a small sectional force is generated compared with a moment (+ M1) generated in a conventional beam.

According to the present invention, as shown in (C) of FIG. 5, a tensile force of + P2 magnitude is generated by the same vertical load W1 acting on the beam, Although the tensile force is not generated in a conventional beam due to the load, a tensile force of + P2 size in the member according to the present invention shows a sectional force characteristic generated in the beam.

From the above results, it can be seen that the bending moment (+ M1) is dominant in the ordinary beam due to the same vertical load (W1) acting on the beam, and the relatively small bending moment + M2) and tensile force (+ P2) are generated at the same time.

When the prestress is introduced into the beam 200 in order to compensate the compressive stress of the member upper edge generated in the member 200 due to external force and the tensile stress generated in the lower edge of the member, The effect of introduction is distinctly different.

That is, even when the normal beam is applied to introduce the prestress, as shown in (B) of FIG. 8, the member lowering stress frL3 effectively exhibits a stress reducing effect in the final stress after the introduction of the prestress, It is difficult to expect a stress canceling effect using a prestress.

On the other hand, in the case of applying the beam according to the present invention, as shown in (B) of FIG. 9, the posterior residual stress frL6 and the posterior residual stress frU6 in the final stress after the introduction of the prestress are effectively reduced, The effect of introducing the prestress can be appropriately utilized.

As described above, when a structural system capable of minimizing the bending moment generated in the member by the external force is formed, it is expected that the effect of using the member in the beam 200 and the member utilization efficiency by introducing the prestress can be expected.

In order to solve the above-mentioned problems, the present invention provides a method of manufacturing a steel plate, comprising a beam 200 composed of a steel box, a hollow circular steel pipe, and the like and a bottom plate 100 installed at the upper end of the beam, And a connecting process.

As shown in FIGS. 2 and 3, the bottom plate 100 provided at the upper end of the beam is designed to prevent excessive displacement due to the load acting on the bottom plate and to secure the longitudinal bending stiffness A rib plate 101 having a predetermined height RibH1 in the vertical direction is installed on the bottom surface of the bottom plate.

According to the present invention, the bottom plate 100 made of the above-described member is provided on the lower surface of the rib 101 in the longitudinal direction at a predetermined interval (2.5 m to 5.0 m) And the upper surface of the structure lower structure SL is welded to the lower surface of the enlarged rib 102 to integrate both members.

The enlarged ribs 102 of the upper curved structure SU in which the working height GH2 varies in the longitudinal direction as shown in Figs. 2 (b) and 2 (b) gradually increase in height from both ends toward the center with respect to xx It changes greatly.

The lower joint portion of the enlarged rib 102 becomes a member connecting and load transmission path of the upper structure SU and the lower structure SL and serves to reinforce the bottom plate reinforcement members 103 and 104 for smooth load transmission and member stress dispersion. (201, 202, 203, 204, 205).

Here, a member which is located on the upper surface of the structure GD and which is composed of the bottom plate 100 and the rib 101 provided on the bottom of the bottom plate, the enlarged eaves 102, and the reinforcing members 103 and 104 is referred to as an upper structure (SU), which is located on the lower surface of the structure GD and includes a beam 200 such as a steel box or a hollow circular steel pipe and a diaphragm 205 installed to reinforce the inside of the beam 200 ), The vertical stiffener 201, the horizontal stiffeners 202 and 203, and the member including the tension member and the fixing mechanism is referred to as the lower structure SL.

The structure GD according to the present invention includes an upper floor plate 100 and ribs 101 provided on the bottom surface of the bottom plate and a portion of the rib 101 extending vertically downward, (SU), a steel box or a hollow steel pipe (steel tube) composed of a rib vertical stiffener 103 and a bracket 104 which are installed for buckling prevention and load transferring function of the upper vertical structure A vertical stiffener 201, horizontal stiffeners 202 and 203 installed to reinforce the inside of the beam 200 of the joint connected to the enlarged rib 102 of the upper structure SU, And a lower structure SL constituted by a tension member member for introduction purpose.

The upper structure SU and the lower structure SL of the structure GD are connected by the junction of the enlarged rib 102 and the ribs, the vertical stiffener 103 and the bracket 104, SU) and the connection of the substructure SL.

As shown in FIG. 4, in the structure GD constructed as described above, the sectional force characteristic according to the present invention is divided into the upper structure SU and the lower member SL, and the principle thereof is explained through a free object diagram.

4A, the upper structure SU is a plate-like structure composed of a bottom plate member 100, a rib 101, and an enlarged rib 102. The upper structure SU is a plate- Horizontal and rotational spring coefficients Kv, Kh, and Kr in consideration of the cross-sectional characteristics of the lower structure SL are applied to the lower surface of the enlarged rib 102, The vertical reaction force Rv and the horizontal reaction force Rh are generated at the respective point spring support points as shown in FIG. 4 (C).

As described above, the point reaction force of the upper structure SU generated by the external force is loaded at the same point of the lower structure SL with the same size and opposite direction load. At this time, the enlarged rib 102 of the lower structure SL, (Kv ', Kh', Kr ') considering the cross-sectional characteristics of the upper structure (SU) are applied to the boundary conditions.

When the external force W1 is applied in the above structure, a bending moment (+ M2), axial force (+ P2), shear force (-S2, + S2) .

In order to confirm the sectional force characteristics according to the present invention, a general steel structure analysis solution was used to measure a steel pipe 200 having a diameter of 800 mm and a steel pipe thickness of 16 mm, a bottom plate plate 100 having a thickness of 12 mm and a width of 2.0 m, A rib plate 101 having a height of 0.4 m and an enlarged rib 102 having a member thickness of 10 mm and a height of 0.5 m are used to form a sectional configuration and a sectional force diagram when a load of 1.0 tonf / In order to confirm the sectional force characteristic of a conventional beam 200, a sectional force generated by loading a load of 2 ton / m on a steel pipe 200 having a diameter of 800 mm and a steel pipe thickness of 16 mm is calculated, Respectively.

As can be seen from the results of the analysis using the universal analysis solution, it is possible to minimize the bending moment generated in the member by the external force, to form a structure in which a tensile force is generated, and to induce a proper structure for introducing the prestress into the member 200, Securing means.

When the sectional force due to the external force is generated in the structure GD constructed through the solution of the problem as described above, it is possible to control the upper and lower stresses of the beam 200 effectively by using the tensile force of the tensile material installed inside the beam 200 , It is possible to plan the structure between the longitudinals without excessively increasing the thickness of the member of the beam or increasing the height (D) of the beam 200, thereby reducing the required steel amount and providing the advantage of economical and long- .

Since the connection between the upper structure SU and the lower structure SL of the structure GD is performed at the lower end of the enlarged rib 102, the unit connection welding area is minimized to reduce the production cost of the member, It is possible to secure the quality of welded joint workability and welding surface.

Since the height GH and rigidity of the structure can be easily secured without increasing the cross section of the structure substructure SL by adjusting the height of the enlarged ribs RibH2 and RibH3 of the structure upper structure SU, By reducing the amount of material used for securing the rigidity, it is possible to reduce the production cost of the member and provide the technical idea necessary for manufacturing the economical member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a member configuration and a sectional force of a conventional beam member,
FIG. 2 is a structural view and a cross-sectional view of a steel box, a hollow circular steel pipe,
3 is a perspective view showing in detail the structure of the structure superstructure (SU) in the member shown in FIG. 2,
4 is a free object diagram of an upper structure (SU) and a lower structure (SL) for expressing the behavior of a member sectional force by an external force in the structure in the member constitution according to the present invention,
5 is a cross sectional view showing sectional forces of a conventional beam member and a structure according to the present invention,
6 is a conceptual diagram and cross-sectional view showing a cross-sectional force due to tension of a tension member during a prestress introduction process and a prestress introduction process in a structure according to the present invention,
Fig. 7 is a cross-sectional view showing the behavior of the member sectional force according to the present invention,
FIG. 8 is a conceptual view showing a process of calculating an external force of a conventional beam member and a member stress generated in the course of introducing a prestress,
9 is a conceptual diagram showing a process of calculating the external force of the structure GD according to the present invention and the member stress generated in the course of introducing the prestress,

In order to reduce the amount of members used and to construct a structure (GD) having a girder type structure, a lower structure (SL) composed of a steel box, a hollow circular steel tube, (SU) to the upper structure (SU) to secure member connection and load transmission path between the upper structure (SU) of the structure (GD) and the lower structure (SL) ) To the outside of the vehicle.

As shown in FIGS. 2 and 3, the bottom plate 100 provided at the upper end of the beam is designed to prevent excessive displacement due to the load acting on the bottom plate and to secure the longitudinal bending stiffness A rib plate 101 having a predetermined height RibH1 is installed on the bottom surface of the bottom plate. Since the vertical rib plate 101 is vertically joined, the longitudinal rigidity of the bottom plate 100 is increased , The bottom plate 100 and the ribs 101 form a structure that behaves as an integral structure.

The ribs 101 are provided on the lower surface of the bottom plate 100 of the upper structure SU having the integral structure in the same line as the ribs 101 provided in the longitudinal direction, And an enlarged rib 102 capable of height adjustment is provided.

It is appropriate to apply the distance in the longitudinal direction of the enlarged rib 102 within the range of 2.5 m to 5.0 m and it is possible to apply the member thickness more than the rib 101 of the general section for smooth load transmission and member connection .

The enlarged ribs 102 may be applied at the same height RibH2 throughout the entire length of the structure GD as shown in RIB1 in FIGS. 2 (A) and 2 (E) The height of the enlarged rib 102 is set to be different from the height of the upper portion xx of the beam 200 by making the shape of the upper curve structure (SU) as shown in (b) and (f) (For example, RibH3).

In the structure to which the enlarged rib 102 is applied, the deformations GH1 and GH2 are values obtained by summing the height of the substructure SL, the enlarged rib heights RibH2 and RibH3, and the thickness of the bottom plate plate 100 . Accordingly, in the case of (B) and (V) in FIG. 2 where the girder type is the upper curve structure (SU), the height RibH3 of the enlarged rib 102 with respect to the xx line can be easily adjusted, (GH2) adjustment is also facilitated.

Since the height of the elongated member is increased and the load transmission point is provided in the section of the enlarged rib 102 as compared with the rib 101 of the general section, the member thickness can be appropriately increased to prevent member buckling or excessive stress generation, A vertical stiffener 103 for integrally connecting the upper surface of the structure substructure SL and a bracket 104 having a function of horizontally supporting the bottom plate slab are provided on the bottom surface of the rib 102 and the bottom plate 100.

The lower structure SL of the structure GD according to the present invention is composed of a beam such as a steel box or a hollow circular steel pipe and the enlarged rib 102 of the structure upper structure SU, The diaphragm 205, the vertical stiffener 201 and the horizontal stiffeners 202 and 203 are installed in order to reinforce the inside of the beam 200 of the joining part to be joined with the diaphragm 205.

The structure superstructure SU and the lower structure SL are connected by the joining of the enlarged rib 102 to the rib vertical stiffener 103 and the bracket 104. The loads applied to the members include the upper structure SU, RTI ID = 0.0 > SL. ≪ / RTI >

As shown in FIG. 4, the shape and characteristics of the member sectional force according to the present invention in the girder-type structure GD constructed as described above are such that the structure free from the member upper structure SU and the lower structure SL The principle is explained through an object diagram.

The structure upper structure SU is a plate-like structure composed of the bottom plate member 100, the rib 101 and the enlarged rib 102 as shown in FIG. 4 (a) (Kv, Kh, and Kr) considering the sectional characteristics of the structure substructure SL are applied to the bottom surface of the enlarged rib 102, The vertical reaction force Rv and the horizontal reaction force Rh are generated at the respective point spring support points as shown in FIG. 4 (C) when the load W1 is loaded as shown in (B) of FIG.

As described above, the point reaction force of the structure upper structure (SU) generated by the external force is loaded at the same point of the structure lower structure SL with the same size and opposite direction load. At this time, 102) Boundary conditions applying vertical, horizontal, and rotation spring coefficients (Kv ', Kh', Kr ') considering the cross-sectional characteristics of the superstructure (SU)

When a load W1 is applied to the girder structure GD according to the above structure, the bending moment + M2, the axial force + P2, the shear force -S2 , + S2) will occur at the cross-sectional force.

In order to confirm the sectional force characteristics according to the present invention, a general steel structure analysis solution was used to measure a steel pipe 200 having a diameter of 800 mm and a steel pipe thickness of 16 mm, a bottom plate plate 100 having a thickness of 12 mm and a width of 2.0 m, A rib plate 101 having a height of 0.4 m and an enlarged rib 102 having a member thickness of 10 mm and a height of 0.5 m are used to form a sectional configuration and a sectional force diagram when a load of 1.0 tonf / 7 shows a cross sectional view of a steel pipe 200 having a diameter of 800 mm and a steel pipe thickness of 16 mm in order to confirm a sectional force characteristic of a conventional beam 200 Is shown in Fig.

5, which is based on the structural system of FIG. 4, can be confirmed through the analysis result using the general-purpose analysis solution described above, and the sectional force induction shown in the solution of the problem according to the present invention, And a proper structure for introducing the prestress into the beam 200 is guided to secure a solution for the problem.

In the girder-type structure (GD) having the above-described member sectional force-generating characteristics, the prestress is introduced by the tension of the tension member 300 installed in the substructure SL to dominate the substructure SL Thereby effectively canceling the tensile stress.

As shown in FIG. 2, the tension member 300 disposed in the structure substructure SL is provided with a fixing mechanism 301 at both ends of the member, passes through the diaphragm 201 installed in the substructure SL, The upward force Pv of the tensile member at the position where the load of the upper structure SU is transmitted to the lower structure SL is obtained by bending the tensile material in each diaphragm, Are formed on the same line.

As shown in FIG. 6, when the steel wire arranged in the structure substructure SL is tensed by the tension of T, the horizontal component of Lp acts as a compressive force on the structure GD, The upward force of the vertical component of Lp is applied at the diaphragm position in the diaphragm SL and the momentum -M3 and compressive force -P3 as shown in FIGS. 6 (C) and 6 (D) .

The both ends of the structure substructure SL are filled with a concrete filling section 400 and the fixing mechanism 301 is buried and the reaction force transmitted to the fixing device is dispersed through the concrete during the tensioning of the tension member, The sheath pipe 302 is installed in the tensioning material placement section of the concrete filling section, and the grouting filling is performed inside the sheath pipe when the tension of the tension material is completed.

 As described above, since the structure according to the present invention can control effectively the upper and lower stresses of the beam 200 by appropriately adjusting the tensile force of the tensile material installed in the lower structure SL when the sectional force is generated by an external force, It is possible to plan the structure between the longitudinals without increasing the member thickness or increasing the height (D) of the beam 200. Thus, it is possible to reduce the required amount of steel members, thereby providing an advantage of economical and large-

Since the connection between the upper structure SU and the lower structure SL of the structure GD is performed at the lower end of the enlarged rib 102, the welding length of the structure connecting welding portion is minimized, Welded joint workability and welding surface quality can be ensured because the welding is performed in an unfired open space.

Also, by adjusting the height of the enlarged ribs (RibH2, RibH3) of the upper structure of the structure, it is easy to easily adjust the height of the structure (GH1, GH2) without increasing the cross section of the substructure SL. It is possible to secure the stiffness by minimizing the member usage amount in order to secure the stiffness of the member, so that the production cost of the member is minimized, which is advantageous in that an economical girder structure is provided.

100: bottom plate plate
101: Rib plate installed on bottom plate plate
102: a rib plate installed according to the present invention, the upper plate 100
A portion of the rib 101 provided on the lower surface is vertically downwardly extended,
103: a vertical stiffener joining the side surfaces of the enlarged ribs 102, the bottom plate plate bottom,
104: a bottom plate supporting bracket for connecting the side surface of the enlarged rib 102, the bottom plate bottom plate,
200: Steel box, hollow tube, etc.
201: vertical stiffener installed inside the beam
202, 203: Horizontal stiffener installed inside the beam
204: Upper plate rib of steel box type beam
205: Hollow Circular Steel Tube Diaphragm installed in the inside of the beam
206: a circular hole in which a diaphragm is perforated in a tension member through position to pass a tensile material installed inside the beam 200
300: Tension material installed inside the beam
301: anchorage of the tension member installed inside the beam
302: Sheath tube of the tension member installed at the inner end of the beam
400: Concrete filled in the inner end of the beam
500: Structure support
RibH1: Height of the rib plate 101 provided on the bottom surface of the bottom plate plate
RibH2: The height of the member 102 of the enlarged rib 102 provided on the bottom surface of the bottom plate plate of Fig. 2 (A)
RibH3: member height of the enlarged rib 102 provided vertically downward on the bottom surface of the bottom plate plate of the upper curved structure SU of Fig. 2 (B) in which the working height GH2 changes
D: beam height and diameter of steel box, hollow tube, etc.
GH: The structure of the structure (GD) produced according to the present invention
GH1: height of the structure GD having a constant false height GH as shown in Fig. 2 (a)
GH2: height of the structure GD in which the mold height GH changes as in the upper curve structure SU in Fig. 2 (B)
W1: external force acting on the girder
SU includes a rib 100 installed on a bottom surface of a bottom plate and an enlarged rib 102 extending vertically downward a part of the rib 101 to prevent buckling and load transfer of the enlarged rib 102. [ And a bracket (104) member for installing the rib vertical stiffener (103)
SL: It is installed to reinforce the inside of the beam 200 of the joining portion joined to the enlarged rib 102 of the upper structure SU in the beam 200 such as a steel box or a hollow circular steel pipe The diaphragm 205, the vertical stiffener 201, the horizontal stiffeners 202 and 203, and the prestressed introduction member
GD: consisting of an upper structure (SU) and a lower structure (SL)
Structure

Claims (5)

A rib 101 having a predetermined height RibH1 is provided in the bottom surface of the bottom plate 100 in the longitudinal direction and a rib 101 having a predetermined height RibH1 is provided in the bottom surface of the bottom plate 100 in the longitudinal direction (SU) having an enlarged rib (102) which is on the same line and has a larger height (RibH2) than that of the rib (101) in a vertical direction is formed. An installation space of the enlarged rib (102) (Steel box) or a hollow circular steel pipe (steel tube), and the lower end of the enlarged rib 102 of the upper structure (SU) And the upper and lower structures (SU) SL are integrally formed by joining the upper ends of the lower structures SL such as the upper and lower structures SU to each other.
The ribs 101 of a certain height RibH1 are provided on the lower surface of the bottom plate 100 in the longitudinal direction of the curved plate while the curved longitudinal direction of the ribs 101 has a predetermined height RibH1, 200 and is a curve having a shape in which the vertical distance to the horizontal plane in the longitudinal direction of the beam 200 gradually increases toward both ends in the longitudinal direction of the beam 200, The height of the ribs 102 that are larger than the ribs 101 in the vertical direction while being on the same curve in the direction of the upper curve structure (SU) having the enlarged ribs 102 that gradually change greatly from both ends toward the center, The enlarged ribs 102 of the upper curved structure SU are installed at intervals of 5.0 m from 2.5 m along the longitudinal direction of the ribs 101, And a steel box or steel box The upper and lower structures SU and SL are integrally formed by joining together the upper ends of the lower structure SL such as a hollow circular steel pipe. Method"
3. The method according to claim 1 or 2,
The upper structure SU and the lower structure SL of the girder structure GD are extended to the enlarged rib 102,
And a moment (+ M2) and a tensile force (+ P2) are induced to occur in a beam 200 member such as a steel box or a hollow round steel pipe during a load operation, And a compressive stress of the beam 200 is introduced by introducing a prestress into the girder.

The method according to claim 1 or 2,
When the prestress is introduced by the tension member for canceling the tensile stress generated in the lower structure SL in the girder structure GD, A diaphragm 201 having a perforation hole 206 is formed in the diaphragm 201 so that the diaphragm 201 can be penetrated through the perforation hole 206 of the diaphragm 201 so that the vertical component of the tensile force And a tensile member is installed so as to act as a force.
5. The method of claim 4,
The method for manufacturing a girder using a rib plate joint according to claim 1, wherein the concrete (400) is filled in both ends of the beam (200) in order to disperse the stress of the fixing member

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