KR101458091B1 - Construction method for cable bridge using transverse prestressed girder - Google Patents

Abstract

The present invention relates to a construction method for a cable-stayed bridge using a transverse pre-stressed girder that can effectively support THE weight of an upper structure of the bridge and a load generated when a cable is installed, by using a girder member to which a moment is applied in the transverse direction as pre-stress. The construction method includes the steps of: a) manufacturing a transverse pre-stressed girder member; b) constructing a lower structure of the bride; c) constructing a cable tower to which an upper end of the cable is mounted; d) placing the girder member on the lower structure so as to apply the pre-stress to the girder member in a transverse direction and thus generate an upward camber; e) constructing a top plate on the girder member; and f) installing a plurality of cables, with one ends being fixed to the cable tower, and the other ends being fixed to both ends of the girder member in a width direction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of constructing a cable bridge using a transverse free moment girder member and a transverse prestressed girder,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cable gantry construction method, and more particularly, to a gantry structure in which a moment as a prestress in a transverse direction is introduced, thereby effectively supporting a load generated by installing a cable To a method of constructing a cable gland using a transverse free moment girder member.

The most common method for shortening the air flow and saving the construction cost and ensuring the economical efficiency of the construction is to increase the length of the girder which is the main structure of the bridge superstructure to reduce the number of bridge piers. There are many related technologies.

Another way to secure the economical efficiency of construction is to increase the lateral stiffness of the bridge to reduce the number of girders arranged in the lateral direction. Since the traffic volume of the bridge is large, If the length is not long like a bridge, it is an effective method.

Prior art related to increasing the lateral stiffness of bridges is disclosed in U.S. Patent No. 10-1004618, entitled " Composite Girder Bridging Method Using Temporary Steel Transverse Ribs and Permanent Concrete Transverse Ribs " And a lateral prestressing method of a PSC box girder bridge using the PC steel wire aligning device and registration method of Registration No. 10-0655654 and a method of reinforcing the lateral direction of a bridge by using a bidirectional prestressing There is a method of introducing the prestress even in the lateral direction of the bridge by using the tensions more positively like the 'system'.

Although the above conventional techniques may be significant in terms of proposing a method for improving the lateral stiffness of bridges, it is not easy to manage quality because there are a lot of field works, and a large number of expensive tension members must be arranged and fixed, It has problems that construction is not easy.

In recent years, a cable is used to construct a bridge having a small size in terms of improving the cityscape. Since the cable C is fixed to both ends of the bridge upper structure in the width direction, The necessity of the width direction reinforcement becomes larger. In a large-scale cable bridge, as shown in Fig. 1, it is possible to increase the dancing of the cross section of the mold or the reinforcement type (1) and to form the lower side thereof as a downward convex shape to increase the rigidity in the width direction. Since the dancing is so large that it is disadvantageous to utilize the mold space, it is not suitable for the construction of small and medium scale cable bridges, and the construction of the bridges is difficult because the reinforced bridges have complicated structures.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior arts, and it is an object of the present invention to provide a bridge structure in which a load caused by installing a self- The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of constructing a cable gland using a transverse free moment girder member capable of ensuring ease of installation and economical efficiency.

According to a preferred embodiment of the present invention for solving the above problems, there is provided a method of constructing a bridge using cables, comprising the steps of: a) providing a pair of I-shaped steel spaced apart in parallel, And a girder member which is composed of an angular member disposed at a right angle with the I-shaped steel at the longitudinal center portion of the I-shaped steel, Wherein the I-shaped steel is composed of a bending web bent in the longitudinal direction so that both sides thereof are curved and an upper and a lower flange contacting the upper and lower end surfaces of the bending web, the concave portion of the bending web being disposed facing each other; The supporting member is disposed so as to be in contact with the bending web on the center height of the cross section of the I-shaped steel while the load is placed so that the I-shaped steel is in a straight line. The bending web A step of installing a prime moment in a transverse direction of the girder member by preparing a girder member by removing the loaded load; b) constructing a substructure of the bridge; c) installing a cable fixture to which the top of the cable will be fixed; d) mounting a girder member on the substructure so that a pre-moment generating a camber upward in the transverse direction of the girder member acts; e) installing an upper plate on the girder member; f) installing a plurality of cables, the upper ends of which are fixed to the cable fixture, and the lower ends of the cables are fixed at both ends in the width direction of the girder member. Method is provided.

According to another embodiment of the present invention, in the step a), the girder member may be manufactured so as to further include a temporary shape retaining member disposed at a right angle to the I-shaped steel around the jig member, There is provided a method of constructing a cable gland using a transverse free moment girder member.

According to another embodiment of the present invention, a reinforcing fixing portion protruding outward in the width direction of the girder member, having a height equal to the height of the bending web to the outside of the bending web between the I- And a lower end of the cable is fixed to an outer end of the reinforcing and fixing unit in the step (f), wherein a cable gland construction method using the transverse prime moment girder member is provided.

According to another embodiment of the present invention, a tensile stiffener is further provided on a lower surface of a position where the cable is fixed to the girder member in the width direction of the girder member and connects each I-shaped steel. A cable gang construction method using a girder member is provided.

Since the moment as the prestress is introduced in the width direction of the girder member used in the cable gang construction method according to the present invention, the moment generated due to the weight of the girder member and the top board, the live load, and the tensional force of the cable can be canceled Therefore, it is possible to build a small bridge with excellent structural performance and dancing of upper structure.

Since a free moment is introduced into the girder member during fabrication, there is no need to perform a troublesome operation to reinforce the width direction rigidity of the upper structure at the time of cable gang construction.

In addition, when the girder member is manufactured to further include the temporary shape retaining member, a free moment can be introduced not only to the girder member but also to the upper plate of the bridge.

When the reinforcement fixing part and the tensile reinforcement are further provided on the girder member, the girder member has a more rigid structure against the concentrated load generated by fixing the cable to the girder member.

1 is a cross-sectional view of a bridge mold (or reinforced type) using a cable as a prior art.
Fig. 2 is an explanatory view showing a cable glazing construction method according to the present invention in order.
3 is an explanatory view of a process of manufacturing a girder member used in the construction of the cable gang.
4 is a girder member used in the construction of the cable gang.
Fig. 5 shows various embodiments of cable fixtures constituting the cable bridge.
Fig. 6 is a perspective view of the case in which the girder member is further provided with a temporary shape retaining member.
FIG. 7 is an explanatory diagram of a case where a reinforcing fixing portion is further provided on the girder member. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, however, it is to be understood that the present invention is not limited to the disclosed embodiments.

The present invention relates to a method of constructing cable gangs, which not only improves the structural performance and aesthetics of a bridge by allowing a cable to support a part of the load acting on the bridge, but also causes the cable to settle at both ends of the bridge width direction The possibility of defects due to local loads in the fixing unit can be reduced.

In Fig. 2, a method of constructing the cable bridge is shown in order.

A method of constructing a cable gang according to the present invention comprises the steps of: a) fabricating a transverse free moment girder member (100); b) constructing a bridge structure (200); c) installing a cable fixture 300 on which the upper end of the cable 500 is to be fixed; d) mounting a girder member (100) on the lower structure (200) so that a free moment for generating a camber upward in the transverse direction of the girder member (100) acts; e) installing an upper plate (400) on the girder member (100); f) installing a plurality of cables 500, fixing the upper ends of the cables 500 to the cable fixture 300, and fixing the lower ends of the cables 500 to both ends of the girder member 100 in the width direction.

Hereinafter, a method of constructing the cable gang will be described step by step.

a) manufacturing the transverse free moment girder member 100 (Fig. 2 (a));

A girder member 100 to be a main structural member of the bridge superstructure is manufactured.

The girder member 100 includes a pair of I-shaped steels 110 spaced apart in parallel and a support member 120 disposed at right angles to the I-shaped steel 110 at both longitudinal ends of the I- And an eccentric member 130 arranged at right angles to the I-shaped steel 110 at the longitudinal center portion of the I-shaped steel 110. By fixing the weight of the bridge upper structure and the cable 500 to the upper structure A moment as a prestress (hereinafter, referred to as a 'free moment') is introduced into the girder member 100 so as to cancel the moment in the width direction that will occur.

3, the process of fabricating the girder member 100 is shown in order.

The girder member 100 is fabricated by: i) a bending web 111 bent in the longitudinal direction so that both sides thereof are curved, and upper and lower flanges 112 and 113 respectively contacting the upper and lower end surfaces of the bending web 111 A process of preparing a pair of I-shaped steel 110 (Fig. 3 (a)); (Ii) a process of disposing a pair of I-shaped steels 110 in parallel and spaced apart (FIG. 3 (b)); Iii) a process of placing a load P on a pair of I-shaped steels 110 so as to straighten each I-shaped steel 110 (Fig. 3 (c)); Iv) a process of connecting a pair of I-shaped steels 110 by disposing a supporting member 120 perpendicular to the I-shaped steel 110 on the I-shaped steel 110 at both ends in the longitudinal direction of the I-shaped steel 110 3 (d)); V) a jig member 130 perpendicular to the I-beam 110 is disposed at the longitudinal center of the I-beam 110 to connect the pair of I-beams 110, (Fig. 3 (e)) of joining the bending web 111 on the lower height with reference to the center of the cross section of the I-shaped steel 110; (Vi) removing the load (P) from the pair of I-shaped steels 110 (FIG. 3 (f)).

Since the I-section steel 110 has a curved shape, the load on the I-section steel 110 is removed to generate a force to return to the original shape. However, since the lower portion to which the upper and lower heavy arm members 130 are bonded is fixed by the moment arm member 130 with respect to the center of the cross section of the I-shaped steel 110, the momentum member 130 is not bonded Only the upper portion is returned to its original shape, and thus the pre-moment Mp for generating the upward camber in the width direction is introduced into the girder member 100. [

4 shows a girder member 100 formed by the above-described manufacturing process. FIG. 4 (b) is a cross-sectional view of the girder member 100 taken along the section center of the I- The free moment Mp is introduced in the direction of generating the upward camber in the width direction at the longitudinal center portion of the girder member 100 when the bending web 111 is joined on the lower height with reference to FIG. a) is a case in which the urging member 130 is joined to the bending web 111 on the upper level with reference to the center of the cross section of the I-shaped steel 110, The free moment Mp is introduced in the direction of generating the free moment Mp.

If a tension member is used to introduce a prestress in the width direction of a bridge, the width of the girder member 100 can be reduced by using the support member 120 and the gimme member 130, It is possible to easily manufacture the girder member 100 and to secure economical efficiency.

In FIG. 3, it can be seen that the I-shaped steel 110 is arranged so that the concave sides of the bending web 111 are opposed to each other in the process of arranging the pair of I-shaped steels 110 of FIG. 3 in parallel, The I-beam 110 may be arranged to face the convex surfaces of the bending web 111.

Although the step a) may be performed before the other steps, the girder member 100 may be prepared only before the step of mounting the girder member 100 of FIG.

b) constructing a substructure 200 of the bridge (Fig. 2 (b));

The girder member 100 is mounted and the lower structure 200 is installed to serve to transmit the load of the upper structure to the ground.

The term " lower structure " as used herein refers to alternation and pier in general bridges. However, a bridge to which the construction method of the present invention is applied requires a structure in which the upper end of cable 500 is to be fixed, such as a pylon in a cable- Herein, it should be understood that the structure for the cable fixing includes a portion located below the girder member 100.

c) installing the cable fixture 300 (Fig. 2 (c));

The upper end of the cable 500 is fixed and the cable fixture 300 is installed to transmit the load acting on the cable 500 to the lower structure 200 or the ground of the bridge.

The cable fixture 300 may be formed in any shape and material as long as it functions as described above. In FIG. 5, various embodiments of the cable fixture 300 are shown.

5 (a) is a cable fixture 300 of a cable-stayed bridge type, in which the cable fixture 300 indicates a portion to be positioned on the upper portion of the girder member 100, and FIG. 5 (b) As the cable fixture 300 of FIG. 1 (a), is positioned at the upper portion of the girder member 100. 5 (c) is a cable fixture 300 of an arch bridge type.

The substructure 200 to be installed in the step b) and the cable fixture 300 to be installed in the step c) are located at the same position in the longitudinal direction of the bridge or the substructure 200 and the cable fixture 300 are integrated Structure, the substructure 200 and the cable fixture 300 may be simultaneously installed.

d) mounting the girder member 100 on the substructure 200 (Fig. 2 (d));

The girder member 100 in which the free moment Mp is introduced in the horizontal direction is mounted on the lower structure 200 so that the direction of the free moment Mp can generate a camber upward in the lateral direction of the bridge.

The free moments Mp introduced into the girder member 100 cancel the upward load acting on both ends in the width direction of the bridge due to the weight of the bridge, the live load acting on the bridge in use, and the tension of the cable 500 . Accordingly, the load acting on the bridge can be effectively supported without increasing the dancing of the girder member 100, and a high mold space can be ensured. Since the free moment Mp is introduced in the process of manufacturing the girder member 100, it is not necessary to perform a complicated operation such as tightening the tension member in order to reinforce the width direction rigidity of the bridge in the field as in the prior art.

In addition, since the girder member 100 has a wide width unlike a general I-shaped steel 110 girder, it can be stably mounted on the lower structure 200 without any other means, none.

e) installing the upper plate 400 on the girder member 100 (Fig. 2 (e));

The upper plate 400 is installed on the girder member 100 so that traffic can be carried on the bridge.

The construction of the top plate 400 should be done in a range that does not interfere with the settlement of the cable 500 in the subsequent step f).

The girder member 100 is further formed to include a temporary shape retaining member 140 disposed at a right angle to the I-shaped steel 110 around the urging member 130 in the step a) 400, the temporary shape retaining material 140 can be removed. 6 shows a girder member 100 further provided with a temporary shape retaining member 140. As shown in Fig.

The temporary shape retaining member 140 may be formed by providing a supporting member 120 and a spindle member 130 between the I-shaped steel members 110 in the process of manufacturing the girder member 100, So that the I-shaped steel 110 can maintain a straight line even if the load is removed. The upper plate 400 is installed on the girder member 100 and then removed to allow the free moment Mp to be introduced into the upper plate 400 as well as the girder member 100.

f) installing the cable 500 (Fig. 2 (f));

A plurality of cables 500 to support a part of the load acting on the bridge is installed.

The upper end of the cable 500 is fixed to the cable fixing base 300 and the lower end is fixed to both ends of the width direction of the girder member 100.

As the cable 500 is installed, a tensional force is generated in the cable 500 and the tensional force raises the girder member 100 and the upper plate 400 to share the support of the load generated by the gravity. Are fixed to both ends in the width direction of the girder member 100. This is because the cable 500 is pulled by the force pulling both ends of the girder member 100 against the moment generated by the weight of the girder member 100 and the upper plate 400 A large moment can be generated in the width direction of the girder member 100 and the top plate 400. [ However, because the free moment Mp is introduced into the girder member 100, the moment generated by the tension of the cable 500 and the weight of the girder member 100 is canceled.

The girder member 100 has a height equal to the height of the bending web 111 to the outside of the bending web 111 between the upper and lower flanges 112 and 113 of the I- The lower end of the cable 500 may be fixed to the outer end of the reinforcing and fixing unit 150 in step f). 7 is an explanatory view of the reinforcing and fixing unit 150. As shown in Fig.

When the cable bridge constructed by the construction method of the present invention is used as a bridge having a small live load such as a walking bridge, the upper plate 400 is mounted on a part of the upper flange 112 of the I-shaped steel 110 of the girder member 100, When the cable bridge is used as a bridge for traffic in an automobile or the like, it is necessary to secure a wide width of the upper plate 400 and a larger load is applied to the cable 500 It is necessary to reinforce the fixing portion of the cable 500 to which a larger concentrated load is applied. The reinforcing and fixing unit 150 prevents the girder member 100 from being deformed by the concentrated load generated by the cable 500 and also fixes the lower end of the cable 500 to the outside of the girder member 100 So that the width of the upper plate 400 can be increased.

The reinforcement fixing unit 150 may be installed at any time before the fixing operation of the cable 500. However, it is advantageous that the reinforcing fixing unit 150 is installed during the manufacturing process of the girder member 100 in terms of quality control and simplification of field work. When the reinforcing and fixing unit 150 is installed during the manufacturing process of the girder member 100, the reinforcing and fixing unit 150 is installed after the free moment Mp is introduced into the girder member 100, .

A tensile stiffener 160 may be further installed on the lower surface of the girder member 100 where the cable 500 is fixed to connect the I-beams 110 in the width direction of the girder member 100.

As described above, in the cable bridge, a large moment is generated in the width direction due to the weight of the girder member 100 and the top plate 400, and the tension of the cable 500, Tensile stress acts. The tensile reinforcement 160 reinforces the lower end of the girder member 100 and particularly the lower end of the girder member 100 in a position where the width members such as the support member 120 and the moment member 130 are not installed, (100) is prevented from being deformed.

When the tensile reinforcement 160 is installed together with the reinforcing and fixing unit 150, it is preferable that the tensile reinforcement 160 is formed up to the outer end of the reinforcing and fixing unit 150 as shown in FIG. 7 .

The tensile reinforcement 160 may be installed at any time before the fixing operation of the cable 500 as in the reinforcement fixing unit 150. However, it is preferable that the tensile reinforcement 160 is installed during the manufacturing process of the girder member 100. [

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be obvious that various modifications may be made within the scope of the idea. It is therefore intended that such modifications are within the scope of the invention as set forth in the claims.

100: girder member 110: I-beam steel
111: bending web 112: upper flange
113: lower flange 120: support member
130: Grommet member 140: Temporary shape retaining member
150: reinforcement fixing section 160: tensile reinforcement
200: substructure 300: cable fixture
400: top plate 500: cable
Mp: free moment

Claims (4)

In the construction of bridges using cables,
a pair of I-shaped steels 110 arranged in parallel to each other and a supporting member 120 disposed at right angles to the I-shaped steel 110 at both longitudinal ends of the I-shaped steel 110; And a hinge member (130) disposed at a right angle with the I-shaped steel (110) at the longitudinal center of the girder member (100).
The I-section steel 110 is composed of a bending web 111 bent in the longitudinal direction so that both side surfaces are curved and upper and lower flanges 112 and 113 contacting the upper and lower end surfaces of the bending web 111, 111) facing each other;
The support member 120 is installed so as to be in contact with the bending web 111 on the center height of the section of the I-shaped steel 110 while the load is applied so that the I-shaped steel 110 is straight, The girder member 100 is installed so as to be in contact with the bending web 111 on the lower height with respect to the center of the cross section of the I-shaped steel 110, Introducing a free moment (Mp);
b) constructing a bridge structure (200);
c) installing a cable fixture 300 on which the upper end of the cable 500 is to be fixed;
d) mounting the girder member (100) such that a free moment (Mp) generating a camber upward in the transverse direction of the girder member (100) acts on the lower structure (200);
e) installing an upper plate (400) on the girder member (100);
f) installing a plurality of cables (500), fixing the upper ends of the cables (500) to the cable fixture (300), and fixing the lower ends of the cables to both ends of the girder member (100) in the width direction Construction method of cable gull using free moment girder members.
The method according to claim 1,
The girder member 100 is manufactured to further include the temporary shape retaining member 140 disposed at a right angle to the I-shaped steel 110 around the gimbal member 130, and the upper plate 400 And the temporary shape retaining material (140) is removed after the construction is completed.
The method according to claim 1,
The girder member 100 has a height equal to the height of the bending web 111 to the outside of the bending web 111 between the upper and lower flanges 112 and 113 of the I- And the lower end of the cable 500 is fixed to the outer end of the reinforcing and fixing unit 150 in the step f) Construction method of cable gland using girder members.
The method according to claim 1,
A tensile reinforcement 160 is further provided on a lower surface of the girder member 100 where the cable 500 is fixed to the transverse girder member 100 and connects the I- A method of constructing a cable gland using a transverse free moment girder member.

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