KR20110095619A - Joint reinforcing method using bending connection member and bridge construction method therewith - Google Patents

Abstract

PURPOSE: A method for reinforcing the joint of a precast prestressed concrete beam using a bending connection member and a bridge construction method using the same are provided to improve the structural stability of a PSC girder using precast segments. CONSTITUTION: A method for reinforcing the joint of a precast prestressed concrete beam using a bending connection member is as follows. Bending connection members(200) are installed by horizontally passing through both ends of precast segments(100a,100b) of a PSC girder. Longitudinal connection members are installed by connecting both ends of the precast segments. Longitudinal and horizontal compression prestress is applied to the connection parts of the precast segments.

Description

Joint reinforcement method of precast prestressed concrete beam using flexural connector and bridge construction method using the same {JOINT REINFORCING METHOD USING BENDING CONNECTION MEMBER AND BRIDGE CONSTRUCTION METHOD THEREWITH}

The present invention relates to a method of reinforcing a connection portion of a precast prestressed concrete beam using a bending connector and a bridge construction method using the same. More specifically, it is possible to secure continuity of a bending moment in a connection portion of a plurality of segmented precast segments. The present invention relates to a method of reinforcing the joint of a precast prestressed concrete beam that is effective in structural integration, and a bridge construction method using the same.

Since the 1980s, PSC (Prestrssed Concrete) girder bridges with cross-sections of I type are generally supplied with high strength concrete of 30MPa ~ 45MPa from the neighboring ready-mixed concrete plant in the temporary fabrication plant around the site, and then temporarily produced after the girders are manufactured, transported and mounted. It was designed and constructed to demolish the factory.

Thanks to the development of the domestic economy and the development of concrete materials technology, from early 2000, it was easy to produce high strength concrete of 50 MPa or more. Accordingly, the Precast Concrete Plant, which has a production facility capable of producing high strength concrete members, Many have been created, allowing bridge girders to be produced at permanent PC plants.

At this time, the PSC girder manufactured in the factory had to be limited to a short span girder between 15m and 25m when manufactured and transported integrally under the limitation of the carrying weight and length.

Considering that most PSC girder bridges have a medium span between 25m and 45m, without the development of design and construction technology for segmented girders, it is possible to use the advanced concrete materials technology and the spreading PC factory efficiently. It is difficult to design and construct PSC girders.

Therefore, in Japan, it is difficult to secure the production site around the site, and because of the increase in labor costs, various segmentation methods are used in which the PC factory manufactures segment PC members and assembles them on site. It is still a rudimentary step, despite the fact that it is being carried out steadily.

That is, in the domestic research paper, the optimum shear key shape for the stability of the shear behavior of the joint was derived by comparing the performance of the segmental girder and the integral girder or examining the stability of the shear behavior at the joint. Some methods of reinforcing connections have been introduced in relation to behavior.

For example, Patent No. 334635 (Segmental Bulb Tee Girder and Construction Method for Long Span Bridges) relating to a conventional technology for constructing a PSC girder bridge by connecting a precast segment girder to each other has been introduced. As a joint of the bulb tee girders 10 and 20 by the above, the method of constructing with splice girders is especially introduced.

That is, in the manufacture of the girder, it is manufactured by segmenting the end segment and the center segment, but moving each girder (10, 20) while moving from the bridge end to the center of the bridge, and forming a shear key (30) on the joint surface to prevent slipping And to improve the shear resistance, and the bonding between the bonding surface between the epoxy 40 to be bonded to each other, and to secure the epoxy bond between the temporary tension member 50 between the girder abdomen to settle after tension It is introduced.

The girder 10 and 20 connected and joined as described above are provided with PC strands installed therein and fixing anchors installed at both ends thereof, so that necessary temporary prestresses are introduced.

However, in the case of the above construction method

Only epoxy bonding and shear keys are used to connect the girders, which makes it difficult to secure the structural safety of the connections. Even if a temporary tension member is used, it is only a supplement to the epoxy bonding. It could not play a big role in the union. In addition, there was a problem that the tension and settlement of the temporary tension material may be somewhat inefficient and economical.

Furthermore, the connection part of the conventional bulb tee girder (10, 20) is to ensure the resistance means to the shear stress that eventually occurs in the joint, the means for securing the continuity for the bending moment acting on the entire girder No, the joint reinforcement method considering this has not been introduced at all.

According to other domestic research papers, the performance of the girder with respect to the flexural behavior of the integral girder and the segmented girder under the working load is the same, but there is no problem in the application of the girder. It is introduced that the integrated girders are judged to be superior to the segmented girders.

In other words, due to the joint opening phenomenon occurring at the segment girder connection, it was estimated that the performance was reduced by about 15% under the extreme load.

As a result, the owners and design engineers who want to build the bridge can have a negative impact on the application of the PSC girder bridge by the segment, thereby reducing the possibility of constructing an eco-friendly bridge with high strength concrete material. In addition, there was a problem that it also excludes the possibility of manufacturing eco-friendly PSC girders in designated permanent PC factories equipped with environmental facilities.

Accordingly, the present invention is particularly suitable for segmented precast prestressed concrete beams, in which the continuity of the bending moments acting at both connecting portions of adjacent precast segments is sufficiently secured to allow the same performance or higher than that of the integral PSC girder. Providing the reinforcement method is the technical problem to be solved.

That is, in the PSC girder, the interest in the connection of the existing precast segment girder, the spliced girder or the segment girder was the continuity to the shear force.

Concerns about shear failure are very natural for the engineer who designs and constructs, and it is true that shear behavior can have a very serious effect on the structure itself.

In this logic, the method mainly studied and strengthened for the connection was focused on shear behavior.

However, in the present invention, a method for controlling the opening phenomenon of the connection part appearing in the extreme load state is focused on the continuity of the bending moment, not the continuity to the shear force.

Therefore, in the design and construction engineers of PSC girders, the fact that the discontinuity of the bending behavior occurs under the extreme load can be sufficiently affected by the reluctance of the segmentation method, and therefore, the technical problem to be solved by the present invention is to solve this problem. It can be said.

The present invention

In order to ensure the continuity of the bending moment acting on each connection part of the segmented precast segment in the segmental fabrication of the precast prestressed concrete beam which is made to introduce the longitudinal compression prestress,

In the connecting portion, a flexible connecting member is installed so as to penetrate both sides of the adjacent precast segment in the transverse direction in the transverse direction and then settles, and connecting the two ends in the longitudinal direction to each other, the additional plate is installed through the flexible connecting member and By installing the same fixing plate, the lateral compression prestress is introduced together with the longitudinal compression prestress in the connecting portion.

In addition to the working load, it is possible to secure the continuity of the bending moment in the connection part of the precast segment girder under extreme load conditions.

It is to ensure the structural safety of the PSC girder by the precast segment.

Furthermore. The flexible connector is to be inserted into the reinforcing hole penetrating both end portions of the precast segment girder, the reinforcing hole is formed in a curved shape to enable a more effective connection reinforcement.

According to the present invention, the use of the flexible connecting portion in the connection portion as compared to the integral PSC girder having the same cross-section has a superior bending behavior performance than the integrated PSC girder, especially in the extreme load state.

Therefore, it is possible not only to secure the continuity of the bending behavior but also to perform the reinforcement of the cross section through the composite behavior until the bending connector is destroyed.

In addition, the greater the lateral compression prestress introduced through the transverse sheath pipe arranged in a curved shape, the greater the role of the flexural tension member, and thus the precast segment girder reinforced with flexural tension member exhibits better performance than the integral girder, especially in static behavior. As a result, it can be seen that the usability and utility of the segmented PSC girder can be improved.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

1 is a front view introducing a method of reinforcing the connection portion of the PSC girder with a conventional splice girders.
Figure 2 shows the connection reinforcement of the precast segment of the PSC girder according to the present invention.
3A, 3B, 3C and 3D are reload images of the precast segment of the present invention by static load.
4A and 4B are sag and strain correlation graphs for loads of a PSC girder integrally manufactured without being segmented with a PSC girder by a precast segment reinforced by the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

First, the present invention is manufactured through the process of manufacturing the PSC girder 100 in a precast manner, segmenting a plurality, and integrating the segmented precast segments 100a, 100b, and 100c longitudinally with each other.

Accordingly, the precast segment has a certain length according to manufacture, transportation, and handling, and this length L may be changed as appropriate.

First, the connection portion (A) of the precast segment is a shear key, shear groove not shown in the prior art as shown in the end surface of the precast segment girder adjacent to the connection portion as in the prior art to ensure the resistance performance against shear stress while integrating behavior And epoxy adhesive can be carried out.

Further, the production of these precast segments 100a, 100b, 100c is all made in a PC factory equipped with manufacturing facilities.

These precast segments 100a, 100b and 100c are longitudinal sheath tubes into which longitudinal tension members (such as PC steel wires) can be inserted so that longitudinal compression prestress can be introduced longitudinally after being integrated with each other. (Not shown) is arranged.

The longitudinal sheath tube is arranged in a straight or parabolic form in the longitudinal direction in advance in a conventional formwork (not shown) for manufacturing precast segments 100a, 100b, and 100c, and is naturally formed by pouring concrete into the formwork. You can.

Furthermore. Reinforcing holes 110a and 110b are formed at both ends to ensure continuity with respect to the bending moment in the connection portion of the precast segment.

These reinforcing holes 110a and 110b are formed to penetrate both end sides b and c of the precast segment. In order to form such reinforcing holes, for example, a transverse sheath tube (not shown) is also first placed inside the formwork. And, as the concrete is poured into the formwork so that the reinforcing hole can be formed naturally.

At this time, the reinforcing holes (110a, 110b) is preferably arranged to be curved.

That is, the reinforcing holes (110a, 110b) is preferably arranged such that the curved pre-stressed by the bending connection member 200, such as PC steel wire or steel bar, such as arc shape to enable more effective connection reinforcement.

That is, when the transverse sheath pipe is arranged in a curved shape, when the flexural connection member 200 is tensioned and fixed, it can be seen that the compression prestress is introduced together in the transverse direction and the connection direction in the longitudinal direction (length direction) by the component force.

When the precast segments 100a, 100b, and 100c formed by including the reinforcing holes 110a and 110b by the transverse sheath pipe are manufactured at the factory, the precast segments are brought into the site by using a vehicle. do.

In the field, a process of integrating the imported precast segments in the longitudinal direction is made.

This first sets a number of precast segments in contact with each other in the longitudinal direction, and then inserts a longitudinal tension member into a longitudinal sheath tube formed inside the precast segment to tension the longitudinal tension members at both ends of the precast segments. Then settled down.

As a result, it can be seen that the plurality of precast segments are integrated with each other in the longitudinal direction, which is to ensure resistance to shear stress in the connection part.

However, the resistance against the bending moment in the connection part A of the precast segments may not be a big problem in the working load state as described above, but in the extreme load state, the continuity for the bending moment in the connection part may be sufficiently secured. Structural vulnerabilities occur, such as cracks in the joints.

In order to prevent this, the present invention allows the compression prestress to be introduced in the transverse direction by inserting the bending connecting member 200 into the reinforcing holes (110a, 110b) by the transverse sheath pipe described above.

That is, the flexible connecting member 200 is inserted into the reinforcing holes 110a and 110b so as to penetrate both end sides of adjacent precast segments.

Both ends of the inserted flexible connecting member 200 are connected to each other in the longitudinal direction, so that the fixing plate 300, such as an add-on plate, which is installed even through the flexible connecting member 200, is installed.

Accordingly, when the bending connector 200 is fixed through the fixing plate 300 after tension, the lateral compression prestress is introduced into the connection portions A.

In addition to the longitudinal compression prestress, the lateral compression prestress is provided in the connection section, ensuring longitudinal integrity of the precast segment girders, ensuring continuity for shear stress in the connection section, and continuity for the bending moment in the connection section. In particular, it is possible to secure structural performance corresponding to an integrated PSC girder rather than structurally segmented under extreme load conditions.

That is, when the fixing plate 300 tries to bend downward due to a load acting on the precast segments 100a, 100b, and 100c, the fixing plate 300 primarily resists such a load, and is compressed by the bending connector 200. It is to resist the load to bend effectively by prestress.

Accordingly, the fixing plate 300 is disposed in the longitudinal direction so that the reinforcing holes 110a and 00b of the adjacent precast segment may be penetrated, and are installed to be connected to each other by the bending connecting member 200, which is basically adjacent to the precast segment. It can be seen that it serves to constrain the cast segments to each other.

In this connection of the plurality of precast segments as shown above the bending load 200 and the fixing plate 300 is installed in the lateral compression prestress is introduced to the load loading experiment to the extreme load in the state to be introduced to Figure 3a, Fig. It can be confirmed by 3b, FIG. 3c, and FIG. 3d.

Furthermore, Fig. 4A and Fig. 4B show the relationship between the deflection and the strain by the load test.

According to FIG. 4a, the ratio of the longitudinal compression prestress by the bending connector to the longitudinal compression prestress is divided into 50% (S50), 100% (S100), and 125% (S125). Looking at the deflection curve, the greater the compression prestress caused by the bending connector, the greater the deflection.

According to Fig. 4b, the ratio of the longitudinal compression prestress by the bending connector to the longitudinal compression prestress is divided into 50% (S50), 100% (S100), and 125% (S125) to determine the strain caused by the load (ultimate load). Looking at the curve, the higher the compressive prestress caused by the flexural connector, the higher the strain.

As a result, the static load test results to verify whether the reinforcement in the transverse direction of the precast segment can exhibit the same bending behavior performance as the girder fabricated integrally without segmentation,

The static performance of the precast segment with flexural connectors is similar to the one-piece girder with the same cross-section, but the flexural behavior is better than the one-piece girder under extreme load.

This is because the flexural connector not only secures the continuity of the flexural behavior until the failure of the girder, but also plays the role of reinforcing the cross section through the composite behavior.

Therefore, the greater the lateral compression prestress is, the greater the lateral compression prestress is, the greater the role of the flexural connector is, compared to the longitudinal compression prestress. Therefore, the segmented precast segment reinforced with the flexural connector is subjected to static behavior. It shows better performance than integrated girder.

100: PSC Girder
100a, 100b: precast segment
110a, 110b: reinforcing hole
200: bending connector
300: fixing plate

Claims (3)

In order to ensure the continuity of the bending moment acting on each connection part of the segmented precast segment girder in the segmental fabrication of the precast prestressed concrete beam which is manufactured to introduce the longitudinal compression prestress,
In the connecting portion, a flexible connecting member is installed so as to penetrate laterally both side ends of adjacent precast segment girder in tension and settle after tension,
By installing the longitudinal connecting member, such as a backing plate that is installed even through the flexible connector while connecting the both side ends in the longitudinal direction, the transverse compression prestress is introduced along with the longitudinal compression prestress to the connection portion. A method of reinforcing the joints of segmented precast concrete beams. The segmented precast concrete beam connection of claim 1, wherein the flexible connecting member is inserted into a reinforcing hole penetrating both end portions of the precast segment girder, and the reinforcing hole is formed in an arc shape. Site reinforcement method. In the method of segmenting and fabricating precast prestressed concrete beams fabricated to introduce longitudinal compression prestresses,
Segment the precast prestressed concrete beams to produce a plurality of precast segment girders, wherein the amount of adjacent precast segment girder adjacent to the joints to ensure continuity of the bending moment acting on each joint of the segmented precast segment girder. Forming a reinforcing hole penetrating the side end portions in a transverse direction, wherein the reinforcing hole is formed in an arc shape;
Inserting a flexible connecting member into the reinforcing hole, and connecting both side end portions in a longitudinal direction to each other to install a longitudinal connecting member such as an adder plate installed through the flexible connecting member;
Introducing longitudinal compression prestress throughout the plurality of precast segment girders and introducing transverse compression prestresses along with tensioning and anchoring the flexural connectors together with longitudinal compression prestresses in the joints; Bridge construction method using reinforcement method of segmented precast concrete beam, characterized in that.

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