KR20130036890A

KR20130036890A - Tied arched p.s.c girder for bridge and construction method for bridge by it

Info

Publication number: KR20130036890A
Application number: KR1020110101104A
Authority: KR
Inventors: 권형규
Original assignee: 권형규
Priority date: 2011-10-05
Filing date: 2011-10-05
Publication date: 2013-04-15

Abstract

PURPOSE: A tied arch type P.S.C(PreStressed Concrete) girder for a bridge and a bridge construction method using the same are provided to apply a crane construction method, and to enable the construction of a long-span bridge by obtaining sufficient strength on an additional erection load. CONSTITUTION: A tied arch type P.S.C girder(1) comprises a lower flange, a web, a mounting hole(7) of a tendon(8), a vertical reinforcing bar(9), a horizontal reinforcing bar(10), and a cable(4). The girder is formed as a T- shaped section in which an upper flange and a web upper surface unit are omitted. The assembly of an additional web reinforcing bar is omitted after a girder is settled by exposing the vertical reinforcing bar and the horizontal reinforcing bar to the upper side of the web of a T-shaped section. The P.S.C girder is manufactured at a manufacturing field and supports the loads for an additional construction after settling the P.S.C girder in a predetermined position using a crane. A web concrete and an upper slab(12) are placed in the block unit step by step by being integrated with the girder.

Description

Tied Arched P.S.C Girder for Bridge and Construction Method for Bridge By it}

In the present invention, after manufacturing (1,100) the PSC girder in the workshop, lift it with a crane and mount the girder on two points 16 at the temporary position so that the mounted girder supports the load corresponding to the additional construction part (AH). As for the girder bridge,

When viewed based on the I-shaped cross section to minimize the weight of the production girder lifted by the crane,

The upper flange 17 and the abdomen 2, the upper surface portion (W2) is omitted, the X-shaped cross-section 22 of the form consisting of the lower flange 3 and the lower abdomen (2),

It is installed over at least one point from the point portion 15 to a predetermined section or across the girder,

In the longitudinal direction, the shape of the lower flange 3 is formed in an arc shape, and the lower flange is supported at both ends 5 and 11 of the girder and is supported at both ends by an external cable 4 arranged in a straight line. As for (1,100),

After mounting the girder to the construction position by a crane is not a type to support the additional construction load in a general simple structure state,

By supporting in an arched state, the load capacity for additional load can be increased, and divided into several block units to construct step by step, and by tensioning the tension members 13 and 8 installed in each construction step,

It is a new type girder bridge that can control the increase in tension of the external cable (4) installed in the lower part of the manufacturing girder, and in the end it is possible to remove the tension.

8 is a conventional tide arch bridge with both ends 11 constrained by a lower chord 18, which generally corresponds to a bridge deck. Structurally, the arch girder 19 generates a compressive force and a lower chord.

Figure 6 is a conventional PSC-I girder bridge is constructed by the crane construction method is good construction work, but the load capacity is less than the arch structure is limited to the construction between the long jijanggi also increases the capacity of the crane construction machine because the girder self-weight is increased during the inter-janggae construction. In addition, the girder type in which the longitudinal shape of the lower surface is arcuate becomes the simple structure type similar to the conventional PSC girder bridge.

Figure 9 is a conventional cantilever temporary installation method is required a separate construction work vehicle 20 is a form that takes a lot of air due to the construction speed is very slow due to site casting.

The advantage of this type is that by constructing each block 23 from the point part 15 toward the center part in a balanced manner, the tension member 13 is provided with a stress during the large construction stress generated at the point part 16 every step. It is possible to control the large cross section as shown in FIG.

In order to reduce the cost of constructing the girder type bridge which is constructed in the long span, the crane method is effective.

In order to construct a bridge type between cranes and cranes, it is necessary to reduce the weight of the girder manufactured in the workshop.

In addition, it is necessary to have a structural form to secure a sufficient strength for the load corresponding to the additional construction (AH) after lifting by the crane.

Therefore, PSC girder bridge, which can be used for crane construction, and arch structure with excellent load-bearing capacity, and a new type of bridge construction method that combines cantilever method that enables construction of long section bridges by allowing construction of large sections through step-by-step construction Required.

When viewed based on the I-shaped cross section to minimize the weight of the production girder lifted by the crane

The upper flange 17, SL and the abdomen upper surface portion W2 are omitted so that the X-shaped cross section 22 formed of the lower flange 3 and the abdomen lower surface portion W1 is at least from the point portion 15 to a predetermined section. It is installed over the entire length of the installation or girder,

In addition, when manufacturing the girder to expose the vertical reinforcement (9) and the horizontal reinforcement (10) over the abdomen (2) of the X-shaped cross-section to omit the assembly of additional abdominal reinforcement after the girder.

In the longitudinal direction, the shape of the bottom of the lower flange (3) is made in the shape of an arch,

Cable anchorages 5 formed with holes 6 at both ends of the girder are provided,

Under the lower flange 3, an external cable 4 which is supported through a hole in the fixing unit 5 provided at both ends 11 of the girder and arranged in a straight line is installed, and is supported at both ends by the cable 4, respectively. Is made in the shape of an arch,

After mounting the fabricated girders (1,100) on the two points (16) to be lifted by a crane

Abdominal concrete (W2) and upper slab (SL, 12) integrally with the production girder (1,100) on the top surface of the production girder in the state that the tide arched manufacturing girder (1,100) serves as a support girder for the additional construction (AH) ) Into several blocks (23) to pour step by step,

From the point portion 15 of the pier to the center portion of the inter-portion at the same time to be balanced in both left to right, or to the left and right alternately,

Later to remove the tensile stress generated in the upper slab 12 of the concrete block and the tensile stress generated in the lower surface (3) of the manufacturing girder by the concrete concrete block,

Installed to remove the tension of the external cable (4),

After tensioning the tension member 13 inserted into the sheath pipe disposed inside the upper slab 12 cast in the predetermined block unit at the construction joint 24 after tension is fixed, or

By tensioning and fixing the tension member 8 provided in the lower flange 3 of the production girder

The tension increase of the external cable (4) installed in the lower part of the manufacturing girder can be controlled

Eventually, a greater tension is introduced into the tension members 13 and 8 to allow the cable 4 to be removed.

In this way, the longitudinal shape of the final bridge is the lower flange (3) is arcuate, long cross-section bridge of the long cross-section type of the high cross-section height of the point portion 15, the center portion can be implemented.

In order to cope with the lower surface of the intermediate point portion 15 of the bridge implemented by the present invention generally takes a large compressive stress,

After the two girders (1,100) are arranged in the longitudinal direction and two or more in the transverse direction, the lower flange (3) of each girder is connected to a predetermined thickness, and the end surface of the bridge 14 is closed. It is configured to include the characterized in that the section of the closed cross-section is installed in the quarter to at least 1/4 of the interval from at least the intermediate point portion 15.

Due to the omission of the upper part of the upper part (W2) and the upper flanges (12, SL) on the girder cross-section can reduce the weight of the manufacturing girder (1,100) can be applied to the crane construction method in the bridge construction between the long,

By installing the cable 4 which is supported at both ends 11 and exposed to the lower part of the girder, it is possible to safely support the additional temporary load (AH) in the arch structure.

By applying tension to block tensions (13, 8) installed in each block and the step of concrete placing, such as the cantilever method, tension is increased in the lower cable (4) of the production girder (1,100) by the concrete placing loads in each stage. Facilitates the transition to (13,8).

In other words, the increase in the stress of the production girder during any construction stage is generated by the load placed in the construction stage, and after the concrete is cured, the stress applied to the fabrication girder is introduced by introducing tension force to the tension member 13 disposed at the stage. As a result, the strength of the production girder is sufficient to support only the block load corresponding to one construction stage throughout all construction stages. Therefore, the rigidity of the production girder does not have to be very large, but it can have the advantages of the cantilever method. have.

In other words, it is possible to construct a bridge between the long sections. Above all, there is no need for a separate upper construction work vehicle 20 and the air is greatly shortened.

6 and 7 are longitudinal cross-sectional views of a conventional PSC girder bridge. In general, the fabrication beam is composed of an upper flange 17, an abdomen 2, and a lower flange 3, and a type I cross section is used. At this time, the upper flange 17 and the lower flange 3 is kept horizontal.

Recently, in consideration of aesthetics, the lower surface of the lower flange 3 may be used in the case of an arch shape. In this case, the upper flange 17 remains horizontal and structurally behaves as a simple PSC girder bridge. .

8 is a tide arch structure in which both ends are constrained to the lower chord.

Features of the present invention will be described in comparison to conventional bridge formats.

The present invention is about the structural form at the time of construction, and after completion of the bridge, it will behave like the general girder bridge. In other words, the construction form at the time of construction is hypothesized to combine ordinary PSC girder bridge and tide arch structure form.

In more detail, the manufacturing girder (1,100)

When the shape is viewed in the longitudinal direction of the girder, the lower surface of the lower flange 3 has an arch shape with a high ELEVATION in the center and a low point, and is supported by the fixing unit 5 provided at both ends of the girder. It is a structure reinforced by an external cable 4 arranged horizontally while being exposed under the girder lower flange 3.

In addition, unlike ordinary PSC girder bridge, the abdomen is cast twice when manufacturing the girder and after the girder is mounted. This is distinguished from the type in which only the lower flange 3 is arched. The type in which only the lower flange is arched is the same condition. At the point 15, the weight of the girder becomes too large due to the increase in the self weight.

Therefore, one of the features of the present invention is that the abdominal height (W1) of the production girder (1,100) produced on the ground from the entire length of the PSC girder to at least a certain section from the point 15, than the abdominal height (W3) after the completion of the final bridge It is provided with an arcuate girder formed with a small predetermined height and including an X-shaped cross section 22.

Therefore, the longitudinal shape of the lower surface of the lower flange (3) of the girder is formed in an arc shape, and is arranged in a straight line exposed under the lower surface of the arcuate lower flange (3) and supported by the fixing holes (5) at both ends of the girder. By installing the external cable 4, a tide arched PSC girder 1,100 having a so-called curved cross section 22 is realized.

The installation section of the X-shaped cross section 22 is provided over the entire length of the girder, or at least 15% of the space from both of the point portions 15. On the other hand, the important reason for splitting the girder's abdomen twice during manufacturing and after mounting is to reduce the weight of the girder point and to install two or more span bridges.

The connection of the continuous girder can be assured more than the connection of the intermediate point portion 15 of the ordinary girder bridge. This is because there is much space to connect and pour as much as the abbreviated abdomen W2 and the upper flanges 17 and SL.

And more importantly, the construction of the construction girders (1,100) against the pour load (AH) after the girder through the construction by enabling the step-by-step construction by dividing the construction by a predetermined block unit from the middle point portion 15 to the center of the girder The cross section of the point portion 15 can be transferred.

This is realized by providing a tension member 13 in the upper slab 12 at each stage and introducing a tension force after curing.

This is described in more detail as follows.

Tide arch PSC girder (1,100) with an abdominal shape (W2) and an upper flange (17) omitted, an arcuate shape in the longitudinal direction, and both ends supported by a cable (4), and then lifted by a crane It is mounted on two points 16 of. After repeating this process for more than two spans in a row, the intermediate point portion (16) is added to the additional visible powder (AH) to be constructed after the additional construction.

In other words, the arc-shaped manufacturing girder (1,100) is sagging by the additional load for the additional construction (AH). At this time, the girder structural state behaves as an arch structure rather than a simple structure, and most of the stress increase occurs in the form of an increase in tension in the cable 4 disposed below the concrete girder cross section 22. During the construction of the block of the intermediate point 15, the tension member 13 is disposed inside the upper slab 12, and after the block 23 is cured, the tension member 13 is introduced into the tension member 13.

Then, the structural system is a continuous structure because the intermediate point portion 15 is already connected, and causes a rise in the manufacturing girder 1,100 by the tension force introduced into the upper slab 12 of the intermediate point portion. That is, the deflection of the production girder 1,100 generated by the weight of the concrete block 23 to be poured at each stage can be controlled by introducing a tension force to the tension member 13 disposed in the upper slab 12 to be cast in-situ.

In addition, it can also be controlled by introducing a tension force to the tension member (8) installed in the lower flange (3) of the production girder in advance.

In addition to this, when the tension corresponding to the amount of rise greater than the deflection is introduced, the initial tension of the cable 4 of the production girder 1,100 can be removed, and the cable 4 can be removed after the final bridge is completed.

Of course, if there is no restriction in the bridge lower space according to the construction position, the cable (4) can exist even after the completion of the bridge and the technical scope of the present invention includes both the case of the cable is present and removed after completion of the bridge.

The above example is the case of a continuous bridge, and the same is true of a simple bridge having one span.

That is, even in the case of a simple bridge, as in the continuous bridge, the tide arch-shaped manufacturing girder (1,100) supports the load under construction in an arch structure for additional load, and several blocks from both point portions 16 toward the center portion. The construction can be divided into (23) units, and the deflection occurs in the production girder (1,100) by the weight of the concrete block in each step.

At this time, the deflection can be controlled by introducing a tension force to the tension member 8 installed in the lower flange 3 of the production girder in advance.

In general, PSC girder bridges are constructed with cranes and have good constructional properties, and are particularly advantageous in terms of air compared with other construction methods (for example, field-casting cantilever construction, copper-barrier construction, etc.).

On the other hand, the maximum possible space has been limited by excessive girder weight and lack of complete continuity at the mid-point. The bridge embodied by the present invention ultimately has a purpose to replace the cantilever on-site casting method.

In other words, the cantilever method is generally constructed by balancing one block (23) from the middle point portion (15) toward the center portion of the trunk, and the length of one block is very small, such as 4M. Therefore, it takes too much time to construct the whole space and requires a separate construction work car 20. Of course, the cross section is composed of a closed cross section of the lower flange and the cross section itself is a large cross section.

In the present invention, the abdomen (W2) and the upper flange (17) is omitted, it is possible to fully lift the production girders (1,100) at a time by the crane construction method, and also the arch structure that can fully support the block weight that is installed on the girder even in the long-term state Once the middle head portion 15, which is the main head, is connected, there is an advantage of supporting the construction load in a continuous arch structure can replace the existing cantilever method of the bridge construction method.

2 or more spans in the longitudinal direction, two or more girders are arranged in the transverse direction, and the lower flange 3 of each girder is connected to a predetermined thickness to form a cross-sectional shape in which the bridge 14 is closed. It is characterized in that the section of the closed cross-section is characterized in that it is installed in the quarter or less at least 1/4 of the interval from the middle point portion 15.

1 is a longitudinal sectional view of a manufacturing girder implemented by the present invention. The abdomen 2 is divided into two parts during the girder fabrication and after the girder is placed (shape cross section) throughout the entire region, and FIG. 2 is a cross-sectional view at the point and the center of the form. As shown in the figure, the vertical reinforcing bar 9 and the horizontal reinforcing bar 10 are constructed and exposed on the upper abdomen of the manufacturing girder. This is to omit the girder reinforcing step after the girder is mounted. It also plays a role in ensuring complete connectivity at the abdominal construction interface. In addition, the cable anchorage 5 in the girder end 11 is provided with a through hole 6.

3 is another form embodied by the present invention, and the section (shape section) for partitioning the abdomen 2 is installed to a certain distance from both point portions 16 rather than the girder length. The section other than the divided casting section is composed of an I-shaped section composed of an upper flange 17, an abdomen 2, and a lower flange 3, similar to a general PSC girder cross section. This form also has the same behavior as that shown in FIG.

Unlike the type in which the cable 4 is supported by the girder end anchorage 5 at the time of fabrication of the girder as shown in FIGS. 1 and 3, after the anchorage is not installed in the girder 1,100 and the girder is mounted thereon. After the two girders are arranged in the transverse direction, the two girders (crossbeams connecting the girders and girders in the transverse direction) installed at the ends are also included within the technical scope of the present invention.

Figure 5 is a construction sequence diagram of a three-span continuous bridge as an example implemented in the present invention.

1: Longitudinal cross-sectional view of a tide arched PSC girder composed of a curved cross section over the entire span

Fig. 2: Cross sectional view of a tide arched PSC girder composed of an arcuate cross section over the whole section.

3: Longitudinal cross-sectional view of a tide arched PSC girder composed of an arcuate cross section from a point portion to a predetermined section.

4 is a cross-sectional view of a tide arched PSC girder composed of an arcuate section from a point portion to a predetermined section.

5 is a construction sequence diagram of a three-span continuous bridge that is one example implemented by the present invention

6: Longitudinal sectional view of a conventional PSC girder

7: Cross sectional view of conventional PSC girder

8: Longitudinal cross-sectional view of a conventional tide arch bridge

9: Longitudinal sectional view of the bridge constructed by the conventional cantilever method

10 is a cross sectional view of a bridge constructed by a conventional cantilever method.

1: Tide arched PSC fabrication girder consisting of a curved cross section across cells

2: abdomen

3: lower flange

4: external cable

5: end fixture

6: through hole

7: tension anchorage

8: tension member disposed in the lower flange

9: vertical rebar

10: horizontal rebar

11: end

12: Upper slab

13: tension material disposed in the upper slab

14: Lower flange for single side closing

15: middle point

16: branch

17: Upper flange

18: the present

19: Arch Girder

20: working car

21: Interior department of upper flange

22: Cross section manufactured in the shape of ┻

23: Block

24: Construction joint end

100: Tide arched PSC manufacturing girder consisting of a curved cross section over a predetermined section at the point portion

W1: Abdomen height of the production girder

W2: Additional abdominal height after placing production girder

SL: Top slab height added after mounting production girder

AH: Height of additional construction after installation

BH: Height at the time of girder production

W3: Final abdominal height after bridge completion

Claims

Bridges are constructed by manufacturing a bridge PSC girder on the ground, placing them on two points 16 on the alternating or pier, and then placing slab concrete 12 on the top of the girder to be integrated with the girder. When the bridge is completed based on the direction, the height of the abdomen 2 of the girder is changed to the point 15 having a high shape and the center portion having a low shape.

In the above-mentioned P.S.C girder produced for the bridge constructed in the shape of an arch,

A lower flange 3 of the girder, which is formed in the same arch shape as the shape of the final lower bridge 3 based on the axial direction and reinforced with the tension member 8;

On the girder section, at least four (one pair) or more are installed in the girder section at the upper surface 21 of the inner section of the lower flange having left and right inner sections with respect to the abdomen, and after the girder is mounted on the alternating or pier, reinforce the lower flange. Anchoring member 7 of tension member 8 which serves;

The abdomen 2 of the PSC manufacturing girder 1,100 is formed to a predetermined height W1 smaller than the final abdominal height W3 after the completion of the bridge, so that the cross-sectional shape of the manufacturing girder is manufactured in a ┻ shape, and manufactured in the ┻ shape. The abdomen 2 integrally provided with the lower flange 3 so that the section 22 is at least 15% of the interval between the entire section and at least the two points 15 and 16 of the girder toward the center in the longitudinal direction of the girder;

Vertical reinforcing bars 9 and horizontal reinforcing bars 10 arranged to protrude outward from the upper surface of the abdomen 2;

At least one pair of at least one pair of upper ends of the lower flanges 3 of the both ends 11 of the girder and the through holes 6 formed therein are exposed to the outside, and are provided at the both ends of the fasteners 5. A cable (4) penetrating the inside of the hole and straightly disposed under the arched girder to be exposed to the outside and fixed after tension in the end fixing unit (5) provided with the through hole (6);

Comprising the above elements, a predetermined abdominal height W1, which is smaller than the final abdominal height W3 after completion of the bridge, is formed so that a cross-section 22 formed in the shape of a zigzag is in the girder longitudinal direction at least from the predetermined length of both points. PSC manufacturing girder (1,100) formed over the section 16, characterized in that formed in the form of a tide arch girder supported by the cable (4) in the fixing unit (5) at both ends

In the continuous bridge over two spans that are arch-shaped and constructed by the P.S.C method,

Mounting the girder such that the tie arched PSC fabrication girder (1,100) of claim 1 is mounted on two points (16) of alternating and pier positions so that the girder is arranged in two or more spans;

The abdominal concrete (W2) and the upper slab (12, SL) can be integrally formed with the fabrication girder on the fabrication girder (1,100) while the PSC fabrication girder serves as a support girder for the additional construction (AH) after the girder is mounted. Dividing into three blocks (23) to pour step by step,

Later, by removing the tensile stress generated in the upper slab 12 of the concrete block and the tensile stress generated in the lower surface (3) of the manufacturing girder by the concrete concrete block, to remove the tension of the external cable (4) A step of fixing the tension member 13 disposed in the interior of the upper slab 12, which is installed for a predetermined length, and is fixed after tension at the end of the construction joint 24 after curing the concrete;

Repeating the process of tensioning and fixing the left and right balanced concrete placing and tensioning material (13) and continuing construction toward the center of the inter-zone so as to be connected to the construction-jointed end (24);

In the process of construction step by step from the point portion 15 toward the center portion of the manufacturing girder (1,100) of the production girder installed for the purpose of removing the tension of the tensile cable generated in the lower surface (3), the external cable (4) Tension-tightening the tension member 8 in the fixing unit 7 provided on the upper surface of the lower flange;

Constructed including the construction step, with the tide arched PSC manufacturing girder 1 supported on the point 16 to serve as a support girder for the additional construction (AH) after the girder is mounted, every construction step Hazardous stress due to the load applied to the fabrication girder 1,100 and the upper slab 12 at each construction stage by introducing a tension force to the tension members 13 and 8 provided in the upper slab 12 to the lower flange 3. And the construction method of the continuous bridge, characterized in that the construction step by block unit through the process of removing the cable tension

The bridge bottom portion 14 is formed by connecting the lower flange 3 of each girder to a predetermined thickness after arranging two or more girders 1 and 100 in the lateral direction and having two or more girders in the transverse direction. The construction method of the continuous bridge, characterized in that the section consisting of a closed section and the section of the closed section is installed in the range of the quarter to at least one quarter between the inter-section and at least the intermediate point portion (15).

Placing the tide arched PSC fabrication girder (1,100) of claim 1 on two points (16) alternately;

In the state where the PSC manufacturing girder 1,100 serves as a support girder for the additional construction AH after the girder is mounted, the abdominal concrete W2 and the upper slab 12 are integrally formed with the manufacturing girder 1,100 on the manufacturing girder. , SL) into several blocks (23) to pour in stages of block units,

Simultaneously construct from the point part 16 of the alternating part to the center part of the trunk to be balanced at the right and left sides or alternately from left to right, and from the tensile stress generated from the lower surface 3 of the production girder, Tension-tightening the tension member 8 in the fixing unit 7 provided on the upper surface of the lower flange of the manufacturing girder installed for the purpose of removing the tension of 4);

Repeating the above-mentioned process of tension-fixing of the concrete placing and the tensioning material, which is the left and right balance construction, connecting and constructing the connection to the center portion of the inter-zone to be connected to the construction joint 24;

The construction step including the construction step, the tide arched PSC manufacturing girder (1,100) is supported on the point 16 to serve as a support girder for the additional construction part (AH) after the girder, every construction step By introducing a tension force to the tension member (8) provided in the lower flange, the construction is carried out step by step through the process of removing the harmful stress and the cable (4) tension due to the load in each construction step applied to the manufacturing girder Hypothesis method of simple bridge