KR100724739B1 - Construction method of PSC Girder bridge using Retensionable and Detensionable anchorage with unbonded tendon - Google Patents

Abstract

The present invention relates to a method for constructing a PSC girder bridge, wherein the primary steel wire is tensioned by the weight of the PSC girder and the weight of the half-section precast deck, and then a half-section precast deck is formed on the beam installed on the bridge. In addition to the construction, the continuous point portion is cast in the field, connected to the cross beam, the secondary steel wire is tensioned, the site-pouring bottom slab is constructed, the upper surface is paved, the second fixed load is loaded, and the bridge is completed; In addition, by using the anchorage and steel wire which can adjust the tension, the bottom plate can be replaced while the tension of the secondary steel is removed and the additional tension can be added if the load capacity needs to be increased, thereby improving the structural efficiency and ensuring the stability of the bridge. Provide construction method of

Continuous steel wire, half-section precast deck, tension adjustment, protrusions, tension

Description

Construction method of PSC Girder bridge using Retensionable and Detensionable anchorage with unbonded tendon}

1A is a schematic side view of a PS girder according to the present invention applied to the center span of a multi-span continuous bridge.

FIG. 1B is a schematic perspective view of the PS girder shown in FIG. 1A.

FIG. 1C is a cross-sectional view taken along the line A-A of FIG. 1A.

1D is a cross-sectional view taken along line A′-A ′.

FIG. 2A is a schematic perspective view showing part of a continuous point portion in a state where two PSC girders having completed tension of a primary steel wire in a two-span continuous bridge are hypothetically arranged side by side on a pier or alternating bridge in accordance with the present invention; FIG. .

FIG. 2B is a schematic side view of a state in which two PSC girders are hypothesized continuously in a longitudinal direction in a two span continuous bridge according to the present invention. FIG.

FIG. 2C is a schematic side view of a state in which a part of the bottom plate slab is constructed at the connecting portion when two PSC girders are continuously laid vertically in a two-span continuous bridge; FIG.

FIG. 2D is a cross-sectional view taken along the line B-B of FIGS. 2B and 2C.

FIG. 2E is a cross-sectional view taken along the line B'-B 'of FIG. 2C.

3A and 3B are schematic side views showing the secondary steel wire passing continuously inside the protrusions in a two-span continuous bridge according to the present invention, and FIG. 3A shows a shape in which the secondary steel wire is arranged in the state of FIG. 2B. 3b shows a shape in which secondary steel wires are arranged in the state of FIG. 2c.

Figure 4 is a schematic side view showing a state in which the secondary fixed load due to the weight of the concrete slab slab and the weight of the facility after the construction of the concrete slab slab is completed in the present invention.

5 is a cross-sectional view showing a schematic cross-sectional shape in the middle of the span of the bridge to explain the effect according to the present invention.

6 is a cross-sectional view comparing the cross-sectional state at the continuous point portion of the bridge to explain the effect according to the present invention.

7A, 7B, 8A, 8B and 9 are schematic side views showing the working process when replacing the bottom plate of a continuous bridge constructed in accordance with the present invention, respectively.

10 is a schematic cross-sectional view for explaining the bridge mold height reduction effect according to the present invention.

11 is a view showing the construction step of the short span bridge as another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: 1st steel wire 5: 2nd steel wire

10: PS girder 14: protrusion

30: continuous point part 40: bottom plate slab

The present invention relates to a method for constructing a PSC girder bridge, and in particular, by introducing a secondary tension force in the non-synthetic state of the bottom plate and the PS girder, it is possible to enhance the efficiency of the tension force introduction and to ensure stability when replacing the bottom plate. The construction method of the CS girder bridge having a configuration that allows the release and retension of the tension force so as to enable.

In general, Prestressed Concrete (PSC) bridges are heavy and take a long time to cure, and the cross-sectional force generated by the construction stage is severe. However, there is an advantage that the change in the sectional force according to the construction stage can be efficiently managed using the steel wire.

As a result, FCM (Free Cantilevering Method), ILM (Incremental Launching Method), MSS (Movable Scaffolding System), PSM (Precast Segmental Method) are applied at home and abroad. The cross-sectional force generated according to the stage is constructed by appropriately placing the wire and adjusting the amount of steel in each stage.

In the case of PS girder, due to the convenience of construction, a construction method in which the steel dose to the load acting on the girder is collectively introduced and hypothesized at the time of manufacture of the girder is common. In the 1990s, however, the Splice Girder method was applied to construct the effective cross-section overseas and to construct the PS girder over long spans. Tension was performed.

As a related art, a design method and a girder of "structural continuity method of prestressed concrete composite i-beam bridge" disclosed in Korean Patent Laid-Open Publication No. 1999-68518, and a "multistage tensioned prestress girder disclosed in Publication No. 2001-36486 Manufacturing method "and the like.

However, the invention disclosed in Korean Patent Laid-Open Publication No. 2001-36486 is theoretically possible, but it is practically impossible, and it is applied to actual construction with a different content from that of developing a public method. In particular, the following problems are being applied to design and construction without providing solutions.

First of all, the theory suggested to pursue economic feasibility by increasing the efficiency of the steel wire by tensioning the continuous steel before hardening the bottom concrete, but in reality, the tension of the continuous steel is impossible before the concrete of the bottom concrete is hardened. And on construction, the bottom plate concrete is strained after hardening. Therefore, not only a large amount of tension is required, but also a cause of structural instability and economic deterioration due to overtension of the beam.

In addition, in the above-mentioned Patent Publication No. 2001-36486, it is possible to reduce the sentence height by the concept of step tension, but when the bottom plate of the PS girder is replaced, the loading load (bottom plate weight + secondary fixed load + live load) disappears. Therefore, the problem of exceeding the concrete allowable compressive stress of the beam due to the overtension due to the tension in the center of the beam rather occurs. Therefore, in order to solve this problem, unlike the claim in 2001-36486, the situation is designed and constructed to maintain the beam height of the larger than before.

That is, the actual construction state is to replace the bottom plate in the state of securing the stability of the beam sufficiently large, so that it is no different from the stress state according to the general method of the PS girder that was applied in the past, eventually There is a problem in that the effect of the sentence of death is reduced.

The present invention was developed to solve the above problems of the prior art, in the tension of the PS girder in a multi-stage, in the central portion of the PS girder, a half-section precast bottom plate is formed on both sides of the upper surface of the girder, At the point of the CS girder, the cross beam and the cast-in-place connection are placed in the bottom plate , and the second steel wire is tensioned, thereby increasing the efficiency of introducing the steel wire and replacing the bottom plate with the steel wire removed. It aims to ensure the stability of the bottom plate replacement, thereby enabling the construction of economical bridges with a low profile in the long span.

In order to realize the above problem, in the present invention, the primary steel wire is installed in the PS girder, and the primary tension force is introduced into the PS girder by being strained by the weight of the PS girder and the weight of the half-section precast bottom plate. ; Laying the PS girder over a piers or alternating, and then laying a half-section precast deck between the top flanges of the PS girder arranged side by side; Introducing a secondary tension force into the PS girder by tensioning the secondary steel wire disposed on the PS girder while the PS girder and the half-section precast deck are unsynthesized; And constructing the bottom slab by constructing the cast-in-place concrete on top of the half-section precast deck, thereby providing a method of constructing a PSC girder bridge using a tension-adjustable anchorage.

In the present invention, the construction method, the construction method of the PS girder bridge using the anchorage controllable anchorage, characterized in that it comprises the step of further strengthening the tension force by further tensioning the secondary steel wire after completing the bridge Is provided.

Particularly, in the present invention, in the above-described construction method, when the bridge slab is replaced after the bridge is completed, a part of the tension of the secondary steel wire is removed, and when the replacement of the slab slab is completed, the secondary steel wire is retensioned again. Provided is a method of constructing a PS-C girder bridge using a fixing device capable of adjusting the tension force.

In addition, in the present invention, in order to construct a two-span or multi-span continuous bridge by using the above-described construction method, in the case of mounting the PS girder in which the primary tension force is introduced, a plurality of PS girder is continuously hypothetically installed and; In the continuous point portion of the longitudinally continuous PS girder, the bottom plate slab is constructed by cast-in-place concrete; The secondary steel wire is disposed continuously in the longitudinally continuous PSC girder; The tension of the secondary steel wire is made after the bottom slab slab by the in-situ concrete is constructed in the continuous point portion; Construction of the bottom slab by constructing the cast-in-place concrete on top of the half-section precast deck over the foreground is performed after the introduction of the secondary tension due to the tension of the secondary steel wire. Provided are methods for constructing PS Girder bridges.

In this construction method, the continuous point portion of the PS girder has a projection formed on the upper flange upper surface; The continuous secondary steel wire is preferably disposed to pass through the protrusion at the continuous point portion.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, the configuration of the present invention will be described in the order of an embodiment for a multi-span continuous bridge and an embodiment for a short-span bridge.

FIG. 1A is a schematic side view of a PS girder according to the present invention applied to a center span of a multi-span continuous bridge, and FIG. 1B is a schematic perspective view of the PS girder shown in FIG. 1A. FIG. 1C is a cross-sectional view taken along the line A-A of FIG. 1A, and FIG. 1D is a cross-sectional view taken along the line A'-A '. In FIG. 1A, the primary steel wire 1 embedded in the girder is indicated by a solid line for convenience.

As shown in the drawings, the primary steel wire 1 is disposed inside the PS girder 10, and the weight of the PS girder 10 and the weight of the half-section precast bottom plate 20 to be described later are equal to the weight. Prestressing the primary steel wire (1) introduces a primary tension force. In the embodiment shown in the drawing, the CS girder 10 consists of an 'I' beam consisting of an upper flange 12, an abdomen 18 and a lower flange 16, the lower flange 16 being pier or alternating. Installed above, the upper flange 12 supports the bottom plate.

When constructing a two-span continuous bridge or a multi-span continuous bridge, the upper flange of the PS girder 10 at the continuous point portion in which both side PS girder 10 continuously arranged in the longitudinal direction are continuous as shown in the drawing. (12) The protrusion part 14 is formed in the center part of the upper surface. In particular, in the case of a multi-span continuous bridge, as shown in FIGS. 1A and 1B, the CS girder 10 between the middle grounds has a symmetrical structure, and the protrusions 14 protrude from the center of the upper surface of the upper flange 12. Has As described above, the continuous steel wires, that is, the secondary steel wires 5 pass through the PS 14 in the protrusions 14 formed at the continuous point portions in which both sides of the PSG girder 10 are continuous to each other. However, in the case of a short span bridge, such a protrusion 14 is not necessary. In the case of a two-span continuous bridge, the protrusion 14 is formed only at the girder continuous point portion on the pier, and the protrusion is not necessary at each end of each girder outer side.

When the PS girder 10 is manufactured and the introduction of the primary tension force by the tension of the primary steel wire 1 is completed, the PS girder 10 is hypothesized on the pier or the shift, and the upper portion of the PS girder 10 is formed. Install the half-section precast bottom plate 20. In multi-span continuous bridges or two-span continuous bridges, in-situ concrete is casted at continuous points between the CS girder 10 to form a connection to connect neighboring PS girder 10 to each other in the longitudinal direction. Horizontal beams made of steel or precast concrete are installed between the PS girder 10 arranged side by side in the lateral direction.

Specifically, FIG. 2A schematically shows a part of the continuous point portion in a state where two PSC girders 10 in which the tension of the primary steel wire 1 is completed in a two-span continuous bridge are hypothetically arranged side by side on a pier or shift. 2B is a schematic side view of a state in which two PSG girders 10 are continuously installed in a longitudinal direction in a two-span continuous bridge, and FIG. 2C shows two PSC girders ( A schematic side view of a state in which a part of the bottom plate slab is constructed at the connecting portion in the longitudinal succession of 10 is shown in FIG. 2D, a cross-sectional view along the line BB of FIG. 2C, and in FIG. 2E. A cross-sectional view along line B'-B 'of 2c is shown.

As shown in the figure, the upper flanges of the PSC girder 10 which are side by side in the state in which the two PSC girders 10, in which the tension of the primary steel wire 1 is completed, are laid side by side in the lateral direction. 12, half-section precast bottom plate 20 is installed. In the case of the multi-span continuous bridge or the two-span continuous bridge, the connecting portion is formed so that the girder 10 is connected by the site-casting concrete at the continuous point portion between the neighboring PS girder 10 in the longitudinal direction. As shown in FIG. 2C, concrete may also be poured on top of the connection part so that a part of the bottom slab slab 30 may be constructed. In addition, the concrete cross beam 50 may be formed in the transverse direction between the PS girder (10).

Here, the half-section precast floor plate 20 is configured to be prefabricated and transported in a factory or a manufacturing site, and is installed between the CS girder 10 as described above and then casts concrete on the site to bridge the bridge. It forms a bottom plate. By using such a half-section precast bottom plate 20, formwork, clubs, etc. are not necessary at the time of bridge deck construction.

As such, when the installation of the semi-sectional precast deck 20 and the construction of the connection part by the site concrete at the continuous point part are completed, the secondary steel wires disposed in the PS girder 10 continuously arranged in the longitudinal direction ( Sequential wire) (5) to introduce a secondary tension. At this time, since only the half-section precast bottom plate 20 is placed in the center portion of the CS girder 10, the cross section of the bridge is in a non-synthesized state in which the cross section of the PS girder 10 and the bottom plate section of the upper portion thereof are not synthesized. In this non-synthetic cross-sectional state, the secondary steel wire 5 is tensioned to introduce a secondary tension force, thereby achieving sufficient reinforcement effect even with a small amount of secondary tension. In other words, it is possible to exert a sufficient reinforcing effect even with a small amount of wire or a small amount of tension.

As shown in the drawing, the PS girder 10 is provided with a sheath tube in which the secondary steel wire 5 is inserted and installed. In particular, in the continuous placement of the secondary steel wire (5) in the CS girder (10) continuously placed in the longitudinal direction, the secondary steel wire (5) at the continuous point portion of the upper flange ( 12) passes through the inside of the protrusion 14 formed to protrude. 3A and 3B are schematic side views showing the secondary steel wire 5 continuously passing through the inside of the protrusion 14 in a two-span continuous bridge, in which the secondary steel wire in the state of FIG. 2B is shown. FIG. 3B illustrates a shape in which the secondary steel wire is disposed in the state of FIG. 2C. 3A and 3B, the primary steel wire 1 and the secondary steel wire 5 are indicated by solid lines for convenience.

In this way, after the introduction of the secondary tension by the tension of the secondary steel wire (5), the concrete is placed on top of the half-section precast bottom plate 20 that has already been installed, the concrete slab slab (40) for the entire span Will be constructed. After the construction of the concrete slab slab 40 is completed, if the pavement work is performed and other road facilities are installed, the bridge is completed and the vehicle can pass. 4 is a schematic side view showing a state in which the secondary fixed load due to the weight of the concrete slab slab 40 and the weight of the facility after the construction of the concrete slab slab 40 is completed.

In the following, advantages according to the present invention will be described in comparison with the case of the prior art Patent Publication No. 2001-36486.

Figure 5 shows a schematic cross section in the middle of the span, Figure 5 (a) shows the non-synthetic cross-sectional state presented in the Patent Publication No. 2001-36486, (b) is the actual Patent Publication 2001 -36486 shows a cross section of the synthesized state when the technique of -36486 is actually applied, (c) shows a non-synthetic cross section state in the construction method according to the present invention.

In the middle of the interval, Korean Patent Laid-Open Publication No. 2001-36486 proposes a non-synthetic cross-sectional state in which the bottom plate and the PSC girder are not synthesized with each other, as theoretically, before the bottom plate is cured as shown in FIG. 5 (a). The method of introducing the secondary tension by prestressing the secondary steel wire only to the sea girder (B), but in practice, it is impossible to tension the secondary steel wire before the concrete of the bottom plate is cured. As shown in (b) of 5, the concrete slab slab (S) is completely cured on the CS girder (B) to prestress the secondary steel wire in the cross-sectional state where the bottom plate and the PS girder are combined to introduce the secondary tension force. You have no choice but to use the method.

However, in the present invention, as described above, as shown in (c) of FIG. 5, the secondary steel wire is formed in a non-synthetic cross-sectional state in which the half-section precast sole plate 20 is simply placed on the top of the PS girder 10. Prestressing introduces secondary tension. Therefore, since the load by the half-section precast bottom plate 20 is in a loaded state, there is an advantage that the secondary steel wire 5 can be additionally tensioned, and prestressing is performed for the non-synthetic cross section. The effect of increasing the efficiency of prestressing is exerted.

On the other hand, the present invention also has advantages in the continuous point portion. 6 is a cross-sectional view comparing the cross-sectional state of the continuous point portion of the PS girder, Figure 6 (a) is a non-synthetic cross-sectional state of the continuous point portion shown in the Patent Publication No. 2001-36486 (B) shows the cross section of the state where the girder and the bottom plate are synthesized in the continuous point portion when the technique of the actual patent application 2001-36486 is actually applied, (c) is in the construction method according to the present invention It shows the non-synthetic cross section of the continuous point.

Even in the case of the continuous point portion, Korean Patent Laid-Open Publication No. 2001-36486 describes a theoretically non-synthetic cross-sectional state in which the bottom plate and the PSC girder are not synthesized with each other as the state before the bottom plate is cured, as shown in FIG. 6 (a). The method of introducing the secondary tension by prestressing the secondary steel wire only to the sea girder (B), but in practice, it is impossible to tension the secondary steel wire before the concrete of the bottom plate is cured. As shown in 6 (b), the concrete slab slab (S) is completely cured on the PS girder (B) to prestress the secondary steel wire in the cross-sectional state where the bottom plate and the PS girder are combined to introduce the secondary tension. You have no choice but to use the method.

However, in the present invention, as described above, as shown in FIG. 6C, the secondary steel wire is formed in a non-synthetic cross-sectional state in which the half-section precast sole plate 20 is simply placed on the top of the PS girder 10. Prestressing introduces secondary tension.

In particular, in such a case, in the present invention, as shown in FIG. 6C, a protrusion 14 is formed on the top of the PS girder 10, and the secondary steel wire 5 is formed on the protrusion 14. Since it is configured to pass through, the eccentric distance e2 in FIG. 6 (c) becomes larger than the eccentric distance e1 in FIG. 6 (b), which ultimately maximizes the amount of eccentricity of the wire, thereby maximizing tension efficiency. It becomes possible. Therefore, according to the present invention, the most efficient cross section and steel wire management is possible, and all the loads can be satisfied in common.

On the other hand, Figure 7a to Figure 9 is a schematic side view showing the working process when replacing the bottom plate of the continuous bridge constructed by the method as described above, Figures 7a and 7b shows a state in which the tension is partially removed 8A and 8B illustrate a state in which the bottom plate is removed, and FIG. 9 illustrates a restrained state. 7A and 8A show the state in which all of the bottom plate slab 30 is removed, and FIGS. 7B and 8B show a state in which a part of the bottom plate slab 30 formed in the connection part is left.

When the bottom plate slab 40 is removed in order to replace the bottom plate slab 40 installed on the top of the PS girder 10, the self weight, the secondary fixed load, and the live load of the bottom plate slab 40 are removed. As the load acting on the PS girder 10 is reduced and the cross-sectional area is reduced, the PS girder 10 is in an overtension state. In order to alleviate the overtension when the bottom plate slab 40 is replaced, first, the tension of the secondary steel wire 5 is alleviated to remove some of the secondary tension force and prevent the overtension state (FIG. 7a, 7b) the bottom plate slab 40 is replaced (FIGS. 8A and 8B), and when the bottom plate slab 40 is replaced, the secondary steel wire 5 is re-tensioned again (FIG. 9).

In this case, the secondary steel wire 5 uses an unbonded steel wire to remove tension and retension. In addition, the fixing device for fixing both ends of the secondary steel wire (5) is to use the anchoring opening capable of retensioning and tension relaxation (detensioning).

The anchorage capable of adjusting the tension force is configured to allow the tension and relaxation of the secondary steel wire 5, and connects a jack to an anchor head or the like as well as a wedge at both ends of the secondary steel wire 5 as employed in a general cable-stayed bridge. It is configured to remove tension or retension of the steel wire.

On the other hand, the secondary steel wire (5) is usually maintained to the maximum possible tension of only 75% or about 60 ~ 65% of the maximum tensile stress (GUTS), so that the tension can be added if necessary, easy maintenance of the bridge And load capacity can be increased. Therefore, according to the present invention, it is possible to reduce the height of the bridge. FIG. 10 is a schematic cross-sectional view for explaining such a bridge mold height reduction effect, FIG. 10A is a schematic cross-sectional view of a conventional preplex beam, and FIG. 10B is a schematic cross-sectional view of a bridge according to the present invention.

As shown in the figure, the present invention can further reduce the mold height of the bridge mold (Y2 in FIG. 10B) than in the prior art, so that the height Y2 of the bridge according to the present invention is shown in FIG. 10A, as shown in FIG. 10B. It can be reduced to a degree similar to the height of the preflex (Y1) of the preflex, so that sufficient competitiveness can be secured for the preflex beam.

11 is a view showing a construction step of a short span bridge as another embodiment of the present invention. In Fig. 11, the PS girder 10 is shown in simplified form.

Looking at each construction step, as shown in Figure 11a to manufacture a PS C girder 10, the primary steel wire 1 is disposed in the manufacturing site, the weight of the PS girder 10 and the bottom plate 20 to be described later Prestressing the primary steel wire (1) by the weight of the) to introduce the primary tension force and then hypothesized in the shift. In the case of the PS girder 10 for the multi-span bridge shown in FIGS. 1A and 1B, the protrusion 14 is formed on the upper flange, but in the case of the PS girder 10 for the construction of the short-span bridge. No such protrusions 14 are needed.

Subsequently, as shown in FIG. 11B, a cross beam is constructed between the PSG girders 10 arranged side by side, and a half-section precast bottom plate 20 is installed on the upper surface of the PSC girders 10. . After introducing the secondary tension force by tensioning the secondary steel wire 5 as shown in FIG. 11C, and then constructing the bottom plate slab 40 over the foreground using the site-casting concrete as shown in FIG. Road facilities such as this will be installed.

In the construction method of the PS girder bridge according to the present invention configured and operated as described above, the secondary steel wire in a non-synthetic cross-sectional state in which the half-section precast sole plate 20 is simply placed on the top of the PS girder 10. Since the second tension is introduced by prestressing, there is an advantage that the second steel wire (5) can be additionally tensioned, and the prestressing for the non-synthetic cross section is made, thereby increasing the efficiency of prestressing. Exerted.

In addition, when the construction method according to the present invention is applied to a two-span or multi-span continuous bridge, the secondary steel wire 5 is configured to pass through the protrusions 14 formed on the upper part of the PS girder 10, thereby making it secondary. It is possible to increase the eccentricity distance (e2) of the steel wire (5), thereby maximizing the amount of eccentricity of the steel wire is effective to maximize the tension efficiency. Therefore, according to the present invention, the most efficient cross-section and steel wire management is possible, and all loads can be satisfied during common use, and the construction of low-profile bridges in long spans is possible, thereby increasing economic efficiency.

In addition, the secondary steel wire 5 in the present invention is configured to be able to remove the tension and re-tension, when replacing the bottom plate slab 40 installed on the top of the PS girder 10, the secondary steel wire ( 5) to reduce the tension of the secondary slab to remove some of the secondary tension to prevent the overstress state to replace the slab 40, and after the replacement of the bottom slab 40, the second steel wire (5) will be retensioned. Therefore, the effect of being able to prevent the overtension state of the PS girder 10 that may occur when the bottom plate slab 40 is replaced.

Claims (5)

Installing a primary steel wire to the PS girder and introducing the primary tension force to the PS girder by tensioning the weight of the PS girder and the weight of the half-section precast deck; A PS girder installation step of installing the PS girder in which the primary tension force is introduced side by side in a lateral direction on a piers or shifts; Installing a half-section precast bottom plate between the upper flanges of the PS girder installed side by side in the transverse direction; A second tension force introduction step of introducing a secondary tension force into the PS girder by tensioning a secondary steel wire disposed on the PS girder while the PS girder and the half-section precast bottom plate are unsynthesized; And A construction method of the PS girder bridge using the anchorage adjustable anchorage, comprising: a bottom plate slab construction step of constructing the bottom plate slab by constructing the site-cast concrete on top of the half-section precast bottom plate. The method according to claim 1, After the completion of the bridge further comprising the step of additional tension of the secondary steel wire to further reinforce the tension force construction method of the PS girder bridge using a tension adjustable anchorage. The method according to claim 1, When the bridge slab is replaced after the bridge is completed, the tension of the secondary steel wire is partially removed, and when the replacement of the slab slab is completed, the second steel wire is re-tensioned, the anchorage is adjustable tension fixing device Construction method of used PS Girder bridge. The method according to any one of claims 1 to 3, In the PS girder installation step, a plurality of PS girder is mounted in the longitudinal direction neighboring between the shift and the piers or between the piers and the piers; Simultaneously with or after the installation of the half-section precast deck, successive points between the longitudinally neighboring PS girders are placed on-site pour concrete to install connections between the PS girders, and A secondary tension introduction step is performed; The secondary tension introducing step is carried out with the secondary steel wire being continuously arranged in the longitudinally continuous PSC girder; The bottom plate slab construction step is performed after the secondary tension is introduced across the foreground of the continuously placed PS girder, thereby constructing a multi-span continuous bridge. Construction method " The method according to claim 4, On the continuous point portion of the PS girder, a projection is formed on the upper flange; The continuous secondary steel wire is arranged to pass through the protrusion at the continuous point portion, the construction method of the PS girder bridge using a tension controllable anchorage

Images