Corrugated steel web combined continuous beam bridge in prepressing hogging moment area and construction method of corrugated steel web combined continuous beam bridge

Abstract

The invention relates to the field of bridges, and aims to provide a pre-pressing hogging moment area corrugated steel web combined continuous beam bridge and a construction method thereof.The pre-pressing hogging moment area corrugated steel web combined continuous beam bridge comprises bridge piers sequentially arranged at intervals and corrugated steel web combined box beams erected at the tops of the bridge piers, and a plurality of steel pipe supports are arranged between every two adjacent bridge piers; the upper end of each steel pipe support is provided with a retractable bearing mechanism used for bearing the corrugated steel web combined box girder, and a tensioning mechanism used for applying pre-compressive stress to a hogging moment area of the corrugated steel web combined box girder is further connected between each steel pipe support and the corrugated steel web combined box girder. According to the invention, the pre-compressive stress can be applied to the hogging moment area of the corrugated steel web combined continuous beam bridge, so that the influence of cracking of a bridge concrete panel is reduced.

Description

Technical Field

[0001] The invention relates to the field of bridges, and in particular to a pre-stressed negative bending moment zone corrugated steel web composite continuous beam bridge and a construction method thereof. Background Art

[0002] The corrugated steel web composite box girder bridge, also known as the corrugated steel web PC bridge, refers to a box girder that uses corrugated steel plates to replace concrete webs as a new type of web. Its notable feature is that 10-20 mm thick corrugated steel plates replace 30-80 cm thick concrete webs, which reduces the deadweight of the bridge while ensuring the bearing capacity. Due to the supporting structural characteristics of the bridge body, the bridge body will be subjected to positive or negative bending moments in different areas. The positive bending moment refers to the tension at the bottom of the bridge body and the compression at the top, which is a "concave" shape; while the negative bending moment refers to the tension at the top of the bridge body and the compression at the bottom, which is a "convex" shape. Among them, the negative bending moment area of ​​the bridge body has an unfavorable situation in which the concrete top plate is tensile and the corrugated steel web box girder is compressed. This force structure easily causes the concrete top plate to crack and directly affects driving safety. Therefore, it is necessary to apply pre-stress to the concrete slab in the negative bending moment area of ​​the bridge body to reduce the impact of concrete top plate cracking.

[0003] In order to apply prestress to the concrete slab in the negative bending moment area of ​​the bridge, the traditional methods are:

[0004] Prestressing tendon method, preloading weight method, and raising support method, etc. Prestressing tendon method is to insert prestressed steel bars inside the concrete slab to preload the concrete slab; preloading weight method is to place weights in the positive bending moment area of ​​the beam to make the beam deflect downward, install the concrete slab in the negative bending moment area after deflection, and then unload the weights to preload the concrete slab; raising support method is to raise the support in the negative bending moment area to make the beam in the negative bending moment area deflect upward, install the concrete slab in the negative bending moment area after deflection, and then restore the support to preload the concrete slab. Summary of the invention

[0005] One of the purposes of the present invention is to provide a prestressed negative moment zone corrugated steel web composite continuous beam bridge, which can apply prestressed stress to the negative moment zone of the corrugated steel web composite continuous beam bridge to reduce the impact of cracking of the bridge concrete panel.

[0006] The object of the present invention is achieved through the following technical scheme: a prestressed negative bending moment zone corrugated steel web composite continuous beam bridge, which includes bridge piers arranged in sequence and spaced apart and a corrugated steel web composite box beam erected on the top of the bridge piers, a plurality of steel pipe supports are arranged between two adjacent piers, and a retractable supporting mechanism for supporting the corrugated steel web composite box beam is provided at the upper end of each steel pipe support, and a tensioning mechanism for applying prestress to the negative bending moment zone of the corrugated steel web composite box beam is also connected between each steel pipe support and the corrugated steel web composite box beam.

[0007] The second object of the present invention is to provide a bridge construction method for a pre-stressed negative moment zone corrugated steel web composite continuous beam bridge, and the object of the present invention is achieved by the following technical solutions:

[0008] A bridge construction method for a pre-stressed negative bending moment zone corrugated steel web composite continuous beam bridge:

[0009] Step S1: driving the bridge pier and the steel pipe columns with partition plates, discharge ports and plugging parts into the soil of the base under the bridge according to the designed positions, and connecting the steel pipe columns with each other using transverse pipe connectors, welding an annular stiffening steel plate for supporting high-strength steel bars on the upper outer peripheral wall of the steel pipe column, then filling the upper side of the partition plate with fine aggregate and inserting a supporting column on the top of the steel pipe column;

[0010] Step S2: hoisting the corrugated steel web composite box girder in sections between the bridge piers, and supporting the bottom of the corrugated steel web composite box girder on the supporting column, then laying the concrete bridge deck of the corrugated steel web composite box girder positive moment section, and pouring the wet joint of the concrete bridge deck positive moment section;

[0011] Step S3: remove the blocking member to discharge the fine aggregate out of the steel pipe column through the discharge port, so that the supporting column gradually descends and is separated from the bottom of the corrugated steel web composite box girder by a certain distance, completing the contraction work of the contractible supporting mechanism;

[0012] Step S4: firstly weld a box-shaped stiffening steel plate on the lower wing plate of the composite box girder with corrugated steel webs, then pass both ends of a plurality of high-strength steel bars through corresponding through holes on the box-shaped stiffening steel plate and the annular stiffening steel plate, and screw locking nuts on the passing parts at both ends of the high-strength steel bars to make the beam body deflect downward;

[0013] Step S5: laying a concrete bridge deck in the negative moment section of the corrugated steel web composite box girder, and casting a wet joint in the negative moment section of the concrete bridge deck to complete the construction of the entire bridge deck;

[0014] Step S6: When the wet joint strength of the concrete bridge deck on the negative bending moment section reaches 90%, unscrew the locking nut to release the tension, so that the tension under the bridge is eliminated and the bridge deflects upward in the middle of the span;

[0015] Step S7: cutting the steel pipe columns.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] 1. Through the steel pipe support and the retractable supporting mechanism, the corrugated steel web composite box girder can be reliably supported during the construction stage. At the same time, the fine aggregate is discharged through the unloading port, so that the supporting column is separated from the corrugated steel web composite box girder, and the frame is quickly unloaded, which reduces the construction cost and improves the construction efficiency;

[0018] 2. By setting up the tensioning mechanism on the composite box girder with corrugated steel webs, pre-stress can be applied to the concrete bridge deck in the negative bending moment area of ​​the bridge, reducing its cracking risk and significantly improving the stress state in the negative bending moment area of ​​the bridge body. In addition, through the coordination of the tensioning mechanism and the steel pipe support, when the prestress of the concrete bridge deck is insufficient in the later stage, it can be supplemented, achieving the effect of fast and convenient maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a pre-stressed negative moment zone corrugated steel web composite continuous beam bridge of the present invention;

[0020] Figure 2 It is a structural schematic diagram of a composite box girder with corrugated steel webs according to the present invention;

[0021] Figure 3 It is a simplified structural diagram of the steel pipe support of the present invention;

[0022] Figure 4 yes Figure 3 A simplified structural diagram of Part A;

[0023] Figure 5 It is a partial structural diagram of the tensioning mechanism of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the annular stiffening steel plate of the present invention;

[0025] Figure 7 It is a schematic diagram of the composite box girder with corrugated steel webs supported on supporting columns of the present invention;

[0026] Figure 8 It is a schematic diagram of the tensioning mechanism of the present invention for implementing tensioning;

[0027] Fig. 9 It is a schematic diagram of the prestressing method of the present invention;

[0028] Fig.10 yes Fig. 9 Schematic diagram of the local structure.

[0029] Explanation of numbers: 1 bridge pier, 2 composite box girder with corrugated steel web, 21 upper wing plate, 22 lower wing plate, 23 corrugated steel web, 3 steel pipe bracket, 31 steel pipe column, 32 transverse inter-tube connector, 4 retractable supporting mechanism, 41 supporting column, 42 partition, 43 fine aggregate, 44 unloading port, 45 plugging part, 5 tensioning mechanism, 51 box-shaped stiffening steel plate, 52 ring-shaped stiffening steel plate, 53 high-strength steel bar, 6 concrete bridge deck. DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to the accompanying drawings and embodiments:

[0031] like Figure 1-6 FIG. 1 is a schematic diagram of an embodiment of a prestressed negative moment zone corrugated steel web composite continuous beam bridge provided by the present invention:

[0032] A prestressed negative moment zone corrugated steel web composite continuous beam bridge, comprising piers 1 arranged in sequence and at intervals and a corrugated steel web composite box beam 2 erected on the top of the piers 1, a plurality of steel pipe supports 3 are arranged between two adjacent piers 1, a retractable supporting mechanism 4 for supporting the corrugated steel web composite box beam 2 is provided at the upper end of each steel pipe support 3, and a tensioning mechanism 5 for applying prestress to the negative moment zone of the corrugated steel web composite box beam 2 is also connected between each steel pipe support 3 and the corrugated steel web composite box beam 2.

[0033] Preferably, the steel pipe supports 3 are arranged at 1 / 4, 1 / 2, and 3 / 4 of the span in the middle of the side span and the middle span, and can be appropriately densely arranged according to the actual span size.

[0034] The corrugated steel web composite box girder 2 includes an upper wing plate 21 , a lower wing plate 22 and two corrugated steel web plates 23 disposed between the upper wing plate 21 and the lower wing plate 22 at the front and rear sides. A concrete bridge deck 6 is also laid on the top side of the upper wing plate 21 .

[0035] Preferably, the concrete bridge deck 6 is prefabricated in a factory.

[0036] Furthermore, a shear connector for transmitting shear force is provided between the corrugated steel web composite box girder 2 and the concrete bridge deck 6 , and the shear connector can be a shear steel bar or other shear steel member pre-embedded in the concrete bridge deck 6 .

[0037] The steel pipe support 3 includes a plurality of steel pipe columns 31 with lower ends buried in the ground and transverse inter-tube connectors 32 connected between the steel pipe columns 31 .

[0038] The retractable supporting mechanism 4 includes a supporting column 41 inserted into the top of the steel pipe column 31 and a partition plate 42 fixed on the inner wall of the steel pipe column 31, the partition plate 42 is located below the supporting column 41, and fine aggregate 43 for supporting the supporting column 41 is filled between the partition plate 42 and the supporting column 41;

[0039] The outer wall of the steel pipe column 31 is also provided with a discharge port 44 corresponding to the bottom of the fine aggregate 43. The discharge port 44 is detachably connected with a plugging member 45 for plugging the discharge port 44. When the plugging member 45 is removed, the fine aggregate 43 can be discharged to the outside of the steel pipe column 31 through the discharge port 44 under the action of gravity, and drive the supporting column 41 to slide downward.

[0040] Furthermore, the partition plate 42 is welded to the inner wall of the steel pipe column 31, and the distance from the partition plate 42 to the top surface of the steel pipe column 31 is 50 cm to 150 cm.

[0041] Furthermore, the discharge port 44 is located 1 cm to 5 cm above the partition plate 42.

[0042] Preferably, the supporting column 41 is made of steel material, and the outer diameter of the supporting column 41 is 1 mm to 10 mm smaller than the inner diameter of the steel pipe column 31.

[0043] The tensioning mechanism 5 includes a box-shaped stiffening steel plate 51 fixed on the lower wing plate 22, an annular stiffening steel plate 52 fixed on the outer periphery of the steel pipe column 31, and a plurality of high-strength steel bars 53. The box-shaped stiffening steel plate 51 and the annular stiffening steel plate 52 are provided with a plurality of one-to-one corresponding through holes, and both ends of the high-strength steel bars 53 pass through the box-shaped stiffening steel plate 51 and the annular stiffening steel plate 52 through the corresponding through holes, and locking nuts are screwed on the passing parts of the two ends of the high-strength steel bars 53.

[0044] A nut corresponding to the discharge port 44 is welded on the outer wall of the steel pipe column 31, and the blocking member 45 is a bolt threadedly matched with the nut.

[0045] In some embodiments, an internal thread is provided on the peripheral wall of the discharge port 44 , and the blocking member 45 is a bolt provided with an external thread, and the bolt can directly cooperate with the thread of the discharge port 44 .

[0046] Preferably, the diameter of the steel pipe column 31 can be selected to be 400mm ~ 800mm.

[0047] Preferably, the fine aggregate 43 is fine sand with good gradation, and the particle size of the fine sand can be smoothly discharged from the discharge port 44.

[0048] A bridge construction method using the above-mentioned pre-stressed negative moment zone corrugated steel web composite continuous beam bridge:

[0049] Step S1: The bridge pier 1 and the steel pipe column 31 with the partition plate 42, the discharge port 44 and the plugging member 45 are driven into the soil of the base under the bridge according to the designed position (a circular hole is opened in the lower part of the steel pipe column 31 driven into the soil, and during construction, the grouting pipe is fixed on the inner side of the steel pipe column 31, and the grouting pipe is used to inject the grout into the inner and outer soil of the steel pipe column 31 to increase the bearing pressure and pull-out resistance of the steel pipe column 31), and the steel pipe columns 31 are connected to each other with the transverse inter-tube connector 32, and the annular stiffening steel plate 52 for supporting the high-strength steel bar 53 is welded on the upper outer peripheral wall of the steel pipe column 31, and then the fine aggregate 43 is filled on the upper side of the partition plate 42 and the supporting column 41 is inserted into the top of the steel pipe column 31;

[0050] Step S2: Figure 7 As shown, the corrugated steel web composite box girder 2 is hoisted in sections, so that the bottom of the corrugated steel web composite box girder 2 is supported on the supporting column 41, and then the concrete bridge deck 6 of the positive moment section of the corrugated steel web composite box girder 2 is laid, and the wet joint of the positive moment section of the concrete bridge deck 6 is poured;

[0051] Step S3: Figure 8 As shown, the blocking member 45 is removed, so that the fine aggregate 43 is discharged from the steel pipe column 31 through the discharge port 44, so that the supporting column 41 gradually descends and is separated from the bottom of the corrugated steel web composite box girder 2 by a certain distance, achieving the purpose of unloading, that is, completing the contraction work of the contractible supporting mechanism 4;

[0052] Step S4: Figure 8 As shown, a box-shaped stiffening steel plate 51 is first welded on the lower wing plate 22 of the corrugated steel web composite box beam 2, and then the two ends of a plurality of high-strength steel bars 53 are passed through the corresponding through holes on the box-shaped stiffening steel plate 51 and the annular stiffening steel plate 52, and locking nuts are screwed on the passing parts of the two ends of the high-strength steel bars 53 to make the beam body deflect downward;

[0053] Step S5: laying a concrete bridge deck 6 in the negative bending moment section of the corrugated steel web composite box girder 2, and pouring a wet joint in the negative bending moment section of the concrete bridge deck 6 to complete the construction of the entire bridge deck;

[0054] Step S6: When the wet joint strength of the concrete bridge deck 6 on the negative bending moment section reaches 90%, unscrew the locking nut to release the tension, so that the tension under the bridge is eliminated and the bridge deflects upward in the middle of the span;

[0055] Step S7: cutting the steel pipe column 31.

[0056] Step S8: Figure 9-10 As shown, a portion of the height of the steel pipe column 31 on the ground is retained, and an annular stiffening steel plate 52 is re-welded on the outer peripheral wall of the remaining steel pipe column 31 for later supplementation of pre-compression stress;

[0057] When the prestress needs to be supplemented during the operation stage, the concrete bridge deck 6 in the negative bending moment area is removed, and the high-strength steel bars 53 are re-inserted for tensioning to make the beam body deflect downward. Then the concrete bridge deck 6 in the negative bending moment area is reinstalled, and the wet joints are poured. When the wet joint strength of the bridge deck in the negative bending moment area reaches 90%, the locking nuts are unscrewed for tensioning, so that the concrete bridge deck 6 in the negative bending moment area regains the prestress.

[0058] Furthermore, the above tension deformation degree can be calculated using this tension deformation control formula:

[0059]

[0060] in:

[0061] ——Tension deformation of beam body (mm);

[0062] ——Deformation caused by vehicle load (mm);

[0063] ——Deformation caused by the second-stage load (mm);

[0064] ——10-year concrete shrinkage and creep deformation (mm);

[0065] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A prestressed negative moment zone corrugated steel web composite continuous beam bridge, comprising bridge piers (1) arranged in sequence and spaced apart and a corrugated steel web composite box beam (2) erected on top of the bridge piers (1), characterized in that: A plurality of steel tube supports (3) are provided between two adjacent bridge piers (1); a retractable supporting mechanism (4) for supporting the corrugated steel web composite box girder (2) is provided at the upper end of each steel tube support (3); and a tensioning mechanism (5) for applying pre-compression stress to the negative bending moment zone of the corrugated steel web composite box girder (2) is also connected between each steel tube support (3) and the corrugated steel web composite box girder (2).

2. The prestressed negative moment zone corrugated steel web composite continuous beam bridge according to claim 1, characterized in that: The corrugated steel web composite box girder (2) comprises an upper wing plate (21), a lower wing plate (22), and two corrugated steel web plates (23) arranged between the front and rear sides of the upper wing plate (21) and the lower wing plate (22), and a concrete bridge deck (6) is also laid on the top side of the upper wing plate (21).

3. The prestressed negative moment zone corrugated steel web composite continuous beam bridge according to claim 2, characterized in that: The steel pipe support (3) comprises a plurality of steel pipe columns (31) whose lower ends are buried in the ground and transverse inter-tube connectors (32) connected between the steel pipe columns (31).

4. The prestressed negative moment zone corrugated steel web composite continuous beam bridge according to claim 3, characterized in that: The retractable supporting mechanism (4) comprises a supporting column (41) inserted into the top of the steel tube column (31) and a partition plate (42) fixed on the inner wall of the steel tube column (31), wherein the partition plate (42) is located below the supporting column (41), and fine aggregate (43) for supporting the supporting column (41) is filled between the partition plate (42) and the supporting column (41); The outer wall of the steel pipe column (31) is provided with a discharge port (44) corresponding to the bottom of the fine aggregate (43). A plugging member (45) for plugging the discharge port (44) is detachably connected to the discharge port (44). When the plugging member (45) is removed, the fine aggregate (43) can be discharged to the outside of the steel pipe column (31) through the discharge port (44) under the action of gravity, and drive the supporting column (41) to slide downward.

5. The prestressed negative moment zone corrugated steel web composite continuous beam bridge according to claim 4, characterized in that: The tensioning mechanism (5) comprises a box-shaped stiffening steel plate (51) fixed on the lower wing plate (22), an annular stiffening steel plate (52) fixed on the outer periphery of the steel pipe column (31), and a plurality of high-strength steel bars (53); the box-shaped stiffening steel plate (51) and the annular stiffening steel plate (52) are provided with a plurality of one-to-one corresponding through holes; the two ends of the high-strength steel bars (53) pass through the box-shaped stiffening steel plate (51) and the annular stiffening steel plate (52) through the corresponding through holes; and locking nuts are screwed on the passing portions of the two ends of the high-strength steel bars (53).

6. The prestressed negative moment zone corrugated steel web composite continuous beam bridge according to claim 5, characterized in that: A nut corresponding to the discharge port (44) is welded on the outer wall of the steel pipe column (31), and the blocking member (45) is a bolt threadably matched with the nut.

7. A bridge construction method for a prestressed negative moment zone corrugated steel web composite continuous beam bridge as claimed in claim 5, characterized in that: Step S1: driving the bridge pier (1) and the steel tube column (31) with the partition plate (42), the discharge port (44) and the plugging member (45) into the soil of the base under the bridge according to the designed position, and connecting the steel tube columns (31) to each other with the transverse tube connecting member (32), welding the annular stiffening steel plate (52) for supporting the tensile high-strength steel bars (53) on the upper outer peripheral wall of the steel tube column (31), then filling the upper side of the partition plate (42) with fine aggregate (43) and inserting the supporting column (41) at the top of the steel tube column (31); Step S2: hoisting the corrugated steel web composite box girder (2) in sections between the bridge piers (1), and supporting the bottom of the corrugated steel web composite box girder (2) on the supporting column (41), then laying the concrete bridge deck (6) of the positive moment section of the corrugated steel web composite box girder (2), and pouring the wet joint of the positive moment section of the concrete bridge deck (6); Step S3: removing the blocking member (45) so that the fine aggregate (43) is discharged from the steel pipe column (31) through the discharge port (44), thereby causing the supporting column (41) to gradually descend and be separated from the bottom of the corrugated steel web composite box girder (2) by a certain distance, thereby completing the contraction work of the contractible supporting mechanism (4); Step S4: firstly, a box-shaped stiffening steel plate (51) is welded on the lower wing plate (22) of the corrugated steel web composite box girder (2), then both ends of a plurality of high-strength steel bars (53) are passed through corresponding through holes on the box-shaped stiffening steel plate (51) and the annular stiffening steel plate (52), and locking nuts are screwed on the passing parts at both ends of the high-strength steel bars (53) to make the beam body deflect downward; Step S5: laying a concrete bridge deck (6) in the negative bending moment section of the corrugated steel web composite box girder (2), and casting a wet joint in the negative bending moment section of the concrete bridge deck (6) to complete the construction of the entire bridge deck; Step S6: When the wet joint strength of the concrete bridge deck (6) on the negative bending moment section reaches 90%, unscrew the locking nut to release the tension, so that the tension under the bridge is eliminated and the bridge deflects upward in the middle of the span; Step S7: cutting the steel pipe column (31).

8. The bridge construction method according to claim 7, characterized in that: The following steps are also included: Step S8: retaining a portion of the height of the steel tube column (31) on the ground, and re-welding the annular stiffening steel plate (52) on the outer peripheral wall of the remaining steel tube column (31) for later supplementation of pre-compression stress; When the prestressing stress needs to be supplemented during the operation phase, the concrete bridge deck (6) in the negative bending moment area is removed, and high-strength steel bars (53) are re-inserted for tensioning to cause the beam body to deflect downward. Subsequently, the concrete bridge deck (6) in the negative bending moment area is re-installed, and the wet joint is poured. When the wet joint strength of the bridge deck in the negative bending moment area reaches 90%, the locking nut is unscrewed for tensioning, so that the concrete bridge deck (6) in the negative bending moment area regains the prestressing stress.

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