Construction method of large-span portal pier structure of bridge

Abstract

The application discloses a construction method of a large-span portal pier structure of a bridge, and the steel cover beam of the bridge and the bridge pier column are released from transverse rotation constraint before the upper structure of the bridge is erected, and are fixedly connected after the main beam is erected, so that the column end bending moment of the bridge pier column under the constant load of the upper structure of the bridge is released, the stress performance of the stand column can be effectively improved, and the cross-sectional size and the reinforcement requirement of the bridge pier column are reduced. The force transmission path of the steel-concrete connecting section (the column head steel sleeve) at the top of the bridge pier column is clear, the local pressure bearing capacity is high, and the safety of the bridge pier column in the whole construction and operation process is ensured. The application solves the problem that the large-span steel cover beam is fixedly connected with the conventional pier or stand column, a large stand column end bending moment is easily generated, and the stand column is in a large eccentric compression state.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a construction method for a long-span portal pier structure for bridges. Background Technology

[0002] With the growth of urban transportation demand, wide-body bridges and multi-level elevated bridges are becoming increasingly common in urban bridge design. For bridges crossing major traffic arteries, due to the limitations of ground road layout and traffic control, the substructure of the bridge usually adopts large-span portal piers. The location of the piers is generally limited to the ground median strip and green belt, which cannot be adjusted according to the stress requirements and does not meet the conditions for setting up temporary supports.

[0003] For large-span portal piers under constrained conditions, lightweight steel cap beams that can be hoisted in one go are generally used. If conventional piers, columns, and steel cap beams are fixedly connected, a large bending moment will be generated at the column ends under the dead load of the bridge superstructure, resulting in the column being under large eccentric compression, with an extremely unreasonable stress state and extremely large column size requirements.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, a construction method for a long-span portal pier structure for bridges is provided to address the problem that a large bending moment at the end of the column is easily generated when a long-span steel cap beam is fixedly connected to a conventional pier or column, resulting in the column being under large eccentric compression.

[0006] To achieve the above objectives, a construction method for a long-span portal pier structure for bridges is provided, comprising the following steps:

[0007] The prefabricated bridge pier has a steel sleeve covering the upper end of the pier, and a grid internal support is connected inside the steel sleeve. The grid internal support is embedded in the upper end of the bridge pier.

[0008] Pile foundation caps are poured on opposite sides of the bridge construction site, and the bridge piers are erected on the pile foundation caps.

[0009] A steel cap beam with a pre-camber is provided, and the two ends of the steel cap beam are respectively placed on the column head steel sleeves of the two bridge piers, so that the bottom of the steel cap beam is in contact with the upper end face of the column head steel sleeve.

[0010] Tie-fitting components for preventing the steel cap beam from overturning are installed on opposite sides of the steel cap beam in the width direction and between the steel cap beam and the column head sleeve, respectively.

[0011] The superstructure of the bridge is installed on the steel cap beam, such that the bottom of the steel cap beam is in full contact with the upper end face of the column head steel sleeve;

[0012] The steel cap beam is welded to the column head steel sleeve, so that the steel cap beam and the bridge pier are released from lateral rotation constraints before the superstructure is installed, and the end bending moment of the bridge pier under the dead load of the superstructure is released after the superstructure is installed.

[0013] Furthermore, the column head steel sleeve includes:

[0014] A vertically installed steel sleeve is fitted onto the upper end of the bridge pier column;

[0015] A top plate is laid on the upper surface of the bridge pier column. The top plate is connected to the upper port of the steel sleeve. The inner support of the grid is connected to the inner wall of the steel sleeve and the inner wall of the top plate.

[0016] Furthermore, the inner wall of the steel sleeve is connected to multiple shear studs.

[0017] Furthermore, the multiple vertical main reinforcement bars of the bridge pier are spaced apart along the circumferential direction of the bridge pier, and the multiple shear studs are alternately arranged with the multiple vertical main reinforcement bars.

[0018] Furthermore, the top plate is provided with grout outlet holes.

[0019] Furthermore, two opposing partitions are vertically arranged in the inner cavity of the steel cap beam. The positions of the two partitions correspond one-to-one with the positions of the opposite sides of the steel sleeve. A force-transmitting grid plate is connected between the two partitions and is supported between the inner wall of the top plate and the inner wall of the bottom of the inner cavity. The position of the force-transmitting grid plate corresponds to the position of the support inside the grid.

[0020] Furthermore, the internal support of the grid includes multiple horizontal plates and multiple vertical plates, the horizontal plates and the vertical plates are respectively arranged vertically and the horizontal plates and the vertical plates are arranged intersectingly.

[0021] Furthermore, the ends of the transverse plate and the longitudinal plate respectively extend downward to form supporting flanges, which are connected to the inner wall of the column head steel sleeve.

[0022] Furthermore, the tying assembly includes:

[0023] Upper ear plates are respectively connected to the opposite sides of the steel cap beam;

[0024] The lower ear plate is connected to the opposite sides of the column head steel sleeve, and the positions of the lower ear plate and the upper ear plate correspond one-to-one.

[0025] A tie rod is provided, with through holes in the upper ear plate and the lower ear plate respectively. The tie rod is movably inserted into the through holes in the upper ear plate and the lower ear plate. Pressing members are detachably installed at both ends of the tie rod, and the pressing members at both ends of the tie rod press against the opposite sides of the upper ear plate and the lower ear plate respectively.

[0026] The beneficial effects of this invention are as follows: The construction method for large-span portal pier structures of bridges is applicable to the construction of large-span portal pier structures under constrained conditions. The steel cap beam and bridge pier column release lateral rotation constraints before the completion of the bridge superstructure erection and are rigidly connected after the main beam erection. This releases the bending moment at the end of the bridge pier column under the dead load of the bridge superstructure, effectively improving the stress performance of the column and reducing the cross-sectional dimensions and reinforcement requirements of the bridge pier column. The force transmission path of the steel-concrete connection section (column head steel sleeve) at the top of the bridge pier column is clear, with strong local bearing capacity, ensuring the safety of the bridge pier column throughout the construction and operation process. This construction method for large-span portal pier structures of bridges is also applicable to situations where the superstructure is constructed using a bridge erecting machine and the superstructure is asymmetrically erected on both sides of the pier along the bridge direction. Furthermore, the steel cap beam is hoisted in one go, avoiding interference with traffic arteries and accelerating the construction progress. At the same time, the column top connection section has a simple structure, is convenient to construct, avoids welding in confined spaces on site, and maintains consistency with the appearance style of traditional portal piers. Attached Figure Description

[0027] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 and Figure 2 This is a schematic diagram illustrating the construction steps of a bridge long-span portal pier structure according to an embodiment of the present invention.

[0029] Figure 3 This is a structural schematic diagram of the connection node between the steel cap beam and the bridge pier column in an embodiment of the present invention.

[0030] Figure 4 for Figure 3 Sectional view at point AA.

[0031] Figure 5 for Figure 3 Sectional view at point BB.

[0032] Figure 6 This is a schematic diagram of the structure of the tie assembly according to an embodiment of the present invention.

[0033] Figures 7 to 9 This is a schematic diagram illustrating the changes in the contact surface between the steel cap beam and the bridge pier column in an embodiment of the present invention. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Reference Figures 1 to 9 As shown, this invention provides a construction method for a long-span portal pier structure for bridges, comprising the following steps:

[0037] S1: Precast bridge pier 1.

[0038] See Figure 3 , Figure 5 and Figure 6 As shown, in this embodiment, the bridge pier is a precast pier. Specifically, the upper end of the bridge pier 1 is covered with a column head steel sleeve 11. The column head steel sleeve 11 is internally connected to a grid inner support 12. The grid inner support 12 is pre-embedded in the upper end of the bridge pier 1.

[0039] The column head steel sleeve 11 includes a steel sleeve 111 and a top plate 112. The steel sleeve 111 is vertically arranged and fitted onto the upper end of the bridge pier column 1. The top plate 112 is laid on the upper end face of the bridge pier column 1 and connected to the upper end of the steel sleeve 111. The grid inner support 12 is connected to the inner wall of the steel sleeve 111 and the inner wall of the top plate 112.

[0040] Continue reading Figure 5 In this embodiment, multiple shear studs 13 are connected to the inner wall of the steel sleeve 111. These shear studs are arranged in a matrix on the inner wall of the steel sleeve. The cross-section of the bridge pier is rectangular. Multiple vertical main reinforcement bars 14 are embedded in the concrete of the bridge pier. The multiple vertical main reinforcement bars 14 of the bridge pier 1 are spaced apart along the circumferential direction of the bridge pier 1. The multiple shear studs 13 and the multiple vertical main reinforcement bars 14 are arranged alternately.

[0041] The top slab 112 is provided with grout outlet holes to ensure that the concrete grouting at the top of the bridge pier is dense during the pouring process.

[0042] The internal support 12 of the grid includes multiple horizontal plates 121 and multiple vertical plates 122. The horizontal plates 121 and the vertical plates 122 are respectively arranged vertically and the horizontal plates 121 and the vertical plates 122 are arranged intersectingly.

[0043] Continue reading Figure 3As shown, the ends of the transverse plate 121 and the longitudinal plate 122 extend downward to form supporting flanges a. The supporting flanges a are connected to the inner wall of the column head steel sleeve 11.

[0044] S2: Pile foundation caps 2 are poured on opposite sides of the bridge construction location, and bridge piers 1 are erected on the pile foundation caps 2.

[0045] S3: Provide a steel cap beam 3 with pre-camber. Place both ends of the steel cap beam 3 on the column head steel sleeves 11 of the two bridge pier columns 1, so that the bottom of the steel cap beam 3 is in partial contact with the upper end face of the column head steel sleeve 11. See the specific contact surface. Figure 7 As shown.

[0046] See Figure 3 , Figure 4 and Figure 6 In this embodiment, two opposing partition plates 31 are vertically arranged within the inner cavity of the steel cap beam 3. The positions of the two partition plates 31 correspond one-to-one with the positions of the opposite sides of the steel sleeve 111. A force-transmitting grid plate 32, supported between the inner walls of the top plate 112 and the bottom inner wall of the inner cavity, connects the two partition plates 31. The position of the force-transmitting grid plate 32 corresponds to the position of the grid support 12, ensuring a clear and reliable force transmission path.

[0047] S4: Tie-up components 4 for preventing the steel cap beam 3 from overturning are installed on opposite sides of the steel cap beam 3 in the width direction and between the steel cap beam 3 and the column head steel sleeve 11.

[0048] See Figure 6 As shown, the tie assembly 4 includes: an upper ear plate 41, a lower ear plate 42, and a tie steel bar 43. The upper ear plate 41 is connected to opposite sides of the steel cap beam 3. The lower ear plate 42 is connected to opposite sides of the column head steel sleeve 11. The positions of the lower ear plate 42 and the upper ear plate 41 correspond one-to-one.

[0049] The upper ear plate 41 and the lower ear plate 42 are each provided with a through hole. The tie rod is movably inserted into the through holes of the upper ear plate 41 and the lower ear plate 42. Both ends of the tie rod 43 are detachably fitted with a retaining member. The retaining members at both ends of the tie rod 43 press against the opposite sides of the upper ear plate 41 and the lower ear plate 42, respectively.

[0050] In this embodiment, the tie rod is a high-strength alloy structural steel rod. The tie assembly is a temporary construction measure used to temporarily connect the steel cap beam and the bridge pier to ensure that the steel cap beam does not overturn under asymmetrical loads.

[0051] S5: Install the superstructure 5 of the bridge on the steel cap beam 3, so that the bottom of the steel cap beam 3 is in full contact with the upper end face of the column head steel sleeve 11.

[0052] For details, please refer to Figure 1The superstructure is installed on the steel cap beam using a bridge erecting machine 6.

[0053] See Figure 2 The superstructure includes main beams and auxiliary structures. The main beams are multi-span small box girders. The auxiliary structures include pavement, guardrails, etc. Under the downward pressure of the superstructure, the steel cap beam deflects downwards at mid-span, causing it to fully contact the top plate of the steel cap beam on the bridge pier's column head. The specific contact surface is detailed in [details omitted]. Figure 9 As shown.

[0054] S6: Weld the steel cap beam 3 to the column head steel sleeve 11 so that the steel cap beam 3 and the bridge pier column 1 release the lateral rotation constraint before the superstructure 5 is installed, and release the end bending moment of the bridge pier column 1 under the dead load of the superstructure 5 after the superstructure 5 is installed.

[0055] See Figure 7 The steel cap beam is pre-cambered so that when the steel cap beam is placed on the steel sleeve of the column head of the bridge pier, the bottom plate of the steel cap beam only partially contacts the top plate on the steel sleeve of the column head (contact surface b).

[0056] See Figure 8 After the steel cap beam is placed on the steel sleeve of the column head of the bridge pier, the bottom plate of the steel cap beam is in contact with the top plate on the steel sleeve of the column head (contact surface c).

[0057] See Figure 9 After the superstructure construction is completed and the steel cap beam deflects downwards at mid-span, the bottom plate of the steel cap beam will then make full contact with the top plate 7 of the column connection section (contact surface d). Because the position of the force-transmitting grid plate 32 of the steel cap beam corresponds to the position of the grid internal support 12 on the bridge pier, the local bearing capacity of the bridge pier is enhanced, ensuring that the concrete of the bridge pier will not be crushed even when the bottom plate of the steel cap beam is not in full contact with the top plate of the bridge pier, and the structure can still transmit force smoothly.

[0058] The construction method for large-span portal pier structures of this invention is applicable to the construction of large-span portal pier structures under constrained conditions. The steel cap beam and bridge pier column release lateral rotation constraints before the completion of the bridge superstructure erection and are rigidly connected after the main beam erection. This releases the bending moment at the end of the bridge pier column under the dead load of the bridge superstructure, effectively improving the stress performance of the column and reducing the cross-sectional dimensions and reinforcement requirements of the bridge pier column. The force transmission path of the steel-concrete connection section (column head steel sleeve) at the top of the bridge pier column is clear, with strong local bearing capacity, ensuring the safety of the bridge pier column throughout the construction and operation process. The construction method for large-span portal pier structures of this invention is also applicable to situations where the superstructure is constructed using a bridge erecting machine and the superstructure is asymmetrically erected on both sides of the pier along the bridge direction. Furthermore, the steel cap beam is hoisted in one go, avoiding interference with traffic arteries and accelerating the construction progress. At the same time, the column top connection section has a simple structure, is convenient to construct, avoids welding in confined spaces on site, and maintains consistency with the appearance style of traditional portal piers.

[0059] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A construction method of a bridge large-span portal pier structure, characterized by, The method comprises the following steps: a prefabricated bridge pier column, an upper end of the bridge pier column is covered with a column head steel sleeve, an inner part of the column head steel sleeve is connected with a grid inner support, the grid inner support is embedded in the upper end of the bridge pier column; pile foundation caps are respectively cast on opposite sides of a bridge construction site, and the bridge pier column is vertically arranged on the pile foundation caps; a steel cover beam provided with a pre-camber is provided, two ends of the steel cover beam are respectively arranged on the column head steel sleeves of the two bridge pier columns, so that the bottom of the steel cover beam is partially in contact with the upper end surface of the column head steel sleeve; tie components for preventing the steel cover beam from overturning are respectively arranged between opposite sides of the steel cover beam in the width direction and the column head steel sleeves; an upper structure of the bridge is arranged on the steel cover beam, so that the bottom of the steel cover beam is fully in contact with the upper end surface of the column head steel sleeve; the steel cover beam is welded to the column head steel sleeve, so that the steel cover beam and the bridge pier column are released from transverse rotation constraint before the upper structure is completed, and the end bending moment of the bridge pier column under the dead load of the upper structure is released after the upper structure is completed; the tie component comprises: upper ear plates, the opposite sides of the steel cover beam are respectively connected with the upper ear plates; lower ear plates, the opposite sides of the column head steel sleeve are respectively connected with the lower ear plates, the positions of the lower ear plates correspond to the positions of the upper ear plates one by one; a tie steel bar, the upper ear plates and the lower ear plates are respectively provided with through holes, the tie steel bar is movably arranged in the through holes of the upper ear plates and the lower ear plates, the two ends of the tie steel bar are respectively detachably provided with pressing members, and the pressing members at the two ends of the tie steel bar are respectively pressed against the opposite sides of the upper ear plates and the lower ear plates.

2. The construction method of a long-span portal pier structure of a bridge according to claim 1, characterized by, the column head steel sleeve comprises: a vertically arranged steel sleeve, which is sleeved on the upper end of the bridge pier column; a top plate, which is arranged on the upper end surface of the bridge pier column, is connected to the upper end of the steel sleeve, and the grid inner support is connected to the inner side wall of the steel sleeve and the inner side wall of the top plate.

3. The construction method of a long-span portal pier structure of a bridge according to claim 2, characterized by, The inner side wall of the steel sleeve is connected with a plurality of shear nails.

4. The construction method of a long-span portal pier structure of a bridge according to claim 3, characterized by, A plurality of vertical main reinforcements of the bridge pier column are arranged along the circumferential direction of the bridge pier column, and a plurality of the shear nails and a plurality of the vertical main reinforcements are arranged alternately.

5. The construction method of a long-span portal pier structure of a bridge according to claim 2, characterized by, The top plate is provided with a steam hole.

6. The construction method of a long-span portal pier structure of a bridge according to claim 2, characterized by, Two oppositely arranged partition plates are vertically arranged in the inner cavity of the steel cover beam, the positions of the two partition plates correspond to the positions of the opposite sides of the steel sleeve one by one, and a force transmission grid plate is connected between the top inner wall and the bottom inner wall of the inner cavity of the steel cover beam, the position of the force transmission grid plate corresponds to the position of the grid inner support.

7. The construction method of a long-span portal pier structure of a bridge according to Claim 1, wherein The grid inner support comprises a plurality of transverse plates and a plurality of longitudinal plates, the transverse plates and the longitudinal plates are vertically arranged and the transverse plates and the longitudinal plates are cross arranged.

8. The construction method of a long-span portal pier structure of a bridge according to claim 7, characterized in that, The end portions of the transverse plates and the longitudinal plates respectively extend downward to form support flanges, and the support flanges are connected to the inner wall of the column head steel sleeve.

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