Combined T-shaped rigid frame bridge combining box girders and gate-type piers and construction method of combined T-shaped rigid frame bridge

Abstract

The invention relates to a box girder and gate-type pier combined T-shaped rigid frame bridge and a construction method thereof. The box girder and gate-type pier combined T-shaped rigid frame bridge comprises concrete box girders, gate-type main piers and side piers. The gate-type main pier comprises two pier bodies and a cover beam, the two pier bodies are located on the two sides of the existing line, and the cover beam is located above the existing line and intersects with the existing line; the concrete box girder and the cover beam are arranged in a crossed manner and are positioned above the cover beam, and at the joint of the cover beam and the concrete box girder, the top of the cover beam and the bottom of the No.0 block of the concrete box girder are poured into a whole; the side piers are located on the two sides of the existing line, and the side piers are longitudinally arranged and supported at the bottom of the concrete box girder. Under the condition that the line height is limited, the pier-beam combination height can be reduced, the span is increased, and meanwhile the clearance requirement under the bridge is met; and meanwhile, the pier and the beam are fused, the integrity is good, material use can be reduced, the structural rigidity and the bearing capacity are improved, the span is increased, and better anti-seismic performance is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a combined T-shaped rigid frame bridge with a combined box beam and a portal pier and a construction method thereof. Background Art

[0002] With the continuous increase in bridge construction, more and more new bridges need to cross existing lines. In order to save investment, avoid special geology or bridges close to stations, it is often difficult to set up bridges because the height of the new line is too low.

[0003] As a structural form that crosses existing railways and highways, portal piers have many advantages. Portal piers can cross existing lines at a very small angle or even run parallel to existing lines, so they have strong crossing capacity and little interference with operating lines. Due to their simplicity and economy, they have been widely used in highways, railways, bridges and water conservancy projects. The existing portal pier viaduct structure generally has portal piers, cap beams, main beams and bridge carriageways. The portal piers are arranged on both sides of the bridge carriageway, the cap beam is arranged on the top of the portal piers, the main beam is arranged on the cap beam, and the bridge carriageway is arranged on the top surface of the main beam. In this structure, since the main beam is located at the top of the cap beam, the sum of the heights of the two is the sum of their respective heights, so the overall height is large, and the design is more difficult when the clearance height under the main beam is small. The line height is difficult to raise, and the height of crossing the existing line is limited, which increases the difficulty of matching the upper and lower structures. In addition, the spacing of the portal piers (the distance across the existing line), the width of the cap beam, the width of the main beam and the width of the bridge carriageway remain relatively consistent, so the width of the bridge carriageway is basically the same as the distance across the existing line. However, for some actual working conditions, the design distance across the existing line is large, but the required width of the lane on the bridge is small, which increases the difficulty of matching the upper and lower structures.

[0004] Therefore, it is necessary to propose new measures to overcome the above-mentioned defects. Summary of the invention

[0005] The object of the present invention is to provide a combined T-shaped rigid frame bridge of a combined box girder and a portal pier and a construction method thereof, so as to solve the problem of the overall height of the existing structure being relatively large, and the matching design problem of the upper and lower structures when the design distance for crossing the existing line is relatively large but the width requirement of the carriageway on the bridge is relatively small.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A combined T-shaped rigid frame bridge with a combined box girder and a portal pier, wherein the combined T-shaped rigid frame bridge comprises a concrete box girder, a portal main pier and side piers;

[0008] The portal main pier includes two pier bodies and a cap beam, the two pier bodies are located on both sides of the existing line, and the cap beam is located above the existing line and intersects with the existing line;

[0009] The concrete box beam is arranged to intersect with the cap beam and is located above the cap beam. At the intersection of the cap beam and the concrete box beam, the top of the cap beam and the bottom of block No. 0 of the concrete box beam are cast as one piece;

[0010] The side piers are located on both sides of the existing line, and the side piers are arranged longitudinally and supported at the bottom of the concrete box girder.

[0011] Furthermore, at the intersection of the cap beam and the concrete box beam, the concrete box beam is embedded downwardly into the cap beam.

[0012] Furthermore, a support is provided on the top of the side pier, and the concrete box beam is supported on the support.

[0013] Furthermore, a portal pier pile foundation and a portal pier cap are provided below the pier body of the portal main pier.

[0014] Furthermore, a side pier pile foundation and a side pier cap are provided below the side pier.

[0015] Furthermore, prestressed steel strands are arranged inside the concrete box body of the concrete box beam.

[0016] On the other hand, a construction method of a combined T-shaped rigid frame bridge of a combined box girder and a portal pier is provided, wherein the method is used to construct the combined T-shaped rigid frame bridge, comprising:

[0017] Construction foundation;

[0018] Set up formwork on the foundation, tie up steel bars and cast the pier body and side piers of the portal main pier;

[0019] After the pier body of the portal pier is constructed to the pier top, the bracket and the cap beam template of the portal pier are set up, and the cap beam of the portal pier is cast. A groove at the junction position is reserved on the top surface in the middle and the steel bars are exposed;

[0020] At the intersection of the concrete box beam and the portal main pier cap beam, the structural steel bars of the two are tied together, and the No. 0 block of the concrete box beam is cast in a mold, so that the bottom of the No. 0 block and the top of the cap beam are cast as a whole, and the upper and lower parts are locked together;

[0021] The construction of concrete box beams continued using cantilever casting method;

[0022] Set up the support and cast the concrete box beam to the side pier, and remove the formwork and support after the concrete reaches the required strength;

[0023] Install the bearings on the top of the side pier to support the concrete box girder and complete the construction.

[0024] Further, the construction foundation includes:

[0025] Excavate portal pier foundation pits and side pier foundation pits on both sides of the existing line, construct portal pier pile foundations and side pier pile foundations by drilling and pouring, and then construct portal pier caps and side pier caps;

[0026] Before excavation, drainage work should be done on the top and bottom of the foundation pit, 1 to 2 collection wells should be made at the corners of the foundation pit, and cushion concrete should be poured. The elevation of the top surface should not be higher than the designed elevation of the bottom of the pedestal.

[0027] Furthermore, the cantilever casting method is used to continue the construction of the concrete box beam, including:

[0028] After pouring block No. 0, set up a hanging basket on block No. 0 and cantilever pour block No. 1 on both sides;

[0029] Then move the hanging basket to block 1 and cantilever cast blocks 2 on both sides;

[0030] Finally, set up the support and formwork to cast the cast-in-place box girder to the side pier position. After the concrete reaches sufficient strength, remove the formwork and support.

[0031] Furthermore, when casting block No. 1, block No. 2 and the cast-in-place box girder, prestressed steel strands are tensioned in batches.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides a combined T-shaped rigid frame bridge with a box girder and a portal pier and a construction method thereof, which can reduce the combined height of the piers and beams when the line height is limited, thereby increasing the span and meeting the clearance requirements under the bridge. At the same time, the present invention can enable the newly built line to cross the existing line with a small intersection angle with the existing line, and the piers and beams are integrated with good integrity, which can reduce the use of materials, increase the structural rigidity and bearing capacity, and then increase the span, and have better seismic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is an elevation view of a combined T-shaped rigid frame bridge in an embodiment of the present invention.

[0036] Figure 2It is a stereoscopic diagram of a combined T-shaped rigid frame bridge in an embodiment of the present invention.

[0037] Figure 3 yes Figure 1 Section II in .

[0038] Figure 4 yes Figure 3 Section II-II in .

[0039] Figure 5 It is a construction step diagram of the box girder in the present invention.

[0040] The symbols in the figure are:

[0041] 1-superstructure, 2-lower structure, 3-foundation, 4-concrete box girder, 5-portal main pier, 6-side pier, 7-side pier cap, 8-portal pier cap, 9-side pier pile foundation, 10-portal pier pile foundation, 11-support, 12-concrete box body, 13-prestressed steel strands, 14-existing line. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0043] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as “middle”, “upper”, “lower”, “top”, “bottom”, “inside” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connection", "setting", etc. should be understood in a broad sense, for example, it can be fixed connection, setting, or detachable connection, setting, or integral connection, setting. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] It should also be noted that although the order of steps is mentioned in the method description, in some cases, they may be performed in an order different from that shown here, and it should not be understood as a limitation on the order of steps.

[0046] In a specific implementation manner, the direction of the newly constructed line, that is, the length direction of the concrete box girder 4 is defined as the longitudinal direction, and the direction perpendicular thereto is defined as the transverse direction.

[0047] After the existing line 14 is completed and put into operation, it is necessary to plan and design a new line to intersect it according to the new traffic demand in the later stage. Generally, a new bridge will be used to cross the existing line 14. The rigid frame bridge has the characteristics of good integrity, continuous beam body and consolidated beam piers. It not only maintains the advantages of continuous beams without expansion joints and smooth driving, but also maintains the advantages of T-type rigid frames without supports and conversion systems. It has large bending stiffness along the bridge and lateral stiffness, which can meet the force requirements of large-span bridges.

[0048] In actual projects, the clearance height under the bridge may be small, the overall height cannot be too high, and the road width does not need to be too large. In view of the situation that the height limit and required width of the newly built bridge in actual projects are small, the present invention provides a combined T-shaped rigid frame bridge of a combined box girder and a portal pier, which effectively controls the overall height and can adapt to a box girder structure with a smaller width.

[0049] Specifically, Figure 1 and Figure 2 The combined T-shaped rigid frame bridge includes an upper structure 1, a lower structure 2 and a foundation 3. The upper structure 1 includes a concrete box girder 4, the lower structure 2 includes a portal main pier 5 and a side pier 6, and the foundation 3 includes a pier pile foundation and a pier cap. Below the portal main pier 5 are a portal pier pile foundation 10 and a portal pier cap 8, and below the side pier 6 are a side pier pile foundation 9 and a side pier cap 7.

[0050] The portal main pier 5 includes two pier bodies and a cap beam. The two pier bodies are located on both sides of the existing line 14 and can cross the existing line at a very small angle. The cap beam is located above the existing line 14 and intersects with the existing line 14. The concrete box beam 4 is arranged to intersect with the cap beam and is located above the cap beam. At the intersection of the cap beam and the concrete box beam 4, the top of the cap beam and the bottom of the No. 0 block of the concrete box beam 4 are cast as one, that is, rigidly connected. The side pier 6 is located on both sides of the existing line 14. The side pier 6 is arranged longitudinally and supported at the bottom of the concrete box beam 4. The portal main pier 5, the portal pier cap 8 and the portal pier pile foundation 10 do not interfere with the existing line, and the side pier 6, the side pier cap 7 and the side pier pile foundation 9 do not interfere with the existing line. The portal pier cap 8 and the side pier cap 7 transmit the force transmitted from the portal main pier 5 and the side pier 6 to the portal pier pile foundation 10 and the side pier pile foundation respectively.

[0051] like Figure 3In this structure, at the intersection of the cap beam and the concrete box beam 4, the concrete box beam 4 is embedded downward into the cap beam, and the overall height of the cap beam and the concrete box beam 4 is less than the sum of the actual heights of the two, and the overall height is significantly reduced. In addition, since the concrete box beam 4 is embedded downward into the cap beam, the width of the concrete box beam 4 is less than the width of the cap beam, so it is suitable for box beam structures with smaller widths, and there is no need to build a box beam and road surface with the same width as the cap beam.

[0052] like Figure 4 The concrete box beam 4 includes a concrete box body 12 and a prestressed steel bundle 13. The prestressed steel bundle 13 runs through the concrete box body 12 and is located in the top plate and the web plate thereof. The prestressed steel bundle 13 provides prestressing and is tightly combined with the concrete box body 12, providing compressive stress to the concrete box body 12, thereby greatly improving the load-bearing capacity of the beam body.

[0053] A support 11 is provided on the top of the side pier 6, and the concrete box beam 4 is supported on the support 11, and the support 11 can constrain the lateral movement of the concrete box beam 4. The portal main pier 5 provides intermediate consolidation support for the concrete box beam 4, and the side pier 6 provides movable support for the concrete box beam 4 through the support 11, constraining the lateral displacement of the concrete box beam 4 so as not to cause it to fall, and releasing the longitudinal constraint so that the concrete box beam 4 can freely expand and contract under the action of temperature changes.

[0054] The combined T-shaped rigid frame bridge of the above-mentioned combined box girder and portal pier is constructed by the following construction method:

[0055] First, it is necessary to determine the angle between the new line and the existing line and the height difference with the existing line, lay out the lines to determine the positions of the portal pier pile foundation 10 and the side pier pile foundation 9, and level the site and access road. Then, construction begins:

[0056] S1: Construction foundation 3, including:

[0057] S101: excavating portal pier foundation pits and side pier foundation pits on both sides of the existing line 14, drilling and pouring portal pier pile foundations 10 and side pier pile foundations 9, and then constructing portal pier caps 8 and side pier caps 7;

[0058] S102: Before excavation, drainage work should be done on the top and bottom of the foundation pit, 1 to 2 collection wells should be made at the corners of the foundation pit, and cushion concrete should be poured. The top surface elevation should not be higher than the designed elevation of the bottom of the pedestal.

[0059] S2: After measuring the line height, a formwork is erected on the foundation 3, steel bars are tied, and the pier body and side pier 6 of the portal main pier 5 are cast and constructed.

[0060] S3: After the pier body of the portal main pier 5 is constructed to the pier top, the support and the cap beam formwork of the portal main pier 5 are set up, and the cap beam of the portal main pier 5 is cast. A groove for the junction position is reserved on the middle top surface and the steel bars are exposed.

[0061] S4: At the intersection of the concrete box girder 4 and the cap beam of the portal main pier 5, structural reinforcement needs to be set in the middle position of the portal main pier cap beam, so that the reinforcement of the portal main pier 5 enters the concrete box girder 4, and the reinforcement of the concrete box girder 4 enters the portal main pier 5, and the mold is erected to cast block No. 0 of the concrete box girder 4, so that the bottom of block No. 0 and the top of the cap beam are cast as a whole, and are embedded in each other from top to bottom.

[0062] S5: Continue to construct the concrete box beam 4 by cantilever casting, tension the prestressed steel strands 13 in batches with a certain length as a section, until the end is cast to form a T-shaped rigid frame force form, such as Figure 5 ,include:

[0063] S501: After pouring block No. 0, set up a hanging basket on block No. 0, cantilever pour block No. 1 on both sides and tension the top plate prestressed steel strands;

[0064] S502: Then move the hanging basket to block No. 1, cantilever cast blocks No. 2 on both sides and tension the top plate prestressed steel strands;

[0065] S503: Finally, set up the support and formwork to cast the cast-in-place box girder to the side pier. After the concrete reaches the required strength, remove the formwork and support.

[0066] S6: Set up the support and cast the concrete box beam 4 to the side pier 6 in the formwork, and remove the formwork and support after the concrete reaches the required strength;

[0067] S7: Install the support 11 on the top of the side pier 6. The support 11 provides upward support force and lateral displacement constraint, so that the whole forms a T-shaped rigid frame stress state and completes the bridge state.

[0068] In the above method, the concrete box girder 4 and the portal main pier 5 are integrally cast by the method of vertical formwork casting, and then connected into a whole. This connection method can transmit bending moment, shear force and axial force between the concrete box girder 4 and the portal main pier 5, and the favorable stress state can increase the span of this structure. The combination of the concrete box girder 4 and the portal main pier 5 requires precise positioning. According to the design size, the clearance size under the bridge is controlled to determine the position of the concrete box girder 4, and a template is formulated for the combined position to achieve the purpose of simultaneous casting.

[0069] The combined T-type rigid frame bridge of the combined box girder and the portal pier provided by the present invention has the advantage of greater rigidity and increased driving comfort compared to ordinary T-type rigid frame bridges; compared to the traditional structural form of portal piers plus simply supported beams, the combined T-type rigid frame bridge of the combined box girder and the portal pier can cross the existing line when the line is lower, and has good integrity and good seismic resistance.

[0070] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A combined T-shaped rigid frame bridge with a box girder and a portal pier, characterized in that: The combined T-shaped rigid frame bridge comprises a concrete box girder (4), a portal main pier (5) and a side pier (6); The portal main pier (5) comprises two pier bodies and a cap beam, the two pier bodies are located on both sides of the existing line (14), and the cap beam is located above the existing line (14) and intersects with the existing line (14); The concrete box beam (4) is arranged to intersect with the cap beam and is located above the cap beam. At the intersection of the cap beam and the concrete box beam (4), the top of the cap beam and the bottom of block No. 0 of the concrete box beam (4) are cast as one piece. The side piers (6) are located on both sides of the existing line (14), and the side piers (6) are arranged longitudinally and supported on the bottom of the concrete box girder (4).

2. The combined T-shaped rigid frame bridge of the combined box girder and portal pier according to claim 1 is characterized in that: At the intersection of the cap beam and the concrete box beam (4), the concrete box beam (4) is embedded downwardly into the cap beam.

3. The combined T-shaped rigid frame bridge of the combined box girder and portal pier according to claim 1 is characterized in that: A support (11) is provided on the top of the side pier (6), and the concrete box beam (4) is supported on the support (11).

4. The combined T-shaped rigid frame bridge of the combined box girder and portal pier according to claim 1 is characterized in that: A portal pier pile foundation (10) and a portal pier cap (8) are arranged below the pier body of the portal main pier (5).

5. The combined T-shaped rigid frame bridge of the combined box girder and portal pier according to claim 1 is characterized in that: A side pier pile foundation (9) and a side pier cap (7) are arranged below the side pier (6).

6. The combined T-shaped rigid frame bridge of the combined box girder and portal pier according to claim 1 is characterized in that: Prestressed steel strands (13) are arranged inside the concrete box body (12) of the concrete box beam (4).

7. A construction method for a combined T-shaped rigid frame bridge with a combined box girder and a portal pier, characterized in that: The method is used to construct the combined T-shaped rigid frame bridge according to claim 1, comprising: Construction foundation (3); Forming a formwork on the foundation (3), tying steel bars, and pouring and constructing the pier body and side piers (6) of the portal main pier (5); After the pier body of the portal-type main pier (5) is constructed to the pier top, a support and a cap beam template of the portal-type main pier (5) are set up, and the cap beam of the portal-type main pier (5) is cast, and a groove at the junction position is reserved on the middle top surface and steel bars are exposed; At the intersection of the concrete box beam (4) and the cap beam of the portal main pier (5), the structural steel bars of the two are tied together, and the No. 0 block of the concrete box beam (4) is cast in a mold, so that the bottom of the No. 0 block and the top of the cap beam are cast as a whole and are locked in each other from top to bottom; Continue to construct the concrete box girder (4) by cantilever casting; Setting up a support and casting a concrete box beam (4) to the position of the side pier (6), and removing the formwork and support after the concrete reaches a certain strength; The support (11) is installed on the top of the side pier (6) to support the concrete box beam (4) to complete the construction.

8. The construction method of a combined T-shaped rigid frame bridge with a combined box girder and a portal pier according to claim 7, characterized in that: Construction foundation (3), including: Excavating portal pier foundation pits and side pier foundation pits on both sides of the existing line (14), constructing portal pier pile foundations (10) and side pier pile foundations (9) by drilling and pouring, and then constructing portal pier caps (8) and side pier caps (7); Before excavation, drainage work should be done on the top and bottom of the foundation pit, 1 to 2 collection wells should be made at the corners of the foundation pit, and cushion concrete should be poured. The elevation of the top surface should not be higher than the designed elevation of the bottom of the pedestal.

9. The construction method of a combined T-shaped rigid frame bridge with a combined box girder and a portal pier according to claim 8, characterized in that: The concrete box girder (4) is constructed by cantilever casting, including: After pouring block No. 0, set up a hanging basket on block No. 0 and cantilever pour block No. 1 on both sides; Then move the hanging basket to block 1 and cantilever cast blocks 2 on both sides; Finally, set up the support and formwork to cast the cast-in-place box girder to the side pier position. After the concrete reaches sufficient strength, remove the formwork and support.

10. The construction method of a combined T-shaped rigid frame bridge with a combined box girder and a portal pier according to claim 9, characterized in that: When casting block No. 1, block No. 2 and cast-in-place box beam, prestressed steel tendons (13) are tensioned in batches.

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