Continuous rigid frame bridge capable of reducing mid-span downwarping of main beam and construction method

Abstract

The invention relates to a continuous rigid frame bridge capable of reducing mid-span downwarping of a main beam and a construction method, and belongs to the technical field of bridge engineering. Comprising a plurality of web sagging moment prestressed steel beams, a main beam and a plurality of piers, the web sagging moment prestressed steel beams are composed of two first steel beams, two second steel beams and a third steel beam, two main beam webs and a plurality of main beam toothed plates are arranged in the main beam, the first steel beams are arranged above the third steel beam, and the first steel beams and the third steel beam are horizontally arranged; the two ends of the third steel beam are connected with the two first steel beams in a one-to-one correspondence mode through the two second steel beams, the second steel beams are in arc transition connection with the first steel beams and the third steel beams, the first steel beams, the second steel beams and the third steel beams are all arranged in a main beam web, and the ends, away from the second steel beams, of the first steel beams are anchored to a main beam toothed plate. And the third steel beam is arranged at the lower part of the main beam web. According to the invention, the problem of down-warping of the prestressed concrete continuous rigid frame bridge caused by the radial acting force of the prestressed steel beams of the bottom plate is solved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to a continuous rigid frame bridge capable of reducing the deflection of a main beam mid-span and a construction method. Background Art

[0002] Large-span prestressed concrete continuous rigid frame bridges have the following advantages: (1) good mechanical performance, comfortable and smooth driving, and easy maintenance in the later stage; (2) the bridge has a large span and is usually constructed by cantilever casting, which has low requirements for site, construction equipment and transportation conditions. It is the preferred bridge type for crossing large rivers and deep valleys in mountainous areas; (3) the construction cost is lower than that of steel tube concrete arch bridges, cable-stayed bridges and other bridge types with the same span. Therefore, prestressed concrete continuous rigid frame bridges have become one of the most competitive bridge types with a span of 100m-300m.

[0003] However, large-span prestressed concrete continuous rigid frame bridges also have shortcomings: the existing large-span prestressed concrete continuous rigid frame bridges experience unexpected mid-span deflection during the operation stage, which seriously affects the safe operation of the bridge.

[0004] According to research by scholars, the mid-span deflection of long-span prestressed concrete continuous rigid frame bridges is caused by the following reasons: (1) Concrete shrinkage and creep. The common construction method for long-span continuous rigid frame bridges is cantilever casting with a hanging basket. The construction period of each construction section is about 10 days. In the actual construction process, construction units generally use early strength agents to improve the early strength of concrete to speed up the construction progress. After adding early strength agents, the concrete can reach the design strength within 3-5 days. However, due to the intervention of early strength agents, although the early strength of concrete is improved to a certain extent, the concrete age is too short when prestressing is applied, and the elastic modulus of concrete is still low. The prestress is affected by the shrinkage and creep of concrete, which increases the stress of the entire structure for a long time; (2) The radial force of the prestressed steel strands of the bottom plate. Due to the needs of cantilever construction and structural stress, the beam height of prestressed concrete continuous rigid frame bridges is generally set to a circular curve gradient or parabola shape. When the prestressed tendons are tensioned after the mid-span of the large-span prestressed continuous rigid frame bridge is closed, the prestressed steel strands of the bottom plate that are stretched tight by the tension force will squeeze the prestressed pipe wall, thereby generating an additional load effect on the surrounding concrete, namely, the radial force of the steel strands. Existing research shows that the radial force deflection effect of the prestressed steel strands of the bottom plate is greater than the sum of the effects of the vehicle load and the secondary constant load effects such as the bridge deck pavement.

[0005] In response to the shrinkage and creep of concrete, the current technical measures taken are to develop concrete with low shrinkage and creep, appropriately increase the loading age, reduce the creep of concrete, and reserve sufficient reserves for the shrinkage and creep deformation of concrete in the pre-camber design.

[0006] One technical solution to the deflection of prestressed concrete continuous rigid frame bridges caused by the radial force of the prestressed steel strands on the bottom plate is to use horizontal bottom plate cables, that is, to change the curved bottom plate cables to horizontal bottom plate cables. From the existing engineering cases, horizontal bottom plate cables can effectively suppress the deflection of continuous rigid frame bridges. However, horizontal bottom plate cables have two disadvantages: first, a section of equal height needs to be set in the middle of the main beam span, which is inconsistent with the curved arrangement of the bottom of the beam, affecting the appearance and not conforming to the force characteristics of the continuous rigid frame bridge; second, thickened bottom plate sections need to be set on both sides of the equal height section, which increases the deadweight of the main beam. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a continuous rigid frame bridge and a construction method that can reduce the deflection of the main beam mid-span, so as to solve the deflection problem of the prestressed concrete continuous rigid frame bridge caused by the radial force of the prestressed steel strands of the bottom plate, and avoid the shortcomings of the existing technology in the background technology.

[0008] The technical solution of the present invention to solve the above technical problems is as follows: A continuous rigid frame bridge capable of reducing the deflection of the middle span of the main beam, comprising: a plurality of web positive bending moment prestressed steel bundles, a main beam and a plurality of bridge piers, wherein the main beam is arranged at the top of the plurality of bridge piers, and the web positive bending moment prestressed steel bundle is arranged in the middle span of the main beam; the web positive bending moment prestressed steel bundle is composed of two first steel bundles, two second steel bundles and a third steel bundle, two main beam webs and a plurality of main beam tooth plates are arranged in the main beam, the first steel bundle is arranged above the third steel bundle, the first steel bundle and the third steel bundle are both arranged horizontally, the two ends of the third steel bundle are connected to the two first steel bundles through the two second steel bundles in a one-to-one correspondence, the second steel bundle is connected to the first steel bundle and the third steel bundle by an arc transition, the first steel bundle, the second steel bundle and the third steel bundle are all arranged in the web of the main beam, the end of the first steel bundle away from the second steel bundle is anchored on the main beam tooth plate, and the third steel bundle is arranged at the lower part of the web of the main beam.

[0009] The beneficial effects of the present invention are as follows: by arranging the web positive bending moment prestressed steel strands in the web of the main beam, the main beam produces an upward deflection, which is beneficial to offset the vertical downward deflection effect of the main beam caused by the radial force of the bottom plate prestressed steel strands in the existing main beam, thereby solving the problem of downward deflection of the prestressed concrete continuous rigid frame bridge caused by the radial force of the bottom plate prestressed steel strands. At the same time, the middle span of the main beam does not need to be provided with equal height sections and bottom plate thickening sections, which not only reduces the dead weight of the main beam, but also ensures the beautiful bridge shape of the prestressed concrete continuous rigid frame bridge. In addition, the web positive bending moment prestressed steel strands can bear the positive bending moment in the middle span of the main beam and can replace a part of the bottom plate prestressed steel strands.

[0010] Based on the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, the anchoring points of the two first steel bundles and the main beam tooth plate are arranged outside the quarter points of the middle span of the main beam.

[0012] The beneficial effect of adopting the above further scheme is that it is conducive to making the length of the web positive bending moment prestressed steel strands as long as possible to correspond to the bottom plate prestressed steel strands, thereby achieving a better solution to the deflection problem of the prestressed concrete continuous rigid frame bridge.

[0013] Furthermore, the main beam also includes a main beam top plate and a main beam bottom plate, the main beam top plate is arranged above the main beam bottom plate, the two main beam webs are arranged in parallel between the main beam top plate and the main beam bottom plate, and the main beam tooth plate is arranged at the connection between the main beam top plate and the main beam web.

[0014] The beneficial effects of adopting the above further scheme are: the main beam top plate is conducive to providing location for the subsequent construction of bridge deck ancillary projects such as bridge deck paving, railings, expansion joint installation, etc., and the main beam bottom plate is conducive to providing space for the installation of prestressed steel strands of the bottom plate.

[0015] Furthermore, the distance between the first steel bundle and the main beam top plate is 30-50 cm.

[0016] The beneficial effect of adopting the above further solution is that it is helpful to provide operating space for subsequent construction.

[0017] Furthermore, a plurality of bottom plate prestressed steel bundles for applying an additional vertical downward load to the main beam are arranged in the bottom plate of the main beam, and the bottom plate prestressed steel bundles are parabolic in shape.

[0018] The beneficial effect of adopting the above further scheme is that the bottom plate prestressed steel strands are conducive to providing prestress for the long-span prestressed continuous rigid frame bridge, and bear the positive bending moment in the middle of the main beam span, thereby meeting the force requirements of the bridge.

[0019] A construction method for a continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span comprises the following steps:

[0020] S1: Determine the number of positive moment prestressing tendons in the web;

[0021] S2: Complete the construction of the main beam of the continuous rigid frame bridge;

[0022] S3: threading, tensioning and grouting of prestressed steel strands in the main beam bottom plate of the continuous rigid frame bridge;

[0023] S4: threading, tensioning and grouting of positive moment prestressed steel tendons in the web of the main beam of a continuous rigid frame bridge;

[0024] S5: Complete the construction of the bridge deck ancillary works of the continuous rigid frame bridge.

[0025] The beneficial effects of the present invention are: the bottom plate prestressed steel bundles and the web plate positive bending moment prestressed steel bundles are constructed successively, the structure is simple, and at the same time, in conjunction with the conventional continuous rigid frame bridge construction method, the construction quality is guaranteed and the cost is controllable.

[0026] Further, step S1 includes the following steps:

[0027] S11: Calculate the vertical additional load of the web positive bending moment prestressed steel tendons and the bottom plate prestressed steel tendons on the main beam using the equivalent load method;

[0028] S12: inputting the vertical additional loads of the web positive bending moment prestressed steel tendons and the bottom plate prestressed steel tendons obtained in step S11 into a bridge structure calculation model;

[0029] S13: Determine the number of the web positive moment prestressing steel tendons by making the sum of the downward deflections caused by the equivalent loads of the web positive moment prestressing steel tendons and the bottom plate prestressing steel tendons zero.

[0030] The beneficial effect of adopting the above further scheme is that it is helpful to accurately determine the required number of web positive bending moment prestressed steel strands through the existing bridge structure calculation model, so that the sum of the downward deflections caused by the equivalent loads of the web positive bending moment prestressed steel strands and the bottom plate prestressed steel strands is zero.

[0031] Further, step S2 includes the following steps:

[0032] S21: Complete the construction of bridge piers;

[0033] S22: constructing the main beam by using a symmetrical cantilever method, and pre-embedding the corrugated pipe of the bottom plate prestressed steel bundle in the bottom plate of the main beam, and pre-embedding the corrugated pipe of the web positive bending moment prestressed steel bundle in the web of the main beam;

[0034] S23: completing the closing of the main beam.

[0035] The beneficial effect of adopting the above further scheme is that the construction of the web positive bending moment prestressed steel strands adopts the same conventional construction method as the bottom plate prestressed steel strands, without increasing the construction steps, the construction period, and the cost is controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of a web positive moment prestressed steel strand on a continuous rigid frame bridge provided by an embodiment of the present invention;

[0037] Figure 2 A side view of a main beam provided by an embodiment of the present invention;

[0038] Figure 3 for Figure 1 A magnified schematic diagram of the middle A area;

[0039] Figure 4 for Figure 1 The top view of the enlarged area A in the middle;

[0040] Figure 5 A schematic diagram of the structure of a main beam tooth plate, a main beam top plate and a main beam web plate provided in an embodiment of the present invention;

[0041] Figure 6 A schematic diagram of the structure of the bottom plate prestressed steel strands on a continuous rigid frame bridge provided by an embodiment of the present invention;

[0042] Figure 7 A flow chart of a construction method provided in an embodiment of the present invention.

[0043] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0044] 1. Web plate positive bending moment prestressed steel strand; 2. Main beam; 3. Pier; 11. First steel strand; 12. Second steel strand; 13. Third steel strand; 21. Main beam top plate; 22. Main beam web; 23. Main beam bottom plate; 24. Main beam tooth plate; 231. Bottom plate prestressed steel strand. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0046] A continuous rigid frame bridge in a certain place, the main bridge superstructure adopts a set of (96m+180m+96m) prestressed concrete variable height continuous box beams, the box beam is a single box single chamber straight web section, the top width of the box beam is 15.0m, the bottom width is 8.0m; the height of the box beam (the beam height is measured by the distance from the bottom plate of the box beam to the center of the top surface of the box beam) is 12.0m within the 13.0m range of the beam section corresponding to the middle pier body, and the beam height is 4.5m at the abutment and the middle span. The beam height of other parts changes according to a 1.8-fold parabola; the thickness of the box girder top plate is 0.8m at the main pier, and the thickness of the box girder top plate is 0.30m after the chamfer gradually changes to 4.5m; the thickness of the box girder bottom plate is 2.3m at the top of the main pier, and the thickness of the bottom plate is 1.092m after the chamfer gradually changes to 4.5m, and it is 0.32m at the abutment and the middle of the middle span, and the rest changes according to a 1.8-fold parabola; the thickness of the box girder web changes between 0.90m and 0.6m according to the shear force.

[0047] The original design of the box girder longitudinal prestressed steel strands is divided into three categories: top plate prestressed steel strands, bottom plate prestressed steel strands, and web prestressed steel strands. The longitudinal prestressing adopts prestressed steel strands with a nominal diameter of φS15.2mm. The prestressed steel strands adopt a combination of 25, 21, 19, and 15 steel strands. The anchors are YM15-25, 21, 19, and 15 respectively. The design tensioning control stress of the steel strands is 1339.2MPa (0.72fpk). The prestressing is carried out using intelligent tensioning equipment to detect and control the effective prestress.

[0048] The prestressed steel strands of the bottom plate are in a downward curved line, with 10 strands in each web. Calculations based on material parameters in the specification show that 10 years after the opening of the line, the radial force of the prestressed steel strands of the bottom plate can cause a downward deflection of up to 11 cm in the mid-span of the main beam.

[0049] The bridge has a large span. In order to prevent excessive downward deflection of the main beam in the middle of the span, four bundles of prestressed steel bundles 1 are arranged in each web. Each bundle is composed of 19 steel strands with a nominal diameter of φS15.2mm. The equivalent load method is used to calculate the equivalent load effects of the bottom plate prestressed steel bundles and the prestressed steel bundles 1.

[0050] The equivalent load method regards the prestressed tendons and anchors in the structure as load carriers, separates them from the structure, and equates their effects to loads. These equivalent loads are applied to the structure composed of concrete and non-prestressed tendons like external loads to calculate the internal forces of the structure under the action of prestressing.

[0051] Then, the equivalent load effects of the bottom plate prestressed steel bundle and the prestressed steel bundle 1 are calculated. Each prestressed steel bundle 1 has 19 steel strands, which can offset the radial load deflection effect of the bottom plate prestressed steel bundle.

[0052] Based on the above calculation and analysis, the original design is improved, such as Figures 1 to 4As shown, a continuous rigid frame bridge capable of reducing the deflection of the main beam in the middle span comprises: a plurality of web positive bending moment prestressed steel strands 1, a main beam 2 and a plurality of bridge piers 3, wherein the main beam 2 is arranged at the top of the plurality of bridge piers 3, and the web positive bending moment prestressed steel strands 1 are arranged in the middle span of the main beam 2; the web positive bending moment prestressed steel strands 1 are composed of two first steel strands 11, two second steel strands 12 and a third steel strand 13, the main beam 2 is provided with two main beam webs 22 and a plurality of main beam tooth plates 24, the first steel strand 11 is arranged above the third steel strand 13, and the first steel strand 11 and the third steel bundle 13 are all arranged horizontally, and the two ends of the third steel bundle 13 are connected to the two first steel bundles 11 through the two second steel bundles 12 in a one-to-one correspondence, and the second steel bundle 12 is connected to the first steel bundle 11 and the third steel bundle 13 in an arc transition. The first steel bundle 11, the second steel bundle 12 and the third steel bundle 13 are all arranged in the main beam web 22, and the end of the first steel bundle 11 away from the second steel bundle 12 is anchored on the main beam tooth plate 24, and the third steel bundle 13 is arranged at the lower part of the main beam web 22.

[0053] It should be noted that: in the technical solution of the present invention, the second steel bundle 12 is inclined when connected with the first steel bundle 11 and the third steel bundle 13 in an arc transition, and the inclination angle with the horizontal plane is 45 degrees;

[0054] The middle span of the main beam 2 refers to the middle part of the entire main beam, that is, Figure 1 and Figure 6 The main beam 2 is located above the two middle piers 3, and the side span refers to the part of the main beam located next to the middle span, that is, Figure 1 and Figure 6 The main beam 2 above the area between the two middle piers 3 and the two adjacent piers 3;

[0055] The principle of the present invention is as follows: due to the need for cantilever construction and structural stress, the main beam height of the prestressed concrete continuous rigid frame bridge is generally set to a circular curve gradient or parabola shape, so that the bottom plate prestressed steel bundle is also in a circular curve or parabola shape. When the prestressed tendons are tensioned after the mid-span of the large-span prestressed continuous rigid frame bridge is closed, the bottom plate prestressed steel bundle that is tightened by the tension force will squeeze the prestressed pipe wall, thereby generating an additional load effect on the surrounding concrete, that is, the radial force of the steel bundle, the steel of the bottom plate prestressed steel bundle The radial force of the tendons is downward, causing the mid-span deflection of the prestressed concrete continuous rigid frame bridge; for this purpose, multiple web positive moment prestressed steel tendons are arranged in the web of the main beam, and are bent upward and anchored at the junction of the web of the main beam and the main beam top plate. The web positive moment prestressed steel tendons produce an upward additional load effect at the bent part, causing the main beam to have an upward deflection, which is offset by the deflection caused by the downward radial force of the bottom plate prestressed steel tendons. At the same time, the arrangement of multiple web positive moment prestressed steel tendons can also bear the positive bending moment of the main beam.

[0056] The beneficial effects of the present invention are as follows: by arranging the web positive bending moment prestressed steel strands in the web of the main beam, the main beam produces an upward deflection, which is beneficial to offset the vertical downward deflection effect of the main beam caused by the radial force of the bottom plate prestressed steel strands in the existing main beam, thereby solving the problem of downward deflection of the prestressed concrete continuous rigid frame bridge caused by the radial force of the bottom plate prestressed steel strands. At the same time, the middle span of the main beam does not need to be provided with equal height sections and bottom plate thickening sections, which not only reduces the dead weight of the main beam, but also ensures the beautiful bridge shape of the prestressed concrete continuous rigid frame bridge. In addition, the web positive bending moment prestressed steel strands can bear the positive bending moment in the middle span of the main beam and can replace a part of the bottom plate prestressed steel strands.

[0057] Preferably, Figure 1 As shown, the anchoring points of the two first steel bundles 11 and the main beam tooth plate 24 are arranged outside the quarter points of the mid-span of the main beam 2 .

[0058] Among them, it should be noted that: the quarter point of the middle span of the main beam 2 refers to the position that divides the middle span of the main beam 2 into four parts. There are three quarter points. The two anchor points of the first steel bundles 11 and the main beam tooth plate 24 are arranged on the outside of the quarter points on both sides, that is, the two anchor points of the first steel bundles 11 and the main beam tooth plate 24 cross the quarter points on both sides in the direction of the side span of the main beam 2.

[0059] The beneficial effect of adopting the above preferred solution is that it is conducive to making the length of the web positive bending moment prestressed steel strands as long as possible to correspond to the bottom plate prestressed steel strands, thereby achieving a better solution to the deflection problem of the prestressed concrete continuous rigid frame bridge.

[0060] Preferably, Figures 2 to 5As shown, the main beam 2 also includes a main beam top plate 21 and a main beam bottom plate 23, the main beam top plate 21 is arranged above the main beam bottom plate 23, the two main beam webs 22 are arranged in parallel between the main beam top plate 21 and the main beam bottom plate 23, and the main beam tooth plate 24 is arranged at the connection between the main beam top plate 21 and the main beam web 22.

[0061] The beneficial effects of adopting the above-mentioned preferred scheme are: the main beam top plate is conducive to providing a location for the subsequent construction of bridge deck ancillary projects such as bridge deck paving, railings, expansion joint installation, etc., and the main beam bottom plate is conducive to providing space for the installation of prestressed steel strands of the bottom plate.

[0062] Preferably, the distance between the first steel bundle 11 and the main beam top plate 21 is 30-50 cm.

[0063] The beneficial effect of adopting the above preferred solution is that it is helpful to provide operating space for subsequent construction.

[0064] Preferably, Figure 6 As shown, a plurality of bottom plate prestressed steel strands 231 for applying an additional vertical downward load to the main beam 2 are arranged in the main beam bottom plate 23, and the bottom plate prestressed steel strands 231 are parabolic in shape.

[0065] The beneficial effect of adopting the above-mentioned preferred solution is that the bottom plate prestressed steel strands are conducive to providing prestress for the long-span prestressed continuous rigid frame bridge, and bear the positive bending moment in the middle of the main beam span, thereby meeting the force requirements of the bridge.

[0066] like Figure 7 As shown, a construction method of a continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span comprises the following steps:

[0067] S1: Determine the number of web positive moment prestressing tendons 1;

[0068] S2: Complete the construction of the main beam of the continuous rigid frame bridge;

[0069] S3: threading, tensioning and grouting the bottom plate prestressed steel strands 231 in the main beam bottom plate 23 of the continuous rigid frame bridge;

[0070] S4: threading, tensioning and grouting the web positive moment prestressed steel tendon 1 in the web 22 of the main beam of the continuous rigid frame bridge;

[0071] S5: Complete the construction of the bridge deck ancillary works of the continuous rigid frame bridge.

[0072] It should be noted that: in step S5, the construction of the bridge deck ancillary works includes the installation of bridge deck paving, railings, expansion joints, etc.

[0073] The beneficial effects of the present invention are: the bottom plate prestressed steel bundles and the web plate positive bending moment prestressed steel bundles are constructed successively, the structure is simple, and at the same time, in conjunction with the conventional continuous rigid frame bridge construction method, the construction quality is guaranteed and the cost is controllable.

[0074] Preferably, step S1 comprises the following steps:

[0075] S11: Calculate the vertical additional load of the web positive bending moment prestressed steel tendon 1 and the bottom plate prestressed steel tendon 231 on the main beam 2 by using the equivalent load method;

[0076] S12: inputting the vertical additional loads of the web positive bending moment prestressed steel tendon 1 and the bottom plate prestressed steel tendon 231 obtained in step S11 into the bridge structure calculation model;

[0077] S13: Determine the number of the web positive moment prestressed steel tendons 1 by making the sum of the downward deflections caused by the equivalent loads of the web positive moment prestressed steel tendons 1 and the bottom plate prestressed steel tendons 231 zero.

[0078] The beneficial effect of adopting the above-mentioned preferred scheme is that it is helpful to accurately determine the required number of web positive bending moment prestressed steel strands through the existing bridge structure calculation model, so that the sum of the downward deflections caused by the equivalent loads of the web positive bending moment prestressed steel strands and the bottom plate prestressed steel strands is zero.

[0079] Preferably, step S2 comprises the following steps:

[0080] S21: Complete the construction of pier 3;

[0081] S22: construct the main beam 2 by using a symmetrical cantilever method, and pre-embed the corrugated pipe of the bottom plate prestressed steel strand 231 in the main beam bottom plate 23, and pre-embed the corrugated pipe of the web positive bending moment prestressed steel strand 1 in the main beam web plate 22;

[0082] S23: completing the closing of the main beam 2.

[0083] The beneficial effect of adopting the above preferred solution is that the construction of the web positive bending moment prestressed steel strands adopts the same conventional construction method as the bottom plate prestressed steel strands, without increasing the construction steps, the construction period, and the cost is controllable.

[0084] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0085] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0086] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0087] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0089] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span, characterized in that: include: A plurality of web plate positive bending moment prestressed steel strands (1), a main beam (2) and a plurality of bridge piers (3), wherein the main beam (2) is arranged at the top ends of the plurality of bridge piers (3), and the web plate positive bending moment prestressed steel strands (1) are arranged in the middle span of the main beam (2); The web positive bending moment prestressed steel bundle (1) is composed of two first steel bundles (11), two second steel bundles (12) and a third steel bundle (13); the main beam (2) is provided with two main beam webs (22) and a plurality of main beam tooth plates (24); the first steel bundle (11) is arranged above the third steel bundle (13); the first steel bundle (11) and the third steel bundle (13) are both arranged horizontally; two ends of the third steel bundle (13) are connected to the two second steel bundles (12) in a one-to-one correspondence manner. The first steel bundle (11) is connected to the second steel bundle (12), the second steel bundle (12) is connected to the first steel bundle (11) and the third steel bundle (13) by an arc transition, the first steel bundle (11), the second steel bundle (12) and the third steel bundle (13) are all arranged in the main beam web (22), one end of the first steel bundle (11) away from the second steel bundle (12) is anchored on the main beam tooth plate (24), and the third steel bundle (13) is arranged at the lower part of the main beam web (22).

2. A continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to claim 1, characterized in that: The anchoring points of the two first steel bundles (11) and the main beam tooth plate (24) are arranged outside the quarter points of the mid-span of the main beam (2).

3. A continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to claim 1, characterized in that: The main beam (2) further comprises a main beam top plate (21) and a main beam bottom plate (23), wherein the main beam top plate (21) is arranged above the main beam bottom plate (23), the two main beam web plates (22) are arranged in parallel between the main beam top plate (21) and the main beam bottom plate (23), and the main beam tooth plate (24) is arranged at the connection between the main beam top plate (21) and the main beam web plate (22).

4. A continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to claim 3, characterized in that: The distance between the first steel bundle (11) and the main beam top plate (21) is 30-50 centimeters.

5. A continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to claim 3, characterized in that: A plurality of bottom plate prestressed steel strands (231) for applying an additional vertical downward load to the main beam (2) are arranged in the main beam bottom plate (23), and the bottom plate prestressed steel strands (231) are parabolic in shape.

6. A construction method for a continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span, characterized in that: A continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to any one of claims 1 to 5, the construction method comprises the following steps: S1: Determine the number of web positive moment prestressing tendons (1); S2: Complete the construction of the main beam of the continuous rigid frame bridge; S3: threading, tensioning and grouting the bottom slab prestressed steel strands (231) in the main beam bottom slab (23) of the continuous rigid frame bridge; S4: threading, tensioning and grouting the web positive moment prestressing steel tendons (1) in the web of the main beam (22) of the continuous rigid frame bridge; S5: Complete the construction of the bridge deck ancillary works of the continuous rigid frame bridge.

7. A construction method for a continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to claim 6, characterized in that: Step S1 includes the following steps: S11: using an equivalent load method to calculate the vertical additional loads of the web positive bending moment prestressed steel strand (1) and the bottom plate prestressed steel strand (231) on the main beam (2); S12: inputting the vertical additional loads of the web positive bending moment prestressed steel strand (1) and the bottom plate prestressed steel strand (231) obtained in step S11 into a bridge structure calculation model; S13: The number of the web positive moment prestressed steel tendons (1) is determined by making the sum of the downward deflections caused by the equivalent loads of the web positive moment prestressed steel tendons (1) and the bottom plate prestressed steel tendons (231) equal to zero.

8. A construction method for a continuous rigid frame bridge capable of reducing the deflection of the main beam mid-span according to claim 6, characterized in that: Step S2 includes the following steps: S21: Complete the construction of the bridge pier (3); S22: constructing the main beam (2) by using a symmetrical cantilever method, and pre-embedding the corrugated pipe of the bottom plate prestressed steel bundle (231) in the bottom plate (23) of the main beam, and pre-embedding the corrugated pipe of the web positive bending moment prestressed steel bundle (1) in the web plate (22) of the main beam; S23: completing the closing of the main beam (2).

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