Hybrid ultra-high performance concrete continuous structural system bridge and construction method thereof

Abstract

The application relates to the technical field of bridge engineering, in particular to a mixed type super high performance concrete continuous structure system bridge and a construction method thereof. The mixed type super high performance concrete continuous structure system bridge comprises a pier and an upper bridge structure, the upper bridge structure comprises a web hollowed section box girder and a solid web section box girder; the bridge adopts a mixed type large-span prestressed super high performance concrete continuous structure system bridge, the weight of the bridge is reduced, and the span capacity of the bridge is greatly improved; the structure formed by the design of a No. 1 pi-shaped beam, a channel beam and a stand column is combined with external prestress to balance the construction bending moment, the thickness of each part is ensured, the problems of local buckling, shear instability and overall instability are effectively avoided, and for the cross section distortion problem, the prestressed reinforcement is reasonably arranged and pre-tightening force is applied by means of prestress active constraint, so that the generation of cross section warping deformation is effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, and in particular to a hybrid ultra-high performance concrete continuous structure system bridge and its construction method. Background Technology

[0002] With the rapid development of ultra-high performance concrete (UHVPC), its application in bridge engineering is constantly expanding, especially in box girder structures where it has demonstrated unique technical advantages. UHVPC's high strength allows box girder structures to meet design requirements for load-bearing capacity and stiffness even with reduced cross-sectional dimensions. Compared to traditional ordinary concrete box girders, UHVPC box girders have smaller and lighter cross-sections, which not only reduces self-weight but also effectively lowers the design burden on bridge support structures, providing greater flexibility for the design of long-span and lightweight bridges. UHVPC's excellent fluidity and self-compacting properties give it significant advantages in the construction of box girders with complex cross-sections. Due to its extremely high strength and compressive strength, UHVPC's application in box girder structures is particularly prominent in long-span bridges.

[0003] However, as the size of box girder structures decreases, especially the thickness of the box girder web, thin-walled box girders can reduce self-weight and material usage, but their webs are prone to instability during stress, such as local buckling, shear instability and overall instability. In addition, thin-walled structures may also cause cross-sectional distortion problems, such as torsional deformation and warping, which in turn affect the stress safety and long-term stability of bridge structures.

[0004] The aforementioned problems make bridge stability and cross-sectional distortion issues key limiting factors in the design of thin-walled box girders. In particular, when the web thickness of a thin-walled box girder is reduced, the structural stability may reach the design limit earlier than the material strength. Therefore, a new structure is needed to address the problem of web instability during stress and the cross-sectional distortion that thin-walled structures may cause. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a hybrid ultra-high performance concrete continuous structure system bridge, including piers and a bridge superstructure, wherein the bridge superstructure includes a box girder with a hollowed-out web section and a box girder with a solid web section;

[0006] The hollowed-out section box girder is arranged on the top of the pier and on both sides of the top of the pier, accounting for 60% to 70% of the entire bridge deck. The solid section box girder is arranged between the two hollowed-out section box girders, and the two ends of the solid section box girder are cast and fixedly connected to the hollowed-out section box girders on both sides.

[0007] As a preferred technical solution of the present invention, the box girder with the web cutout section is integrally cast and formed, which includes a No. 1 π-shaped beam, a channel beam, a column, and an anchor block. The No. 1 π-shaped beam is located above the channel beam, and the two are fixedly connected by the column.

[0008] As a preferred technical solution of the present invention, the solid web box girder is cast in place and consists of three parts: a top plate, a connecting plate, and a bottom plate. The top plate is located above the bottom plate, and the two are connected by the connecting plate.

[0009] As a preferred embodiment of the present invention, each of the solid-web box girder segments and each of the hollowed-out web box girder segments are collectively referred to as a beam segment. Each beam segment is divided into blocks No. 1, No. 2, No. 3, and so on, according to its distance from the pier, until the bridge closure point. The beam segment located directly above the pier is block No. 0, which does not belong to either the solid-web box girder segment or the hollowed-out web box girder segment. Block No. 1 is located on the left and right sides of block No. 0 and is fixedly connected to block No. 0 by casting. Block No. 2 is located at the end of block No. 1 furthest from the pier and is fixedly connected to block No. 1 by casting. Block No. 3 is located at the end of block No. 2 furthest from the pier and is fixedly connected to block No. 2 by casting, and so on, until the last beam segment. The ends of the two beam segments furthest from the pier are connected to each other.

[0010] As a preferred technical solution of the present invention, the box girder with the web cutout section adopts an overall external prestressing system, and multiple prestressing reserved holes are opened on the zero block and the anchor block.

[0011] As a preferred technical solution of the present invention, an external prestressed steel strand is inserted into the prestressed reserved hole on the zero block. The two ends of the external prestressed steel strand are respectively anchored in the prestressed reserved hole on two anchor blocks symmetrical along the central axis of the pier. The external prestressed steel strand is also symmetrical along the central axis of the pier.

[0012] As a preferred technical solution of the present invention, the solid web box girder adopts an internal prestressing system, and an internal prestressing steel strand is provided between every two solid web box girders symmetrical along the central axis of the pier. The two ends of the internal prestressing steel strand are respectively anchored to the two corresponding solid web box girders symmetrical along the central axis of the pier.

[0013] As a preferred technical solution of the present invention, the middle part of the zero block is inverted Y-shaped, and the prestressed reserved hole is opened on the upper half of the inverted Y-shaped part of the zero block. The second π-shaped beam is fixedly installed on the upper side of the zero block, and the second π-shaped beam is fixedly connected to the first π-shaped beam. The prestressed steel strands in the body pass through the second π-shaped beam and all the π-shaped beams and the top plate along its path.

[0014] In addition, the present invention also provides a construction method for a hybrid ultra-high performance concrete continuous structure system bridge: S1, construction of pile foundation and pier: firstly, the pile foundation and pier are constructed, and the pier is a thin-walled flexible pier.

[0015] Construction of S2, Zero Block and Web Section: After the substructure is completed, the Zero Block on the top of the pier is constructed. During the pouring, prestressed ducts and hanging basket embedded parts are pre-embedded. The web section box girder is constructed symmetrically. During the pouring process, the web section box girder is poured according to the portal frame unit. Each time, two beam segments are poured symmetrically on the left and right. After the segment concrete strength reaches the requirements, the external prestressed steel strands are tensioned symmetrically in sequence.

[0016] S3. Conversion of formwork system for bridge construction: The conversion node is at the junction of the excavated section and the solid section of the web. First, the portal frame formwork is dismantled in sections, and then the formwork for the solid section is installed. The hanging basket is hoisted, and the formwork elevation and alignment are adjusted to make the formwork smoothly connected with the already constructed section. After the installation is completed, the mechanical analysis of the converted formwork support system is carried out to ensure that the bearing capacity meets the construction load requirements.

[0017] S4. Construction of the solid web section: The cantilever casting method using hanging baskets is adopted, and the concrete is poured in two stages: first, the bottom slab and connecting slab are poured, and then the top slab is poured to ensure the integrity of the structure; then, the prestressed steel strands in the body are tensioned in sequence according to the design, and vacuum-assisted grouting process is used to ensure full grouting; the elevation of the hanging basket and the prestressing tensioning parameters are adjusted in real time through the construction monitoring system to ensure that the box girder alignment meets the design requirements.

[0018] The beneficial effects of this invention are as follows: First, the groundbreaking design broadens the scope of application; the bridge of this invention adopts a groundbreaking hybrid large-span prestressed ultra-high performance concrete continuous structure system, which not only reduces the weight of the bridge, but also significantly improves the span capacity of the bridge; this design innovation makes the bridge system have a broader application prospect and stronger market competitiveness in the field of large-scale bridge engineering.

[0019] Second, seamless integration with existing construction technologies improves construction efficiency; the bridge design of this invention fully considers seamless integration with existing construction technologies, enabling the construction team to quickly adapt and efficiently execute construction tasks; this design not only simplifies the construction process but also significantly improves construction speed, helps to shorten the project cycle and improve construction efficiency.

[0020] Third, it has significant cost-effectiveness and optimizes economic efficiency. By reducing the self-weight of the hybrid large-span prestressed ultra-high performance concrete continuous structure bridge, this invention can effectively reduce the load-bearing requirements of the bridge foundation and supporting structure. Especially in areas with complex geological conditions, it can significantly reduce construction costs. In addition, the box girder with hollowed-out web sections on both sides of the pier further reduces material and construction costs while ensuring the overall strength of the bridge, thus improving the economic benefits of the project. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is the front view of the present invention.

[0023] Figure 2 This is a partial front view of the present invention.

[0024] Figure 3 yes Figure 2 Enlarged view of point I.

[0025] Figure 4 yes Figure 2 Sectional view at point AA.

[0026] Figure 5 yes Figure 2 Cross-sectional view of BB section.

[0027] Figure 6 yes Figure 2 Cross-sectional view at CC.

[0028] Figure 7 yes Figure 2 Cross-sectional view at DD.

[0029] Figure 8 yes Figure 2 Sectional view of EE.

[0030] Figure 9 This is a three-dimensional cross-sectional schematic diagram of block number zero of the present invention.

[0031] Figure 10 This is a schematic diagram of the segmentation of the beam segment of the present invention.

[0032] Figure 11 yes Figure 10 Enlarged view of section II.

[0033] In the diagram: 1. Pier; 2. Bridge superstructure; 20. Block 0; 201. No. 2 π-shaped beam; 21. Box girder with hollowed-out web section; 22. Box girder with solid web section; 23. Internal prestressed steel strands; 24. External prestressed steel strands; 211. No. 1 π-shaped beam; 212. Channel beam; 213. Column; 214. Anchor block; 215. Prestressed reserved duct; 221. Top slab; 222. Connecting plate; 223. Bottom slab. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0035] See Figures 1-2 A hybrid ultra-high performance concrete continuous structure bridge includes piers 1 and a bridge superstructure 2. The bridge superstructure 2 includes a box girder 21 with a hollowed-out web section and a box girder 22 with a solid web section. The box girder 21 with a hollowed-out web section is arranged on the top of the pier 1 and on both sides of the top of the pier 1, accounting for 60% to 70% of the entire bridge deck. The box girder 22 with a solid web section is arranged between the two box girder 21s with a hollowed-out web section, and the two ends of the box girder 22 with the box girder 21s with a hollowed-out web section are cast and fixedly connected.

[0036] See Figures 2-3 , Figures 5-7 The hollowed-out section box girder 21 is integrally cast and includes a first π-shaped beam 211, a channel beam 212, a column 213, and an anchor block 214. The first π-shaped beam 211 is located above the channel beam 212, and the two are fixedly connected by the column 213. The solid-web section box girder 22 is cast and consists of three parts: a top plate 221, a connecting plate 222, and a bottom plate 223. The top plate 221 is located above the bottom plate 223, and the two are connected by the connecting plate 222.

[0037] This invention relates to a bridge system employing a hybrid, large-span, prestressed, ultra-high-performance concrete continuous structure, which not only reduces bridge weight but also significantly increases span capacity. The invention utilizes a structure formed by a first π-shaped beam 211, a second π-shaped beam 201, a channel beam 212, and columns 213. Combined with external prestressing to balance construction bending moments and ensuring sufficient thickness in each component, this effectively avoids problems such as local buckling, shear instability, and overall instability. Regarding cross-sectional distortion, the invention employs prestressing active restraint to rationally arrange prestressing tendons and apply preload, effectively suppressing cross-sectional warping. Furthermore, the use of a hollowed-out box girder structure further optimizes the internal stress distribution, reducing stress concentration and thus preventing torsional deformation and warping distortion during structural stress.

[0038] See Figures 1-3 , Figures 10-11Each of the solid-web box girder 22 and each of the hollowed-out-web box girder 21 are collectively referred to as a beam segment. Each beam segment is divided into block 1, block 2, block 3, and so on, according to its distance from the pier 1, until the bridge closure point. The beam segment located directly above the pier 1 is block 0, which does not belong to the solid-web box girder 22 or the hollowed-out-web box girder 21. Block 1 is located on the left and right sides of block 0 and is fixedly connected to block 0 by casting. Block 2 is located at the end of block 1 furthest from the pier 1 and is fixedly connected to block 1 by casting. Block 3 is located at the end of block 2 furthest from the pier 1 and is fixedly connected to block 2 by casting, and so on, until the last beam segment. The two beam segments furthest from the pier 1 are connected to each other at the ends furthest from the pier 1.

[0039] See Figures 7-11 The box girder 21 with the web cutout section adopts an overall external prestressing system. Multiple prestressing reserved holes 215 are opened on both the zero block 20 and the anchor block 214. External prestressing steel strands 24 are inserted into the prestressing reserved holes 215 on the zero block 20. The two ends of the external prestressing steel strands 24 are respectively anchored in the prestressing reserved holes 215 on the two anchor blocks 214 symmetrical along the central axis of the pier 1. The external prestressing steel strands 24 are also symmetrical along the central axis of the pier 1.

[0040] See Figures 2-3 , Figures 10-11 The solid web box girder 22 adopts an internal prestressing system. An internal prestressing steel strand 23 is provided between every two solid web box girders 22 that are symmetrical along the central axis of the pier 1. The two ends of the internal prestressing steel strand 23 are respectively anchored to the two corresponding solid web box girders 22 that are symmetrical along the central axis of the pier 1.

[0041] This invention shifts the traditional design of "passively meeting strength requirements" to a collaborative design of "actively adapting to stress characteristics." Through structural innovation in segments, systems, and functions, it not only solves the pain points of instability and distortion in existing technologies, but also achieves added value such as increased span capacity, reduced costs, and convenient maintenance. It provides a brand-new technical path for the design and application of long-span ultra-high-performance concrete bridges and has significant engineering practical significance. This design innovation makes the bridge system have broader application prospects and stronger market competitiveness in the field of large-scale bridge engineering.

[0042] See Figures 2-3 , Figures 9-11The middle part of the zero block 20 is inverted Y-shaped. The prestressed reserved hole 215 is opened on the upper half of the inverted Y-shaped part of the zero block 20. The second π-shaped beam 201 is fixedly installed on the upper side of the zero block 20, and the second π-shaped beam 201 is fixedly connected to the first π-shaped beam 211. The prestressed steel strand 23 in the body passes through the second π-shaped beam 201 and all the first π-shaped beams 211 and the top plate 221 along its path.

[0043] This invention effectively reduces the load-bearing requirements of bridge foundations and supporting structures by reducing the self-weight of hybrid, long-span, prestressed, ultra-high-performance concrete continuous structure bridges. Especially in areas with complex geological conditions, such as fractured rock formations and insufficient bearing capacity, this significantly reduces the design and construction investment for foundation reinforcement and special support structures, substantially compressing overall construction costs. Furthermore, the excavated section design of this bridge further optimizes material usage, reducing the consumption of core building materials such as concrete and steel reinforcement, and simplifying construction procedures: such as reducing formwork erection and concrete pouring volume. This lowers material procurement and labor costs while shortening the construction cycle, ultimately comprehensively improving the project's economic benefits.

[0044] A construction method for a bridge using a hybrid ultra-high performance concrete continuous structure system includes the following steps:

[0045] S1. Construction of pile foundation and pier 1: First, the construction of pile foundation and pier 1 is carried out. Pier 1 is a thin-walled flexible pier.

[0046] Construction of S2, Block 20 and the hollowed-out section of the web: After the substructure is completed, Block 20 on the top of Pier 1 is constructed. During the pouring, prestressed ducts and hanging basket pre-embedded parts are pre-embedded. The box girder 21 with the hollowed-out section of the web is constructed symmetrically. During the pouring process, the box girder 21 with the hollowed-out section of the web is poured according to the portal frame unit. Each time, two beam segments are poured symmetrically on the left and right. After the concrete strength of the segment reaches the requirements, the external prestressed steel strands 24 are tensioned symmetrically in sequence.

[0047] S3. Conversion of formwork system for bridge construction: The conversion node is at the junction of the excavated section and the solid section of the web. First, the portal frame formwork is dismantled in sections, and then the formwork for the solid section is installed. The hanging basket is hoisted, and the formwork elevation and alignment are adjusted to make the formwork smoothly connected with the already constructed section. After the installation is completed, the mechanical analysis of the converted formwork support system is carried out to ensure that the bearing capacity meets the construction load requirements.

[0048] S4. Construction of the solid web section: The cantilever casting method using a hanging basket is adopted, and the concrete is poured in two stages: first, the bottom slab 223 and connecting slab 222 are poured, and then the top slab 221 is poured to ensure the integrity of the structure; then, the prestressed steel strands 23 in the body are tensioned in sequence according to the design, and vacuum-assisted grouting process is used to ensure full grouting; the elevation of the hanging basket and the prestressing tensioning parameters are adjusted in real time through the construction monitoring system to ensure that the box girder alignment meets the design requirements.

[0049] This invention seamlessly integrates with existing construction technologies (such as cantilever construction, which uses a movable formwork as a construction platform, with the pier as the center, to symmetrically pour each length of the cantilever beam. After the cantilever sections are completed, they are connected into a continuous beam through a closure section, ultimately forming a rigid frame system of "pier-beam integration"). The bridge design of this invention fully considers seamless integration with existing construction technologies, enabling construction teams to quickly adapt and efficiently execute construction tasks. This design not only simplifies the construction process but also significantly improves construction speed, helps shorten the project cycle, and enhances construction efficiency.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention, which are still covered within the protection scope of the present invention.

Claims

1. A bridge with a hybrid ultra-high performance concrete continuous structure system, characterized in that, It includes bridge piers (1) and bridge superstructure (2), wherein the bridge superstructure (2) includes a box girder with a hollowed-out web section (21) and a box girder with a solid web section (22). The hollowed-out section box girder (21) is arranged on the top of the pier (1) and on both sides of the top of the pier (1), accounting for 60% to 70% of the entire bridge deck. The solid section box girder (22) is arranged between the two hollowed-out section box girders (21), and the two ends of the solid section box girder (22) are cast and fixedly connected to the hollowed-out section box girders (21) on both sides. The box girder (21) with the web section cut out is cast in one piece. It includes a No. 1 π-shaped beam (211), a channel beam (212), a column (213), and an anchor block (214). The No. 1 π-shaped beam (211) is located above the channel beam (212), and the two are fixedly connected by the column (213). Each of the solid web box girder (22) and each of the hollowed-out web box girder (21) are collectively referred to as a beam segment; the beam segment located directly above the pier (1) is block zero (20), and block zero (20) does not belong to the solid web box girder (22) or the hollowed-out web box girder (21). The middle part of the zero block (20) is inverted Y-shaped. The prestressed reserved hole (215) is opened on the upper half of the inverted Y-shaped part of the zero block (20). The second π-shaped beam (201) is fixedly installed on the upper side of the zero block (20), and the second π-shaped beam (201) is fixedly connected to the first π-shaped beam (211). The prestressed steel strand (23) in the body passes through the second π-shaped beam (201) and all the first π-shaped beams (211) and the top plate (221) along its path.

2. The hybrid ultra-high performance concrete continuous structure bridge according to claim 1, characterized in that, The solid web box girder (22) is cast in place and consists of three parts: a top plate (221), a connecting plate (222), and a bottom plate (223). The top plate (221) is located above the bottom plate (223), and the two are connected by the connecting plate (222).

3. A hybrid ultra-high performance concrete continuous structure bridge according to claim 2, characterized in that, Each beam segment is divided into block 1, block 2, and block 3 according to its distance from the pier (1), and so on until the bridge closure point; block 1 is located on the left and right sides of block 0 (20) and is fixedly connected to block 0 (20) by pouring; block 2 is located at the end of block 1 away from the pier (1) and is fixedly connected to block 1 by pouring; block 3 is located at the end of block 2 away from the pier (1) and is fixedly connected to block 2 by pouring, and so on until the last beam segment, the two beam segments farthest from the pier (1) are connected to each other at the ends farthest from the pier (1).

4. A hybrid ultra-high performance concrete continuous structure bridge according to claim 3, characterized in that, The box girder (21) with the web section cut out adopts the whole external prestressing system, and multiple prestressing reserved holes (215) are opened on the zero block (20) and the anchor block (214).

5. A hybrid ultra-high performance concrete continuous structure bridge according to claim 4, characterized in that, External prestressed steel strands (24) are inserted into the prestressed reserved ducts (215) on the zero block (20). The two ends of the external prestressed steel strands (24) are respectively anchored in the prestressed reserved ducts (215) on two anchor blocks (214) symmetrical along the central axis of the pier (1). The external prestressed steel strands (24) are also symmetrical along the central axis of the pier (1).

6. A bridge with a hybrid ultra-high performance concrete continuous structure system according to claim 5, characterized in that, The solid web box girder (22) adopts an internal prestressing system. An internal prestressing steel strand (23) is set between every two solid web box girders (22) symmetrical along the central axis of the pier (1). The two ends of the internal prestressing steel strand (23) are respectively anchored on the two corresponding solid web box girders (22) symmetrical along the central axis of the pier (1).

7. A construction method for a hybrid ultra-high performance concrete continuous structural system bridge, applied to the hybrid ultra-high performance concrete continuous structural system bridge as described in any one of claims 5-6, characterized in that, Includes the following steps: S1. Construction of pile foundation and pier (1): First, the construction of pile foundation and pier (1) is carried out. The pier (1) adopts thin-walled flexible pier. Construction of S2, Block 0 (20) and the hollowed-out section of the web: After the construction of the substructure is completed, the construction of the top of the pier (1) Block 0 (20) is carried out. During the pouring, the prestressed pipes and the pre-embedded parts of the hanging basket are pre-embedded. The box girder (21) of the hollowed-out section of the web is constructed symmetrically. During the pouring process, the box girder (21) of the hollowed-out section of the web is poured according to the portal frame unit. Each time, two beam segments are poured symmetrically on the left and right. After the concrete strength of the segment reaches the requirements, the external prestressed steel strands (24) are tensioned symmetrically in sequence. S3. Conversion of formwork system for bridge construction: The conversion node is at the junction of the excavated section and the solid section of the web. First, the portal frame formwork is dismantled in sections, and then the formwork for the solid section is installed. The hanging basket is hoisted, and the formwork elevation and alignment are adjusted to make the formwork smoothly connected with the already constructed section. After the installation is completed, the mechanical analysis of the converted formwork support system is carried out to ensure that the bearing capacity meets the construction load requirements. S4. Construction of the solid web section: The cantilever casting method using hanging baskets is adopted, and the concrete is poured in two stages: first, the bottom slab (223) and connecting slab (222) are poured, and then the top slab (221) is poured to ensure the integrity of the structure; then, the prestressed steel strands (23) in the body are tensioned in sequence according to the design, and the vacuum-assisted grouting process is used to ensure full grouting; the elevation of the hanging basket and the prestressing tensioning parameters are adjusted in real time through the construction monitoring system to ensure that the box girder alignment meets the design requirements.

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