High-rigidity cross beam large-span beam type aqueduct span structure

Abstract

The invention discloses a large-span beam type aqueduct span structure with high-rigidity cross beams. The large-span beam type aqueduct span structure is a large-span giant beam type aqueduct space structure different from a traditional aqueduct span structure form. The aqueduct span structure is characterized in that the aqueduct span structure is mainly composed of four parts including high-rigidity side walls, a bottom plate, high-rigidity cross beams and side ribs. The aqueduct structure has the advantages that the structure is simple and reasonable, dimensionality reduction calculation can be achieved, load distribution is reasonable, the structure force transmission path is clear, design and construction are easy, building materials are saved, the side wall rigidity advantage is fully played, and the crossing performance is higher than that of a traditional beam aqueduct structure.

Description

Technical Field

[0001] The invention relates to a new type of building structural component and a construction method in water conservancy projects, in particular to a high-rigidity crossbeam and large-span beam-type aqueduct span structure. Background Art

[0002] An aqueduct is a bridge-like water channel built over valleys, depressions, rivers, and roads for water transport, flood drainage, and diversion. It is also called an elevated canal, flying canal, water trough, and water bridge.

[0003] Among the water diversion, irrigation, drainage and water supply structures in water conservancy and hydropower projects, concrete aqueducts are the most important cross-overhead water transmission structures. They are widely used in projects such as inter-basin water diversion, farmland irrigation, industrial and urban domestic water use, and large aqueducts are also navigable.

[0004] Due to the complexity and diversity of the terrain and geological conditions of water transmission line projects, the span of aqueducts has developed from small and medium spans across general rivers, valleys, depressions and roads to large and even extra-large spans across deep mountain canyons, river reservoirs, village houses and densely populated areas, as well as high-grade highways and railways.

[0005] Among large-span aqueducts, the most common are concrete beam and arch aqueduct structures. Their high rigidity and strong bearing capacity can better adapt to the needs of large-span aqueducts and have been widely used and developed.

[0006] Arch aqueducts are suitable for valleys or river valleys with favorable geological conditions. Their design and construction techniques are complex and costly. Beam aqueducts organically integrate the water conveyance and load-bearing structures. The span structure serves as both a water conveyance and a spanning load-bearing structure. Their rational load-bearing characteristics, ease of construction, and cost-effectiveness have led to their continued development and application in large-span aqueducts. Beam aqueducts commonly employ structural systems such as simply supported beams, continuous beams, and continuous rigid frames.

[0007] Modern large-span aqueducts are primarily constructed of reinforced concrete and prestressed concrete. Common cross-sections include rectangular and U-shaped. U-shaped aqueducts, due to their low longitudinal bending stiffness due to their cross-sectional characteristics, are unsuitable for single-span, large-span aqueducts and are primarily used for small and medium-sized aqueducts. Large and giant aqueducts often utilize rectangular aqueducts, which can be categorized into beamless, box-type, multi-sidewall, and multi-longitudinal beam types.

[0008] There is no beam support below the bottom plate of the beamless aqueduct, and it deforms greatly after being loaded. It is generally used for small aqueducts with narrow width.

[0009] The box-type aqueduct body is closed on all sides, with only air vents on the top. The overall bending stiffness of the body is very high, but at the same time, it uses a lot of concrete, has a large deadweight, is difficult to build, and is not conducive to observing the internal conditions of the body and conducting maintenance during operation.

[0010] The multiple side walls of a multi-wall aqueduct also serve as longitudinal bending beams, and the longitudinal stiffness of the entire aqueduct is relatively large. However, when the width of the water-passing section remains the same, the middle wall needs to occupy part of the water-passing section, and the head loss caused by the water flow resistance is large, which hinders flood discharge, water discharge, and water transmission, and is not conducive to navigation. In addition, large-scale multi-wall aqueducts require a large amount of concrete to build, the aqueduct body is heavy, and have disadvantages such as a long construction period, high construction difficulty, and high project investment.

[0011] Multi-longitudinal-beam aqueducts avoid the water-blocking drawback of multi-sidewall aqueducts, making them suitable for wide, shallow aqueducts with high flow rates. Multiple longitudinal beams under the base plate provide exceptional flexural rigidity and minimize deformation under load. However, the central longitudinal beams, compared to the side beams, are much less rigid and experience significant deformation under load. This significant difference in flexural rigidity between the central and side beams leads to unbalanced deformation under load, resulting in a complex distribution of water loads between the side walls and the bottom beams. This results in a significant difference in vertical displacement between the center and periphery of the base plate, excessive tensile stress, and severe concrete cracking in the base plate and central longitudinal beams. The overall spatial structure is subject to complex loads, with irrational load transfer and distribution. Excessive differential deflection in the longitudinal structure can lead to excessive internal forces in the transverse structure of the trough, potentially causing structural failure. Various experiments have been conducted to reduce the flexural rigidity difference between the central and side beams. For example, vertical expansion joints can be added to the side longitudinal beams and sealed with waterstops; or longitudinal expansion joints can be added between the base plate and the side walls and sealed with waterstops, thereby transforming the rigid connection between the base plate and the side walls into a flexible one. Both designs deprive the side longitudinal beams of their longitudinal bending resistance, rendering them merely water-retaining side walls. The vertical water loads are then borne entirely by the bottom longitudinal beams. Not only do these designs fail to fundamentally address the problem, but they also damage the primary load-bearing components of the beam aqueduct, depriving it of its fundamental characteristics and making it less economical and practical.

[0012] In summary, in the practical application of large-span aqueducts, it is urgent to invent a large-span giant aqueduct spatial structure that is completely different from the traditional structural form. Summary of the Invention

[0013] In order to solve the above problems, a high-rigidity beam and large-span beam-type aqueduct span structure was invented.

[0014] The technical solution of the present invention is as follows: the high-rigidity beam large-span beam-type aqueduct span structure is mainly composed of four parts: high-rigidity side walls, bottom plates, high-rigidity beams, and side ribs.

[0015] The high-rigidity side walls are located on both sides of the trough body and are arranged vertically. They are used to block water and bear lateral water loads, and are also the most important longitudinal bending-resistant components of the entire trough span structure.

[0016] The bottom plate is located at the bottom between two high-rigidity side walls, arranged horizontally, and is used to bear vertical water loads.

[0017] The high-rigidity cross beam is located at the bottom of the bottom plate, perpendicular to the axis of the trough body, and arranged horizontally. Multiple high-rigidity cross beams serve as supports for the bottom plate and together with the bottom plate form a beam-plate system with greater rigidity.

[0018] The side ribs are located on the outside of the high-rigidity side wall and are arranged horizontally and vertically to improve the anti-thrust stiffness of the side wall. The vertical side ribs can be arranged corresponding to the high-rigidity cross beams, and one or more horizontal side ribs can be arranged on a single side. This can not only increase the stability of each vertical side rib and prevent the vertical side ribs and side walls from becoming unstable, but also improve the bending stiffness of the longitudinal section of the side wall. The side ribs and the high-rigidity side walls together form a beam-slab system with greater stiffness.

[0019] The supports of the entire trough span structure are located at both ends of the high-rigidity side walls. There is a support at each end of each high-rigidity side wall. The single-trough trough span structure has 4 supports per span. Furthermore, in order to improve the stress conditions, the ends of the high-rigidity side walls and high-rigidity beams at the supports can be appropriately enlarged to avoid stress concentration.

[0020] From the perspective of vertical load transfer, the bottom plate transfers the vertical water load to the high-rigidity beams, and the high-rigidity beams then transfer the vertical water load to the high-rigidity side walls on both sides and the entire trough body. The entire trough body and span structure then transfers the vertical water load to the trough piers and foundation.

[0021] From the perspective of lateral load transfer, the beam-slab structure composed of the high-rigidity side walls and side ribs transfers the lateral water load to the beam-slab structure composed of the bottom plate and high-rigidity beams in the form of end bending moment load, reducing the mid-span bending moment of the beam-slab structure composed of the bottom plate and high-rigidity beams, which is beneficial to reducing the vertical displacement of the lower surface of the bottom plate and the mid-span of each high-rigidity beam and the tensile stress at the bottom of the beam; at the same time, in the lateral direction, the beam-slab structure composed of the bottom plate and high-rigidity beams is a simply supported structure, and the vertical water load it will bear reacts to the beam-slab structure composed of the high-rigidity side walls and side ribs in the form of end bending moment load, thereby further improving the anti-thrust stiffness of the high-rigidity side walls.

[0022] The crossbeam is a key component of the entire slot-span spatial structure. Improving the bending stiffness of the high-rigidity crossbeam can promote the redistribution of loads in the entire slot-span structure, adjust the redistribution of internal forces, and thus improve the overall stress and strain.

[0023] Preferably, each high-rigidity beam can be made of prestressed concrete beam to improve its bending rigidity.

[0024] Preferably, the high-rigidity cross beams can adopt large-rigidity cross sections such as I-beams and box beams to improve their bending rigidity, so that the load from the bottom plate can be effectively transferred to the high-rigidity side walls, improving the stress and deformation of the trough body.

[0025] Preferably, prestressed beams are arranged in the high-rigidity side walls along the longitudinal direction of the trough body, and the linear prestressed beams are arranged in combination with the curved and broken line prestressed beams to improve the longitudinal bending stiffness thereof.

[0026] Preferably, the width of the top and bottom flanges of the high-rigidity side wall can be increased, and a large-rigidity cross-section such as an I-beam can be used to improve the longitudinal bending stiffness of the high-rigidity side wall, thereby enhancing the bending resistance of the entire slot span structure and improving stress and deformation.

[0027] Preferably, both the side walls and the high-rigidity cross beams can adopt variable-section beams according to the internal force distribution characteristics.

[0028] Preferably, both the vertical and transverse side ribs may adopt T-shaped cross-sections to increase their cross-sectional rigidity, reduce the amount of concrete used, and improve the stress conditions.

[0029] Preferably, for giant aqueducts with large spacing between high-rigidity beams, longitudinal ribs perpendicular to the beams can be added below the bottom plate to improve the stress on the bottom plate.

[0030] Preferably, the trough span structure can adopt a simply supported beam type, a continuous beam type, a continuous rigid frame type or other structural forms.

[0031] Preferably, the slot span structure can adopt a single slot or multi-slot structure.

[0032] Preferably, the trough-span structure can be constructed by integral cast-in-situ, prefabricated assembly, overlapping, and other construction methods.

[0033] Compared with the prior art, the present invention has the following beneficial effects.

[0034] A new type of beam-type aqueduct design concept and structural form is proposed, which is different from traditional aqueduct structural forms such as beamless type, box type, multi-side wall type, and multi-longitudinal beam type. Since the influence of the three-dimensional spatial effect of the structure is eliminated, the design process can be simplified to a two-dimensional plane structure for design and calculation. The longitudinal direction of the trough body can be simplified to structural forms such as simply supported beams, continuous beams, and continuous rigid frames. The transverse direction of the trough body can be simplified to simply supported beams and cantilever beams with bending moments at both ends for structural calculation. This not only simplifies the design process and reduces the calculation cost, but also improves the calculation accuracy and is close to the actual stress state of the structure.

[0035] The vertical water load transfer path of the aqueduct is: bottom plate → high-rigidity beam → high-rigidity side wall → overall trough body → support → trough pier and foundation. The load transfer path is clearer and more specific. Larger loads are borne by components with greater rigidity. The load distribution is more reasonable, the stress and deformation of each component are greatly improved, and the advantages of the components can be fully utilized.

[0036] By applying prestress and employing high-strength beams with large cross-sections, such as I-shaped or box-shaped beams, the high-rigidity crossbeams significantly enhance their structural flexural rigidity. This redistributes the load across the entire span structure, adjusting internal force redistribution and improving overall stress and strain. The side walls can be fully utilized as longitudinal bending members, further leveraging the advantages of combining a beam-type aqueduct water conveyance structure with a load-bearing structure.

[0037] The side ribs transfer part of the end bending moment generated by the transverse water load at the bottom of the side wall to each beam, which is beneficial to reducing the vertical displacement of each beam in the span and the longitudinal tensile stress at the bottom of the beam; at the same time, after the beam is loaded, the end bending moment is generated on the lower part of the vertical side rib, and is transferred to the side wall by the vertical side rib, thereby further improving the anti-thrust stiffness of the side wall.

[0038] Straight and curved prestressed tendons are arranged in the side walls, and large flange cross-sections are adopted in the middle and lower parts of the side walls, which greatly improves the longitudinal bending stiffness and thus enhances the spanning capacity of the slot-span structure.

[0039] Due to the reasonable stress of the structure, compared with aqueducts of the same cross-sectional size or spanning capacity, the high-rigidity beam and large-span beam-type aqueduct span structure uses less concrete, steel bars and prestressed tendons, which can further reduce construction costs and has significant economic effects. The main components not only meet the crack resistance and deformation requirements under normal use, but also the bearing capacity of the components under the limit state is significantly improved. The mechanical and economic performances are good, and it can be widely used in the construction of aqueducts with large spans or even extra-large spans.

[0040] Compared to U-shaped aqueducts, these aqueducts have greater longitudinal rigidity, making them more suitable for large-span, massive aqueducts. Compared to beamless aqueducts, they offer a wider water surface, facilitating navigation and flood discharge. Compared to box-type aqueducts, they use less construction materials, are navigable, and facilitate management, observation, and maintenance. Compared to multi-sidewall aqueducts, they offer less head loss, facilitating flood discharge, water transfer, and navigation. They also utilize less construction materials, have a lighter aqueduct body, and offer advantages such as a shorter construction period, lower construction difficulty, and lower project investment. Compared to multi-longitudinal beam aqueducts, these high-rigidity, long-span beam aqueducts offer a more rational structural design and load transfer, a clearer force transmission path, and better leverage the longitudinal bending resistance of the sidewalls. Therefore, under the same conditions, they offer greater spanning potential than traditional aqueducts. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1This is a three-dimensional schematic diagram of the high-rigidity beam and large-span beam-type aqueduct span structure;

[0042] Figure 2 This is a schematic diagram of the cross section of a large-span beam-type aqueduct structure with high-rigidity crossbeams;

[0043] Figure 3 This is a schematic diagram of the longitudinal section of the long-span beam-type aqueduct structure with high-rigidity crossbeams;

[0044] Figure 4 This is a side elevation diagram of a large-span beam-type aqueduct structure with high-rigidity crossbeams;

[0045] Figure 5 This is a schematic diagram of the arrangement of high-rigidity cross beams on the bottom surface of the long-span beam-type aqueduct span structure;

[0046] Figure 6 This is a schematic diagram of the cross section of the high-rigidity side wall of the long-span beam-type aqueduct structure with high-rigidity cross beams;

[0047] Figure 7 This is a schematic diagram of the cross section of a high-rigidity beam in a large-span beam-type aqueduct span structure;

[0048] Figure 8 This is a schematic diagram of the layout of prestressed tendons in the side walls of a long-span beam-type aqueduct with high-rigidity crossbeams;

[0049] Figure 9 This is a schematic diagram of the layout of prestressed tendons of high-rigidity beams in a large-span aqueduct structure;

[0050] Figure 10 This is a schematic diagram of the span structure of a multi-slot high-rigidity beam-type aqueduct with a large span;

[0051] Figure 11 This is a simplified two-dimensional transverse structural diagram of a high-rigidity beam and large-span aqueduct span structure;

[0052] Figure 12 This is a simplified two-dimensional longitudinal structural diagram of a high-rigidity beam and large-span aqueduct span structure;

[0053] Figure 13 This is the force transmission diagram of the long-span beam-type aqueduct structure with high-rigidity crossbeams.

[0054] In the figure: 1- high-rigidity side wall; 2- bottom plate; 3- high-rigidity cross beam; 4- side rib; 5- straight prestressed tendon; 6- curved prestressed tendon; 7- broken-line prestressed tendon; 8- top flange of high-rigidity side wall; 9- bottom flange of high-rigidity side wall; 10- vertical side rib; 11- horizontal side rib; 12- support; 13- vertical water load; 14- horizontal water load; 15- upper chamfer of the connection between side wall and bottom plate; 16- lower chamfer of the connection between side wall and bottom plate; 17- water-facing surface of the trough body; 18- water-repelling surface of the trough body. DETAILED DESCRIPTION

[0055] The present invention provides a high-rigidity crossbeam, long-span, beam-type aqueduct span structure suitable for the construction of large-span, even extra-large-span, aqueducts. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0056] The high rigidity beam and large span beam type aqueduct span structure is as follows Figure 1-4 As shown, the high-rigidity beam large-span aqueduct span structure is mainly composed of four parts: high-rigidity side wall 1, bottom plate 2, high-rigidity beam 3, side rib 4, etc. Figure 1-9 .

[0057] The high-rigidity side walls 1 are located on both sides of the aqueduct body and are arranged vertically. They are used to block water and bear lateral water loads. They are also the most important longitudinal bending-resistant components of the entire span structure. Preferably, prestressed beams are arranged in the high-rigidity side walls 1 along the longitudinal direction of the aqueduct body. The linear prestressed beams 5 can be combined with the curved prestressed beams 6 and the broken line prestressed beams 7 to improve their longitudinal bending stiffness. Figure 8 Preferably, the width of the top flange 8 and bottom flange 9 of the high-rigidity side wall 1 can be increased, and a high-rigidity cross-section such as an I-beam can be used to increase the longitudinal bending stiffness of the high-rigidity side wall 1, thereby improving the bending resistance of the entire slot span structure and improving stress and deformation. Preferably, the high-rigidity side wall 1 can adopt a variable-section beam body based on the internal force distribution characteristics.

[0058] The bottom plate 2 is located at the bottom between the two high-rigidity side walls 1 and is arranged horizontally to withstand vertical water loads. Preferably, for large-scale aqueducts with high-rigidity beams 3 spaced widely apart, longitudinal ribs perpendicular to the high-rigidity beams 3 can be added below the bottom plate 2 to improve the load bearing capacity of the bottom plate 2.

[0059] The high-rigidity beams 3 are located at the bottom of the bottom plate 2, perpendicular to the axis of the trough body, and arranged horizontally. A plurality of the high-rigidity beams 3 serve as supports for the bottom plate 2, and together with the bottom plate 2 form a beam-plate system with relatively high rigidity. The high-rigidity beams 3 are key components of the entire trough-span spatial structure. Improving the bending rigidity of the high-rigidity beams 3 can promote the redistribution of loads in the entire trough-span structure, adjust the internal force redistribution, and thus improve the overall stress and strain. Preferably, each of the high-rigidity beams 3 can adopt a prestressed concrete beam body, in which straight prestressed beams 5, curved prestressed beams 6, and broken line prestressed beams 7 can be arranged to improve its bending rigidity, see Figure 9Preferably, each high-rigidity beam 3 can be made of a high-rigidity cross-section such as an I-beam or box beam to improve its bending stiffness, thereby effectively transferring the load from the bottom plate 2 to the high-rigidity side wall 1, improving the stress and deformation of the trough body. Preferably, the high-rigidity beam 3 can be a variable-section beam body based on the internal force distribution characteristics.

[0060] The side ribs 4 are located on the outside of the high-rigidity side wall 1 and are arranged horizontally and vertically to increase the anti-thrust rigidity of the high-rigidity side wall 1. The vertical side ribs 10 can be arranged corresponding to the high-rigidity cross beams 3, and one or more horizontal side ribs 11 can be arranged on a single side. This can not only increase the stability of each vertical side rib 10 and prevent the vertical side rib 10 from becoming unstable, but also improve the longitudinal bending rigidity of the high-rigidity side wall 1. Preferably, both the vertical side ribs 10 and the horizontal side ribs 11 can adopt a T-shaped cross-section to increase their cross-sectional rigidity, reduce concrete consumption, and improve stress conditions.

[0061] The supports 12 of the entire slot span structure are located at both ends of the high rigid side wall 1. There is a support 12 at each end of each high rigid side wall 1. The slot span structure of a single slot has 4 supports 12 per span. Figure 5 Furthermore, in order to improve the stress conditions, the ends of the high-rigidity side walls 1 and the high-rigidity beams 3 near the supports 12 can be appropriately enlarged to reduce stress concentration.

[0062] The working principle and force transmission path of the present invention are as follows:

[0063] The bottom plate 2 transfers the vertical water load 13 to the high-rigidity beams 3, and the high-rigidity beams 3 then transfer the load to the high-rigidity side walls 1 on both sides and the entire trough body. The entire trough body and span structure then transfers the load to the supports 12, trough piers and foundations. Figure 13 .

[0064] The high-rigidity side wall 1 and the side ribs 4 form a beam-slab structure, which transmits the transverse water load 14 in the form of end bending moment load to the beam-slab structure composed of the bottom plate 2 and the high-rigidity beams 3, reducing the mid-span bending moment of the beam-slab structure composed of the bottom plate 2 and the high-rigidity beams 3, which is beneficial to reducing the vertical displacement of the lower surface of the bottom plate 2 and the mid-span of each high-rigidity beam 3 and the tensile stress at the bottom of the beam; at the same time, the beam-slab structure composed of the bottom plate 2 and the high-rigidity beams 3 is a simply supported structure in the transverse direction, and the vertical water load 13 it bears is reacted to the beam-slab structure composed of the high-rigidity side wall 1 and the side ribs 4 in the form of end bending moment load, thereby further improving the anti-thrust stiffness of the high-rigidity side wall 1, see Figure 13 .

[0065] Although the functions and working processes of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific functions and working processes. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A high-rigidity beam and large-span aqueduct span structure, characterized in that: It consists of four parts: high-rigidity side walls, bottom plates, high-rigidity beams, and side ribs.

2. The high-rigidity beam and large-span aqueduct span structure according to claim 1 is characterized in that: There are only cross beams below the bottom plate, and the cross beams are extremely rigid. There are no longitudinal beams below the bottom plate, and the load on the bottom plate is directly transferred to the high-rigidity cross beams, and then to the side walls on both sides by the high-rigidity cross beams.

3. The high-rigidity beam and large-span aqueduct structure according to claim 1 is characterized in that: The supports of the entire trough-span structure are located at both ends of the high-rigidity side walls. There is a support at each end of each high-rigidity side wall, and the trough-span structure of a single trough has 4 supports per span.

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