A mid-through arch bridge and construction method thereof

Abstract

The present invention relates to the technical field of bridge construction, and in particular to a mid-span arch bridge and a construction method thereof, wherein the mid-span arch bridge consolidates a main beam, a main arch rib and a side arch rib into a whole, the main beam not only bears the bridge deck load, but also participates in the overall stress of the structure, and no additional external tie rod is required to balance the arch rib thrust, thereby effectively avoiding multiple tensioning of the external tie rod during the construction process, simplifying the construction process, saving the construction period, and greatly reducing the project investment; and the mid-span arch bridge structure also has good stress performance, and also has sufficient vertical stiffness under the vertical live load of a train, and the main beam end has a small turning angle, which can also meet the driving requirements of ultra-high speed, thereby ensuring the safety and comfort of high-speed railway driving.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, in particular to a mid-through arch bridge and a construction method thereof. Background Technology

[0002] For bridges across rivers on flat terrain, cable-stayed bridges or suspension bridges are often used as long-span bridges. However, the vertical stiffness of cable-stayed bridges and suspension bridges is low, which does not meet the requirements of high-speed train operation. In order to ensure the safety and comfort of high-speed train operation, the railway operating department will take speed limit measures on such bridges, which will have a negative impact on the passenger experience and the operating efficiency of the train. Especially with the further development of high-speed railways, there are higher driving requirements for ultra-high speeds above 350km / h. Therefore, it is necessary to select arch bridges with large vertical stiffness and small beam end angles as bridges for high-speed trains.

[0003] In the prior art, a patent document with application number CN202110969570.1 proposes a mid-span arch bridge suitable for ultra-high-speed railways. The arch bridge structure includes a main beam, a main arch rib, a side arch rib, a rigid tie rod, a main pier and a side pier. The main beam is erected between the side piers, and the main beam is a continuous structure. The main arch rib is erected between the main piers, and the side arch rib is erected between the main piers and the side piers. One end of the side arch rib is fixedly connected to the main arch rib, and the other end of the side arch rib supports the main beam. The rigid tie rod is fixed between the side arch rib and the main arch rib. During the construction of this arch bridge, the skeleton ends of the side arch ribs and the main arch ribs on both sides are fixed to the main pier on the same side, and the main beam is constructed by cable hoisting; then an external tie rod is set on the main beam, and the two ends of the external tie rod are anchored to the top of the two side arch ribs respectively. In the process of gradually applying the outer concrete to the rigid skeleton of the main arch rib, the horizontal thrust of the main arch rib gradually increases. Therefore, in order to ensure the safety of the main pier, it is necessary to use the external tie rod to adjust the tension cable force to apply external prestress to eliminate the horizontal thrust of the main arch rib and ensure the force balance. On this basis, the rigid tie rod is constructed to fix the side arch ribs and the main arch ribs, thereby reducing the thrust of the main arch rib and achieving the purpose of optimizing the force structure.

[0004] Although the structural scheme of the arch bridge can make the structure of the mid-span arch bridge have good stress performance through the coordination of the side arch ribs and rigid tie rods and the design of the main beam continuous structure, it has sufficient vertical stiffness under the vertical live load of the train, reduces the beam end rotation angle generated by the main beam, and can meet the requirements of ultra-high speed driving, but the main beam in the arch bridge only bears the bridge deck load and does not participate in the overall stress of the structure. Instead, the external tie cable bears the axial tension to resist the arch rib thrust. Therefore, this type of bridge has the defects of complicated external tie tensioning process, long construction period, difficult maintenance and repair of the external tie cable body in the later stage, and high risk of cable breakage. SUMMARY OF THE INVENTION

[0005] The purpose of the present invention is to provide a mid-span arch bridge and a construction method thereof, in view of the problem that the mid-span arch bridge structure in the prior art has a large vertical stiffness and a small beam end rotation angle under the vertical live load of the train, and can meet the driving requirements of ultra-high speed vehicles above 350 km / h, but the main beam only bears the bridge deck load and does not participate in the overall stress of the structure, and an external tie rod needs to be set to apply prestress to resist the thrust of the arch rib. The tensioning process of the external tie rod is cumbersome, which leads to a long construction period for this type of bridge structure.

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

[0007] A mid-span arch bridge comprises a main beam, a main arch rib, a side arch rib, a main pier and a side pier, wherein the main arch rib is erected between the main piers, the side arch rib is erected between the main pier and the side pier, the main beam is erected between the side piers and the main beam is a continuous structure, the main beam is supported on the side arch rib, the main beam and the side arch rib are fixedly connected, and the main arch rib runs through the main beam.

[0008] The present invention adopts a main beam design with a continuous structure to maintain the integrity and continuity of the main beam between the side piers, thereby avoiding excessive beam end rotation angles at the existing main beam fracture structure under the vertical live load of the train; in order to enable the arch seat foundation at the pier or arch foot to constrain the deformation of the beam body and provide the beam body with greater vertical stiffness, the present invention sets the main arch rib connecting the main pier through the main beam, and in this way, the beam body itself can be used to resist the arch rib thrust along the longitudinal bridge direction; further, the beam body part between the connection between the main beam and the main arch rib and the end of the main beam is used as a rigid tie rod to overcome the arch rib thrust, and at the same time, cooperates with the side arch ribs respectively consolidated with the main beam and the main pier, and the main arch rib part that consolidates the main pier and the main beam to form a stable triangular connection structure, which can offset most of the thrust of the main arch rib, thereby ensuring the stress safety of the bridge structure.

[0009] The mid-span arch bridge provided by the present invention has a main beam and main arch ribs and side arch ribs that are consolidated as a whole. The main beam not only bears the bridge deck load, but also participates in the overall stress of the structure. There is no need to set up additional external tie rods to balance the arch rib thrust, which effectively avoids multiple tensioning of the external tie rods during construction, simplifies the construction process, saves construction time, and greatly reduces project investment. Moreover, the mid-span arch bridge structure also has good stress-bearing performance and has sufficient vertical stiffness under the vertical live load of the train. The main beam end has a small turning angle and can also meet the requirements of ultra-high-speed driving, ensuring the safety and comfort of high-speed railway driving. The above-mentioned mid-span arch bridge is used in high-speed railways. Compared with the upper-span arch, it is more suitable for construction in poor geological environments, and it is also more suitable for large-span bridge design than the lower-span arch.

[0010] Preferably, the main girder includes side girders and cross girders. The side girders are arranged longitudinally along the bridge axis and are located on both sides of the main girder. The cross girders are arranged transversely along the bridge axis and are spaced between the two side girders. The main arch rib penetrates through the side girders and is integrally connected with the side girders. Compared with the prior art method of adding rigid tie rods on both sides of the steel box main girder to connect the main arch rib and the side arch rib to overcome the arch bridge thrust, this solution overcomes the arch bridge thrust by using the side girders of the main girder as rigid tie rods, which can save the materials of the external tie rods. Moreover, the main girder adopts a frame structure formed by side girders and cross girders, which has good integrity and continuity, and fewer hoisting segments. It not only has high construction efficiency but also low construction cost.

[0011] Preferably, the side arch rib is a concrete structure. The end of the main girder is embedded in the top of the side arch rib, and the top of the main girder is flush with the top of the side arch rib. Shear studs are provided between the main girder and the side arch rib. The shear studs are used for force transmission. By using shear studs, the consolidation strength between the main girder and the side arch rib is enhanced, and the internal force of the main girder can be transmitted to the side arch rib. Then, through the stable triangular structure formed among the side arch rib, the main girder and the main arch rib, it reaches a self-stabilized state, and the mechanical properties of the main piers are good. Moreover, by adopting a concrete arch rib, compared with the conventional steel pipe arch bridge, the stiffness is greatly improved, and the temperature deformation is reduced. The side arch can be a stiffened frame concrete structure or a reinforced concrete structure.

[0012] Preferably, the side arch rib includes two limb arch rib units. A cross brace is provided between the two limb arch rib units. Each limb arch rib unit is correspondingly consolidated with one side girder. The outer distance between the two limb arch rib units is greater than the outer distance between the two side girders. The end face of the side girder is aligned with the end face of the arch rib unit. The end face of the side arch rib is provided with an end bearing pressure plate, and the end bearing pressure plate is used for anchoring the side girder.

[0013] Preferably, the side arch rib is provided with a corbel, and the corbel is used for supporting the simply supported beam butt-jointed with both ends of the main girder. By placing one end of the simply supported beam on the corbel instead of directly supporting it through the side pier, it is ensured that the side arch rib can bear the gravity of the simply supported beam through the corbel and can smoothly receive its internal thrust at the end of the main girder, avoiding the situation of the simply supported beam losing contact with the support during the process of the main girder releasing internal force. Moreover, the weight of the simply supported beam of the bridge is fully utilized to overcome the negative reaction force of the side pier caused by the live load loading in the mid-span, optimizing the mechanical properties of the side arch rib.

[0014] Preferably, the above-mentioned half-through arch bridge further includes arch columns located on the main piers or the side arch ribs, and the arch columns are fixedly connected with the main girder. The arch columns are used for supporting the main girder to increase the structural strength and reduce the deformation.

[0015] Preferably, the main beam is a steel structure, with through holes and main arch ribs on the main beam, and concrete is filled between the through holes and the main arch ribs. This is convenient for construction, and the bridge is lightweight. The main arch ribs are consolidated by filling the through holes of the main beam with concrete, so that the main beam and the main arch ribs have a higher consolidation strength, which is more convenient for smooth force transmission. In addition, the deformation constraint force on the main arch ribs and the main beam is large, the horizontal thrust of the main arch ribs on the main piers is small, and the bridge has better force-bearing performance.

[0016] Preferably, a hanger is provided between the main arch rib and the main beam, and the hanger is connected to the bottom of the side beam through an anchor plate, which reduces the concentrated stress and makes the force more secure.

[0017] The present invention provides a construction method for the above-mentioned half-through arch bridge, comprising the following steps:

[0018] When constructing the main pier and side pier, install the longitudinal sliding hinge and temporarily lock it when constructing the arch foundation on the main pier;

[0019] Establish the side arch construction support and construct the side arch ribs and arch columns, and embed part of the side beams at the top of the side arch ribs;

[0020] Use cable crane and buckle tower with buckle cable to construct the main arch rib rigid frame;

[0021] The side beams are hoisted in sections along the longitudinal direction of the bridge, and the main arch ribs are connected to the side beams by installing hangers until the side beams are closed. The main arch rib rigid frame passes through the side beams and is integrated with the side beams;

[0022] After the side beams are closed, release the temporary lock of the longitudinal sliding hinge, release the buckle cable, and remove the side arch construction support;

[0023] Construct the main arch rib concrete;

[0024] Install beams and bridge decks, and complete the paving of the bridge track structure;

[0025] The arch seat and the main pier are cast together to form an arch pier consolidation system.

[0026] In the present invention, a longitudinal sliding hinge is installed at at least one arch springing pier of the main arch rib. After the closure construction of the main arch rib stiffening girder and the side beam is completed in the locked state, the upper load is small, and the bridge can maintain the overall force balance by relying on its own structure. At this time, the temporary locking of the longitudinal sliding hinge is released, so that the longitudinal sliding hinge has the ability to adapt to deformation along the longitudinal bridge direction. During the subsequent construction process of casting the outer concrete of the main arch rib stiffening girder, it can effectively ensure that the dead load thrust does not act on the pier foundation but drives the rigid tie rod to longitudinally stretch along with the longitudinal deformation of the main arch rib. The horizontal thrust of the main arch is balanced by the rigid tie rod, that is, the side beam section that consolidates the main arch rib and the side arch rib on the main beam bears the force. Further, after the casting construction of the main arch rib stiffening girder concrete is completed in the present invention, the main beam cross beam, the bridge deck and the bridge deck track structure are paved. In this way, compared with the method of completing the installation of all the upper structures before releasing the temporary locking of the longitudinal sliding hinge, the load applied to the main pier is smaller and the construction is safer and more reliable. After the arch rib concrete and the upper structure construction are completed in the present invention, after the arch rib and the main beam complete the coordinated deformation, the internal force of the bridge will be redistributed and optimized. At this time, the arch seat and the main pier are cast to form an arch pier consolidation system, which can make the whole bridge system have better mechanical properties.

[0027] The construction method of the half-through arch bridge provided by the present invention releases the thrust of the main arch rib by adopting a temporary longitudinal sliding spherical hinge, and the arch rib thrust is borne by the side beam itself. The whole construction process does not need to balance the arch rib thrust by tensioning and adjusting the external tie rod to apply external prestress, and the construction period is short; moreover, the built half-through arch bridge has good mechanical properties, has sufficient vertical stiffness and small beam end rotation angle, can meet the driving requirements of ultra-high speed with a speed higher than 350 km / h, and ensures the safety and comfort of high-speed railway driving.

[0028] Preferably, the main arch rib stiffening girder is hoisted in sections during construction. The main arch rib stiffening girder includes multiple skeleton sections, and side beam sections are pre-consolidated on the skeleton sections corresponding to the height of the main beam. After the hoisting of the main arch rib stiffening girder is completed, the remaining side beams are hoisted from the side to the middle until closure.

[0029] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0030] 1. The half-through arch bridge provided by the present invention has the main beam, main arch rib and side arch rib consolidated into a whole. The main beam not only bears the deck load, but also participates in the overall structural force. There is no need to additionally set up external tie rods, saving the materials of external tie rods, reducing the project investment, and effectively avoiding multiple tensionings of external tie rods during the construction process, thus simplifying the construction process and saving the construction period. Moreover, the structural form of this half-through arch bridge also has good mechanical properties, has sufficient vertical stiffness under the action of the vertical live load of the train, has a small rotation angle at the beam end of the main beam, and can also meet the driving requirements of ultra-high speeds, ensuring the safety and comfort of high-speed railway driving.

[0031] 2. The present invention uses a concrete arch rib, which greatly improves the stiffness, reduces the temperature deformation compared with the conventional steel structure arch rib, and also reduces the workload and cost of later maintenance and painting.

[0032] 3. The main beam in the present invention adopts a frame-type continuous structure. The side beam of the main beam is used as a rigid tie rod to be rigidly connected with the side arch rib and the main arch rib. The rotation angle at the beam end of the arch bridge is greatly reduced, and the integrity and continuity of the main beam are good, and the force transmission is smooth.

[0033] 4. In the half-through arch bridge of the present invention, the deck system is consolidated with the side main beam, so that the beam body and the arch rib form a whole, and the support between the main beam and the lower structure can be cancelled, avoiding the later maintenance and replacement of the support, and also saving the project cost.

[0034] 5. The construction method of the half-through arch bridge provided by the present invention releases the thrust of the main arch rib by adopting a temporary longitudinal sliding spherical hinge, and the arch rib thrust is borne by the side beam itself. The whole construction process does not need to balance the arch rib thrust by tensioning and adjusting the external tie rod to apply external prestress, and the construction period is short. Moreover, the built half-through arch bridge has good mechanical properties, has sufficient vertical stiffness and a small rotation angle at the beam end, and can meet the driving requirements of ultra-high speeds higher than 350 km / h, ensuring the safety and comfort of high-speed railway driving. Brief Description of the Drawings

[0035] Figure 1 is the elevation view of the half-through arch bridge in Embodiment 1;

[0036] Figure 2 is Figure 1 the sectional view at A-A of

[0037] Figure 3 is Figure 1 the sectional view at B-B of

[0038] Figure 4 is Figure 1 the sectional view at C-C of

[0039] Figure 5 is Figure 1Large-scale drawing of part D;

[0040] Figure 6 It is a schematic structural diagram at the end of the side arch rib;

[0041] Figure 7 It is Figure 6 Top view of;

[0042] Figure 8 It is Figure 6 Large-scale drawing of the side arch rib structure at part E in (the bracket is omitted);

[0043] Figure 9 It is a schematic process diagram for constructing a half-through arch bridge in Embodiment 2;

[0044] Figure 10 It is Figure 9 Enlarged drawing of part G in;

[0045] Figure 11 It is Figure 9 Enlarged drawing of part H in;

[0046] Figure 12 It is a finite element calculation model diagram of the half-through arch bridge in Embodiment 1.

[0047] Icon: 1 - main beam; 1A - side beam; 1B - cross beam; 1C - bridge deck; 1D - through hole; 2 - main arch rib; 21 - stiffening skeleton; 3 - side arch rib; 3A - arch rib unit; 3B - bracket; 4 - main pier; 5 - side pier; 6 - arch-column on the arch; 7 - suspender; 8 - anchor plate; 9 - shear stud; 10 - end bearing plate; 11 - simply supported beam; 12 - longitudinal sliding hinge; 13 - side arch construction support. Detailed implementation manners

[0048] The present invention will be described in detail below with reference to the accompanying drawings.

[0049] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] Embodiment 1

[0051] As Figure 1-8As shown in the figure, this embodiment provides a half-through arch bridge, which includes a main beam 1, main arch ribs 2, side arch ribs 3, main piers 4 and side piers 5. The main arch ribs 2 are erected between the two side main piers 4 on both sides, and the side arch ribs 3 are erected between the main pier 4 and the side pier 5 on the same side. Each side pier 5 has a portal structure. The main beam 1 is erected between the two side piers 5 and the main beam 1 is a continuous structure. The main beam 1 is supported on the side arch ribs 3, and the main beam 1 is fixedly connected to the top ends of the side arch ribs 3. The arch feet at the bottom ends of the side arch ribs 3 and the arch feet of the main arch ribs 2 are jointly fixed on the corresponding side main pier 4, and the main arch ribs 2 penetrate through the main beam 1.

[0052] In this embodiment, in order to reduce the thrust of the arch ribs, the main beam 1 is made of steel structure. The main beam 1 includes side beams 1A, cross beams 1B and orthotropic bridge decks 1C. The side beams 1A are continuously arranged along the longitudinal bridge direction and are respectively arranged on both sides of the main beam 1. The cross beams 1B are arranged along the transverse bridge direction and are spaced between the two side beams 1A on both sides. The bridge deck 1C is laid on the top of the main beam 1 and is fixedly connected to the two side beams 1A on both sides, and the bearings between the main beam 1 and the lower structure are cancelled; the main beam 1 in this embodiment is fixedly connected to the main arch ribs 2 through suspender bars 7. One end of the suspender bar 7 is anchored to the main arch rib 2 through an anchor plate 8, and the other end is anchored to the bottom of the side beam 1A through the anchor plate 8, with small concentrated stress and safer force. Through holes 1D for passing through the main arch ribs 2 are provided at the corresponding sections of the two side beams 1A on both sides. The main arch ribs 2 penetrate through the side beams 1A from the through holes 1D, and the through holes 1D and the main arch ribs 2 are filled with concrete to realize the integral connection between the main arch ribs 2 and the side beams 1A, which is convenient for smooth force transmission. Compared with the prior art method of adding rigid tie rods on both sides of the steel box main beam 1 to connect the main arch ribs 2 and the side arch ribs 3 to overcome the thrust of the arch bridge, this solution uses the side beam 1A of the main beam 1 as a rigid tie rod to overcome the thrust of the arch bridge, without applying external prestress to ensure the safety of bridge construction, avoiding multiple tensioning of the external tie rods during the construction process, thus simplifying the construction process, saving the construction period, and also saving the materials for the external tie rods; moreover, the main beam 1 adopts a frame structure formed by the side beams 1A and the cross beams 1B, with good integrity and continuity, and fewer hoisting segments, not only with high construction efficiency, but also with low construction cost. The rigid connection and consolidation form of the main beam 1, the main arch ribs 2 and the side arch ribs 3 has a large deformation constraint force on the main arch ribs 2, the side arch ribs 3 and the main beam 1, greatly reducing the end rotation angle of the arch bridge; it can not only improve the force of the arch feet, but also effectively reduce the calculated span of the main arch ribs 2. The distance between the two sides of the main arch ribs 2 at the connection with the side beam 1A becomes the calculated span of the main arch ribs 2, and the calculated span of the main arch ribs 2 can be reduced by more than 20%, improving the vertical stiffness of the main arch ribs.

[0053] Among them, the main arch rib 2 is a stiffening skeleton 21 concrete structure. The stiffening skeleton 21 is mainly composed of steel pipes. By pouring concrete into the steel pipes and covering the steel pipes of the stiffening skeleton 21 with concrete, the main body of the main arch rib 2 is formed.

[0054] The main arch rib 2 and the side arch rib 3 are formed as a whole by using two-limb arch ribs and cross braces between arch ribs. The four arch feet corresponding to the two ends of the main arch rib 2 are respectively fixed to a main pier 4. The main piers 4 on both sides of the bridge are located between two side piers 5. The side arch rib 3 is erected between the adjacent main piers 4 and side piers 5. One end of the side arch rib 3 is fixedly connected to the arch foot of the main arch rib 2, and the other end of the side arch rib 3 is placed on the side pier 5. The main arch rib 2 and the side arch rib 3 are both in the shape of a catenary. The main arch rib 2 is fixed at two main piers 4 and is bent upward into a catenary shape. The side arch rib 3 is fixed at one adjacent main pier 4 and one side pier 5. Since the height of the two main piers 4 is lower than that of the two side piers 5, the side arch rib 3 is bent obliquely upward into a catenary shape based on the height difference. The side arch rib 3 and the main pier 4 are provided with arch columns 6, which are fixed to the top side beam 1A. The arch columns 6 are used to support the main beam 1 to increase the structural strength and reduce the negative bending moment.

[0055] The side arch rib 3 is a concrete structure. The end of the main beam 1 is pre-buried at the top of the side arch rib 3. The main beam 1 is flush with the top of the side arch rib 3. Shear nails 9 are provided between the main beam 1 and the side arch rib 3. The shear nails 9 are used to transmit force. The consolidation strength between the main beam 1 and the side arch rib 3 is strengthened by the shear nails 9. The internal force of the main beam 1 can be transmitted to the side arch rib 3, and then the stable triangular structure formed between the side arch rib 3, the main beam 1 and the main arch rib 2 can achieve a self-stabilizing state. The main pier 4 has good force-bearing performance. Moreover, by using concrete arch ribs, the rigidity is greatly improved compared with conventional steel tube arch bridges, and the temperature deformation is reduced.

[0056] Specifically, the side arch rib 3 includes two arch rib units 3A, a cross brace is provided between the two arch rib units 3A, each arch rib unit 3A is correspondingly fixed to a side beam 1A, the outer spacing of the two arch rib units 3A is greater than the outer spacing between the side beams 1A on both sides, the end face of the side beam 1A is aligned with the end face of the arch rib unit 3A, and the end face of the side arch rib 3 is provided with an end pressure plate 10, which is used to anchor the side beam 1A. The end faces of the four arch rib units 3A at the side pier 5 are all provided with corbels 3B, and the simply supported beams 11 at both ends of the main beam 1 are placed on the corbels 3B of the side arch rib 3 at the end close to the main beam 1, and the corbels 3B are used to support the simply supported beams 11 butted against the two ends of the main beam 1. By placing one end of the simply supported beam 11 on the corbel 3B without directly supporting it through the side pier 5, it is ensured that the side arch rib 3 can bear the gravity of the simply supported beam 11 through the corbel 3B, and can smoothly bear its internal thrust at the end of the main beam 1, avoiding the situation where the support of the simply supported beam 11 is empty during the release of the internal force of the main beam 1, and also optimizing the force condition of the side arch rib 3.

[0057] This embodiment adopts a main beam 1 design with a continuous structure to maintain the integrity and continuity of the main beam 1 between the side piers 5, avoiding the excessive beam end rotation angle at the fracture structure of the existing main beam 1 under the vertical live load of the train; in order to enable the arch seat foundation at the pier or arch foot to constrain the deformation of the beam body and provide a larger vertical stiffness for the beam body, this embodiment sets the main arch rib 2 connected to the main pier 4 through the main beam 1, and in this way, the beam body itself can be used to resist the arch rib thrust along the longitudinal bridge direction; further, the beam body part from the connection between the main beam 1 and the main arch rib 2 to the end of the main beam 1 is used as a rigid tie rod to overcome the arch rib thrust, and at the same time, cooperates with the side arch rib 3 respectively fixed to the main beam 1 and the main pier 4, and the main arch rib 2 part fixed to the main pier 4 and the main beam 1 to form a stable triangular connection structure, which can offset most of the thrust of the main arch rib 2, thereby ensuring the stress safety of the bridge structure.

[0058] In the mid-span arch bridge provided in this embodiment, the main beam 1, the main arch rib 2, and the side arch rib 3 are consolidated as a whole. The main beam 1 not only bears the bridge deck load, but also participates in the overall force of the structure. No additional external tie rods are required to balance the arch rib thrust, which shortens the construction period and reduces the use of external tie rod steel strands by 814 tons, saving more than 23 million yuan in engineering investment. Based on the structure of the mid-span arch bridge, a finite element analysis is performed, and the structural diagram of the finite element model of the mid-span arch bridge is shown in Figure 12 As shown in the figure, according to the analysis of the ZK static live load deflection diagram, its maximum ZK static live load deflection is about 90mm, the deflection-span ratio is 1 / 3550, and the maximum beam end angle is 0.5‰. Compared with the existing mid-span arch bridge in which rigid tie rods are set on both sides of the main beam to rigidly connect the side arch ribs and the main arch ribs, the mid-span arch bridge structure of this scheme can reduce the beam end angle of the main beam and improve the vertical stiffness of the arch bridge. The CRH3 and CRH380 EMUs currently on the railway were used to cross the bridge at different speeds in single and double car conditions, and the maximum values ​​of the bridge deflection and slope (characterizing the size of the beam end angle) under different working conditions were obtained, as shown in Table 1 below:

[0059]

[0060] It can be seen that the mid-through arch bridge structure also has good stress-bearing performance and sufficient vertical stiffness under the vertical live load of the train. The end angle of the main beam 1 is small, which meets the design requirements.

[0061] Furthermore, by using MSC.PATRAN, MSC.NASTRAN and MSC.ADAMS / RAIL dynamic analysis programs, the spatial vibration analysis models of trains and bridges were established respectively, and the vehicle-bridge coupled dynamic response analysis and calculation were carried out on the above-mentioned mid-through arch bridge scheme using computer simulation analysis methods. The index results of the vehicle-bridge coupled dynamic response at a certain detection point on the bridge are shown in Table 2 below:

[0062]

[0063] It can be seen that when the CRH3 EMU passes the bridge at a speed of 200-420km / h, and when the CRH380 EMU passes the bridge at a speed of 200-480km / h, the train safety and comfort meet the regulatory requirements.

[0064] The mid-span arch bridge in this embodiment has the advantages of simple structure, beautiful shape, high structural rigidity, good stability, low maintenance cost, convenient construction, short construction period, etc. It can meet the driving requirements of ultra-high-speed railways. There is no need to limit the speed when passing through the bridge, which effectively improves the promotion and application of arch bridges in the field of ultra-high-speed railway bridge construction, improves the construction efficiency of large-span arch bridges, shortens the bridge construction period, and improves the operation efficiency of high-speed railway trains.

[0065] Example 2

[0066] Based on Example 1, this embodiment provides a construction method for the above-mentioned mid-through arch bridge, such as Figure 9-Figure 11 As shown, the following steps are included:

[0067] S1. Build construction access roads and trestle bridges, carry out temporary construction of cable (buckle) tower systems, construct the pile foundation and pier body of the main pier 4, and install the longitudinal sliding hinge 12 and temporarily lock it when constructing the right arch foundation;

[0068] S2. Construct the pile foundation, pedestal and pier body of the side piers 5 on both sides, set up the side arch construction brackets 13 on both sides of the main pier 4, symmetrically construct the side arch concrete and the cross braces between the arch ribs, and at the same time construct the pre-buried part of the side beam 1A on the side arch rib 3 and the arch column 6;

[0069] S3. Use cable cranes and buckle towers in conjunction with buckle cables to install the main arch rigid frame 21 in sections until it is closed;

[0070] S4. Use a cable crane to hoist the side beam 1A from the side to the middle in sections, and install the corresponding section of the suspension rod 7 until it is closed;

[0071] S5. After the side beam 1A is closed, release the temporary locking of the longitudinal sliding hinge 12, release the arch rib buckle cable, and remove the side arch construction support 13;

[0072] S6. Pour concrete inside the rigid skeleton 21 steel tube, and wrap the arch rib concrete in sections, rings and working surfaces;

[0073] S7. Install the bridge deck beam 1B and the orthotropic steel bridge deck 1C to complete the bridge deck track structure paving;

[0074] S8. Cast the right arch seat and the main pier 4 into a whole to form an arch pier consolidation system;

[0075] S9. Complete the installation of the auxiliary structures on the bridge, remove all temporary construction measures, and complete the construction of the entire bridge.

[0076] During the process of hoisting the main arch rigid frame 21 in sections, the frame segments corresponding to the main beam setting height have been pre-consolidated with the corresponding side beam segments during hoisting. After the main arch rib 2 rigid frame 21 is assembled and closed, the remaining side beams 1A are hoisted from the edge to the middle until they are closed.

[0077] In this embodiment, a longitudinal sliding hinge 12 is installed at at least one arch foot main pier 4 of the main arch rib 2. After the main arch rib 2 rigid frame 21 and the side beam 1A are closed in the locked state, the upper load is small and the bridge can rely on its own structure to maintain the overall force balance; at this time, the temporary locking of the longitudinal sliding hinge 12 is released so that the longitudinal sliding hinge 12 has the ability to adapt to deformation along the longitudinal direction of the bridge. In the subsequent construction process of outsourcing concrete to the rigid frame 21 of the main arch rib 2, it can be effectively ensured that the constant load thrust does not act on the foundation of the main pier 4 but is borne by the rigid tie rod, that is, the side beam on the main beam 1 that consolidates the main arch rib 2 and the side arch rib 3. The main pier 4 is subjected to stress; further, in this embodiment, after the concrete pouring construction of the main arch rib 2 rigid skeleton 21 is completed, the main beam 1, cross beam 1B, bridge deck 1C and bridge deck track structure are paved. Compared with the method of completing the installation of all superstructures before releasing the temporary locking of the longitudinal sliding hinge 12, the load applied to the main pier 4 is smaller and the construction is safer and more reliable; in this embodiment, after the construction of the arch rib concrete and superstructure is completed, after the arch rib and the main beam 1 complete the coordinated deformation, the internal force of the bridge will be redistributed and optimized. At this time, the arch seat and the main pier 4 are poured to form an arch pier consolidation system, which can make the entire bridge system have better stress performance.

[0078] The construction method of the mid-span arch bridge provided in this embodiment uses a temporary longitudinal sliding ball joint to release the thrust of the main arch rib 2, and the arch rib thrust is borne by the side beam 1A itself. The entire construction process does not require the application of external prestressing by tensioning and adjusting the external tie rod to balance the arch rib thrust, and the construction period is short; and the built mid-span arch bridge has good stress performance, sufficient vertical stiffness and a small beam end rotation angle, which can meet the ultra-high speed driving requirements of more than 350km / h, ensuring the safety and comfort of high-speed railway driving.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A mid-through arch bridge, comprising a main beam (1), a main arch rib (2), a side arch rib (3), a main pier (4) and a side pier (5), wherein the main arch rib (2) is erected between the main piers (4), the side arch rib (3) is erected between the main pier (4) and the side pier (5), the main beam (1) is erected between the side piers (5) and the main beam (1) is a continuous structure, characterized in that: The main beam (1) is supported on the side arch rib (3), the main beam (1) is fixedly connected to the side arch rib (3), and the main arch rib (2) is arranged to penetrate the main beam (1); The main beam (1) comprises a side beam (1A) and a cross beam (1B), wherein the side beam (1A) is arranged along the longitudinal direction of the bridge and is located on both sides of the main beam (1), and the cross beam (1B) is arranged along the transverse direction of the bridge and is arranged at intervals between the side beams (1A) on both sides; the main arch rib (2) passes through the side beam (1A) and is integrally connected to the side beam (1A); The side arch rib (3) is a concrete structure, the end of the main beam (1) is pre-buried at the top of the side arch rib (3), and shear studs (9) are provided between the main beam (1) and the side arch rib (3); The side arch rib (3) comprises two arch rib units (3A), a cross brace is provided between the two arch rib units (3A), each arch rib unit (3A) is fixed to a corresponding side beam (1A), the outer spacing between the two arch rib units (3A) is greater than the outer spacing between the side beams (1A) on both sides, the end face of the side beam (1A) is aligned with the end face of the arch rib unit (3A), and the end face of the side arch rib (3) is provided with an end pressure plate (10), and the end pressure plate (10) is used to anchor the side beam (1A).

2. The mid-through arch bridge according to claim 1, characterized in that: The side arch rib (3) is provided with a corbel (3B), and the corbel (3B) is used to support a simply supported beam (11) butted against both ends of the main beam (1).

3. The mid-through arch bridge according to claim 1, characterized in that: It also includes an arch column (6) located on the main pier (4) or the side arch rib (3), and the arch column (6) is fixedly connected to the main beam (1).

4. The half-through arch bridge according to any one of claims 1 to 3, characterized in that: The main beam (1) is a steel structure, a through hole (1D) is provided on the main beam (1) and the main arch rib (2) is penetrated therethrough, and the space between the through hole (1D) and the main arch rib (2) is filled with concrete.

5. The half-through arch bridge according to any one of claims 1 to 3, characterized in that: A suspension rod (7) is provided between the main arch rib (2) and the main beam (1), and the suspension rod (7) is connected to the bottom of the side beam (1A) via an anchor plate (8).

6. The construction method of a half-through arch bridge according to any one of claims 1 to 3, characterized in that: The following steps are involved: Constructing the main pier (4) and the side pier (5), and when constructing the abutment foundation on the main pier (4), installing the longitudinal sliding hinge (12) and temporarily locking it; Setting up a side arch construction support (13) and constructing the side arch ribs (3) and the arch upper columns (6), while pre-embedding a portion of the main beam (1) at the top of the side arch ribs (3); The main arch rib (2) rigid frame (21) is constructed by using cable cranes and pylons in combination with pylons; The side beams (1A) are hoisted in sections along the longitudinal direction of the bridge, and a hanger (7) is installed on the side beams (1A) to connect the main arch ribs (2) until the side beams (1A) are closed; After the side beams (1A) are closed, the temporary locking of the longitudinal sliding hinge (12) is released, the buckle cable is released, and the side arch construction support (13) is removed; Construct main arch rib concrete; Install the cross beam (1B) and the bridge deck (1C) to complete the bridge track structure paving; The arch seat and the main pier (4) are cast together to form an arch pier consolidation system.

7. The construction method according to claim 6, characterized in that: When constructing the main arch rib (2) rigid frame (21), the main arch rib rigid frame (21) is hoisted in sections. The main arch rib rigid frame (21) includes a plurality of frame sections, wherein the frame sections corresponding to the height of the main beam are pre-fixed with side beam sections. After the rigid frame (21) is assembled and closed, the remaining side beams (1A) are hoisted from the side to the middle until they are closed.

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