Arch seat and its steel frame structure

Abstract

The present application provides an arch seat and a steel frame structure thereof, wherein the steel frame structure includes vertical main bars and stirrups, the vertical main bars are arranged in two rows along the transverse direction of the bridge, the stirrups are arranged transversely and sleeved on the two rows of vertical main bars, the bottom of the vertical main bars is pre-embedded and anchored in the pedestal, and the top of the vertical main bars is connected with a steel mesh inclined toward the center line of the arch seat. The steel frame structure of the present application extends from the pedestal to the top of the arch seat, which can effectively control cracks caused by concrete shrinkage, reduce the probability of crack formation, and improve the bearing capacity of the arch seat; at the same time, it is convenient for the pouring construction of the arch seat concrete, ensures the pouring quality of the concrete, and improves the construction efficiency.

Description

Technical Field

[0001] The present application relates to the field of bridge construction, and in particular to an arch seat and a reinforced steel frame structure thereof. Background Art

[0002] In recent years, with the rapid development of my country's high-speed railway construction, more and more high mountain valley terrains that need to be crossed by large-span continuous arch bridges have been encountered in railway bridge design. In these areas, continuous arch bridges have better terrain adaptability, and can provide greater structural rigidity, better driving stability and comfort, reasonable force and beautiful appearance, which can better meet the requirements of high-speed railways for bridge structures.

[0003] The arch seat of a traditional continuous arch bridge generally adopts an open-cut foundation, and the arch bridge is a thrust structure, which has very high requirements for the geological conditions at the bridge location. Especially for large-span railway continuous arch bridges, the basic bearing capacity of the underlying bedrock must generally reach more than 1.0MPa to meet the bearing capacity requirements. Therefore, when the external load is large or the temperature influence is large, the horizontal thrust of the arch foot increases. Since the volume of concrete required for the foundation size of the arch seat is large, the generation of cracks in the large-volume concrete structure in the later stage is difficult to control, which is extremely unfavorable for the safe operation of the continuous arch bridge. Summary of the invention

[0004] The main purpose of the present application is to provide a steel frame structure of an abutment for improving the bearing capacity of the abutment.

[0005] Another object of the present application is to provide an abutment including the above-mentioned steel bar skeleton structure.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] As a first aspect, the present application relates to a steel skeleton structure of an arch seat, including vertical main bars and stirrups, the vertical main bars are arranged in two rows along the transverse direction of the bridge, the stirrups are arranged transversely and sleeved on the two rows of vertical main bars, the bottom of the vertical main bars are embedded and anchored in the pedestal, and the top of the vertical main bars is connected to a steel mesh inclined toward the center line of the arch seat.

[0008] It is further provided that: the length of the vertical main reinforcement pre-embedded and anchored in the pedestal is not less than 30d, where d is the diameter of the vertical main reinforcement.

[0009] It is further configured that: the vertical main reinforcement and the stirrup are connected by double-sided welding, and the welding length is greater than 5d, where d is the diameter of the vertical main reinforcement;

[0010] Alternatively, the vertical main reinforcement and the stirrup are connected by single-sided welding, and the welding area is greater than 10d, where d is the diameter of the vertical main reinforcement;

[0011] Alternatively, the vertical main reinforcement and the stirrups are connected by sleeve binding.

[0012] It is further configured that: the vertical main reinforcement includes N2 and / or N3 steel bars, and the diameter Φ of the vertical main reinforcement is 28 mm.

[0013] It is further arranged that two adjacent vertical main reinforcements in each row are arranged with an interval of 10 cm.

[0014] It is further configured that: a plurality of stirrups are provided along the same vertical direction, and the plurality of stirrups are arranged at intervals of 45 cm.

[0015] It is further provided that: the stirrups include N4, N4a, and N11 steel bars, and the stirrups are connected end to end to form a ring-shaped whole.

[0016] It is further arranged that: a plurality of protective layer pads are tied to the vertical main reinforcement and stirrups, and the plurality of protective layer pads are staggered and dispersedly arranged.

[0017] Further configuration: the steel mesh includes a plurality of N10 steel bars arranged in a staggered manner.

[0018] As a second aspect, the present application relates to an arch seat, comprising a steel frame structure as described above and a concrete structure cast on the steel frame structure.

[0019] Compared with the prior art, the solution of this application has the following advantages:

[0020] 1. The steel skeleton structure of the arch seat of the present application extends from the inside of the pedestal to the top of the arch seat, which can effectively control the cracks caused by concrete shrinkage, reduce the probability of crack formation, and improve the bearing capacity of the arch seat; at the same time, it is convenient for the pouring construction of the arch seat concrete, ensures the pouring quality of the concrete, and improves the construction efficiency.

[0021] 2. The steel skeleton structure of the arch seat of the present application is encrypted in the key stress-bearing area of ​​the arch seat, and a large number of protective layer pads are arranged to expand the pressure-bearing area of ​​the steel skeleton structure to improve the bearing capacity of the steel skeleton, making the arch seat of the present application more suitable for continuous arch bridges.

[0022] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0024] Figure 1A schematic structural diagram of an embodiment of a steel reinforcement skeleton structure of an arch seat of the present application;

[0025] Figure 2 A front view of an embodiment of the steel reinforcement skeleton structure of the arch seat of the present application;

[0026] Figure 3 A top view of an embodiment of the steel reinforcement skeleton structure of the arch seat of the present application.

[0027] In the figure, 1. vertical main reinforcement; 2. stirrups; 3. steel mesh; 4. pedestal; 5. steel bar assembly; 6. seismic anchor bolts. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application.

[0029] See also Figures 1 to 3 The present application relates to a steel skeleton structure of an arch seat, which solves the safety problem that cracks are generated in the existing arch seat after long-term use, resulting in reduced bearing capacity. The bearing capacity of the arch seat can be improved, and the construction of a large-volume arch seat can be facilitated. The steel skeleton structure of the arch seat is arranged on the pedestal 4, so that the arch seat is connected to the pile foundation through the pedestal 4, ensuring the structural strength of the arch seat.

[0030] Specifically, the steel skeleton structure includes vertical main bars 1 and stirrups 2. The bottom of the vertical main bars 1 is embedded and anchored in the pedestal 4. The vertical main bars 1 are used to bear gravity loads in the arch seat. By embedding the vertical main bars 1 in the pedestal 4, it is beneficial to improve the connection strength between the arch seat and the pedestal 4, so as to improve the bearing capacity of the arch seat. The vertical main bars 1 are arranged in two rows along the transverse direction of the bridge. The distance between the two rows of vertical main bars 1 defines the width of the arch seat along the longitudinal direction of the bridge. At the same time, the stirrups 2 are arranged transversely and sleeved on the two rows of vertical main bars 1, so as to meet the shear strength of the inclined section of the arch seat. In addition, the tops of the two rows of vertical main bars 1 are respectively connected with steel meshes 3 inclined toward the center line of the arch seat.

[0031] Preferably, when installing the vertical main reinforcement 1 of the present application, the entire steel skeleton structure can be pre-processed and manufactured before being buried in the pedestal 4, and the length of the vertical main reinforcement 1 pre-embedded and anchored in the pedestal 4 is not less than 30d, where d is the diameter of the vertical main reinforcement.

[0032] In addition, after the entire steel frame structure is buried in the cap 4, positioning and installation are required. First, the position of each vertical main reinforcement 1 is marked on the steel frame before installation, and then the vertical main reinforcement 1 is positioned and installed.

[0033] When the entire steel skeleton structure is prefabricated, the arrangement position of the stirrups 2 can be drawn on the vertical main reinforcement 1 with a stone pencil, and then the vertical main reinforcement 1 and the stirrups 2 can be connected one by one according to the drawn position. The vertical main reinforcement 1 and the stirrups 2 can be connected by double-sided welding, single-sided welding and sleeve connection. Among them, if the vertical main reinforcement 1 and the stirrup 2 are connected by double-sided welding, the welding length should be greater than 5d, where d is the diameter of the vertical main reinforcement 1; if the vertical main reinforcement 1 and the stirrup 2 are connected by single-sided welding, the welding length should be greater than 10d, where d is the diameter of the vertical main reinforcement 1; if the vertical main reinforcement 1 and the stirrup 2 are tied by sleeve connection, the various properties of the connected joints should comply with the provisions of the "Technical Code for Mechanical Connection of Rebars" (JGJ 107), and the distance between the two joints should not be less than 1.3 times the lap length, and the lap length of the steel bar binding should not be less than 35d for HR335 steel bars, where d is the diameter of the vertical main reinforcement, and not less than 45d for HRB400 steel bars, which is the diameter of the vertical main reinforcement.

[0034] It should be noted that the welding length between the vertical main reinforcement 1 and the stirrup 2 is based on the diameter d of the vertical main reinforcement 1 when the diameter of the vertical main reinforcement 1 is larger than the diameter of the stirrup 2. If the diameter of the stirrup 2 is larger than the diameter of the vertical main reinforcement 1, the welding length is based on the diameter d of the stirrup 2.

[0035] Furthermore, the vertical main reinforcement 1 of this embodiment adopts N2Φ10 and / or N3Φ10 steel bars, and the diameter Φ of the vertical main reinforcement 1 is 28 mm. A plurality of vertical main reinforcements 1 are arranged in each row along the transverse direction of the bridge, and the adjacent two vertical main reinforcements 1 in each row are arranged at an interval of 10 cm.

[0036] The stirrups 2 may be made of at least one of N4, N4a, and N11 steel bars. The stirrups 2 are connected end to end by single-sided welding to form an annular integral structure. The stirrups 2 of the annular integral structure may be rectangular stirrups, diamond stirrups, polygonal stirrups, tic-tac-toe stirrups, and circular stirrups. The specific structure of the stirrups 2 may be selected according to the arrangement position of the vertical main reinforcement 1. Multiple groups of stirrups 2 are provided along the same vertical direction, and the multiple groups of stirrups 2 are arranged at intervals of 45 cm.

[0037] In addition, as a preferred embodiment, please combine Figure 3In the same horizontal plane of the arch seat, a stirrup 2 is sleeved on every five vertical main reinforcements 1 of the two rows of vertical main reinforcements 1, and the stirrups 2 are arranged along the transverse direction of the bridge. Two adjacent stirrups 2 are sleeved on at least the same vertical main reinforcement 1, and the two adjacent vertical main reinforcements 1 can be connected and fixed by one of double-sided welding, single-sided welding and binding, thereby improving the connection strength between the vertical main reinforcements 1.

[0038] It should also be noted that the steel bar model and arrangement position used for the vertical main reinforcement 1 and stirrups 2 of the present application are set according to the stress design of the arch seat.

[0039] A plurality of protective layer pads (not shown in the figure, the same below) are also tied to the vertical main reinforcement 1 and the stirrup 2. The plurality of protective layer pads are staggered and dispersed. When the protective layer pads are tied to the vertical main reinforcement 1 and the stirrup 2, the pressure-bearing area of ​​the steel skeleton structure can be expanded to improve the bearing capacity of the steel skeleton structure.

[0040] In addition, the heights of the two rows of vertical main bars 1 of the present application are different, so that the two steel meshes 3 connecting the two are staggered, so that the slope of the arch seat at the intersection of the arch seat and its two adjacent arch rings is staggered, so as to achieve the effect of adjusting the longitudinal slope of the bridge. Preferably, the steel mesh 3 of this embodiment is made of staggered N10 steel bars.

[0041] The specifications, shapes, quantity, positions, and lap lengths of the steel bars used in this application shall comply with the design requirements and construction acceptance specifications. In addition, the steel bars for inspection shall have a factory quality certificate and a test report, and the steel bars shall be immediately witnessed for sampling and inspection upon arrival. After the steel bars arrive on site, the Materials Department will issue an "Inspection Notice" to the laboratory, and the laboratory will notify the supervisor to witness the sampling and inspection in batches. If qualified, they will be used normally. If unqualified, double sampling will be taken for re-inspection, and those that fail the re-inspection will be removed from the site. The steel bars shall be inspected and accepted in batches according to different steel types, grades, brands, specifications, and manufacturers, and stacked separately without mixing, and identification marks shall be set up.

[0042] The present application also relates to an arch seat, which includes a steel frame structure as described above and a concrete structure cast on the steel frame structure, wherein the concrete cast in the concrete structure adopts C40 concrete, and the compressive strength of C40 concrete is 40Mpa, which has good compressive strength and avoids excessive rigidity to reduce the occurrence of cracks in the later stage of the use of the arch seat.

[0043] Specifically, the arch seat formwork must be used for pouring the concrete structure of the arch seat. After the steel skeleton structure is installed and passed the inspection, the formwork can be installed. When the formwork is installed, its bottom should be firmly connected to the foundation embedded parts, and the upper part should be fixed with a tie rod. At the same time, during the installation of the formwork, anti-overturning facilities must be set up. The embedded parts and reserved holes fixed on the formwork must not be omitted, and the installation should be firm and the position should be accurate. When the steel formwork is installed, the positions of the bolt holes correspond one by one, and all the bolts are filled, and then the concrete can be poured. It should also be noted that the installation of the formwork should be coordinated with the reinforcement process. The formwork that interferes with the tying of the reinforcement should be installed after the reinforcement process is completed.

[0044] Preferably, the formwork of this embodiment is a combined steel formwork, wherein the panel of the formwork is made of 5mm steel plate, the flange is made of 80mm×12mm strip steel, and the flange is provided with a hole with a diameter of φ22 and a depth of 30mm, and is equipped with M20×50 bolts; the inner crossbar is made of 8# channel steel, with specific dimensions of 80mm×43mm×5mm, the rib plate size is 80mm×6mm, the back rib is made of 14# double channel steel, the connecting plate is made of 12mm steel plate, the angle tie rod seat is made of 125mm×12mm angle steel, the angle tie rod is made of HRB400C30 steel bar, the tie rod is made of HRB400C20 steel bar, and the number of protective layer pads tied to the steel bars in this application corresponding to the side formwork and the bottom formwork should be no less than 3 / m 2 .

[0045] In addition, a steel bar assembly 5 can be set up on the top of the arch seat to cast and form an inter-arch wall. The steel bar assembly 5 is connected and fixed to the steel mesh 3, which is beneficial to improve the connection strength between the inter-arch wall and the arch seat.

[0046] Furthermore, the steel bar assembly 5 is also provided with embedded steel bars (not shown in the figure, the same below) extending into the arch seat to further improve the bearing capacity and structural stability of the arch wall. The top of the steel bar assembly 5 is also provided with a seismic anchor bolt 6, which can be used to strengthen the seismic resistance between the hollow slab of the bridge deck of the arch wall and the abutment cap beam.

[0047] In summary, the present application adopts a built-in steel skeleton structure to facilitate the construction operation of large arch seats, and the steel skeleton structure extends from the inside of the pedestal to the top of the arch seat, which can effectively control cracks caused by concrete shrinkage and reduce the probability of crack formation. At the same time, the steel skeleton structure is also encrypted in the key stress-bearing area of ​​the arch seat, and a large number of protective layer pads are arranged to expand the pressure-bearing area of ​​the steel skeleton structure to improve the bearing capacity of the steel skeleton structure, making the arch seat of the present application more suitable for continuous arch bridges.

[0048] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A steel frame structure of an arch seat, characterized by: The bridge comprises vertical main bars and stirrups, wherein the vertical main bars are arranged in two rows along the transverse direction of the bridge, the stirrups are arranged transversely and sleeved on the two rows of vertical main bars, the bottom of the vertical main bars are embedded and anchored in the pedestal, the top of the vertical main bars is connected with a steel mesh inclined toward the center line of the arch seat, the heights of the two rows of vertical main bars are different, the two steel meshes connected by the two rows of vertical main bars are staggered so that the inclined surfaces of the arch seat at the intersection of the arch seat and its two adjacent arch rings are staggered, a plurality of protective layer pads are tied to the vertical main bars and stirrups, the plurality of protective layer pads are staggered and dispersed, a steel bar assembly is set on the top of the arch seat to cast and form an inter-arch vertical wall, the steel bar assembly is connected and fixed to the steel mesh, the steel bar assembly is also provided with embedded steel bars extending into the arch seat, and a seismic anchor bolt is provided on the top of the steel bar assembly.

2. The steel frame structure of the arch seat according to claim 1 is characterized in that: The length of the vertical main reinforcement embedded and anchored in the pedestal is not less than 30d, where d is the diameter of the vertical main reinforcement.

3. The steel frame structure of the arch seat according to claim 1 is characterized in that: The vertical main reinforcement and the stirrups are connected by double-sided welding, and the welding length is greater than 5d, where d is the diameter of the vertical main reinforcement; Alternatively, the vertical main reinforcement and the stirrup are connected by single-sided welding, and the welding area is greater than 10d, where d is the diameter of the vertical main reinforcement; Alternatively, the vertical main reinforcement and the stirrups are connected by sleeve binding.

4. The steel frame structure of the arch seat according to claim 1 is characterized in that: The vertical main reinforcement includes N2 and / or N3 steel bars, and the diameter Φ of the vertical main reinforcement is 28 mm.

5. The steel frame structure of the arch seat according to claim 1 or 4, characterized in that: The two adjacent vertical main bars in each row are arranged with an interval of 10 cm.

6. The steel frame structure of the arch seat according to claim 1 is characterized in that: The stirrups are provided in multiple groups along the same vertical direction, and the multiple groups of stirrups are arranged at intervals of 45 cm.

7. The steel frame structure of the arch seat according to claim 1 is characterized in that: The steel mesh includes a plurality of N10 steel bars arranged in a staggered manner.

8. An abutment, characterized in that: It comprises a steel frame structure as described in any one of claims 1 to 7 and a concrete structure cast on the steel frame structure.

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