Installation and construction technology of a steel box tied arch bridge

Abstract

The invention discloses an installation and construction process of a steel box tie arch bridge, comprising the following steps: (1) constructing a foundation structure; (2) assembling a rigid support frame of a side span and a secondary span at one end, and constructing a main beam structure and a steel box arch rib of 1 / 3 span; (3) assembling a rigid support frame of a middle span, and constructing a main beam structure and a steel box arch rib of the full span; (4) installing and tensioning a hanger and a temporary tie of the middle span; (5) assembling a rigid support frame of a side span and a secondary span at the other end, and constructing a main beam structure and a steel box arch rib of 1 / 3 span; (6) constructing the remaining steel box arch ribs at the same time, and completing the jointing; (7) installing and tensioning a hanger and a temporary tie of the side span and the secondary span at the same time; (8) removing the rigid support frame and the temporary tie to complete the system conversion; (9) completing the construction of the bridge deck system structure; and adjusting the rod force value. The invention can ensure the construction quality, improve the construction speed, and improve the economy of the construction.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to an installation and construction process of a steel box tied arch bridge. Background Art

[0002] With the development of science and technology and the improvement of productivity, the development of arch bridges has been fully developed in terms of spanning capacity, combination of structural forms and application of various new materials. As an arch-beam combination system that combines the advantages of arches and beams, the steel box tie arch bridge fully exerts the combined effect of beam bending and arch compression. By tensioning the tie cables to offset the horizontal force of the arch ribs, the bridge piers do not need to bear horizontal forces; this type of bridge can minimize the bridge deck elevation, shorten the bridge length, save engineering costs, and make up for the high foundation requirements of arch bridges and the lack of aesthetics of ordinary bridges, becoming the preferred bridge type on the waterway.

[0003] In the prior art, during the construction of steel box tied arch bridges, due to the great difficulties in the construction method of large steel components, the method of prefabrication in sections and assembly on site is often adopted. However, due to the large length and large number of steel segments, the structural force and linear control during the assembly process are more complicated, and the construction is more easily affected by environmental factors, resulting in problems such as the arch ribs cannot be closed and the linearity cannot meet the design goals.

[0004] Therefore, a convenient, stable and safe construction method is urgently needed for the erection of steel box tied arch bridges. Summary of the invention

[0005] In order to solve the defects in the prior art, the present invention provides an installation construction process for a steel box tied arch bridge. The construction method of the present invention can effectively reduce the number of construction facilities while ensuring the overall construction quality of the steel box tied arch bridge and improving the construction speed, making the construction more efficient and convenient, effectively shortening the construction period, and improving the economic efficiency of the construction.

[0006] To achieve the above object, the present invention provides an installation and construction process for a steel box tied arch bridge, comprising the following steps:

[0007] (1) Carry out the basic structure construction of the steel box tied arch bridge, including pile foundation construction, concrete cap and pier construction, and arch foot structure construction;

[0008] (2) Assemble the rigid support frame of the side span and secondary span at one end of the steel box tied arch bridge, and carry out the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0009] (3) Assemble the rigid support frame of the middle span of the steel box tied arch bridge, and carry out the construction of the main beam structure of the middle span and the steel box arch rib of the full span;

[0010] (4) Install and tension the hangers and temporary tie rods of the mid-span;

[0011] (5) Assemble the rigid support frame of the side span and secondary span at the other end of the steel box tied arch bridge, and construct the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0012] (6) Simultaneously carry out the construction of the remaining steel box arch ribs of the side spans and secondary spans at both ends of the steel box tied arch bridge, and complete the closure with the previously completed steel box arch ribs;

[0013] (7) Simultaneously install and tension the hangers and temporary tie rods of the side spans and secondary spans at both ends of the steel box tied arch bridge;

[0014] (8) After the construction is completed, all rigid support frames and temporary tie rods are removed, permanent long tie rods are installed, the system conversion is completed and tensioning is carried out;

[0015] (9) Complete the construction of the bridge deck structure and the installation of other ancillary structures; adjust the force of the hangers and permanent long ties to the design value to complete the construction of the entire bridge.

[0016] Preferably, real-time monitoring and control are carried out during the installation and construction process, specifically including: establishing a monitoring network for the overall construction, main beam structure offset monitoring, hanger offset monitoring, arch rib offset monitoring and stress monitoring; the main beam structure offset monitoring includes the elevation monitoring and control of the main beam structure, controlling its elevation h=H-tanθ*l, wherein l is the horizontal distance between the main beam structure and the arch foot, θ is the angle between the arch foot and the horizontal plane, and H is the elevation of the main beam structure at the horizontal distance l from the arch foot.

[0017] In any of the above schemes, it is preferred that in steps (2) and (5), the main beam structure and the bridge deck structure of the entire span of the side span and the secondary span are constructed, and the steel box arch rib construction of 1 / 3 span is carried out to complete the steel box arch rib construction of 1 / 3 span of the side span and the steel box arch rib construction of 1 / 3 span of the secondary span respectively.

[0018] In any of the above schemes, it is preferred that in steps (2) and (5), the construction order of the steel box arch ribs of 1 / 3 of the span of the side span is from the connection with the arch foot to the middle span; the construction order of the steel box arch ribs of 1 / 3 of the span of the secondary span is from the connection pier position between the side span and the secondary span to the middle span.

[0019] In any of the above schemes, it is preferred that the steel box arch rib is constructed by a gantry crane and a crawler crane; the middle span steel box arch rib is constructed by uniformly assembling it from both ends of the middle span to the center position; in the step (6), the steel box arch rib is uniformly assembled from both ends to the middle span position; each arch rib stage segment is provided with 4 lifting points, which are placed on a rigid support frame after being lifted into place, and adjusted by a horizontal, vertical and three-way adjustable hydraulic device to achieve accurate positioning, and then the connection between adjacent segments is fixed; the design temperature requirements must be met during the closure.

[0020] In any of the above schemes, it is preferred that temporary piers are installed when the main beam structure is constructed. The temporary piers are symmetrically arranged on both sides of the main beam structure. The temporary piers include an enlarged foundation, H-shaped steel columns and a pier top structure. The pier top structure is provided with a hydraulic adjustment mechanism for adjusting the elevation of the main beam structure. After the arch ribs are closed, the hydraulic adjustment mechanism is used to unload the temporary piers so that the tied arch bridge is fully supported on the designed supports to complete the system conversion.

[0021] In any of the above schemes, it is preferred that the steel structure units of the steel box arch rib and the main beam structure are prefabricated in the factory and assembled on site, and the steel structure units are welded by automatic welding machines to control welding deformation while ensuring quality; the steel structure units are pre-assembled on a special tire frame with sufficient bearing capacity, and the foundation does not sink during the pre-assembly process. After the prefabrication of the steel structure units, the welds are ultrasonically inspected; in the step (9), the bridge deck structure is constructed by on-site casting, and the concrete model is C60.

[0022] The beneficial effects of the present invention are:

[0023] 1. The construction method of the present invention can effectively reduce the number of construction facilities while ensuring the overall construction quality of the steel box tied arch bridge and improving the construction speed, making the construction more efficient and convenient, effectively shortening the construction period, and improving the economy of the construction.

[0024] 2. The construction method of the present invention has little impact on traffic, requires less temporary facilities, effectively utilizes the stiffness of the tie beam itself, and reduces the designed load; the construction period is shorter, the construction safety factor is high, the longitudinal movement and rotation of the bridge are avoided, and the construction difficulty is greatly reduced.

[0025] 3. The construction method of the present invention is different from the conventional method of installing the two ends symmetrically toward the center, and mainly adopts an asymmetrical installation method, which is combined with a symmetrical installation method to reduce the large amount of engineering work during symmetrical construction, and can accurately control the positioning and deformation of the arch rib and the main beam structure, thereby ensuring the force requirements of the arch rib and greatly improving the accuracy and convenience of construction.

[0026] 4. Compared with the existing overall lifting method, the construction method of the present invention reduces the workload of high-altitude operations, and on the other hand reduces the deformation of the arch ribs during the lifting process, ensuring that the arch rib line shape is reasonable when the bridge is completed, and avoiding residual deformation caused by uneven force on the arch ribs. DETAILED DESCRIPTION

[0027] The technical solution of the present application will be described in detail below in conjunction with the specific implementation methods of the present application, but the following examples are only for understanding the present invention. The embodiments in the present application and the features in the embodiments can be combined with each other, and the present application can be implemented in a variety of different ways as defined and covered by the claims.

[0028] Example 1

[0029] An installation and construction process for a steel box tied arch bridge comprises the following steps:

[0030] (1) Carry out the basic structure construction of the steel box tied arch bridge, including pile foundation construction, concrete cap and pier construction, and arch foot structure construction;

[0031] (2) Assemble the rigid support frame of the side span and secondary span at one end of the steel box tied arch bridge, and carry out the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0032] (3) Assemble the rigid support frame of the middle span of the steel box tied arch bridge, and carry out the construction of the main beam structure of the middle span and the steel box arch rib of the full span;

[0033] (4) Install and tension the hangers and temporary tie rods of the mid-span;

[0034] (5) Assemble the rigid support frame of the side span and secondary span at the other end of the steel box tied arch bridge, and construct the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0035] (6) Simultaneously carry out the construction of the remaining steel box arch ribs of the side spans and secondary spans at both ends of the steel box tied arch bridge, and complete the closure with the previously completed steel box arch ribs;

[0036] (7) Simultaneously install and tension the hangers and temporary tie rods of the side spans and secondary spans at both ends of the steel box tied arch bridge;

[0037] (8) After the construction is completed, all rigid support frames and temporary tie rods are removed, permanent long tie rods are installed, the system conversion is completed and tensioning is carried out;

[0038] (9) Complete the construction of the bridge deck structure and the installation of other ancillary structures; adjust the force of the hangers and permanent long ties to the design value to complete the construction of the entire bridge.

[0039] Real-time monitoring and control are carried out during the installation and construction process, specifically including: establishing a monitoring network for the overall construction, main beam structure offset monitoring, hanger offset monitoring, arch rib offset monitoring and stress monitoring; main beam structure offset monitoring includes main beam structure elevation monitoring and control, controlling its elevation h=H-tanθ*l, where l is the horizontal distance between the main beam structure and the arch foot, θ is the angle between the arch foot and the horizontal plane, and H is the elevation of the main beam structure at the horizontal distance l from the arch foot.

[0040] In the steps (2) and (5), the main beam structure and the bridge deck structure of the entire span of the side span and the secondary span are constructed, and the steel box arch rib construction of 1 / 3 span is carried out to complete the steel box arch rib construction of 1 / 3 span of the side span and the steel box arch rib construction of 1 / 3 span of the secondary span respectively.

[0041] In the steps (2) and (5), the construction order of the steel box arch ribs of 1 / 3 of the span of the side span is from the connection with the arch foot to the middle span; the construction order of the steel box arch ribs of 1 / 3 of the span of the secondary span is from the connection pier position between the side span and the secondary span to the middle span.

[0042] The steel box arch rib is constructed by a gantry crane and a crawler crane. When constructing the middle span steel box arch rib, the ribs are assembled uniformly in the order of closing from both ends of the middle span to the center. In step (6), the ribs are assembled uniformly in the order of closing from both ends to the middle span. Each arch rib segment is provided with four lifting points. After being lifted into place, it is placed on a rigid support frame and adjusted by a hydraulic device adjustable in three directions, horizontally, vertically and vertically, to achieve accurate positioning. Then, the connection between adjacent segments is fixed. When closing, the design temperature requirement must be met.

[0043] Temporary piers are installed during the construction of the main beam structure. The temporary piers are symmetrically arranged on both sides of the main beam structure. The temporary piers include an expanded foundation, H-shaped steel columns and a pier top structure. A hydraulic adjustment mechanism is arranged on the pier top structure to adjust the elevation of the main beam structure. After the arch ribs are closed, the hydraulic adjustment mechanism is used to unload the temporary piers so that the tied arch bridge is fully supported on the designed supports to complete the system conversion.

[0044] The steel structure units of the steel box arch rib and the main beam structure are all prefabricated in the factory and assembled on site. The steel structure units are welded by automatic welding machines to control welding deformation while ensuring quality. The steel structure units are pre-assembled on a special tire frame with sufficient bearing capacity. The foundation does not sink during the pre-assembly process. After the prefabrication of the steel structure units is completed, the welds are ultrasonically inspected. In the step (9), the bridge deck structure is constructed by on-site casting, and the concrete model is C60.

[0045] Example 2

[0046] An installation and construction process for a steel box tied arch bridge comprises the following steps:

[0047] (1) Carry out the basic structure construction of the steel box tied arch bridge, including pile foundation construction, concrete cap and pier construction, and arch foot structure construction;

[0048] (2) Assemble the rigid support frame of the side span and secondary span at one end of the steel box tied arch bridge, and carry out the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0049] (3) Assemble the rigid support frame of the middle span of the steel box tied arch bridge, and carry out the construction of the main beam structure of the middle span and the steel box arch rib of the full span;

[0050] (4) Install and tension the hangers and temporary tie rods of the mid-span;

[0051] (5) Assemble the rigid support frame of the side span and secondary span at the other end of the steel box tied arch bridge, and construct the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0052] (6) Simultaneously carry out the construction of the remaining steel box arch ribs of the side spans and secondary spans at both ends of the steel box tied arch bridge, and complete the closure with the previously completed steel box arch ribs;

[0053] (7) Simultaneously install and tension the hangers and temporary tie rods of the side spans and secondary spans at both ends of the steel box tied arch bridge;

[0054] (8) After the construction is completed, all rigid support frames and temporary tie rods are removed, permanent long tie rods are installed, the system conversion is completed and tensioning is carried out;

[0055] (9) Complete the construction of the bridge deck structure and the installation of other ancillary structures; adjust the force of the hangers and permanent long ties to the design value to complete the construction of the entire bridge.

[0056] Real-time monitoring and control are carried out during the installation and construction process, specifically including: establishing a monitoring network for the overall construction, main beam structure offset monitoring, hanger offset monitoring, arch rib offset monitoring and stress monitoring; main beam structure offset monitoring includes main beam structure elevation monitoring and control, controlling its elevation h=H-tanθ*l, where l is the horizontal distance between the main beam structure and the arch foot, θ is the angle between the arch foot and the horizontal plane, and H is the elevation of the main beam structure at the horizontal distance l from the arch foot.

[0057] In the steps (2) and (5), the main beam structure and the bridge deck structure of the entire span of the side span and the secondary span are constructed, and the steel box arch rib construction of 1 / 3 span is carried out to complete the steel box arch rib construction of 1 / 3 span of the side span and the steel box arch rib construction of 1 / 3 span of the secondary span respectively.

[0058] In the steps (2) and (5), the construction order of the steel box arch ribs of 1 / 3 of the span of the side span is from the connection with the arch foot to the middle span; the construction order of the steel box arch ribs of 1 / 3 of the span of the secondary span is from the connection pier position between the side span and the secondary span to the middle span.

[0059] The steel box arch rib is constructed by a gantry crane and a crawler crane. When constructing the middle span steel box arch rib, the ribs are assembled uniformly in the order of closing from both ends of the middle span to the center. In step (6), the ribs are assembled uniformly in the order of closing from both ends to the middle span. Each arch rib segment is provided with four lifting points. After being lifted into place, it is placed on a rigid support frame and adjusted by a hydraulic device adjustable in three directions, horizontally, vertically and vertically, to achieve accurate positioning. Then, the connection between adjacent segments is fixed. When closing, the design temperature requirement must be met.

[0060] Temporary piers are installed during the construction of the main beam structure. The temporary piers are symmetrically arranged on both sides of the main beam structure. The temporary piers include an expanded foundation, H-shaped steel columns and a pier top structure. A hydraulic adjustment mechanism is arranged on the pier top structure to adjust the elevation of the main beam structure. After the arch ribs are closed, the hydraulic adjustment mechanism is used to unload the temporary piers so that the tied arch bridge is fully supported on the designed supports to complete the system conversion.

[0061] The steel structure units of the steel box arch rib and the main beam structure are all prefabricated in the factory and assembled on site. The steel structure units are welded by automatic welding machines to control welding deformation while ensuring quality. The steel structure units are pre-assembled on a special tire frame with sufficient bearing capacity. The foundation does not sink during the pre-assembly process. After the prefabrication of the steel structure units is completed, the welds are ultrasonically inspected. In the step (9), the bridge deck structure is constructed by on-site casting, and the concrete model is C60.

[0062] In addition, in order to further improve the technical effect of the present invention, in this embodiment, the hanger is vertically connected between the steel box arch rib and the main beam structure, and the upper and lower ends of the hanger are respectively provided with an upper fixed connection mechanism and a lower fixed connection mechanism, the upper fixed connection mechanism is arranged in the steel box arch rib, and the upper fixed connection mechanism is arranged on the main beam structure; the upper fixed connection mechanism is welded to the bottom plate inside the steel box arch rib, and a buffer layer is arranged between the upper fixed connection mechanism and the bottom plate, and the upper end of the hanger passes through the preset through hole on the steel box arch rib and is connected to the upper fixed connection mechanism via high-strength bolts; the lower fixed connection mechanism includes a steel plate support seat hooking the lower part of the longitudinal beam of the main beam structure, and a buffer layer is arranged between the steel plate support seat and the longitudinal beam structure, and the lower end of the hanger is connected to both sides of the steel plate support seat via high-strength bolts. The hanger is provided with an evenly distributed fixed hole plate, which is arranged in the sleeve of the hanger, and the overall shape of the evenly distributed fixed hole plate is adapted to the shape of the hanger, and has a plurality of evenly distributed through holes, and each sling of the hanger can independently pass through the through holes of the evenly distributed fixed hole plate.

[0063] The specific steps for installing and tensioning the hanger are:

[0064] 1) Carry out anti-corrosion operation on the upper fixed connection mechanism, and weld the upper fixed connection mechanism of each hanger at the set position on the bottom plate inside the steel box arch rib according to the design requirements. Before welding, a buffer layer is fixedly arranged between the upper fixed connection mechanism and the bottom plate;

[0065] 2) Carry out anti-corrosion operation on the upper fixed connection mechanism, and hook the steel plate support of the lower fixed connection mechanism at the set position of the lower part of the longitudinal beam of the main beam structure according to the design requirements, and before hooking, fix a buffer layer between the steel plate support and the longitudinal beam structure;

[0066] 3) Measure the distance between the upper fixed connection mechanism and the lower fixed connection mechanism of each suspender, and prepare the slings of the suspender; pass multiple slings through the evenly distributed fixed hole plate, and install the casing on the outside as a whole to form a suspender, and install the suspender on site so that it is fixedly connected with the upper fixed connection mechanism and the lower fixed connection mechanism respectively;

[0067] 4) Prestressing the hangers one by one according to the sequence and tensioning force specified in the design, and monitoring the stress and displacement changes of the steel box arch rib, the hangers (3) and the main beam structure throughout the process of applying the prestressing force;

[0068] 5) Carry out on-site anti-corrosion operations on the boom.

[0069] The present invention provides a certain compressive stress reserve for the installation and tensioning of the hanger, eliminates cracks, improves the internal force distribution of the arch rib and main beam structure, increases the structural rigidity, and improves the bearing capacity and durability of the bridge; the method has a simple structure, convenient construction, economical cost, and does not affect the overall appearance of the bridge in terms of structure; during use, the hanger can be replaced and adjusted in time according to needs, and the disassembly and assembly are simple and convenient. The hanger structure of the present invention allows each sling to be set independently, which can better control the uniformity of the cable force, is also convenient for construction, and saves construction costs; it ensures that the slings are separated from each other, do not overlap, and do not squeeze, so that the bridge is very convenient in future use and maintenance, and the cable force of any sling can be monitored and replaced without affecting traffic. The hanger of the present invention effectively avoids the lateral expansion and deformation of the casing by setting an evenly distributed fixed hole plate, which facilitates the construction of the hanger and maintains the appearance and normal service life of the hanger.

[0070] Example 3

[0071] An installation and construction process for a steel box tied arch bridge comprises the following steps:

[0072] (1) Carry out the basic structure construction of the steel box tied arch bridge, including pile foundation construction, concrete cap and pier construction, and arch foot structure construction;

[0073] (2) Assemble the rigid support frame of the side span and secondary span at one end of the steel box tied arch bridge, and carry out the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0074] (3) Assemble the rigid support frame of the middle span of the steel box tied arch bridge, and carry out the construction of the main beam structure of the middle span and the steel box arch rib of the full span;

[0075] (4) Install and tension the hangers and temporary tie rods of the mid-span;

[0076] (5) Assemble the rigid support frame of the side span and secondary span at the other end of the steel box tied arch bridge, and construct the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span;

[0077] (6) Simultaneously carry out the construction of the remaining steel box arch ribs of the side spans and secondary spans at both ends of the steel box tied arch bridge, and complete the closure with the previously completed steel box arch ribs;

[0078] (7) Simultaneously install and tension the hangers and temporary tie rods of the side spans and secondary spans at both ends of the steel box tied arch bridge;

[0079] (8) After the construction is completed, all rigid support frames and temporary tie rods are removed, permanent long tie rods are installed, the system conversion is completed and tensioning is carried out;

[0080] (9) Complete the construction of the bridge deck structure and the installation of other ancillary structures; adjust the force of the hangers and permanent long ties to the design value to complete the construction of the entire bridge.

[0081] Real-time monitoring and control are carried out during the installation and construction process, specifically including: establishing a monitoring network for the overall construction, main beam structure offset monitoring, hanger offset monitoring, arch rib offset monitoring and stress monitoring; main beam structure offset monitoring includes main beam structure elevation monitoring and control, controlling its elevation h=H-tanθ*l, where l is the horizontal distance between the main beam structure and the arch foot, θ is the angle between the arch foot and the horizontal plane, and H is the elevation of the main beam structure at the horizontal distance l from the arch foot.

[0082] In the steps (2) and (5), the main beam structure and the bridge deck structure of the entire span of the side span and the secondary span are constructed, and the steel box arch rib construction of 1 / 3 span is carried out to complete the steel box arch rib construction of 1 / 3 span of the side span and the steel box arch rib construction of 1 / 3 span of the secondary span respectively.

[0083] In the steps (2) and (5), the construction order of the steel box arch ribs of 1 / 3 of the span of the side span is from the connection with the arch foot to the middle span; the construction order of the steel box arch ribs of 1 / 3 of the span of the secondary span is from the connection pier position between the side span and the secondary span to the middle span.

[0084] The steel box arch rib is constructed by a gantry crane and a crawler crane. When constructing the middle span steel box arch rib, the ribs are assembled uniformly in the order of closing from both ends of the middle span to the center. In step (6), the ribs are assembled uniformly in the order of closing from both ends to the middle span. Each arch rib segment is provided with four lifting points. After being lifted into place, it is placed on a rigid support frame and adjusted by a hydraulic device adjustable in three directions, horizontally, vertically and vertically, to achieve accurate positioning. Then, the connection between adjacent segments is fixed. When closing, the design temperature requirement must be met.

[0085] Temporary piers are installed during the construction of the main beam structure. The temporary piers are symmetrically arranged on both sides of the main beam structure. The temporary piers include an expanded foundation, H-shaped steel columns and a pier top structure. A hydraulic adjustment mechanism is arranged on the pier top structure to adjust the elevation of the main beam structure. After the arch ribs are closed, the hydraulic adjustment mechanism is used to unload the temporary piers so that the tied arch bridge is fully supported on the designed supports to complete the system conversion.

[0086] The steel structure units of the steel box arch rib and the main beam structure are all prefabricated in the factory and assembled on site. The steel structure units are welded by automatic welding machines to control welding deformation while ensuring quality. The steel structure units are pre-assembled on a special tire frame with sufficient bearing capacity. The foundation does not sink during the pre-assembly process. After the prefabrication of the steel structure units is completed, the welds are ultrasonically inspected. In the step (9), the bridge deck structure is constructed by on-site casting, and the concrete model is C60.

[0087] In addition, in order to further improve the technical effect of the present invention, in this embodiment, the specific construction of the temporary tie rod and the permanent long tie rod is as follows:

[0088] 1) Drill holes, plant reinforcement, and pour concrete at the designed position of the arch foot to form a temporary tension anchor end, and install temporary tie rods symmetrically;

[0089] 2) Temporary tie rods are tensioned symmetrically on both sides at the same time, and the tension of the temporary tie rods is changed in real time, so that the immediate tensioning force of the temporary tie rods is equivalent to the designed tensioning force of the permanent tie rods. The tensioning is carried out step by step in four times;

[0090] 3) Leave it still for 36-48 hours, remove the temporary tie rods, and monitor the stress changes at the designed position of the arch foot;

[0091] 4) Clean the designed position of the arch foot where the temporary tie rods are removed;

[0092] 5) Install permanent long tie rods and tension them symmetrically to the design load value. The tensioning is carried out step by step in four steps;

[0093] 6) C60 concrete is sealed and cured at the designed position of the arch foot to complete the replacement process.

[0094] The construction of the tie rods of the present invention ensures the stability of the stress of the overall structure of the bridge. In the process of converting from temporary tie rods to permanent long tie rods, the perfect transition of the overall stress of the structure is fully guaranteed, and the structural damage caused by sudden stress changes during the construction of the tie-rod arch bridge is avoided. The safety and stability of the structure are guaranteed, the safety reserve of the tie rods is increased, the service life of the bridge is extended, the construction cost is reduced, the work efficiency is improved, the construction period is shortened, and the overall economic and social benefits are good.

[0095] It can be seen from the above embodiments that the construction method of the present invention can effectively reduce the number of construction facilities while ensuring the overall construction quality of the steel box tie arch bridge and improving the construction speed, making the construction more efficient and convenient, effectively shortening the construction period, and improving the economy of the construction.

[0096] The construction method of the present invention has little impact on traffic, requires less temporary facilities, effectively utilizes the stiffness of the tie beam itself, and reduces the designed load; the construction period is shorter, the construction safety factor is high, the longitudinal movement and rotation of the bridge are avoided, and the construction difficulty is greatly reduced.

[0097] The construction method of the present invention is different from the conventional method of installing the two ends symmetrically toward the center, and mainly adopts an asymmetrical installation method, which is combined with a symmetrical installation method to reduce the large amount of engineering work during symmetrical construction, and can accurately control the positioning and deformation of the arch rib and the main beam structure, thereby ensuring the force requirements of the arch rib and greatly improving the accuracy and convenience of construction.

[0098] Compared with the existing overall lifting method, the construction method of the present invention reduces the workload of high-altitude operations, and on the other hand reduces the deformation of the arch ribs during the lifting process, ensuring that the arch rib line shape is reasonable when the bridge is completed, and avoiding residual deformation caused by uneven force on the arch ribs.

[0099] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. An installation and construction process for a steel box tied arch bridge, characterized in that: The following steps are involved: (1) Carry out the basic structure construction of the steel box tied arch bridge, including pile foundation construction, concrete cap and pier construction, and arch foot structure construction; (2) Assemble the rigid support frame of the side span and secondary span at one end of the steel box tied arch bridge, and carry out the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span; (3) Assemble the rigid support frame of the middle span of the steel box tied arch bridge, and carry out the construction of the main beam structure of the middle span and the steel box arch rib of the full span; (4) Install and tension the hangers and temporary tie rods of the mid-span; (5) Assemble the rigid support frame of the side span and secondary span at the other end of the steel box tied arch bridge, and construct the main beam structure of the side span and secondary span and the steel box arch rib of 1 / 3 span; (6) Simultaneously carry out the construction of the remaining steel box arch ribs of the side spans and secondary spans at both ends of the steel box tied arch bridge, and complete the closure with the previously completed steel box arch ribs; (7) Simultaneously install and tension the hangers and temporary tie rods of the side spans and secondary spans at both ends of the steel box tied arch bridge; (8) After the construction is completed, all rigid support frames and temporary tie rods are removed, permanent long tie rods are installed, the system conversion is completed and tensioning is carried out; (9) Complete the construction of the bridge deck structure and installation of other ancillary structures; adjust the force of the hangers and permanent long ties to the design value to complete the construction of the entire bridge.

2. The installation and construction process of the steel box tied arch bridge according to claim 1 is characterized in that: Real-time monitoring and control are carried out during the installation and construction process, including: establishing a monitoring network for the overall construction, monitoring the main beam structure offset, the hanger offset, the arch rib offset and stress monitoring; the main beam structure offset monitoring includes the elevation monitoring and control of the main beam structure, controlling its elevation , where l is the horizontal distance between the main beam structure and the arch foot, θ is the angle between the arch foot and the horizontal plane, and H is the elevation of the main beam structure at the horizontal distance l from the arch foot.

3. The installation and construction process of the steel box tied arch bridge according to any one of claims 1-2 is characterized in that: In the steps (2) and (5), the main beam structure and the bridge deck structure of the entire span of the side span and the secondary span are constructed, and the steel box arch rib construction of 1 / 3 span is carried out to complete the steel box arch rib construction of 1 / 3 span of the side span and the steel box arch rib construction of 1 / 3 span of the secondary span respectively.

4. The installation and construction process of the steel box tied arch bridge according to claim 3 is characterized in that: In the steps (2) and (5), the construction order of the steel box arch ribs of 1 / 3 of the side span is from the connection with the arch foot to the middle span; the construction order of the steel box arch ribs of 1 / 3 of the secondary span is from the connection pier position between the side span and the secondary span to the middle span.

5. The installation and construction process of the steel box tied arch bridge according to claim 4 is characterized in that: The steel box arch rib is constructed by a gantry crane and a crawler crane. During the construction of the middle span steel box arch rib, the ribs are assembled uniformly in the order of closing from both ends of the middle span to the center. In step (6), the ribs are assembled uniformly in the order of closing from both ends to the middle span. Each arch rib segment is provided with four lifting points. After being lifted into place, it is placed on a rigid support frame and adjusted by a hydraulic device adjustable in three directions, horizontally, vertically and vertically, to achieve accurate positioning. Then, the connection between adjacent segments is fixed. When closing, the design temperature requirement must be met.

6. The installation and construction process of the steel box tied arch bridge according to claim 5 is characterized in that: Temporary piers are installed during the construction of the main beam structure. The temporary piers are symmetrically arranged on both sides of the main beam structure. The temporary piers include an expanded foundation, H-shaped steel columns and a pier top structure. A hydraulic adjustment mechanism is arranged on the pier top structure to adjust the elevation of the main beam structure. After the arch ribs are closed, the hydraulic adjustment mechanism is used to unload the temporary piers so that the tied arch bridge is fully supported on the designed supports to complete the system conversion.

7. The installation and construction process of the steel box tied arch bridge according to claim 6 is characterized in that: The steel structure units of the steel box arch rib and the main beam structure are all prefabricated in the factory and assembled on site. The steel structure units are welded by automatic welding machines. The steel structure units are pre-assembled on a special tire frame with sufficient bearing capacity. The foundation does not sink during the pre-assembly process. After the prefabrication of the steel structure units is completed, the welds are ultrasonically inspected. In the step (9), the bridge deck structure is constructed by on-site casting, and the concrete type is C60.