Urban steel structure arch bridge non-support construction method

Abstract

The invention relates to a support-free construction method for an urban steel structure arch bridge, which comprises the following specific steps: in a first dry season, leveling a site in a river channel, and constructing an arch bridge pile foundation, a bearing platform and a concrete skewback; in the second dry season, a steel member assembling site and a hoisting equipment walking area are paved in the river channel, and steel arch rib sections and steel beam sections are synchronously machined in a steel structure machining factory; the first section of steel arch rib is installed, and meanwhile the steel arch ribs are integrally assembled in the river channel; hoisting the main arch ring of the middle section of the steel arch rib, removing the frame, transferring, adjusting the angle and mounting in place; the main crane retreats, the steel strands on the upstream side and the downstream side are tensioned, and arch crown cross braces are installed; steel beam construction conditions are determined according to the construction period progress and weather forecast observation conditions; the auxiliary crane retreats, and the working face is transferred to the bridge deck from the river channel. Industrial and mechanical construction is adopted to the maximum extent, precious operation time in the dry season of the riverway is effectively grabbed, non-support construction of the urban bridge riverway is achieved, and the high-altitude operation risk and the natural disaster risk in the flood season are greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of arch bridge construction, and in particular to a support-free construction method for an urban steel structure arch bridge. Background Art

[0002] In pursuit of beautiful shapes, urban arch bridges usually have a large span-rise ratio, and the arch top is dozens of meters away from the bridge deck. The conventional ground support method consumes a large amount of steel, is uneconomical, and has high risks in high-altitude operations.

[0003] In addition, urban bridge construction is often affected by the seasonal flood season of rivers, and the dry season is the best time to build bridges in rivers. For example, in central and western my country, the dry season is only 4-5 months a year. If the installation of all arch bridge structures cannot be completed in one dry season, the probability of safety accidents caused by flood impact on the unstable structure will be greatly increased. Therefore, during a dry season, it is imperative to keep the installed bridge parts in a stable state and remove the temporary structure from the river in time before the flood season arrives. The conventional beam-first-arch-later ground bracket method cannot complete the installation of beams and arches in one dry season. Even if the main beam is connected, the main beam and the lower bracket will be at risk of being destroyed by floods after the flood season arrives. If the arch-first-beam-later ground bracket method is adopted, the bracket height will be greatly increased. If the arch rib cannot be closed in one dry season, safety accidents will be inevitable when the flood season arrives. In addition, the construction cost of the cable hoisting method is greatly increased, and it is rarely used except for crossing canyons and main river basins.

[0004] In view of the waterless river channels affected by seasonal flood seasons, it is necessary to study a new construction method to complete the bridge construction task in a shorter dry season with lower construction costs. Summary of the invention

[0005] The present invention aims to solve the deficiencies of the prior art and provide a support-free construction method for an urban steel structure arch bridge.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for constructing an urban steel structure arch bridge without a support, comprising the following specific steps:

[0008] S1. During the first dry season, the site in the river channel was leveled and the construction of the arch bridge pile foundation, abutment and concrete arch seat was carried out;

[0009] S2, the second dry season, paving the steel component assembly site and the lifting equipment running area in the river channel, and processing the steel arch rib segments and steel beam segments in the steel structure processing plant;

[0010] S3. Two auxiliary cranes enter the site, and the first section of the steel arch rib is installed. At the same time, the steel arch rib is assembled as a whole in the river channel;

[0011] S4. The main crane enters the site, and the three cranes work together to lift, remove, transfer, adjust the angle, and install the main arch ring in the middle section of the steel arch rib;

[0012] S5. The main crane is withdrawn from the site, and the steel strands on both sides of the upstream and downstream are tensioned to make the lateral spacing of the tops of the upstream and downstream steel arch ribs 2-3cm larger than the designed lateral spacing; the auxiliary crane is used to install the arch cross brace in sections. After the installation and inspection of the arch cross brace are completed, the steel strands and temporary anchors on the upstream and downstream sides of the river are removed;

[0013] S6. Determine the construction status of the steel beam according to the progress of the construction period and the weather forecast observation. If the steel arch ribs are installed as scheduled and the weather forecast observation is normal, the steel beam construction phase will proceed normally; otherwise, the steel beam construction will be carried out in the next dry season.

[0014] The specific process of steel beam installation is as follows:

[0015] The steel beam segment is transported to the lower part of the designed position, and two auxiliary cranes are used to synchronously lift the steel beam segment and lift it near the sling. The sling is manually connected to the pins of the steel beam segment on the top surface of the steel beam to be laid. After all the pins of the steel beam segment are connected, the auxiliary crane withdraws from the operation. The bridge deck elevation of the steel beam segment is adjusted: the elevations of several lifting points of the steel beam segment are measured, and the elongation of the sling is adjusted differentially to make the elevations of several lifting points of the steel beam segment consistent and meet the design and monitoring pre-camber requirements, and the elevation adjustment is completed. The lifting operation of a steel beam segment is completed.

[0016] S7, depending on the meteorological forecast observation, if there is no sudden flood season situation, repeat step S6, complete the hoisting of other steel beam segments and the connection between adjacent steel beam segments during the second dry season, and move the temporary construction facilities in the river channel out of the river channel before the next flood season arrives;

[0017] S8. The auxiliary crane withdraws and the working surface is transferred from the river channel to the bridge deck. The bridge deck pavement and ancillary facilities are constructed, the cable tension is adjusted, and the bridge construction is completed.

[0018] In step S1, a prestressed anchor end connected to the first section of the steel arch rib is embedded in advance during the construction of the concrete arch seat.

[0019] In step S2, when processing the steel arch rib in the steel structure processing plant, the first section of the steel arch rib and the adjacent additional parts are processed together; the additional parts include limit plates and adjustment frames; two sets of adjustment frames and one set of limit plates are arranged on each surface of the steel arch rib, the limit plates are located in the middle of each surface of the steel arch rib, and the two sets of adjustment frames are located on both sides of each surface of the steel arch rib, and jacks are installed on the adjustment frames.

[0020] The specific operations of step S3 are:

[0021] The auxiliary crane enters the site and is used to hoist the first section of steel arch rib brought by the transport vehicle to the designed position of the concrete arch seat, pour concrete in the steel-concrete combined section, and tension the prestressed steel bars to complete the construction of the first section of steel arch rib; a temporary cradle is set up at the steel component assembly site, and the temporary cradle is higher than the river paving surface. The steel arch rib sections are hoisted horizontally onto the temporary cradle section by section until the assembly of the main arch ring of the middle section of the entire steel arch rib is completed. The main arch ring of the middle section of the steel arch rib is assembled horizontally, and the assembly height is higher than the river paving surface. The axial plane of the main arch ring of the middle section of the steel arch rib is parallel to the horizontal plane; the main arch ring of the middle section of the steel arch rib is lifted and flipped into a spatial angle for installation at a later stage; the two ends of the main arch ring of the middle section of the steel arch rib are assembled together with the additional parts at the corresponding positions of the splicing surface of the first section of the steel arch rib.

[0022] The specific operations of step S4 are:

[0023] S41. The main crane enters the site, and one main crane and two auxiliary cranes are used to jointly lift the assembled steel arch rib middle section main arch ring. The main crane lifts the middle area of ​​the steel arch rib middle section main arch ring, and the two auxiliary cranes lift the two arch foot areas of the steel arch rib middle section main arch ring respectively, and lift them at the same time to remove the steel arch rib middle section main arch ring from the frame;

[0024] S42, after the main arch ring of the middle section of the steel arch rib is off the frame and stable, the main hoist continues to lift upwards, and the two auxiliary hoists maintain the lifting angle to ensure that the arch foot is suspended in the air, until the main arch ring of the middle section of the steel arch rib is vertical in the air, the two auxiliary hoists release the hooks, and the main hoist lifts the main arch ring of the middle section of the steel arch rib alone;

[0025] S43. The main crane lifts the main arch ring of the middle section of the steel arch rib and moves it to the erection area according to the designed route. The two auxiliary cranes move to the erection area simultaneously. The two auxiliary cranes continue to lift the arch foot ends of the main arch ring of the middle section of the steel arch rib and gradually lift the two arch feet, so that the main arch ring of the middle section of the steel arch rib gradually tilts from a vertical state until the arch rib presents the designed spatial tilt angle. The three cranes cooperate to slowly move the main arch ring of the middle section of the steel arch rib to the top of the first section of the installed steel arch rib, and adjust the relative positions of the two ends of the main arch ring of the middle section of the steel arch rib and the first section of the steel arch rib so that the attached parts at corresponding positions correspond.

[0026] S44, the main hoist and the auxiliary hoist cooperate to continue to drop the main arch ring of the middle section of the steel arch rib, so that the main arch ring of the middle section of the steel arch rib slowly enters the lateral limit plate of the first section of the steel arch rib; by adjusting the lifting angles of the main hoist and the auxiliary hoist, the two ends of the main arch ring of the middle section of the steel arch rib are parallel to the corresponding cross-section of the first section of the steel arch rib; continue to drop the main arch ring of the middle section of the steel arch rib until the upper and lower limit plates are completely matched; by adjusting the lifting of the jack set in the additional parts and the lifting and lifting coordination of the main hoist and the auxiliary hoist, fine-tune the relative position of the main arch ring of the middle section of the steel arch rib and the first section of the steel arch rib, so that the main arch ring of the middle section of the steel arch rib is accurately matched with the first section of the steel arch rib;

[0027] S45, welding of horse plates, two auxiliary cranes withdraw from operation; connecting the main arch ring in the middle section of the steel arch rib and the steel strands of the temporary anchorage in the river channel, tensioning and pre-tightening; the main crane withdraws from operation; welding the weld of the connection interface between the main arch ring in the middle section of the steel arch rib and the first section of the steel arch rib;

[0028] S46. Follow the same steps to complete the installation of the main arch ring in the middle section of other steel arch ribs.

[0029] In step S6, the steel beam segment length includes two sets of slings.

[0030] The beneficial effects of the present invention are as follows: the present invention adopts industrialized and mechanized construction to the greatest extent, effectively seizes the precious operation time during the dry season of the river, realizes the scaffold-free construction of urban bridges and rivers, greatly reduces the risks of high-altitude operations and natural disasters during the flood season, and solves the problem of urban bridge construction that is greatly affected by seasonal floods. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of step S1 of the present invention;

[0032] Figure 2 A side view of the attachment of the present invention;

[0033] Figure 3 A top view of the attachment of the present invention;

[0034] Figure 4 is a schematic diagram of step S3 of the present invention;

[0035] Figure 5 It is a side view of the hoisting of the main arch ring in the middle section of the steel arch rib of the present invention.

[0036] Figure 6 is a schematic diagram of step S4 of the present invention;

[0037] Figure 7 It is a schematic top view of step S5 of the present invention.

[0038] Figure 8 is a side view schematic diagram of step S5 of the present invention;

[0039] Fig. 9 is a side view schematic diagram of step S8 of the present invention;

[0040] In the figure: 1-arch bridge pile foundation; 2-cap; 3-concrete arch seat; 4-steel arch rib; 5-prestressed anchor end; 6-steel component assembly site; 7-hoisting equipment running area; 8-steel beam; 9-attachment; 10-auxiliary hoist; 11-prestressed steel bar; 12-temporary tire frame; 13-main hoist; 14-temporary anchor; 15-steel strand; 16-arch cross brace; 17-sling;

[0041] 401-the first section of steel arch rib; 402-the main arch ring in the middle section of the steel arch rib;

[0042] 801-Steel beam segment;

[0043] 901-limiting plate; 902-adjusting frame; 903-jack;

[0044] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0046] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0048] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0049] A method for constructing an urban steel structure arch bridge without a support, comprising the following specific steps:

[0050] S1, such as Figure 1 As shown, in the first dry season, the site in the river channel is leveled, and the construction of the arch bridge pile foundation 1, the cap 2, and the concrete arch seat 3 is carried out;

[0051] During the construction of the concrete arch seat 3, a prestressed anchor end 5 connected to the first section of the steel arch rib 401 is pre-buried;

[0052] S2. In the second dry season, a steel component assembly area 6 and a lifting equipment running area 7 are paved in the river channel. Figure 4 As shown; the steel arch rib segment and the steel beam segment 801 are processed simultaneously in the steel structure processing plant;

[0053] Specifically, when the steel arch rib 4 is processed in a steel structure processing plant, the first section of the steel arch rib 401 and the adjacent additional parts 9 are processed together; the additional parts 9 are as follows: Figure 2 , Figure 3 As shown, it includes a limit plate 901 and an adjustment frame 902; two sets of adjustment frames 902 and one set of limit plates 901 are arranged on each surface of the steel arch rib 4, the limit plates 901 are located in the middle of each surface of the steel arch rib 4, and the two sets of adjustment frames 902 are located on both sides of each surface of the steel arch rib 4, and a jack 903 is installed on the adjustment frame 902;

[0054] S3, such as Figure 4 As shown, two auxiliary cranes 10 enter the site, the first section of the steel arch rib 401 is installed, and the steel arch rib 4 is assembled as a whole in the river channel;

[0055] The specific operations are:

[0056] The auxiliary crane 10 enters the site, and the auxiliary crane 10 is used to hoist the first section of the steel arch rib 401 transported by the transport vehicle to the designed position of the concrete arch seat 3, pour the steel-concrete combined section concrete, and tension the prestressed steel bars 11 to complete the construction of the first section of the steel arch rib; a temporary tire frame 12 is set up at the steel component assembly site 6, and the temporary tire frame 12 is higher than the river paving surface. The steel arch rib segments are hoisted horizontally onto the temporary tire frame 12 section by section until the assembly of the main arch ring 402 of the middle section of the entire steel arch rib is completed. The main arch ring 402 of the middle section of the steel arch rib is assembled horizontally, and the assembly height is higher than the river paving surface. The axial plane of the main arch ring 402 of the middle section of the steel arch rib is parallel to the horizontal plane; the main arch ring 402 of the middle section of the steel arch rib is hoisted and turned into a spatial angle for installation at a later stage; the two ends of the main arch ring 402 of the middle section of the steel arch rib are assembled together with the additional parts 9 at the corresponding positions of the splicing surface of the first section of the steel arch rib 401;

[0057] S4, such as Figure 6 As shown, the main crane 13 enters the site, and the three cranes cooperate to jointly carry out operations such as lifting, removing from the frame, transferring, adjusting the angle, and installing the main arch ring 402 in the middle section of the steel arch rib;

[0058] The specific operations are:

[0059] S41, the main crane 13 enters the site, and one main crane 13 and two auxiliary cranes 10 are used to lift and assemble the steel arch rib middle section main arch ring 402. Figure 5 As shown, the main crane 13 lifts the middle area of ​​the main arch ring 402 in the middle section of the steel arch rib, and the two auxiliary cranes 10 lift the two arch foot areas of the main arch ring 402 in the middle section of the steel arch rib respectively, and lift them at the same time to remove the main arch ring 402 in the middle section of the steel arch rib from the frame;

[0060] S42, after the main arch ring 402 of the middle section of the steel arch rib is off the frame and stable, the main hoist 13 continues to lift upward, and the two auxiliary hoists 10 maintain the lifting angle to ensure that the arch foot is suspended in the air, until the main arch ring 402 of the middle section of the steel arch rib is in a vertical plane in the air, the two auxiliary hoists 10 release the hooks, and the main hoist 13 lifts the main arch ring 402 of the middle section of the steel arch rib alone;

[0061] S43, the main crane 13 lifts the main arch ring 402 of the middle section of the steel arch rib and moves it to the erection area according to the designed route, and the two auxiliary cranes 10 move to the erection area simultaneously; the two auxiliary cranes 10 continue to lift the arch foot ends of the main arch ring 402 of the middle section of the steel arch rib, and gradually lift the two arch feet, so that the main arch ring 402 of the middle section of the steel arch rib gradually tilts from a vertical state until the arch rib presents the designed spatial tilt angle; the three cranes cooperate to slowly move the main arch ring 402 of the middle section of the steel arch rib to the top of the installed first section of the steel arch rib 401, and adjust the relative positions of the two ends of the main arch ring 402 of the middle section of the steel arch rib and the first section of the steel arch rib 401, so that the additional parts 9 at the corresponding positions correspond;

[0062] S44, the main hoist 13 and the auxiliary hoist 10 cooperate to continue to drop the main arch ring 402 in the middle section of the steel arch rib, so that the main arch ring 402 in the middle section of the steel arch rib slowly enters the lateral limit plate 901 of the first section of the steel arch rib 401; by adjusting the lifting angle of the main hoist 13 and the auxiliary hoist 10, the two ends of the main arch ring 402 in the middle section of the steel arch rib are parallel to the corresponding cross section of the first section of the steel arch rib 31; continue to drop the main arch ring 402 in the middle section of the steel arch rib until it is completely matched with the upper and lower limit plates 901; by adjusting the lifting of the jack 903 provided in the additional part 9, and the lifting and hoisting coordination of the main hoist 13 and the auxiliary hoist 10, the relative position of the main arch ring 402 in the middle section of the steel arch rib and the first section of the steel arch rib 31 is finely adjusted, so that the main arch ring 402 in the middle section of the steel arch rib is accurately matched with the first section of the steel arch rib 401;

[0063] S45, welding the horse plate, the two auxiliary cranes 10 quit the operation; connect the steel strands 15 of the main arch ring 402 in the middle section of the steel arch rib and the temporary anchor 14 in the river channel, and pre-tighten them; the main crane 13 quits the operation; weld the weld of the connection interface between the main arch ring 402 in the middle section of the steel arch rib and the first section of the steel arch rib 401;

[0064] S46, the same steps are followed to complete the installation of the main arch ring 402 in the middle section of other steel arch ribs;

[0065] S5, such as Figure 6 , Figure 7 As shown, the main crane 13 is withdrawn, and the steel strands 15 on both sides of the upstream and downstream are tensioned, so that the lateral spacing at the top of the upstream and downstream steel arch ribs 4 is 2-3 cm larger than the designed lateral spacing; the auxiliary crane 10 is used to install the arch cross brace 16 in sections. After the installation and inspection of the arch cross brace 16 are completed, the upstream and downstream steel strands 15 and the temporary anchor 14 of the river channel are removed;

[0066] S6, such as Figure 7 , Figure 8As shown, the construction status of the steel beam 8 is determined according to the progress of the construction period and the weather forecast observation; if the steel arch rib 4 is installed as scheduled and the weather forecast observation is normal, the construction stage of the steel beam 8 will be normally entered; otherwise, the construction of the steel beam 8 will be carried out in the next dry season;

[0067] The installation process of steel beam 8 is as follows:

[0068] The steel beam segment 801 is transported to the lower part of the design position, and two auxiliary cranes 10 are used to synchronously lift the steel beam segment 801, and the steel beam segment 801 is lifted to the vicinity of the sling 17; the sling 17 is manually connected to the pins of the steel beam segment 801 on the top surface of the steel beam 8 to be laid, and after all the pin connections of the steel beam segment 801 are completed, the auxiliary crane 10 exits the operation; the bridge deck elevation of the steel beam segment 801 is adjusted: the elevations at several lifting points of the steel beam segment 801 are measured, and the elongation of the sling 17 is differentially adjusted to make the elevations at several lifting points of the steel beam segment 801 consistent and meet the design and monitoring pre-camber requirements, and the elevation adjustment is completed; the lifting operation of one steel beam segment 801 is completed; the length of the steel beam segment 801 includes two sets of slings 17;

[0069] S7, depending on the meteorological forecast observation, if there is no sudden flood season situation, repeat step S6, complete the hoisting of other steel beam segments 801 during the second dry season, complete the connection between adjacent steel beam segments 801, and move the temporary construction facilities in the river channel out of the river channel before the next flood season arrives;

[0070] S8, such as Fig. 9 As shown, the auxiliary crane 10 withdraws and the working surface is transferred from the river channel to the bridge deck, the bridge deck pavement and ancillary facilities are constructed, the cable tension is adjusted, and the bridge construction is completed. During this period, it is no longer constrained by the influence of the river flow during the flood season.

[0071] The present invention adopts industrialized and mechanized construction to the greatest extent, effectively seizes the precious operation time during the dry season of the river, realizes the scaffold-free construction of urban bridges and rivers, greatly reduces the risks of high-altitude operations and natural disasters during the flood season, and solves the problem of urban bridge construction that is greatly affected by seasonal floods.

[0072] 1. Prefabrication of steel structure bridge segments in the factory, on-site assembly of the whole or large segments, and hoisting of multiple equipments fully realize industrialized construction and mechanized operation;

[0073] 2. The present invention realizes the construction of urban cross-river bridges without support, which has positive significance for the protection of river ecological environment;

[0074] 3. Compared with the conventional scaffolding method, it reduces the risk of high-altitude operations and the risk of collapse of the scaffold due to floods during the flood season, and the safety is greatly improved;

[0075] 4. The present invention has multiple advantages in resisting flood risks. First, the steel arch rib 4 is assembled and hoisted as a whole, which is less likely to be delayed by other factors and has a fast construction speed. Second, even if the installation of the steel arch rib 4 is delayed or encounters unfavorable hydrological conditions, the steel beam 8 can wait until the next dry season for construction. Third, after each steel beam segment 801 is installed, it is connected to the steel arch rib 4 through the sling 17 to achieve a stable state, that is, each steel beam segment 801 has the ability to resist floods during the hoisting stage.

[0076] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for constructing an urban steel structure arch bridge without a support, characterized in that: The specific steps are: S1, the first dry season, leveling the site in the river channel, and constructing the arch bridge pile foundation (1), the cap (2), and the concrete arch seat (3); S2, in the second dry season, a steel component assembly site (6) and a lifting equipment running area (7) are paved in the river channel, and steel arch rib segments and steel beam segments (801) are processed in a steel structure processing plant simultaneously; S3. Two auxiliary cranes (10) enter the site, the first section of the steel arch rib (401) is installed, and the steel arch rib (4) is assembled as a whole in the river channel; S4, the main crane (13) enters the site, and the three cranes work together to lift, remove, transfer, adjust the angle, and install the main arch ring (402) in the middle section of the steel arch rib; S5, the main crane (13) is withdrawn, and the steel strands (15) on both sides of the upstream and downstream are tensioned, so that the lateral spacing between the tops of the upstream and downstream steel arch ribs (4) is 2-3 cm larger than the designed lateral spacing; the auxiliary crane (10) is used to install the arch cross brace (16) in sections. After the installation and inspection of the arch cross brace (16) are completed, the upstream and downstream steel strands (15) and the temporary anchor (14) of the river channel are removed; S6. Determine the construction status of the steel beam (8) according to the construction progress and weather forecast observations; if the steel arch rib (4) is installed as scheduled and the weather forecast observations are normal, then enter the construction phase of the steel beam (8) normally; otherwise, wait until the next dry season to proceed with the construction of the steel beam (8); The installation process of the steel beam (8) is as follows: The steel beam segment (801) is transported to the lower part of the design position, and two auxiliary cranes (10) are used to synchronously lift the steel beam segment (801) and lift the steel beam segment (801) to the vicinity of the sling (17); the sling (17) is manually connected to the pins of the steel beam segment (801) on the top surface of the steel beam (8) to be laid, and after all the pin connections of the steel beam segment (801) are completed, the auxiliary crane (10) exits the operation; the bridge deck elevation of the steel beam segment (801) is adjusted: the elevations of several lifting points of the steel beam segment (801) are measured, and the elongation of the sling (17) is differentially adjusted to make the elevations of several lifting points of the steel beam segment (801) consistent and meet the design and monitoring pre-camber requirements, and the elevation adjustment is completed; the lifting operation of one steel beam segment (801) is completed; S7, depending on the meteorological forecast observation, if there is no sudden flood season situation, repeat step S6, complete the hoisting of other steel beam segments (801) during the second dry season, complete the connection between adjacent steel beam segments (801), and move the temporary construction facilities in the river channel out of the river channel before the next flood season arrives; S8, auxiliary crane (10) withdraws, and the working surface is transferred from the river channel to the bridge deck, where the bridge deck pavement and ancillary facilities are constructed, and the cable tension is adjusted to complete the bridge construction.

2. The method for constructing an urban steel structure arch bridge without a support according to claim 1, characterized in that: In step S1, a prestressed anchor end (5) connected to the first section of steel arch rib (401) is pre-embedded in advance during the construction of the concrete arch seat (3).

3. The method for constructing an urban steel structure arch bridge without a support according to claim 2, characterized in that: In step S2, when the steel arch rib (4) is processed in a steel structure processing plant, the first section of the steel arch rib (401) and the adjacent additional parts (9) are processed together; the additional parts (9) include a limit plate (901) and an adjustment frame (902); two sets of adjustment frames (902) and one set of limit plates (901) are arranged on each surface of the steel arch rib (4), the limit plates (901) are located in the middle of each surface of the steel arch rib (4), and the two sets of adjustment frames (902) are located on both sides of each surface of the steel arch rib (4), and a jack (903) is installed on the adjustment frame (902).

4. The method for constructing an urban steel structure arch bridge without a support according to claim 3, characterized in that: The specific operations of step S3 are: The auxiliary crane (10) enters the site, and the auxiliary crane (10) is used to hoist the first section of steel arch rib (401) transported by the transport vehicle to the designed position of the concrete arch seat (3), pour the steel-concrete combined section concrete, and tension the prestressed steel bars (11), so as to complete the construction of the first section of steel arch rib; a temporary frame (12) is set up at the steel component assembly site (6), and the temporary frame (12) is higher than the river paving surface, and the steel arch rib segments are hoisted horizontally onto the temporary frame (12) section by section until the construction is completed. The main arch ring (402) of the middle section of the steel arch rib is assembled horizontally, the assembly height is higher than the river channel paving surface, and the axial plane of the main arch ring (402) of the middle section of the steel arch rib is parallel to the horizontal plane; the main arch ring (402) of the middle section of the steel arch rib is lifted and turned into a spatial angle for installation; the two ends of the main arch ring (402) of the middle section of the steel arch rib are assembled together with the additional parts (9) at the corresponding positions of the splicing surface of the first section of the steel arch rib (401).

5. The method for constructing an urban steel structure arch bridge without a support according to claim 4, characterized in that: The specific operations of step S4 are: S41, the main crane (13) enters the site, and one main crane (13) and two auxiliary cranes (10) are used to jointly lift the assembled steel arch rib middle section main arch ring (402), the main crane (13) lifts the middle area of ​​the steel arch rib middle section main arch ring (402), and the two auxiliary cranes (10) lift the two arch foot areas of the steel arch rib middle section main arch ring (402) respectively, and lift them at the same time, so that the steel arch rib middle section main arch ring (402) is removed from the frame; S42, after the main arch ring (402) of the middle section of the steel arch rib is off the frame and stable, the main hoist (13) continues to lift upward, and the two auxiliary hoists (10) maintain the lifting angle to ensure that the arch foot is suspended in the air, until the main arch ring (402) of the middle section of the steel arch rib is in a vertical plane in the air, the two auxiliary hoists (10) release the hooks, and the main hoist (13) lifts the main arch ring (402) of the middle section of the steel arch rib alone; S43, the main crane (13) lifts the main arch ring (402) of the middle section of the steel arch rib and moves it to the erection area according to the designed route, and the two auxiliary cranes (10) move to the erection area simultaneously; the two auxiliary cranes (10) continue to lift the arch foot ends of the main arch ring (402) of the middle section of the steel arch rib, gradually lift the two arch feet, so that the main arch ring (402) of the middle section of the steel arch rib gradually tilts from a vertical state until the arch rib presents a designed spatial tilt angle; the three cranes cooperate to slowly move the main arch ring (402) of the middle section of the steel arch rib to the top of the first section of the installed steel arch rib (401), and adjust the relative positions of the two ends of the main arch ring (402) of the middle section of the steel arch rib and the first section of the steel arch rib (401) so that the corresponding positions of the additional parts (9) correspond; S44, the main hoist (13) and the auxiliary hoist (10) cooperate to continue to drop the main arch ring (402) of the middle section of the steel arch rib, so that the main arch ring (402) of the middle section of the steel arch rib slowly enters the lateral limit plate (901) of the first section of the steel arch rib (401); by adjusting the lifting angles of the main hoist (13) and the auxiliary hoist (10), the two ends of the main arch ring (402) of the middle section of the steel arch rib are parallel to the corresponding cross section of the first section of the steel arch rib (31); continue to drop the main arch ring (402) of the middle section of the steel arch rib until it is completely matched with the upper and lower limit plates (901); by adjusting the lifting of the jack (903) provided in the additional part (9) and the lifting cooperation of the main hoist (13) and the auxiliary hoist (10), the relative position of the main arch ring (402) of the middle section of the steel arch rib and the first section of the steel arch rib (31) is finely adjusted, so that the main arch ring (402) of the middle section of the steel arch rib and the first section of the steel arch rib (401) are accurately matched; S45, welding the horse plate, the two auxiliary cranes (10) exit the operation; connecting the steel strand (15) of the main arch ring (402) in the middle section of the steel arch rib and the temporary anchor (14) in the river channel, and pre-tensioning; the main crane (13) exits the operation; Welding the weld at the connection interface between the main arch ring (402) in the middle section of the steel arch rib and the first section of the steel arch rib (401); S46, the same steps are followed to complete the installation of the main arch ring (402) in the middle section of other steel arch ribs.

6. The method for constructing an urban steel structure arch bridge without a support according to claim 5, characterized in that: In step S6, the length of the steel beam segment (801) includes two sets of slings (17).

Images