A steel-concrete cable tower for a cable-stayed bridge and a construction method thereof

Abstract

The present invention discloses a steel-concrete cable tower of a cable-stayed bridge and a construction method thereof, and belongs to the technical field of cable-stayed bridge cable tower construction. The purpose is to provide a cable-stayed bridge cable tower and a construction method thereof suitable for complex geological conditions and high-intensity earthquake zones. The following technical scheme is adopted, the steel-concrete cable tower of the cable-stayed bridge comprises a main pier, a lower tower column and an upper tower column, and the structure of the main pier steel reinforcement part in the main pier is: four cross-shaped steel columns are located at four corners, and two rows of steel are arranged between two adjacent cross-shaped steel columns, which are inner steel and outer steel; the steel reinforcement part of the lower tower column in the lower tower column comprises a cross-shaped steel column, an inner steel and an outer steel extending upward. The above-mentioned cable tower construction method is: constructing the main pier pedestal; hoisting the cross-shaped steel column; hoisting the I-beam; hoisting the inner steel and outer steel; casting the main pier; the cross-shaped steel column, the inner steel and the outer steel extend upward; casting the lower tower column; casting the upper tower column. The present invention is suitable for the construction of cable-stayed bridge cable towers.

Description

Technical Field

[0001] The invention discloses a cable-stayed bridge steel concrete cable tower and a construction method thereof, belonging to the technical field of cable-stayed bridge cable tower construction. Background Art

[0002] With the development of my country's transportation industry, the construction of mountain bridges and cross-line bridges is increasing, and most of them are affected by the complex geological terrain or existing lines in the mountainous areas. The span of cable-stayed bridges is constantly increasing, so the structural form and construction requirements of cable-stayed bridge towers are more severe challenges.

[0003] As a key component of the entire cable-stayed bridge structure, the cable tower of the cable-stayed bridge transfers the load of the main beam to the foundation through it, playing its role as the main load-bearing structure. The cable tower must have sufficient strength and rigidity to ensure the stability of the entire system and resist possible wind loads and earthquake loads. At the same time, the shape and size of the cable tower have a significant impact on the overall beauty and landscape effect of the entire bridge. Therefore, the design and construction of the cable tower is one of the core of the cable-stayed bridge project, and the key to its design is to ensure the stability, bearing capacity and safety of the bridge.

[0004] For some areas that cross mountainous areas or existing lines and have high seismic fortification intensity, bridge construction faces more problems. When an earthquake occurs, the bridge piers are the first to be impacted. They may deflect, shear off the bearing anchor bolts, cause the bridge section to break or the bridge to collapse. If the soil of the bridge foundation is soft, the degree of damage will be aggravated. For cable-stayed bridges, their towers and piers, as the main load-bearing components, may suffer local failure and serious damage under extreme seismic loads, and typical bending plastic failure will occur, seriously endangering the safety of the bridge structure. Especially for large-span bridges, large displacement responses will occur under strong earthquakes, which may cause damage and destruction to major components such as towers and piers or minor components such as bearings and expansion joints. Studies have shown that even under low seismic loads, the displacement response of the main beam of a large-span cable-stayed bridge is already large, and under extreme earthquakes, the displacement response is further significantly increased. Therefore, the design requirements of the cable towers of cable-stayed bridges in high-intensity earthquake zones should be targeted and improved, and they should have sufficient seismic resistance to cope with seismic loads. Traditional reinforced concrete towers of cable-stayed bridges have a large deadweight, so to meet structural requirements, the foundation design needs to be strengthened. At the same time, due to their strong seismic response, the risk under earthquake action will also increase. Therefore, additional seismic design and reinforcement measures are required for cable-stayed bridge towers. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a steel-concrete cable tower for a cable-stayed bridge suitable for complex geological conditions and high-intensity earthquake zones and a construction method thereof.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a steel-concrete cable tower of a cable-stayed bridge, comprising a main pier and a lower tower column and an upper tower column sequentially arranged above the main pier, wherein the main pier comprises a main pier concrete part and a main pier steel reinforcement part, the main pier steel reinforcement part is located inside the main pier concrete part, the main pier steel reinforcement part comprises a cross-shaped steel column, an I-shaped steel beam, an inner layer of steel and an outer layer of steel, four cross-shaped steel columns are located at four corners, two rows of vertically arranged steel are arranged between two adjacent cross-shaped steel columns, forming a double-layer square ring, the inner layer is the inner layer of steel, the outer layer of steel is located at the outer layer, multiple layers of horizontal I-shaped steel beams are fixed in the vertical direction between the inner layer of steel and the outer layer of steel, each layer of I-shaped steel beams comprises four I-shaped steels, and both ends of the I-shaped steel are fixed to the corresponding cross-shaped steel columns;

[0007] The lower tower column includes a lower tower column concrete part and a lower tower column steel reinforcement part. The lower tower column steel reinforcement part includes a cross-shaped steel column, an inner steel layer and an outer steel layer extending upward into the lower tower column concrete part. Multiple layers of horizontal positioning steel bars are fixed in the vertical direction between the inner steel layer and the outer steel layer. Each layer of positioning steel bars includes four groups of steel bars, and both ends of the steel bars are inserted into the corresponding cross-shaped steel columns.

[0008] Furthermore, the main pier also includes positioning steel plates, four positioning steel plates form a square ring, are located below the cross-shaped steel columns, inner steel sections, and outer steel sections, and are connected to the cross-shaped steel columns, inner steel sections, and outer steel sections through column base bolts pre-welded on the positioning steel plates.

[0009] Furthermore, the lower tower column also includes vertical structural steel bars, which are located inside the concrete part of the lower tower column and inside the square ring formed by the inner layer of steel sections. The vertical structural steel bars are multiple vertically arranged steel bars.

[0010] Furthermore, the inner sides of all the steel sections in the inner layer of steel sections are densely covered with bolts.

[0011] Furthermore, all the steel sections in the inner layer steel sections and the outer layer steel sections are H-shaped steel sections.

[0012] Furthermore, both ends of the I-beam in the I-beam steel beam are arranged on corbel steel plates, and the corbel steel plates are fixed on the cross-shaped steel columns.

[0013] A construction method for a steel-concrete cable tower of a cable-stayed bridge comprises the following steps:

[0014] S1, construct the main pier cap, and then arrange four positioning steel plates in a square ring shape on the main pier cap, wherein the column foot bolts are pre-welded on the positioning steel plates;

[0015] S2, hoist a cross-shaped steel column into place, accurately align the bottom with the corresponding column foot bolts, and adjust the verticality. The other three cross-shaped steel columns are installed in the same way;

[0016] S3, hoist an I-beam between the corresponding two cross-shaped steel columns, adjust the position, weld the two ends of the I-beam to the cross-shaped steel columns, and hoist and weld the remaining three I-beams in the same way to form a layer of I-beams, then weld the position of the I-beam on each cross-shaped steel column, and weld horizontal stiffening ribs between the webs;

[0017] S4, arrange conventional column vertical reinforcement, column stirrups and tie bars around each cross-shaped steel column;

[0018] S5, using the lifting equipment, lifting one layer of inner steel sections into place one by one, connecting them to the positioning steel plate through the column foot bolts, and welding them to the I-beam, and then using the lifting equipment, lifting one layer of outer steel sections into place one by one, connecting them to the positioning steel plate through the column foot bolts, and welding them to the I-beam;

[0019] S6, extend the cross-shaped steel columns, inner steel sections, and outer steel sections upward to the design height layer by layer, and arrange a layer of I-shaped steel beams between each layer of inner steel sections and outer steel sections;

[0020] S7, carry out conventional reinforcement arrangement, set up formwork, pour high-strength concrete, maintain and remove formwork, and complete the construction of the main pier;

[0021] S8, the cross-shaped steel column, the inner layer steel and the outer layer steel are further extended upwards, and a layer of positioning steel bars is arranged between each layer of inner layer steel and outer layer steel. After extending to the design height, vertical structural steel bars are arranged inside the square ring formed by the inner layer steel;

[0022] S9, carry out conventional reinforcement arrangement, set up formwork, pour high-strength concrete, maintain and remove formwork, and complete the construction of the lower tower column;

[0023] S10, continue to construct the upper tower column and other structures of the cable tower to complete the overall construction of the cable tower.

[0024] Furthermore, in S2, after the four cross-shaped steel columns are hoisted and connected to the positioning steel plates, a formwork is set up and high-strength grouting material is filled into the bottom of each cross-shaped steel column to a filling height of 30-60 cm.

[0025] Furthermore, in S3, before lifting the I-beam, the corbel steel plates are first welded at the corresponding positions on the cross-shaped steel column, and then the I-beam is lifted onto the corresponding two corbel steel plates. After the I-beam is bolted to the corbel steel plates, the I-beam is welded to the cross-shaped steel column.

[0026] Furthermore, when the cross-shaped steel columns, inner steel sections and outer steel sections in S8 are extended upward, a layer of cross-shaped steel columns is hoisted first, and then a layer of inner steel sections is hoisted. Then, positioning steel bars are inserted between two adjacent cross-shaped steel columns. Then, a layer of outer steel sections is hoisted, and the inner steel sections and outer steel sections are welded and connected to the positioning steel bars. In the same way, the cross-shaped steel columns, inner steel sections and outer steel sections are extended upward layer by layer to the designed height.

[0027] The structures of the main pier and the lower tower column in the present invention are generally divided into three parts, namely a core concrete part, a steel reinforcement part and an outer concrete part.

[0028] The core concrete part is made of high-strength concrete and is located in the center of the structure. With the support of the steel hoops, it is under three-way compression, which reduces the development of internal microcracks and thus improves the bearing capacity and stability of the overall structure.

[0029] The steel reinforcement part uses steel materials to arrange the core concrete in the annular direction and provide lateral constraints on the core concrete. The steel is arranged in a double layer, extending from the main pier to the lower tower column to improve the integrity of the structure. Positioning steel plates are arranged at the bottom of the steel reinforcement part in the main pier to facilitate the positioning of the steel during construction and improve the stability of the bottom of the structure. The inner layer of the double-layer steel is embedded in the core concrete with bolts, and the outer layer of the steel is arranged on the periphery of the inner layer of the steel, and the whole is built in the outer concrete. The double-layer steel arrangement can make the structure have greater tensile resistance, improve the resistance of the cross section, and at the same time provide sufficient lateral constraints on the core concrete.

[0030] The outer concrete part also uses high-strength concrete to wrap all the built-in parts. The structural steel bars arranged in this part also have certain lateral constraints on the internal structure, improving the integrity of the entire main pier and lower tower column structure.

[0031] In general, the double-layer steel and high-strength concrete are mutually constrained, which improves the strength of each part and increases the ductility of the structure and components, thereby improving the brittle characteristics that are not conducive to earthquake resistance due to the poor ductility of the concrete itself. Various types of ordinary steel bars are also configured in various parts of the structure. The structure composed of ordinary steel bars and double-layer steel will form two lines of protection under the action of earthquakes. Even in the case of spalling of the outer concrete, the part composed of double-layer steel and core concrete still has strong earthquake resistance.

[0032] From the above analysis, it can be seen that the entire cable tower in the present invention has superior stress-bearing performance and stronger earthquake resistance, and is suitable for the construction of cable-stayed bridge cable towers in complex geological conditions or high-intensity fortification areas.

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

[0034] The present invention focuses on the design of steel-concrete at the main pier and lower tower column of the cable tower, which improves the stress-bearing performance of the entire cable tower and can well resist the maximum in-plane bending moment generated at the root section of the cable tower under earthquake load, making it have higher seismic resistance. In addition, the design of steel-concrete allows the cross-section of the cable tower to be made smaller than that of the existing technology, saving the construction cost of the cable-stayed bridge while reducing the deadweight of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0036] Figure 1 It is a structural schematic diagram of the cable tower in the present invention.

[0037] Figure 2 It is a schematic diagram of the external structure of the main pier in the present invention.

[0038] Figure 3 The structural diagram of the main pier steel reinforcement part in the present invention is shown in FIG. Figure 1 .

[0039] Figure 4 The structural diagram of the main pier steel reinforcement part in the present invention is shown in FIG. Figure 2 .

[0040] Figure 5 The structure diagram of the lower column steel reinforcement part of the present invention is shown in FIG. Figure 1 .

[0041] Figure 6 The structure diagram of the lower column steel reinforcement part of the present invention is shown in FIG. Figure 2 .

[0042] In the figure: 1 is the main pier, 11 is the concrete part of the main pier, 12 is the steel reinforcement part of the main pier, 121 is the cross steel column, 122 is the I-beam, 123 is the inner steel, 124 is the outer steel, 125 is the bolt, 13 is the positioning steel plate, 14 is the column foot bolt, 2 is the lower tower column, 21 is the concrete part of the lower tower column, 22 is the steel reinforcement part of the lower tower column, 221 is the positioning steel bar, 23 is the vertical structural steel bar, 3 is the upper tower column, and 4 is the main pier cap. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The present invention provides the following embodiments.

[0045] like Figure 1-Figure 4 As shown, a steel-concrete cable tower of a cable-stayed bridge of the present invention comprises a main pier 1 and a lower tower column 2 and an upper tower column 3 sequentially arranged above the main pier 1. The main pier 1 comprises a main pier concrete part 11 and a main pier steel reinforcement part 12. The main pier steel reinforcement part 12 is located inside the main pier concrete part 11. The main pier steel reinforcement part 12 comprises a cross-shaped steel column 121, an I-shaped steel beam 122, an inner layer steel 123 and an outer layer steel 124. The four cross-shaped steel columns 121 is located at the four corners, and two rows of vertically arranged steel sections are arranged between two adjacent cross-shaped steel columns 121, forming a double-layer square ring, the inner layer is the inner layer steel section 123, and the outer layer is the outer layer steel section 124. Multiple layers of horizontal I-beams 122 are fixed in the vertical direction between the inner layer steel section 123 and the outer layer steel section 124, and each layer of I-beams 122 includes four I-beams, and both ends of the I-beams are fixed to the corresponding cross-shaped steel columns 121;

[0046] like Figure 5 , Figure 6 As shown, the lower tower column 2 includes a lower tower column concrete part 21 and a lower tower column steel reinforcement part 22. The lower tower column steel reinforcement part 22 includes a cross-shaped steel column 121, an inner steel layer 123 and an outer steel layer 124 extending upward into the lower tower column concrete part 21. Multiple layers of horizontal positioning steel bars 221 are fixed in the vertical direction between the inner steel layer 123 and the outer steel layer 124. Each layer of positioning steel bars 221 includes four groups of steel bars, and both ends of the steel bars are inserted into the corresponding cross-shaped steel columns 121.

[0047] The functions of the I-beam 122 and the positioning steel bars 221 are to increase the structural stability and facilitate the arrangement of the remaining structural steel bars. The remaining structural steel bars can be designed and constructed according to the construction specifications.

[0048] The main pier 1 further includes a positioning steel plate 13, four positioning steel plates 13 forming a square ring, which are located below the cross-shaped steel column 121, the inner steel 123, and the outer steel 124, and are connected to the cross-shaped steel column 121, the inner steel 123, and the outer steel 124 through column foot bolts 14 pre-welded on the positioning steel plates 13. The positioning steel plates 13 use the pre-welded column foot bolts 14 to position the inner steel 123 and the outer steel 124, which facilitates construction and improves the stability of the bottom of the structure.

[0049] The lower tower column 2 also includes vertical structural steel bars 23, which are located inside the lower tower column concrete part 21 and inside the square ring formed by the inner layer of steel sections 123. The vertical structural steel bars 23 are multiple vertically arranged steel bars. The main pier 1 and the lower tower column 2 are tied with conventional ordinary steel bars such as column vertical steel bars, column stirrups, tie bars, and vertical structural steel bars 23 in accordance with the construction specifications. The structure composed of ordinary steel bars and steel reinforcement parts will form two lines of protection under the action of earthquakes. In the case of peeling of the outer layer of concrete, the part composed of steel sections and core concrete still has strong earthquake resistance.

[0050] The inner sides of all the steel sections in the inner layer steel section 123 are densely covered with studs 125. The studs 125 make the inner layer steel section 123 and the core concrete part firmly combined.

[0051] All the steel sections in the inner steel section 123 and the outer steel section 124 are I-beams.

[0052] Both ends of the I-beam in the I-beam beam 122 are arranged on the corbel steel plates, and the corbel steel plates are fixed on the cross-shaped steel column 121. The arrangement of the corbel steel plates facilitates the positioning and construction of the I-beam beam 122.

[0053] In the present invention, the overall height of the cross-shaped steel column 121, the inner steel layer 123, and the outer steel layer 124 are all very high and are generally not integrated. In the description of the present invention, the cross-shaped steel column 121, the inner steel layer 123, and the outer steel layer 124 extend upward, which means that they are hoisted, connected, and welded one by one with steel sections of the same specifications.

[0054] A construction method for a steel-concrete cable tower of a cable-stayed bridge comprises the following steps:

[0055] S1, construct the main pier cap 4, and then arrange four positioning steel plates 13 in a square ring shape on the main pier cap 4, and the column foot bolts 14 are pre-welded on the positioning steel plates 13;

[0056] S2, hoist a cross-shaped steel column 121 into place, accurately align the bottom with the corresponding column foot bolt 14, and adjust the verticality, and install the other three cross-shaped steel columns 121 in sequence in the same way;

[0057] S3, hoist an I-beam between the corresponding two cross-shaped steel columns 121, adjust the position, weld the two ends of the I-beam to the cross-shaped steel column 121, and hoist and weld the remaining three I-beams in the same way to form a layer of I-beam beams 122, then weld the position of the I-beam beam on each cross-shaped steel column 121, and weld horizontal stiffening ribs between the webs;

[0058] S4, arranging conventional column vertical reinforcement, column stirrups and tension bars around each cross-shaped steel column 121;

[0059] S5, using the lifting equipment, lift one layer of inner steel sections 123 into place one by one, connect them to the positioning steel plate 13 through the column foot bolts 14, and weld them to the I-beam 122, then use the lifting equipment to lift one layer of outer steel sections 124 into place one by one, connect them to the positioning steel plate 13 through the column foot bolts 14, and weld them to the I-beam 122;

[0060] S6, extending the cross-shaped steel column 121, the inner layer steel 123, and the outer layer steel 124 upward to the designed height layer by layer, and arranging a layer of I-shaped steel beam 122 between each layer of inner layer steel 123 and outer layer steel 124 during the extension;

[0061] S7, arrange conventional reinforcement, set up formwork, pour high-strength concrete, maintain and remove formwork, and complete the construction of main pier 1;

[0062] S8, the cross-shaped steel column 121, the inner layer steel 123 and the outer layer steel 124 are further extended upwards. During the extension, a layer of positioning steel bars 221 is arranged between each layer of the inner layer steel 123 and the outer layer steel 124. After the extension reaches the designed height, vertical structural steel bars 23 are arranged inside the square ring formed by the inner layer steel 123;

[0063] S9, perform conventional reinforcement arrangement, set up formwork, pour high-strength concrete, maintain and remove formwork, and complete the construction of lower tower column 2;

[0064] S10, continue to construct the upper tower column 3 and other structures of the cable tower to complete the overall construction of the cable tower.

[0065] In order to increase the strength and stability of the bottom of the structure, in S2, the four cross-shaped steel columns 121 are hoisted and connected to the positioning steel plate 13, and then a template is set up to fill the bottom of each cross-shaped steel column 131 with high-strength grouting material, with a filling height of 30-60 cm.

[0066] In order to facilitate the positioning and construction of the I-beam 122, in S3, before lifting the I-beam, the corbel steel plates are first welded at the corresponding positions on the cross-shaped steel column 121, and then the I-beam is hoisted to the corresponding two corbel steel plates. After the I-beam is bolted to the corbel steel plates, the I-beam is welded to the cross-shaped steel column 121.

[0067] When the cross-shaped steel column 121, the inner steel 123 and the outer steel 124 in S8 are extended upward, a layer of cross-shaped steel column 121 is hoisted first, and then a layer of inner steel 123 is hoisted. Then, the positioning steel bars 221 are inserted between two adjacent cross-shaped steel columns 121, and then a layer of outer steel 124 is hoisted. The inner steel 123 and the outer steel 124 are welded and connected to the positioning steel bars 221. In the same way, the cross-shaped steel column 121, the inner steel 123 and the outer steel 124 are extended upward layer by layer to the designed height.

[0068] The high-strength concrete described in the present invention refers to C50-C80 grade concrete prepared by conventional process using cement, sand, stone, high-efficiency water reducing agent and other admixtures and mineral admixtures such as fly ash, ultrafine slag, silica fume, etc. in accordance with the provisions of the Technical Specifications for High-Strength Concrete Structures. The high-strength grouting material is prepared with high-strength materials as aggregates, cement as a binder, and supplemented with high-fluidity, micro-expansion, anti-segregation and other materials, and the compressive strength can reach more than 20Mpa within one day.

[0069] The structure and construction method of the present invention have a wide range of applications and can be applied to the construction of most existing cable towers (single column, double column, A-shaped, H-shaped, etc.), solid section cable towers, and hollow box section cable towers. Conventional support formwork and concrete pouring are sufficient. Figure 1 The cable tower shown is only one embodiment of the present invention. The present invention focuses on reinforcing the main pier 1 and the lower tower column 2. The upper tower column 3 can be constructed in the form of conventional reinforced concrete, or the steel reinforcement part can be further extended into the upper tower column 3. During the construction of S6 and S8, if there is an inclination, when the cross-shaped steel column 121, the inner layer steel 123, and the outer layer steel 124 are extended upward for construction, according to the change of the shape angle, the upper and lower layers of steel connection parts are cut obliquely, and multiple sections are spliced ​​to adapt to the shape angle.

[0070] The cable-stayed rotating bridge over the Beitongpu Railway on the second section of the east extension of Xinyang Street in Yangqu County, which is currently under construction, has half of its main piers located on the steep slope between the Beitongpu Railway and the Zhongshe Reservoir, and half located in the Zhongshe Reservoir, with extremely complex site conditions. In addition, the soil at the bridge site is soft, the soil has a high water content, the groundwater level is high, the silt layer is thick, the geology is complex, and the bridge also needs to have good seismic safety performance. When constructing its main piers and the lower column, the structure and construction method of the present invention were used, and the structure and construction method of the present invention can well meet the requirements of the cable tower for its complex terrain and seismic performance.

[0071] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. The construction method of the steel-concrete cable tower of the cable-stayed bridge is characterized by: The following steps are involved: S1, construct the main pier cap, and then arrange four positioning steel plates in a square ring shape on the main pier cap, wherein the column foot bolts are pre-welded on the positioning steel plates; S2, hoist a cross-shaped steel column into place, accurately align the bottom with the corresponding column foot bolts, and adjust the verticality. The other three cross-shaped steel columns are installed in the same way; S3, hoist an I-beam between the corresponding two cross-shaped steel columns, adjust the position, weld the two ends of the I-beam to the cross-shaped steel columns, and hoist and weld the remaining three I-beams in the same way to form a layer of I-beams, then weld the position of the I-beam on each cross-shaped steel column, and weld horizontal stiffening ribs between the webs; S4, arrange conventional column vertical reinforcement, column stirrups and tie bars around each cross-shaped steel column; S5, using the lifting equipment, lifting one layer of inner steel sections into place one by one, connecting them to the positioning steel plate through the column foot bolts, and welding them to the I-beam, and then using the lifting equipment, lifting one layer of outer steel sections into place one by one, connecting them to the positioning steel plate through the column foot bolts, and welding them to the I-beam; S6, extending the cross-shaped steel column, the inner layer steel and the outer layer steel upwards layer by layer to the design height, and arranging a layer of I-shaped steel beam between each layer of inner layer steel and outer layer steel during the extension; S7, carry out conventional reinforcement arrangement, set up formwork, pour high-strength concrete, maintain and remove formwork, and complete the construction of the main pier; S8, the cross-shaped steel column, the inner layer steel and the outer layer steel are further extended upwards. During the extension, a layer of positioning steel bars is arranged between each layer of the inner layer steel and the outer layer steel. After the extension reaches the designed height, vertical structural steel bars are arranged inside the square ring formed by the inner layer steel; S9, carry out conventional reinforcement arrangement, set up formwork, pour high-strength concrete, maintain and remove formwork, and complete the construction of the lower tower column; S10, continue to construct the upper tower column and other structures of the cable tower to complete the overall construction of the cable tower; The steel-concrete cable tower of the cable-stayed bridge comprises a main pier and a lower tower column and an upper tower column sequentially arranged above the main pier, wherein the main pier comprises a main pier concrete part and a main pier steel reinforcement part, wherein the main pier steel reinforcement part is located inside the main pier concrete part, and the main pier steel reinforcement part comprises a cross-shaped steel column, an I-shaped steel beam, an inner layer of steel and an outer layer of steel, wherein four cross-shaped steel columns are located at four corners, and two rows of vertically arranged steel are arranged between two adjacent cross-shaped steel columns to form a double-layer square ring, wherein the inner layer is the inner layer of steel, and the outer layer of steel is the outer layer of steel, and multiple layers of horizontal I-shaped steel beams are fixed in the vertical direction between the inner layer of steel and the outer layer of steel, wherein each layer of I-shaped steel beams comprises four I-shaped steels, and both ends of the I-shaped steel are fixed to corresponding cross-shaped steel columns; The lower tower column includes a lower tower column concrete part and a lower tower column steel reinforcement part. The lower tower column steel reinforcement part includes a cross-shaped steel column, an inner steel layer and an outer steel layer extending upward into the lower tower column concrete part. Multiple layers of horizontal positioning steel bars are fixed in the vertical direction between the inner steel layer and the outer steel layer. Each layer of positioning steel bars includes four groups of steel bars, and both ends of the steel bars are inserted into the corresponding cross-shaped steel columns.

2. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1, characterized in that: In S2, after the four cross-shaped steel columns are hoisted and connected with the positioning steel plates, a formwork is set up and high-strength grouting material is filled into the bottom of each cross-shaped steel column to a filling height of 30-60 cm.

3. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1 or 2, characterized in that: In S3, before lifting the I-beam, the corbel steel plates are first welded to the corresponding positions on the cross-shaped steel column, and then the I-beam is hoisted to the corresponding two corbel steel plates. After the I-beam is bolted to the corbel steel plates, the I-beam is welded to the cross-shaped steel column.

4. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1 or 2, characterized in that: When the cross-shaped steel columns, inner steel sections and outer steel sections in S8 are extended upward, a layer of cross-shaped steel columns is hoisted first, and then a layer of inner steel sections is hoisted. Then, positioning steel bars are inserted between two adjacent cross-shaped steel columns, and then a layer of outer steel sections is hoisted. The inner steel sections and the outer steel sections are welded and connected to the positioning steel bars. The cross-shaped steel columns, inner steel sections and outer steel sections are extended upward layer by layer to the designed height in the same way.

5. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1 or 2, characterized in that: The main pier in the steel-concrete tower of the cable-stayed bridge also includes positioning steel plates. Four positioning steel plates form a square ring and are located below the cross-shaped steel columns, inner-layer steel sections, and outer-layer steel sections. The positioning steel plates are connected to the cross-shaped steel columns, inner-layer steel sections, and outer-layer steel sections through column foot bolts pre-welded on the positioning steel plates.

6. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1 or 2, characterized in that: The lower tower column in the steel-concrete cable tower of the cable-stayed bridge also includes vertical structural steel bars, which are located inside the concrete part of the lower tower column and inside the square ring formed by the inner layer of steel. The vertical structural steel bars are multiple vertically arranged steel bars.

7. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1 or 2, characterized in that: All the steel sections in the inner layer are densely covered with bolts on the inner side.

8. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 1 or 2, characterized in that: All the steel sections in the inner layer steel sections and the outer layer steel sections are H-shaped steel sections.

9. The construction method of the steel-concrete cable tower of a cable-stayed bridge according to claim 3, characterized in that: Both ends of the I-beam in the I-beam steel beam are arranged on corbel steel plates, and the corbel steel plates are fixed on the cross-shaped steel columns.

Images