CN111472285A - A method for installing the main bridge variable-section continuous steel truss girder using cable crane - Google Patents

Abstract

The invention discloses a method for installing a main bridge variable cross-section continuous steel truss girder by using a cable crane, which belongs to the field of bridges and comprises the following steps: firstly, constructing a pier top steel truss girder; then, girder cantilever assembling construction is carried out: symmetrically suspending steel truss girder segments on two sides of each main pier by using a cable crane through cantilevers, and installing the steel truss girder segments; arranging a parallel connection concrete slab at the steel truss girder segment, and constructing second steel truss girder segments of each main pier; after the third steel truss girder sections of each main pier are connected, concrete is poured into the steel truss girder rod piece of the section; after the concrete in the member reaches the requirement, the construction of the next steel truss girder segment of each main pier is carried out, and the construction of the midspan is stopped when the midspan is constructed to the front segment of the closure segment; and finally, the side span and the mid span are folded, and by adopting the scheme, the acting force of a bridge deck crane on the steel truss girder is avoided, the stress of a pier-girder joint part is reduced, and symmetrical cantilever assembly can be realized for each bridge main pier, so that the construction working face is increased, and the construction progress is accelerated.

Description

A method for installing the main bridge variable-section continuous steel truss girder using cable crane

technical field

The invention relates to the technical field of bridge construction, and more particularly, to a method for installing a main bridge variable-section continuous steel truss girder using a cable crane.

Background technique

Due to the large spanning capacity of the long-span variable-section steel truss girder continuous rigid-frame bridge and the light weight of the superstructure, it is a reasonable bridge structure for spanning deep ravines and rivers. However, due to the limitations of terrain conditions, these bridges are often difficult to install with large cranes, and it is more difficult for large transport vehicles to reach each construction work surface.

At present, the traditional construction technology of continuous rigid frame bridges at home and abroad generally adopts the jacking (pulling) method and the bridge deck crane cantilever assembly method; for long-span steel truss bridges, if the cantilever is too large, the main beam cannot meet the force requirements, generally Temporary buttresses need to be set up between spans or cantilever assembly is carried out using the method of cable-stayed buckles.

The current main bridge is a continuous rigid frame bridge with variable cross-section steel truss girder, and its approach bridges on both sides are long, and the approach bridges are located on the curve. It is still unsolved at home and abroad which process should be used for the construction of such bridges. Factors such as the variable-section steel truss girder, the long approach bridge and its location on the curve determine that the installation of the main girder is not suitable for traditional construction methods such as jacking. Even if the jacking method can be used, there is no rear balance section for mountain bridges. It is also very difficult to set up temporary piers at the same time. If the bridge deck crane is used for cantilever assembly construction, the weight of the bridge deck crane will not only increase the force on the pier-girder joint, but also the components will be transported horizontally and vertically from the assembly yard to the construction work surface. Also very difficult. Therefore, what kind of device is used to construct the main bridge part of such a bridge is a problem that needs to be solved urgently at present.

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, and to provide a method for installing the main bridge variable-section continuous steel truss girder by using a cable crane. By adopting this solution, the effect of the weight of the bridge deck crane on the main truss girder is eliminated. It reduces the stress on the pier-beam junction during the construction process, making the construction safer, and can achieve symmetrical cantilever assembly relative to the main pier of each bridge, without the need for balancing weights and increasing the construction work surface, speeding up the construction. schedule.

Technical solutions

In order to achieve the above object, the technical scheme provided by the invention is:

A method for installing a main bridge variable-section continuous steel truss girder using a cable crane according to the present invention, the steps are as follows:

(1) First complete the installation of the steel truss girder members in the embedded section at the top of the No. 4 main pier, the No. 5 main pier and the No. 6 main pier, and complete the connection of the rest of the steel truss girder members in this section at the top of each main pier. Then pour concrete for the lower chord of the steel truss girder section at the top of the pier according to the design requirements, and then complete the steel truss girder construction of this section at the top of the pier;

(2) Main beam cantilever assembly construction

①. Transport the prefabricated rod segments in the factory to the lifting platform for assembly and welding of steel truss girder segments;

②. Symmetrically hoist the steel truss girder sections on both sides of the No. 4 main pier, on both sides of the No. 5 main pier, and on both sides of the No. 6 main pier with a cable crane, and carry out the steel truss girder sections at each main pier respectively. Positioning and connection; after the connection of the steel truss girder section of this section at each main pier is completed, the lower parallel concrete slab is poured on the steel truss girder section of this section of each main pier to complete the first cantilever of the main girder. Construction of steel truss girder segments;

3. After the lower parallel concrete slab reaches the design strength, carry out the hoisting, positioning and connection of the next steel truss girder section on both sides of each main pier to complete the construction of the second steel truss girder section of the main beam cantilever;

④. After the connection of the third steel truss girder section of the main beam cantilever of each main pier is completed, pour concrete in the steel truss girder member of this section;

⑤. After the concrete in the above-mentioned steel truss girder members reaches the design strength, the next steel truss girder section of the main beam cantilever of each main pier is symmetrically constructed, and the middle span is constructed to the previous steel truss girder section of the closing section. stop for a while;

(3) Complete the side span and middle span closing

①, install the main beam support on the top of the transition pier on both sides;

②. Continue to construct side span to side span closed;

③. First close the mid-span between No. 4 main pier and No. 5 main pier; then close the mid-span between No. 5 main pier and No. 6 main pier.

As a further improvement of the present invention, the cable crane includes a main anchor shaft, a main load-bearing cable, a wind cable, a hoisting trolley, a cable saddle, a left bank tower and a right bank tower;

There are two main anchors on the left and right banks, and the two main anchors on each bank are symmetrically arranged on both sides of the center line of the main bridge of the bridge, and are arranged corresponding to the left and right bridges respectively;

The towers on the left bank and the towers on the right bank are respectively set on the tops of the transition piers on the corresponding banks, and two sets of cable saddles that can be moved laterally are arranged on the towers on the left bank and the tower on the right bank. There are tower cranes on one side;

A set of main load-bearing cables are arranged between the two cable saddles corresponding to the two banks. work order;

The main load-bearing cable is provided with a hoisting trolley, and the hoisting trolley is provided with a traction cable and a hoisting cable. On the traction winch and the hoisting winch;

Wherein, the left bank tower includes an upper tower and a lower tower, a tower foot hinge is provided between the two branches of the upper tower and the lower tower, and between the two branches of the lower tower and the transition pier Both are provided with a portal pier, the portal pier is consolidated with the pier top of the transition pier, and the left bank tower has the same structure as the right bank tower.

As a further improvement of the present invention, the included angle between the rear cable of the main load-bearing cable on the left bank and the horizontal plane is 20.4º, and the included angle between the rear cable of the main bearing cable on the right bank and the horizontal plane is 13.64º;

The bridge includes a curved section and a straight section, wherein the approach bridge on the left bank and the main bridge are straight sections, the approach bridge on the right bank is a curved section, and the transition pier on the right bank is the transition point between the curved section and the straight section, and the direction of the center line of the main bridge of the bridge is is the direction of the longitudinal axis of the cable crane. The included angle between the longitudinal axis of the cable crane and the horizontal axis of the transition pier on the right bank is 89.25°, and the center of the tower on the right bank is 0.335 meters upstream from the vertical centerline of the transition pier on the right bank.

As a further improvement of the present invention, a lifting platform is provided below the main bridge of the bridge.

As a further improvement of the present invention, the tower foot hinge includes three V-shaped brackets arranged in parallel with each other, wherein a base is hinged at the top corner of each V-shaped bracket, and the opening of each V-shaped bracket is provided with a base. There is a steel box girder I, both ends of each steel box girder I protrude from the V-shaped bracket to form a protruding part, and the lower end surface of the protruding part is provided with a vertical downward connecting side ear. Connecting rods are arranged between both ends of the steel box girder I, and reinforcing connecting rods are arranged between the corresponding arms of the adjacent V-shaped brackets;

The base of the tower hinge is fixed on the top of the lower tower, and the bottom of the upper tower is connected with the steel box girder I.

As a further improvement of the present invention, the portal pier frame includes four vertical columns II fixed on the top of the transition pier pier, and the connecting lines of the four vertical columns II together form a rectangular structure, and the The upper part is connected by a flange with a column I, and the ends of the four columns I away from the transition pier are connected end to end by two steel box girders II and two connecting plates. Among them, the two steel box girders II are along the centerline of the main bridge The two connecting plates are arranged in the direction perpendicular to the centerline of the main bridge of the bridge;

Two horizontal connecting plates and an oblique connecting plate I are arranged between the two vertical columns II and the two vertical columns I along the direction perpendicular to the centerline of the main bridge of the bridge, wherein the two horizontal connecting plates between the two vertical columns I and an oblique connecting plate I to form a "Z" shape; the two horizontal connecting plates between the two columns II and an oblique connecting plate I form a reverse "Z" shape;

There are horizontal support tubes and diagonal support tubes between the two columns II and the two columns I along the centerline of the main bridge of the bridge. The horizontal support tube between the two columns I and the two diagonal support tubes form a triangle, and the two One end of each oblique support tube is connected to the column I, and the other end is connected to the steel box girder II obliquely upward.

As a further improvement of the present invention, an oblique connecting plate II is provided between the two horizontal support tubes on the column I, and an oblique connecting plate II is also provided between the two horizontal support tubes on the column II, and the two The inclined connecting plates II are arranged to cross each other.

As a further improvement of the present invention, the upper tower and the lower tower of the left bank tower are respectively provided with four left bank rear wind cables and four left bank front wind cables, and four left bank upstream transverse cables are arranged on the left bank tower. Wind cable and cross wind cable downstream of Erdao Left Bank;

The upper tower and the lower tower of the right bank tower are respectively provided with four right bank front wind cables and four right bank rear wind cables, and four inclined front wind cables are also arranged on the upper tower on the right bank. Four right-bank upstream cross-wind cables and two right-bank downstream cross-wind cables are set up on the frame;

Among them, the four left-bank front wind cables on the tower on the left bank and the four right-bank front wind cables on the tower on the right bank are ventilation cables that are pulled toward each other by the tower tops on both banks.

beneficial effect

Adopting the technical scheme provided by the present invention, compared with the prior art, has the following remarkable effects:

(1) A method of using a cable crane to install a continuous steel truss girder of the main bridge with a variable cross-section of the present invention adopts the cable crane to carry out the construction of the continuous steel truss girder, which has the following advantages: The acting force of the main bridge steel truss girder reduces the stress on the pier-girder joint during the construction process, thereby making the construction safer; ②. Symmetrical cantilever assembly can be realized relative to the main pier of each bridge, without the need for balance weights ; 3. There are two symmetrical construction work surfaces relative to each main pier, which increases the construction work surface, thereby speeding up the construction progress; 4. The use of cable cranes for construction facilitates the vertical and horizontal transportation of components.

(2) A method of using a cable crane to install a continuous steel truss girder of a main bridge with a variable cross-section of the present invention, wherein a portal pier with a net height of 10m is designed on the basis of the existing tower. The frame and the pier top of the transition pier are consolidated. When constructing the approach bridge bent pier, the end of the approach bridge bent pier can be extended into the interior of the portal pier frame, thus effectively avoiding the construction of the tower on the pier top approach bridge bent pier. and through reasonable structural design, the portal pier can meet the requirements of the overall stability of the entire tower. At the same time, the two portal piers on the transition pier are respectively arranged at both ends of the transition pier without affecting the main bridge. Installation of steel truss girders and approach bridge deck girders.

(3) A method of installing a continuous steel truss girder with variable cross-section of a main bridge using a cable crane of the present invention, wherein a tower foot hinge is provided between the two branches of the upper tower and the lower tower, that is, the upper tower The hinged connection between the frame and the lower tower is realized. By setting the upper part of the tower into a mast type, the horizontal load on the top of the tower generated by the cable system can be overcome by the front and rear wind cables of the tower, and the transition pier mainly bears the transmission of the tower. Therefore, the excessive bending moment of the transition pier can be effectively avoided.

Description of drawings

FIG. 1 is a front view of a cable crane in the present invention;

Figure 2 is a top view of a cable crane in the present invention;

3 is a front view of the towers on both banks of the present invention;

4 is a side view of the towers on both banks of the present invention;

Fig. 5 is the enlarged view of A place in Fig. 3;

Fig. 6 is the front view of tower foot hinge in the present invention;

Fig. 7 is the side view of tower foot hinge in the present invention;

Fig. 8 is the top view of tower foot hinge in the present invention;

Fig. 9 is the front view of the portal pier in the present invention;

Figure 10 is a side view of a portal pier in the present invention;

Fig. 11 is the top view of the portal pier in the present invention;

Figure 12 is a view along the direction B-B in Figure 10;

Figure 13 is a view along the C-C direction in Figure 10;

Figure 14 is an enlarged view of the transition pier on the right bank;

Fig. 15 is a construction sequence diagram for installing a continuous steel truss girder with variable cross-section of the main bridge using a cable crane according to the present invention.

Description of the labels in the diagram:

001, No. 4 main pier; 002, No. 5 main pier; 003, No. 6 main pier;

01. Main anchor; 02. Main load-bearing cable; 03. Towing cable; 04. Lifting cable;

05. Left bank tower; 51. Upper tower;

52, tower foot hinge; 521, base; 522, connecting rod; 523, V-shaped bracket; 524, steel box girder I; 525, connecting side ear; 526, strengthening connecting rod;

53. Lower tower;

54, portal pier; 541, steel box girder II; 542, connecting plate; 543, column I; 544, column II; 545, horizontal support pipe; 546, oblique support pipe; 547, horizontal connecting plate; 548, Oblique connecting plate I; 549, Oblique connecting plate II;

061, left bank rear wind cable; 062, left bank front wind cable; 063, left bank upstream cross wind cable; 064, left bank downstream cross wind cable; 065, right bank upstream cross wind cable; 066, right bank downstream cross wind cable; 067, right bank front Wind cable; 068, right bank rear wind cable;

07, right bank tower; 08, lifting platform; 09, tower crane; 010, transition pier; 011, approach bridge bent pier.

Detailed ways

In order to further understand the content of the present invention, the present invention will be described in detail with reference to the accompanying drawings and embodiments.

Example 1

As shown in Figures 1 and 2, a cable crane in this embodiment includes a main anchor 01, a main load-bearing cable 02, a wind cable, a hoisting trolley, a cable saddle and a tower, the tower including a left bank tower Frame 05 and right bank tower 07; wherein, two main anchors 01 are provided on the left and right banks, and the two main anchors 01 on each bank are symmetrically arranged on both sides of the center line of the main bridge of the bridge, and are arranged corresponding to the left and right bridges respectively. The main anchors 01 are arranged facing the center line of the left and right bridges respectively, and each main anchor 01 is 8.5m away from the longitudinal axis of the cable crane (the center line of the main bridge of the bridge), and the main anchors 01 on both sides of the bank adopt reinforced concrete pile foundation caps Structural anchorage.

It should be noted that in this embodiment, the bridge includes a curved section and a straight section, wherein the approach bridge on the left bank and the main bridge are straight sections, the approach bridge on the right bank is a curved section, and the transition pier 010 on the right bank is the transition point between the curved section and the straight section, The direction of the center line of the main bridge of the bridge is the direction of the longitudinal axis of the cable crane. As shown in Figure 14, the angle a between the longitudinal axis of the cable crane and the horizontal axis of the transition pier 010 on the right bank is 89.25°, and the tower on the right bank is 89.25°. The center of 07 deviates from the vertical centerline of the transition pier 010 on the right bank by 0.335 meters upstream. As shown in Figure 2, the approach bridge on the right bank bends downstream. It should be noted here that the upstream and downstream in this embodiment represent the river under the span of the main bridge. upstream and downstream.

The towers 05 on the left bank and the towers 07 on the right bank are respectively arranged on the tops of the transition piers 010 on the corresponding banks. In this embodiment, the towers are arranged on the tops of the transition piers 010 on both banks, which reduces the span of the cable system and the tower. This arrangement not only greatly saves the construction cost and speeds up the construction progress, but also ensures the construction safety of the cable crane applied to the long-span, variable-section steel truss continuous rigid-frame bridge.

The left bank tower 05 and the right bank tower 07 are provided with two sets of cable saddles that can be moved laterally, and the cable saddles can be moved laterally under no-load conditions to meet the needs of different installation positions of the main girder trusses of the left and right bridges, and The tower crane 09 is provided on one side of the tower 05 on the left bank and the tower 07 on the right bank; among them, a group of main load-bearing cables 02 are arranged between the two cable saddles corresponding to the two banks, and the two ends of the main load-bearing cables 02 are respectively extended outward and fixed. On the main anchors 01 corresponding to the two banks, and corresponding to a group of main load-bearing cables 02, a set of working cables is provided. The angle between the rear stay cable of the main load-bearing cable 02 on the right bank and the horizontal plane is 13.64º. In addition, a lifting platform 08 is arranged under the main bridge of the bridge. Specifically, the lifting platform in this embodiment is set on the main bridge in the assembly welding yard. In the position directly below, after the steel structure has been tailor-welded in this group and has been inspected to meet the quality requirements, it will be transported to just below the main load-bearing cable 02 by the on-site crane, and then lifted and installed by the cable crane; There is a hoisting trolley. The hoisting trolley is provided with a traction cable 03 and a lifting cable 04. The traction cable 03 and the lifting cable 04 pass through the traction pulley and the lifting pulley on the saddle respectively, and are connected to the traction winch on the corresponding bank. , on the hoisting winch.

As shown in FIG. 3 , FIG. 4 and FIG. 5 , the left bank tower 05 in this embodiment includes an upper tower 51 and a lower tower 53 , and a tower foot is provided between the two branches of the upper tower 51 and the lower tower 53 A portal pier 54 is provided between the hinge 52, the two branches of the lower tower 53 and the transition pier 010, the portal pier 54 is consolidated with the pier top of the transition pier 010, and the two portal piers 54 are respectively consolidated At both ends of the transition pier 010, the left bank tower 05 and the right bank tower 07 have the same structure. Specifically, the height of the left bank tower 05 in this embodiment is 74.69m, and the height of the right bank tower 07 is 80.69m.

In this embodiment, the reasonable arrangement of the wind cables ensures the stability of the entire cable system even if the approach bridge of the bridge is long. The upper tower 51 and the lower tower 53 of the left bank tower 05 are provided Four left bank rear wind cables 061 and four left bank front wind cables 062, four left bank upstream cross wind cables 063 and two left bank downstream cross wind cables 064 are also set on the left bank tower 05; on the upper tower of the right bank tower 07 51. Four right bank front wind cables 067 and four right bank rear wind cables 068 are respectively set on the lower tower 53. Since the right bank front wind cables 067 and right bank rear wind cables 068 on the upper tower 51 on the right bank are both longer, the opposite to the tower The frame restraint ability is weak, so in this embodiment, four inclined front wind cables are also set on the upper tower 51 on the right bank, and four right bank upstream cross wind cables 065 and two right bank downstream cross wind cables 066 are set on the right bank tower 07 ; Among them, the four left-bank front wind cables 062 on the tower 51 on the left bank and the four right-bank front wind cables 067 on the tower 51 on the right bank are the ventilation cables pulled by the tower tops on both sides, and the rear wind cables on both banks are anchored On the main anchorage 01, the front wind cable (excluding the paired ventilation cable) and the cross wind cable are separately provided with anchors for anchoring.

In this embodiment, in order to avoid the interference between the upstream cross-wind cables on both banks and the tower crane 09, the four left-bank upstream cross-wind cables 063 on the left-bank tower 05 and the four right-bank upstream cross-wind cables 065 on the right-bank tower 07 are divided into two It is a group, and the two groups are separated into eight-shaped wind cables, and each group is arranged with anchors according to a single pile, and the two groups are symmetrically arranged about 20 meters apart from the transverse axis of the tower.

As shown in FIG. 6 , FIG. 7 and FIG. 8 , in particular, the tower hinge 52 in this embodiment includes three V-shaped brackets 523 arranged in parallel with each other, wherein a base is hinged at the top corner of each V-shaped bracket 523 521, the opening of each piece of V-shaped bracket 523 is provided with a steel box beam I524, both ends of each steel box beam I524 protrude from the V-shaped bracket 523 to form a protruding part, and the lower end surface of the protruding part is provided with Vertically downward connecting side lugs 525, it should be noted that the connecting side lugs 525 are used to connect one end of the universal rod, and the other end of the universal rod is connected with the lower tower 53 to realize the temporary restraint and fixation of the tower hinge 52 , After the installation of the cable saddle on the top of the tower is completed, and the installation and pre-tightening of the wind cable are completed, the universal rod is removed to make the hinge 52 of the tower foot into a free hinged state.

In addition, connecting rods 522 are provided between the two ends of the adjacent steel box beams I524, and reinforcing rods 526 are provided between the corresponding arms of the adjacent V-shaped brackets 523, wherein the base 521 of the tower hinge 52 is fixed It is connected to the top of the lower tower 53, and the bottom of the upper tower 51 is connected to the steel box girder I524.

In this embodiment, a tower foot hinge 52 is provided between the two branches of the upper tower 51 and the lower tower 53, that is, the upper tower 51 and the lower tower 53 are hinged. If it is set as a mast, the horizontal load on the top of the tower generated by the cable system can be overcome by the front and rear wind cables of the tower, and the transition pier 010 mainly bears the vertical load transmitted by the tower, thus effectively avoiding the excessive load on the transition pier 010. At the same time, the tower foot hinge 52 in this embodiment has a simple structure and high stability.

As shown in Figure 9, Figure 10, Figure 11, Figure 12 and Figure 13, specifically, the portal pier 54 of this embodiment includes four upright columns II 544 vertically fixed on the top of the transition pier 010. The four upright columns The connecting lines of II544 together form a rectangular structure, and the upper part of each column II544 is connected with a column I543 through flanges. The end and end are connected in sequence, wherein, the two steel box girders II 541 are arranged along the direction of the center line of the main bridge of the bridge, and the two connecting plates 542 are arranged along the direction perpendicular to the center line of the main bridge;

There are two horizontal connecting plates 547 and one inclined connecting plate I548 between the two columns II 544 and the two columns I 543 perpendicular to the centerline of the main bridge of the bridge, wherein the two horizontal connecting plates between the two columns I 543 The plate 547 and an oblique connecting plate I548 form a "Z" shape; the two horizontal connecting plates 547 and an oblique connecting plate I548 between the two columns II544 form a reverse "Z" shape; along the main bridge of the bridge A horizontal support tube 545 and an oblique support tube 546 are arranged between the two columns II 544 and the two columns I 543 in the centerline direction. The horizontal support tube 545 between the two columns I 543 and the two diagonal support tubes 546 form a triangle, and the two One end of each oblique support tube 546 is connected to the column I 543, and the other end is connected to the steel box girder II 541 obliquely upward.

Specifically, in this embodiment, an oblique connecting plate II 549 is provided between the two horizontal support tubes 545 on the column I 543, and an oblique connecting plate II 549 is also provided between the two horizontal support tubes 545 on the column II 544, and the two oblique connecting plates II549 are arranged in a cross-over arrangement.

It should be noted that: in this embodiment, in order to ensure that the deck of the main bridge and the deck of the approach bridge on both sides can be located on the same horizontal plane, it is necessary to set the approach bridge bent pier 011 on the transition pier 010 between the main bridge and the approach bridge, However, how to construct the approach bridge bent pier 011 on the transition pier 010 without being affected by the tower on the top of the pier, and without making the tower interfere with the installation of the main bridge steel truss and the approach bridge deck beam, this problem becomes the present embodiment One of the problems to be solved, in this embodiment, in order to solve the above problems and at the same time starting from the use of existing equipment, a portal pier 54 with a net height of 10m is designed on the basis of the existing tower. 54 is consolidated with the pier top of transition pier 010. As shown in Figure 3 and Figure 4, when the construction of the approach bridge bent pier 011 is carried out, the end of the approach bridge bent pier 011 can be passed through the two horizontal columns on the column I543 and the column II544. The space between the support tubes 545 extends into the interior of the portal pier 54, thereby effectively avoiding the influence of the tower on the construction of the pier top approach bridge pier 011, and through a reasonable structural design, the portal pier 54 can meet the requirements of the entire pier 54. The overall stability of the tower is required, and the two portal piers 54 on the transition pier 010 are respectively arranged at both ends of the transition pier 101, which does not affect the installation of the main bridge steel truss girder and the approach bridge deck girder.

A method for installing a continuous steel truss girder with variable cross-section of a main bridge using a cable crane in this embodiment, the steps are as follows (as shown in Figure 15 ):

(1) First complete the installation of the steel truss girder members of the embedded section at the top of the No. 4 main pier 001, the No. 5 main pier 002, and the No. 6 main pier 003, and complete the rest of the steel truss girder members of this section at the top of each main pier Then, according to the design requirements, the lower chord concrete of this steel truss girder section at the top of the pier is poured, and then the steel truss girder construction of this section at the top of the pier is completed;

(2) Main beam cantilever assembly construction

①. Transport the factory prefabricated rod segments to the lifting platform 08 for assembly and welding of steel truss girder segments;

②. Symmetrically hoist the steel truss girder sections on both sides of No. 4 main pier 001, on both sides of No. 5 main pier 002, and on both sides of No. 6 main pier 003 with cable cranes, and carry out the steel truss girder at each main pier respectively. The positioning and connection of the segments; after the connection of the steel truss girder segments of this segment at each main pier is completed, the lower parallel concrete slabs are poured on the steel truss girder segments of this segment of each main pier to complete the main girder. Construction of the cantilever first steel truss girder segment;

3. After the lower parallel concrete slab reaches the design strength, carry out the hoisting, positioning and connection of the next steel truss girder section on both sides of each main pier to complete the construction of the second steel truss girder section of the main beam cantilever;

④. After the connection of the third steel truss girder section of the main beam cantilever of each main pier is completed, pour concrete in the steel truss girder member of this section;

⑤. After the concrete in the above-mentioned steel truss girder members reaches the design strength, the next steel truss girder section of the main beam cantilever of each main pier is symmetrically constructed, and the middle span is constructed to the previous steel truss girder section of the closing section. stop for a while;

(3) Complete the side span and middle span closing

①, install the main beam support on the top of the transition pier 010 on both sides;

②. Continue to construct side span to side span closed;

③. First close the mid-span between No. 4 main pier 001 and No. 5 main pier 002; then close the mid-span between No. 5 main pier 002 and No. 6 main pier 003.

In this embodiment, the use of cable cranes for the construction of continuous steel trusses has the following advantages: 1. There is no action force of the weight of the bridge deck crane on the steel trusses of the main bridge, thereby reducing the pier-girder joint during the construction process. 2. Relative to each main pier of the bridge, symmetrical cantilever assembly can be realized, and no balance counterweight is required; 3. Relative to each main pier, there are two symmetrical construction working surfaces, which increases the construction 4. Use cable cranes for construction to facilitate vertical and horizontal transportation of components.

The present invention and its embodiments have been described above schematically, and the description is not restrictive, and what is shown in the accompanying drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it, without departing from the purpose of the present invention, any structural modes and embodiments similar to this technical solution are designed without creativity, which shall belong to the protection scope of the present invention. .

Claims (8)

1. a method utilizing a cable crane to install the main bridge variable section continuous steel truss girder is characterized in that, its steps are as follows: (1) First, complete the installation of the steel truss girder members of the three main piers (001), No. 5 main piers (002), and No. 6 main piers (003). The connection of the remaining members of the steel truss girder is carried out, and then the lower chord concrete of the steel truss girder section at the top of the pier is poured according to the design requirements, and then the steel truss girder construction of this section at the top of the pier is completed; (2) Main beam cantilever assembly construction ①. Transport the factory prefabricated rod segments to the lifting platform (08) for assembly and welding of steel truss girder segments; ②. Symmetrically hoist the steel truss girder sections on both sides of the No. 4 main pier (001), on both sides of the No. 5 main pier (002), and on both sides of the No. 6 main pier (003) with a cable crane, and carry out each Positioning and connection of steel truss girder sections at the main pier; after the connection of the steel truss girder sections of this section at each main pier is completed, the lower parallel concrete is poured on the steel truss girder sections of this section of each main pier plate to complete the construction of the first steel truss girder segment of the main girder cantilever; 3. After the lower parallel concrete slab reaches the design strength, carry out the hoisting, positioning and connection of the next steel truss girder section on both sides of each main pier to complete the construction of the second steel truss girder section of the main beam cantilever; ④. After the connection of the third steel truss girder section of the main beam cantilever of each main pier is completed, pour concrete in the steel truss girder member of this section; ⑤. After the concrete in the above-mentioned steel truss girder members reaches the design strength, the next steel truss girder section of the main beam cantilever of each main pier is symmetrically constructed, and the middle span is constructed to the previous steel truss girder section of the closing section. stop for a while; (3) Complete the side span and middle span closing ①. Install the main beam support on the top of the transition pier (010) on both banks; ②. Continue to construct side span to side span closed; ③. First close the mid-span between No. 4 main pier (001) and No. 5 main pier (002); then close the mid-span between No. 5 main pier (002) and No. 6 main pier (003). 2. A method for installing a main bridge variable-section continuous steel truss girder using a cable crane according to claim 1, wherein the cable crane comprises a main anchor bolt (01), a main load-bearing cable (02) ), wind cables, hoisting trolleys, cable saddles and towers on the left bank (05) and towers on the right bank (07); There are two main anchors (01) on the left and right banks, and the two main anchors (01) on each bank are symmetrically arranged on both sides of the center line of the main bridge of the bridge, and are arranged corresponding to the left and right bridges respectively; The left bank towers (05) and the right bank towers (07) are respectively set on the tops of the transition piers (010) on the corresponding banks, and two sets are provided on the left bank towers (05) and right bank towers (07) Traverse cable saddles, and tower cranes (09) are installed on one side of the left bank tower (05) and the right bank tower (07); A set of main load-bearing cables (02) are arranged between the two cable saddles corresponding to the two banks, and the two ends of the main load-bearing cables (02) are respectively extended outward and fixed on the main anchors (01) corresponding to the two banks, and A set of working cables is provided corresponding to a set of main load-bearing cables (02); The main load-bearing cable (02) is provided with a hoisting trolley, and the hoisting trolley is provided with a traction cable (03) and a lifting cable (04), and the traction cable (03) and the lifting cable (04) pass through the cable saddle respectively The traction sheave and hoisting sheave are connected to the traction hoist and hoisting hoist on the corresponding bank; Wherein, the left bank tower (05) includes an upper tower (51) and a lower tower (53), and a tower foot is provided between the two branches of the upper tower (51) and the lower tower (53). hinge (52), a portal pier (54) is provided between the two branches of the lower tower (53) and the transition pier (010), and the portal pier (54) is connected to the transition pier (010) The top of the pier is consolidated, and the left bank tower (05) has the same structure as the right bank tower (07). 3. A method of using a cable crane to install a continuous steel truss girder with variable cross-section of the main bridge according to claim 2, characterized in that: the angle between the rear cable of the left bank main bearing cable (02) and the horizontal plane is 20.4 º, the angle between the rear cable of the main load-bearing cable (02) on the right bank and the horizontal plane is 13.64º; The bridge includes a curved section and a straight section. The left bank approach bridge and the main bridge are straight sections, the right bank approach bridge is a curved section, and the transition pier (010) on the right bank is the transition point between the curved section and the straight section. The center of the main bridge of the bridge The line direction is the longitudinal axis direction of the cable crane. The included angle between the longitudinal axis of the cable crane and the horizontal axis of the right bank transition pier (010) is 89.25°, and the center of the right bank tower (07) deviates from the right bank transition pier (010) The vertical centerline is 0.335 meters upstream. 4. A method for installing a main bridge variable-section continuous steel truss girder using a cable crane according to claim 2, wherein a lifting platform (08) is provided below the main bridge of the bridge. 5. A method for installing a main bridge variable-section continuous steel truss girder by a cable crane according to claim 2, wherein the tower foot hinge (52) comprises three V-shaped brackets (52) arranged in parallel with each other. 523), wherein a base (521) is hinged at the top corner of each V-shaped bracket (523), a steel box girder I (524) is provided at the opening of each V-shaped bracket (523), and each steel Both ends of the box beam I (524) protrude from the V-shaped bracket (523) to form a protruding part, and the lower end surface of the protruding part is provided with a vertical downward connecting side ear (525). Connecting rods (522) are provided between both ends of the steel box girder I (524), and reinforcing connecting rods (526) are provided between the corresponding arms of the adjacent V-shaped brackets (523); The base (521) of the tower hinge (52) is fixed on the top of the lower tower (53), and the bottom of the upper tower (51) is connected with the steel box beam I (524). 6. A method for installing a main bridge continuous steel truss girder with a cable crane according to claim 2, characterized in that: the portal pier (54) comprises four vertical piers fixed on the transition pier (010) Column II (544) at the top of the pier, the connecting lines of the four columns II (544) together form a rectangular structure, and the upper part of each column II (544) is connected by a flange to a column I (543) , the ends of the four columns I (543) away from the transition pier (010) are connected end to end by two steel box girders II (541) and two connecting plates (542), wherein the two steel box girders II (541) The two connecting plates (542) are arranged along the direction perpendicular to the centerline of the main bridge of the bridge; There are two horizontal connecting plates (547) and one inclined connecting plate I (548) between the two columns II (544) and the two columns I (543) perpendicular to the centerline of the main bridge of the bridge. Two horizontal connecting plates (547) and an inclined connecting plate I (548) between the two columns I (543) form a "Z" shape; the two horizontal connecting plates between the two columns II (544) The plate (547) and an inclined connecting plate I (548) form a reverse "Z" shape; There are horizontal support pipes (545) between the two columns II (544) and the two columns I (543) along the centerline of the main bridge of the bridge, among which the horizontal support tubes (545) between the two columns I (543) and Two oblique support tubes (546) form a triangle, and one end of the two oblique support tubes (546) is connected with the upright column I (543), and the other end is connected obliquely upward with the steel box beam II (541). 7. A method for installing a continuous steel truss girder with variable cross-section of a main bridge using a cable crane according to claim 6, characterized in that: there is a The inclined connecting plate II (549) is also provided with an inclined connecting plate II (549) between the two horizontal support tubes (545) on the column II (544), and the two inclined connecting plates II (549) are mutually Cross arrangement. 8. A method for installing a main bridge continuous steel truss girder with a cable crane according to claim 2, characterized in that: the upper tower (51) and the lower tower of the left bank tower (05) (53) Four left-bank rear wind cables (061) and four left-bank front wind cables (062) are respectively set on the left bank tower (05), four left-bank upstream cross-wind cables (063) and two left-bank wind cables (063) are installed on the left bank tower (05). Downstream crosswind cable (064); The upper tower (51) and the lower tower (53) of the right bank tower (07) are respectively provided with four right bank front wind cables (067) and four right bank rear wind cables (068). The frame (51) is also provided with four inclined front wind cables, and four right bank upstream transverse wind cables (065) and two right bank downstream transverse wind cables (066) are set on the right bank tower (07); Among them, the four left-bank front wind cables (062) on the upper tower (51) on the left bank and the four right-bank front wind cables (067) on the upper tower (51) on the right bank are the ventilation cables that are pulled against the tops of the towers on both banks. .

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