CN114382015A - Construction method for vertical rotation of special-shaped steel main tower of cable-stayed bridge - Google Patents

Abstract

The invention discloses a construction method for vertical turning of a special-shaped steel main tower of a cable-stayed bridge, which comprises the steps of erecting a temporary assembling platform, assembling a steel auxiliary tower, debugging hydraulic synchronous vertical turning system equipment, synchronously loading a vertical turning device and a stabilizing rigging in a grading manner, stopping the bridge tower for more than 2 hours after pre-vertical turning, starting formal vertical turning on the premise of ensuring the absolute safety of the whole vertical turning working condition, vertically turning to a position close to a design position, measuring and controlling, slowing down the vertical turning speed, finely adjusting the vertical direction of each bridge tower by using hydraulic vertical turning equipment, accurately positioning, and performing bridge tower folding welding work and hydraulic synchronous vertical turning system equipment unloading work after the vertical turning is in place. The construction method for the vertical rotation of the special-shaped steel main tower of the cable-stayed bridge solves the problems that compared with construction methods such as erecting an integral support and the like, the construction method has great convenience and construction period superiority, construction measure cost is reduced, the total construction period is shortened, and the construction method is high in practicability and innovation.

Description

Construction method of vertical swivel of special-shaped steel main tower of cable-stayed bridge

technical field

The invention relates to the technical field of bridge body construction, in particular to a construction method for vertical swivel of a special-shaped steel main tower of a cable-stayed bridge.

Background technique

With the development of domestic construction technology, more and more bridge types appear in everyone's eyes. In the construction of bridge swivel, there are more applications of horizontal rotation, but less application of vertical rotation. Nowadays, bridges pay more and more attention to aesthetics, and aesthetics puts forward new requirements on construction methods. Vertical swivels will be used more and more in the future, which is also the trend of the times. A cable-suspension bridge, also known as a cable-stayed bridge, is a structural system composed of a compression tower, a tension cable and a bending beam. Cable-stayed bridges, as a kind of cable system, have greater spanning capacity than girder bridges, and are the most important bridge type for long-span bridges.

For the existing traditional bridge construction, compared with the construction methods such as erecting integral supports, its construction is inconvenient. In addition, the traditional construction cannot reduce the cost of construction measures and the construction period, and the traditional construction is not practical and innovative. .

SUMMARY OF THE INVENTION

(1) Technical problems solved

In view of the deficiencies of the prior art, the present invention provides a vertical swivel construction method for the special-shaped steel main tower of a cable-stayed bridge, which solves the inconvenience of construction compared with the construction methods such as erecting an integral bracket, and in addition, the traditional construction cannot reduce the cost of construction measures and construction period, as well as the problems that traditional construction is not practical and innovative.

(2) Technical solutions

In order to achieve the above purpose, the present invention is realized through the following technical solutions: the construction method of vertical swivel of the special-shaped steel main tower of the cable-stayed bridge, comprises the following steps:

S1. Set up a temporary assembly platform, the main tower structure is assembled at a 5° angle to the bridge deck, and the overall assembly is completed on the ground;

S2. Assemble the steel auxiliary tower, install the hanging cages on both sides, hydraulic lifters, twisting, etc., install the steel auxiliary tower gantry on the bridge tower, set the front anchor point on the bridge tower, and set the rear anchor near the pier on the ground point;

S3. Debug the hydraulic synchronous vertical rotation system equipment and test the vertical rotation;

S4, synchronously graded loading of the vertical swivel and stable rigging;

S5. Stay for more than 2 hours after the pre-vertical rotation of the bridge tower, and check the temporary vertical rotation structure, stable cable system, vertical rotation system, foundation, lifting point, bottom hinge point, etc. On the premise that the entire vertical rotation condition is absolutely safe, Start the official vertical rotation

S6. Vertically rotate to the design position, measure and control, slow down the vertical rotation speed, and use hydraulic vertical rotation equipment to fine-tune the vertical direction of each bridge tower for precise positioning;

S7. After the vertical rotation is in place, the bridge tower is closed and welded;

S8. The hydraulic synchronous vertical swivel system equipment is unloaded until the steel strands are completely relaxed, so that the bridge tower can be placed in place as a whole; the hydraulic synchronous vertical swivel equipment and other temporary measures for vertical swivel such as steel auxiliary towers are all removed, and the vertical swivel installation of the bridge tower is completed. Work.

Preferably, in the step S1, the maximum span of the stay cable is 180m, and the main bridge is a 32m, 38m, and 110m single-pylon double-span mixed-beam cable-stayed bridge.

Preferably, in the step S2, the tension anchor points are divided into front anchors and rear anchors, and the front anchors are pre-tensioned anchor points, which are composed of special steel strands for tensioning, front anchor lugs and tensioning hangers. , two tensioning anchor points are respectively set on one side of the bridge tower, and two tensioning spreaders are used for a single tensioning anchor point.

Preferably, the rear anchor is a lifting anchor point, which is composed of a rear pulling foundation, a special steel strand for lifting, a hydraulic lifter, a lifting spreader, a rear anchor embedded ear plate and a temporary pier, and the like. Correspondingly set 2 lifting points for each.

Preferably, in the step S2, the hydraulic lifter is provided with a dedicated lifting platform when in use.

Preferably, in the step S2, the steel auxiliary tower gantry column adopts P420x16 round pipes, and the transverse and inclined web rods are P180x6, the intermediate connection truss transverse rods are P273x10 circular pipes, and the transverse and inclined web rods are P180x6.

Preferably, the adjustment pressure of the hydraulic lifter is 3-4MPa.

Preferably, in the described step 6, the measurement control is a computer control system, and when the synchronism of the lifting point is uneven, the maximum height difference warning value is 20-25mm.

(3) Beneficial effects

The invention provides a construction method for the vertical rotation of a special-shaped steel main tower of a cable-stayed bridge. Compared with the prior art, it has the following beneficial effects: the special-shaped steel main tower vertical rotation construction method of the cable-stayed bridge is carried out by assembling the main tower structure at a 5° angle to the bridge deck, and the overall assembly is completed on the ground, and the suspension on both sides is installed. Cage, hydraulic lifter, twist, etc., the steel auxiliary tower gantry is installed on the bridge tower, the front pull anchor point is set on the bridge tower, the rear pull anchor point is set near the pier on the ground, and the equipment debugging of the hydraulic synchronous vertical rotation system is carried out. Trial the vertical rotation, load the vertical rotator and stabilizing rigging synchronously in stages, stay for more than 2 hours after the pre-vertical rotation of the bridge tower, and check the temporary vertical rotation structure, stable cable system, vertical rotation system, foundation, lifting point, bottom hinge point, etc. On the premise of confirming that the entire vertical rotation condition is absolutely safe, start the official vertical rotation, close the vertical rotation to the design position, measure and control, slow down the vertical rotation speed, and use the hydraulic vertical rotation equipment to fine-tune the vertical direction of each bridge tower. After the positioning and vertical rotation are in place, the bridge tower is closed and welded until the steel strands are completely relaxed, so that the bridge tower is placed in place as a whole. The vertical rotation installation of the tower has great convenience and construction period advantages compared with the construction methods such as erecting an integral bracket. In addition, it reduces the cost of construction measures and shortens the total construction period. It has strong practicability and high innovation, and can effectively solve the problem. The problem of vertical rotation construction of special-shaped steel main tower.

Description of drawings

Fig. 1 is the first schematic diagram of the method of the present invention;

Fig. 2 is the second schematic diagram of the method of the present invention;

Fig. 3 is the third schematic diagram of the method of the present invention;

Fig. 4 is the fourth schematic diagram of the method of the present invention;

Fig. 5 is the fifth schematic diagram of the method of the present invention;

Fig. 6 is the sixth schematic diagram of the method of the present invention;

Fig. 7 is the seventh schematic diagram of the method of the present invention;

Fig. 8 is the eighth schematic diagram of the method of the present invention;

Fig. 9 is the ninth schematic diagram of the method of the present invention;

Figure 10 is a schematic plan view of the steel cable tower assembled temporary buttress of the present invention;

Fig. 11 is the sectional view of the steel cable tower assembled temporary buttress of the present invention;

Figure 12 is a schematic diagram of the method of the present invention for the installation of the code plate;

Figure 13 is a schematic diagram of a bridge pylon hinge according to the method of the present invention;

Figure 14 is a schematic diagram of a hinged connection according to the method of the present invention;

Figure 15 is a cross-sectional view of the hinged connection according to the method of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described, and obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work, all belong to the protection scope of the present invention.

Please refer to Fig. 1-11, the embodiment of the present invention provides a kind of technical scheme: cable-stayed bridge special-shaped steel main tower vertical swivel construction method, comprises the following steps:

S1. Set up a temporary assembly platform, the main tower structure is assembled at a 5° angle to the bridge deck, and the overall assembly is completed on the ground;

S2. Assemble the steel auxiliary tower, install the hanging cages on both sides, hydraulic lifters, twisting, etc., install the steel auxiliary tower gantry on the bridge tower, set the front anchor point on the bridge tower, and set the rear anchor near the pier on the ground point;

S3. Debug the hydraulic synchronous vertical rotation system equipment and test the vertical rotation;

S4, synchronously graded loading of the vertical swivel and stable rigging;

S5. Stay for more than 2 hours after the pre-vertical rotation of the bridge tower, and check the temporary vertical rotation structure, stable cable system, vertical rotation system, foundation, lifting point, bottom hinge point, etc. On the premise that the entire vertical rotation condition is absolutely safe, Start the official vertical rotation

S6. Vertically rotate to the design position, measure and control, slow down the vertical rotation speed, and use hydraulic vertical rotation equipment to fine-tune the vertical direction of each bridge tower for precise positioning;

S7. After the vertical rotation is in place, the bridge tower is closed and welded;

S8. The hydraulic synchronous vertical swivel system equipment is unloaded until the steel strands are completely relaxed, so that the bridge tower can be placed in place as a whole; the hydraulic synchronous vertical swivel equipment and other temporary measures for vertical swivel such as steel auxiliary towers are all removed, and the vertical swivel installation of the bridge tower is completed. Work.

Further, in the step S1, the maximum span of the stay cables is 180m, and the main bridges are 32m, 38m, and 110m single-pylon and double-span hybrid beam cable-stayed bridges.

Further, in the step S2, the tension anchor points are divided into front anchors and rear anchors, and the front anchors are pre-tensioned anchor points, which are composed of special steel strands for tensioning, front anchor lugs and tensioning hangers. , two tensioning anchor points are respectively set on one side of the bridge tower, and two tensioning spreaders are used for a single tensioning anchor point.

Further, the rear anchor is a lifting anchor point, which is composed of a rear pulling foundation, a special steel strand for lifting, a hydraulic lifter, a lifting spreader, a rear anchor embedded ear plate and a temporary pier. Correspondingly set 2 lifting points for each.

Further, in the step S2, the hydraulic lifter is provided with a dedicated lifting platform when in use.

Further, in the step S2, the steel auxiliary tower gantry column adopts the round pipe of P420x16, and the horizontal and inclined web bars are P180x6, and the middle contact truss crossbar adopts the round pipe of P273×10, and the horizontal and diagonal web bars are P180x6.

Further, the adjustment pressure of the hydraulic lifter is 3-4MPa.

Further, in the described step 6, the measurement control is a computer control system, and when the lifting point synchronization is uneven, the maximum height difference early warning value is 20-25mm.

When working, 1. Steel cable tower assembled tire frame installation

According to the self-weight of the steel cable tower segment and the geological conditions of the site, the temporary support pier adopts the structural form of steel pipe lattice column + H-beam + vertical column adjustment section. The method is installed to enhance the overall stability of the temporary buttress. The bottom of the temporary buttress is fixed by the embedded steel bar to fix the flange blind plate of the steel pipe buttress to the concrete foundation. The flange blind plate of the steel pipe buttress is welded with the pre-reinforced reinforcement to enhance the rigidity and stability of the column foot, and the temporary support adjustment is carried out with the adjustment section jack. It is mainly used for adjusting the elevation of the steel tower during hoisting and for the overall unloading of the steel tower after the installation.

2. Assembling the tower segment on the tire frame

(1) The 400t vehicle is hoisted in a good position at the position within the hoisting span, and the road substrate is laid under each outrigger (the vehicle is hoisted with the road substrate);

(2) Select 4 steel wire rope slings with φ64mm and tensile strength ≥1870N/mm2 and 4 shackles each capable of carrying 55t, and lock them on the 4 lifting ears of the steel box girder;

(3) Instruct the truck crane to lift slowly. When the steel box girder is about 100mm above the ground, stop for 10 minutes and then carry out three inspections: (1) Whether the force of the crane is good; (2) Whether the force of the lifting lug is in good condition; (3) The wire rope sling, Whether the force of the shackle is intact. If all are normal, command the floating crane to rotate slowly;

(4) Command the transport vehicle to drive away from the position, put the tower foot on the ground again, and switch the position of the lifting point to lift the tower foot vertically. Instruct the truck crane to lift slowly. When the steel box girder is about 100mm from the ground, stop for 10 minutes and then carry out three inspections: (1) Whether the force of the crane is good; (2) Whether the force of the lifting lug is in good condition; Whether the force is intact. If all are normal, command the floating crane to rotate slowly;

(5) After the cable tower segment is slowly moved forward to the air above the in-position position, slowly change the amplitude and hoist the steel cable tower segment into place. Stabilize the cable tower section, align the orientation, slowly loosen the cable tower section on the temporary support pier, and after the adjustment is completed, instruct the crane to loosen the hook and remove the sling and shackle;

(6) When the second and third sections are hoisted, according to the size of the seam required by the design, use the limit code plate to make a pad to fix it, and the special welding code plate is firmly positioned to ensure the correctness of the central axis;

When assembling on site, a sufficient amount of slats must be provided. The thickness of the slats is 14-28mm. The thickness of the slats is basically the same as the thickness of the component boards. The spacing between the slats is about 500-800mm. The specific setting depends on the actual situation of the interface. , but the maximum shall not exceed 800mm to ensure the rigidity of the double-sided member plate of the interface;

3. On-site welding of steel cable towers

Tack welding and repair welding: using electrode arc welding method;

Butt weld on top plate: use ceramic liner mixed gas (CO2/Ar, CO2 content 20-25%) shielded welding for bottoming, submerged arc automatic welding cover surface, or use ceramic liner mixed gas shielded welding for bottoming and cover face method;

Butt weld of bottom plate and longitudinal web: use ceramic liner mixed gas shielded welding for bottoming and covering method;

Other butt and fillet welds: use mixed gas shielded welding or electrode arc welding.

For the butt welds that require full penetration inside the box girder, the mixed gas shielded welding method of ceramic liner should be used as far as possible to reduce the carbon arc air gouging inside the box girder and reduce the amount of smoke and dust.

4. The twist setting at the bottom of the bridge tower

During the vertical rotation of the bridge tower, because the tower body rotates to 75° in the elevation, a rotating pin is set at the bottom of the tower body. Since the bottom has to bear huge horizontal and vertical loads, and the tower body is not integrated at this time, the integrity is poor, so moderate reinforcement is made at the ear plate to make the local load of the pin shaft more uniformly transmitted to the tower body . After the vertical position, the butt-welded closed section and the built-in rib plate, among which the hinged lug plate will be placed in the bridge tower as a permanent structure without removing it.

5. Setting of front and rear anchor points and lifting equipment

(1) The front anchor is a pre-tensioned anchor point, which consists of special steel strands for tensioning, front anchor lugs, tensioning hangers, etc. Two tensioning anchor points are set on each side of the bridge tower, and a single tensioning anchor The point adopts 2 tension spreaders;

(2) The rear anchor is the lifting anchor point, which consists of the rear pulling foundation, the special steel strand for lifting, the hydraulic lifter, the lifting spreader, the rear anchor embedded ear plate, and the temporary pier. Lift the lifting point;

(3) To hoist the bridge tower with hydraulic synchronous lifting equipment, it is necessary to set up a special lifting platform, that is, a reasonable lifting point, and a hydraulic lifter is arranged at the lifting point. Anchor connection. The lifting point is used as a hydraulic lifter operating platform, which can bear a certain load. In the test, the hydraulic lifter is placed in the hanging cage, and the perforated ear plate of the rear anchor is connected as a whole by the pin shaft. Consider setting the lifting point at the rear anchor of the bridge deck;

6. Steel auxiliary tower (gantry) setting

The vertical rotation tooling of the steel auxiliary tower is mainly composed of a tensioning system, a gantry, a lifting spreader and a hinge. . The gantry column adopts P420x16 round pipe, the transverse and oblique web rods are P180x6, the intermediate connecting truss transverse rod adopts P273x10 round pipe, and the transverse and inclined web rods are P180x6.

7. Vertical rotation lifting

(1) Manually put a single strand of the well-loaded steel strand into the anchor plate in the order from bottom to top on the ground and tighten the clips. The exposed end of the steel strand is about 600mm), to ensure that each exposed length is one to one and the direction of rotation of the steel strand is half. First, put a single steel strand into the upper clip of the anchor hole at one end, and then use the rolling method to pay off the steel strand and then pass it into the upper clip of the other end of the anchor hole. Repeat this sequence until the bundling is completed, install the anti-loosening pressure plates at both ends, and complete the bundling of the steel strands. Lift the tensioning spreader to the universal support of the main and auxiliary steel towers with a car hoist, and use the chain hoist to cooperate with the adjustment and installation pin to connect the tensioning spreader and the universal support firmly. The small station (steel strand) is threaded and the hoisting is completed.

(2) Install the anchor on the lifting sling of the auxiliary steel tower on the bridge deck, and use a 7-shaped steel plate with a thickness of about 16mm to weld firmly with the hoisting sling.

On the bridge deck, manually put the single unloaded steel strand into the anchor plate in the order from bottom to top and tighten the clips, and the exposed steel strand at the end of the lifting sling is about 300mm, ensuring that each exposed length is one to one And the rotation direction of the steel strand is half, and the first steel strand in each lifting spreader is marked with white spray paint. First, put the steel strand into the upper clip of the anchor hole of the hoisting spreader, and then use the rolling method to complete the pay-off of the steel strand and then pass it into the special wire splitting plate corresponding to the hole position. The anchor holes of the lifting spreader are in one-to-one correspondence, and there shall be no anchor holes. Repeat in sequence until the threading is completed, then install the anti-loosening pressure plate of the anchor on the lifting spreader, and the threading of the steel strand is completed.

(3) Comprehensively check the lifting system, anchorage, steel strand, lifting point structure, etc. After everything is normal, the four lifting jacks are loaded with 20%, 40%, 60%, and 80% synchronously in stages for trial rotation. During the loading process, The tower top displacement is monitored in real time to ensure it is within the design range. If everything is normal, continue to load and lift the jacks synchronously in stages, until the main steel tower is about 10cm away from the ground to assemble the tire frame, and then stop lifting and vertical rotation.

After staying for more than 2 hours, check the temporary vertical swivel structure, hoisting system, slack state of steel strands, anchorage state, foundation, lifting point, bottom hinge point, etc. On the premise of confirming that the entire hoisting condition is absolutely safe, start the formal inspection. When lifting and rotating vertically, the elevation of each lifting point is measured every 10 meters, and the displacement of the top of the gantry is monitored in real time to keep it within 60mm within the allowable range to ensure that each lifting point is lifted synchronously. Lift to close to the design position, measure and control, slow down the lifting speed, and use hydraulic lifting equipment to fine-tune the vertical direction of each bridge tower for precise positioning. After the vertical rotation is completed, it is transferred to the next process for welding.

During the vertical rotation process, an observer at each lifting point at the rear anchor is required to maintain smooth communication with the pump station operator at any time to ensure the safe lifting and vertical rotation operation.

Meanwhile, the content not described in detail in this specification belongs to the prior art known to those skilled in the art.

It should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or apparatus that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (8)

1. the construction method of vertical swivel of special-shaped steel main tower of cable-stayed bridge is characterized in that: comprise the following steps: S1. Set up a temporary assembly platform, the main tower structure is assembled at 5° with the bridge deck, and the overall assembly is completed on the ground; S2. Assemble the steel auxiliary tower, install the hanging cages on both sides, hydraulic lifters, twisting, etc., install the steel auxiliary tower gantry on the bridge tower, set the front anchor point on the bridge tower, and set the rear anchor near the pier on the ground point; S3. Debug the hydraulic synchronous vertical rotation system equipment and test the vertical rotation; S4, synchronously graded loading of the vertical swivel and stable rigging; S5. After the pre-vertical rotation of the bridge tower, stay for more than 2 hours, check the temporary vertical rotation structure, stable cable system, vertical rotation system, foundation, lifting point, bottom hinge point, etc. On the premise that the entire vertical rotation condition is absolutely safe, Start the official vertical rotation S6. Vertically rotate to close to the design position, measure and control, slow down the vertical rotation speed, and use hydraulic vertical rotation equipment to fine-tune the vertical direction of each bridge tower for precise positioning; S7. After the vertical rotation is in place, the bridge tower is closed and welded; S8. The hydraulic synchronous vertical swivel system equipment is unloaded until the steel strands are completely relaxed, so that the bridge tower can be placed in place as a whole; the hydraulic synchronous vertical swivel equipment and other temporary measures for vertical swivel such as steel auxiliary towers are all removed, and the vertical swivel installation of the bridge tower is completed. Work. 2. The construction method for vertical swivel of the special-shaped steel main tower of a cable-stayed bridge according to claim 1, characterized in that: in the step S1, the maximum span of the stay cable is 180m, and the main bridge is 32m, 38m, 110m Single tower double span hybrid beam cable-stayed bridge. 3. The construction method for vertical swivel of the special-shaped steel main tower of a cable-stayed bridge according to claim 1, characterized in that: in the step S2, the anchor point is divided into a front anchor and a rear anchor, and the front anchor is pretensioned The tension anchor point is composed of the special steel strand for tensioning, the front anchor ear plate and the tensioning hanger. Tensioning spreader. 4. The construction method for vertical swivel of the special-shaped steel main tower of a cable-stayed bridge according to claim 3, characterized in that: the rear anchor is a lifting anchor point. , lifting spreader, rear anchor embedded ear plate and temporary pier are composed of each other, and two lifting points are set corresponding to each side of the bridge tower. 5 . The construction method for the vertical swivel of the special-shaped steel main tower of the cable-stayed bridge according to claim 1 , wherein: in the step S2 , the hydraulic lifter is provided with a special lifting platform when in use. 6 . 6. the special-shaped steel main tower vertical swivel construction method of the cable-stayed bridge according to claim 1, is characterized in that: in the described S2 step, the steel auxiliary tower gantry column adopts the round pipe of P420x16, and the horizontal and inclined belly The rods are P180x6, the middle connecting truss cross rods are P273x10 round pipes, and the transverse and oblique web rods are P180x6. 7 . The vertical swivel construction method of the special-shaped steel main tower of a cable-stayed bridge according to claim 5 , wherein the hydraulic lifter regulates the pressure to 3-4MPa. 8 . 8. The special-shaped steel main tower vertical swivel construction method of a cable-stayed bridge according to claim 1, characterized in that: in the step 6, the measurement control is a computer control system, and when the lifting points are unevenly synchronized, the maximum height The difference warning value is 20-25mm.

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