CN103321154A - Integral hoisting construction method for long-span steel truss girder - Google Patents

Abstract

The invention discloses a construction method for the overall hoisting of large-span steel truss girders. The construction method includes the following steps: (1) selection of hoisting points for the overall hoisting of steel truss girders, (2) design and construction of slings, (3) overall For hoisting construction, the present invention has the following advantages: the overall hoisting method is adopted to erect the steel truss girder under the navigational condition, compared with the steel truss girder constructed by segmental assembly with few supports and float-over method, the operation is relatively simple, and the precision control is relatively easy; at the same time The safety risk of water operations is reduced, the construction period is shortened, and the construction cost is reduced.

Description

A construction method for overall hoisting of long-span steel truss girders

technical field

The present invention relates to the field of bridge manufacturing, in particular to a construction method for integral hoisting of large-span steel truss girders. the

Background technique

At present, the overall hoisting construction of steel truss girders is a newly developed bridge construction method. Because it has little impact on the normal navigation of the channel, the high-altitude operation is changed to ground operation, the construction is fast, and the technical and economic benefits are high. There are great application advantages and application prospects in regional construction. A breakthrough in this field means standing on a new commanding height, and its economic value and application prospects are very good. the

There are many thousand-ton ships and trailer fleets passing by many rivers in our country, and they must not stop sailing during bridge construction. According to the requirements of the maritime department, if supports are installed in the channel, the net span shall not be less than 45m, and the navigation height limit shall not be less than 7m. The safety hazard of the support itself is very large. The float-over method is used for construction, the construction process is complicated, the construction investment cost is large, and the safety risk is high. the

Contents of the invention

The object of the present invention is to solve the above-mentioned technical problems and provide a construction method for integral hoisting of large-span steel truss girders with simple operation and relatively low investment cost. the

The technical scheme of the present invention: a construction method for integral hoisting of large-span steel truss girders, the construction method includes the following steps:

(1) Selection of lifting points: According to the parameters of the existing floating cranes, select a reasonable lifting point position; use two floating cranes of 500 tons and 300 tons for lifting, and according to the lifting performance of the two floating cranes , Reasonably select the location of the steel truss girder lifting points, set asymmetrical lifting points to meet the problem of non-uniform lifting equipment, and ensure that different types of floating cranes can give full play to their performance. The position of the lifting point should be selected at the node of the truss girder. By calculating the fulcrum reaction force at the lifting point of the steel truss girder during the hoisting process, and according to the actual situation of the on-site hoisting operation, refer to the lifting parameter table of the two floating cranes, and compare and calculate Check whether the reaction force conforms to the value in the floating crane parameter table, and then determine the appropriate lifting point position;

(2) Design and construction of hangers: For the hoisting of the steel truss girder, by using the existing bolt hole groups at the upper chord nodes A2, A4, A3, and A5, a 30mm-thick Q370qE steel plate is attached to the inner and outer sides of the nodes through M24 bolts. The connecting steel plates are all 50cm higher than the top surface of the upper chord of the steel truss girder, and a 720*800*30mm Q370qE cover plate is welded on it to connect the connecting steel plates attached to the inner and outer sides of the nodes, and a 16mm thick reinforcement is set at a distance of 20cm When the steel truss girder is hoisted, in order to effectively reduce the lateral pressure of the sling on the steel truss girder, a φ426*8mm steel pipe is installed on the parallel cross bar at the same node as a cross brace, and the left and right The two lifting points are connected to resist the horizontal force of the transverse bridge generated during the hoisting process; in order to facilitate the fastening of the steel wire rope, a welding pin is connected to the top of the cover plate at the joint. 420*30mm Q235 steel plate, make a hole at the position of the pin shaft, and add a 16mm thick, 200 outer diameter, and 100mm inner diameter ring-shaped reinforced steel plate on the inside and outside of the hole;

(3) Overall hoisting construction process: steel girders are fully assembled at the pre-assembled site, and 500t and 300t floating cranes are used for overall hoisting and erection. The main construction steps are as follows:

① Complete the foundation, main pier and cap beam construction;

② Plan the assembly site to meet the steel truss girder assembly and overall hoisting needs; in order to ensure that the assembled steel truss girder is within the lifting radius of the floating crane, according to the actual conditions on site, the steel truss girder assembly site is selected at the downstream of the new bridge 5.0m of rice field on the river bank, the assembly area is 2.0m away from the existing revetment of the channel to meet the operating radius of the floating crane and facilitate the overall hoisting;

③Use truck cranes to assemble the steel truss girders into a bridge state at the assembly site;

④ Install the spreader;

⑤The steel truss girder is hoisted as a whole by the floating crane, and moved to the bridge position to complete the erection of the steel truss girder;

⑥ After the steel girders are in place, install the concrete prefabricated bridge deck from both ends of the bridge to the middle, and pour the longitudinal joints of each bridge deck;

⑦ After the longitudinal joints reach 100% strength, pour the transverse joints in batches in order, with a difference of 4 days in age between each batch;

⑧ Carry out bridge deck system construction. the

The beneficial effects of the present invention are: (1) a construction method for erecting steel truss beams is provided, which is relatively simple in operation and relatively easy in accuracy control compared with segmental hoisting with less supports and erection of steel truss beams by the float-over method; (2) The construction safety risks of water operations are reduced; (3) the construction period is shortened; (4) the occupation of construction personnel and mechanical resources is reduced, and construction costs are reduced. the

Description of drawings

Fig. 1 is a simplified diagram of the facade of Jinli River Bridge of the present invention;

Fig. 2 is a planar layout diagram of the connection of the suspension points of the present invention;

Fig. 3 is a plane view of the connecting plate of the present invention;

Fig. 4 is the vertical elevation view of the cross bridge of the connecting plate of the present invention;

Fig. 5 is the longitudinal bridge elevation view of the connecting plate of the present invention;

Fig. 6 is a cross-sectional view of a temporary cross brace of the present invention;

Fig. 7 is a bolted connection diagram of the connecting plate at the node of the present invention;

Fig. 8 is a structure diagram of the lug plate of the spreader of the present invention;

Fig. 9 is a schematic diagram of Step 1 of the present invention;

Fig. 10 is a schematic diagram of Step 3 of the present invention;

Fig. 11 is a schematic diagram of Step 4 of the present invention;

Among them: 1. Jinli River Bridge, 2. Steel truss girder, 3. Cover beam, 4. 6# main pier, 5. 7# main pier, 6. Waterway revetment, 7. Capping platform, 8. Channel bottom, 9. Pile foundation, 10. Spreader, 11. Steel truss beam upper chord, 12. Temporary steel pipe cross brace, 13. A3 node, 14. A5 node, 15. Pin shaft, 16. Cover plate, 17. Ear plate, 18. Stiffeners, 19. Connecting steel plates, 20. Pin holes, 21. High-strength bolts, 22. Main truss top chords, 23. Scaffolding, 24. Concrete piers.

Detailed ways

Jinli River Bridge 1 is a newly built bridge at the Jintan section of the Danjin Licao River Changzhou jurisdiction because the waterway of the Danjin Licao River has been renovated from five levels to three levels. The new bridge is located 14m downstream of the old bridge. It is an under-supported steel truss girder with a main span of 81.96m. The span ratio is 1/7.36. The distance between the centers of the two main trusses is 13.2m, the width-span ratio is 1/6.14, and the bridge deck width is 12.0m. The steel truss girder 2 weighs more than 600 tons. the

The overall hoisting construction method of large-span steel truss girders includes the following steps:

(1) Selection of lifting points: According to the existing floating crane equipment, two floating cranes of 500 tons and 300 tons are used for hoisting; according to the lifting performance of the two floating cranes, the location of the steel beam lifting point is reasonably selected. Set up asymmetric lifting points to meet the problem of non-uniform hoisting equipment, to ensure that different types of floating cranes can give full play to their performance and complete the hoisting task.

In order to ensure the safety of the structure itself during the hoisting of the steel truss girder 2, the lifting point should be selected at the node of the truss girder. In order to ensure the hoisting operation, by calculating the fulcrum reaction force at the hoisting point of the steel truss girder 2 during the hoisting process, and according to the actual situation of the on-site hoisting operation, refer to the lifting parameter table of the two floating cranes, and compare the calculated reaction force Whether it conforms to the value in the floating crane parameter table, so that the appropriate position of the lifting point can be selected. the

For example, this project adopts two floating cranes of 500 tons and 300 tons for hoisting, and the horizontal elevation angle of the floating cranes is 60 ⁰ . The steel truss girder 2 plans to set the lifting points at the upper chord nodes A2, A4, A3, and A5.

Through the calculation of steel truss girder hoisting reaction forces were 239.98t, 359.96t. the

At the same time, according to the lifting parameter table of the two floating cranes, it can be known that when the horizontal elevation angle is 60 ^° , the lifting weight of the 300t floating crane is 280t, and the lifting weight of the 500t floating crane is 380t, which is greater than the calculated lifting support reaction force, and the selection of lifting nodes is reasonable. 

300t/500t floating crane lifting load table (main pole length 40m)

(2) Design and construction of the spreader: For the hoisting of the steel truss girder, a 30mm-thick Q370qE is attached to the inner and outer sides of the nodes through M24 bolts by using the 21 hole groups of high-strength bolts at the upper chord nodes A2, A4, A3, and A5. The steel plates, the connecting steel plates 19 are all 50cm higher than the top surface of the steel truss girder upper chord 11, and a Q370qE cover plate 16 of 720*800*30mm is welded on it, and the connecting steel plates 19 attached to the inner and outer sides of the nodes are connected together, and press Set 16mm thick stiffeners 18 at a distance of 20cm to strengthen the inner and outer sides and attach connecting plates. When the steel truss girder 2 is hoisted, in order to effectively reduce the lateral pressure of the sling on the steel truss girder 2, a φ426 *8mm temporary steel pipe cross brace 12, connecting the left and right lifting points to resist the horizontal force of the bridge generated during the hoisting process; in order to facilitate the bolting of the steel wire rope, the welding pin 15 is connected to the top of the cover plate at the node, and the pin 15 adopts The diameter is 10cm, and the material is 40Cr. The ear plate 17 is made of 500*420*30mm Q235 steel plate. A hole is opened at the position of the pin shaft, that is, the pin shaft hole 20, and a 16mm thick piece is attached to the inside and outside of the pin shaft hole 20, and the outer Circular steel plate with a diameter of 200mm and an inner diameter of 100mm;

(3) Overall hoisting construction process: steel girders are fully assembled at the pre-assembled site, and 500t and 300t floating cranes are used for overall hoisting and erection. The main construction steps are as follows:

Step 1: Complete the construction of the foundation, 6# main pier 4, 7# main pier 5 and cover beam 3; as shown in Figure 9.

Step 2: Plan the assembly site to meet the overall hoisting needs; use the overall hoisting method for construction, in order to ensure that the assembled steel truss girder 2 is within the lifting radius of the floating crane, according to the actual conditions on site, assemble the steel truss girder 2 The paddy field on the river bank 5.0m downstream of the new bridge is selected, and the assembly area is 2.0m away from the existing revetment of the channel to meet the operating radius of the floating crane and facilitate overall hoisting; 

Step 3: Use the truck crane to assemble the steel truss girder main truss, upper and lower parallel joints, beams, longitudinal beams, bridge girders and cross joints in the pre-assembled field; as shown in Figure 10.

Step 4: Install the spreader;

Step 5: Lift the steel truss girder 2 as a whole by using the floating crane, and move to the bridge position to complete the erection of the steel truss girder 2; as shown in Figure 11.

Step 6: After the steel truss girder 2 is in place, install the prefabricated bridge deck from both ends to the middle, and pour the longitudinal joints of each bridge deck;

Step 7: After the longitudinal joints reach 100% strength, pour the transverse joints in batches in order, and the age difference of each batch is 4 days;

Step 8: Carry out bridge deck system construction.

Claims (2)

1. A construction method for integral hoisting of large-span steel truss girders, characterized in that the construction method comprises the following steps: 1) Selection of lifting point: According to the parameters of the existing floating crane equipment, select a reasonable lifting point position; use two floating cranes of 500 tons and 300 tons for hoisting, and according to the lifting performance of the two floating cranes, Reasonably select the position of the lifting point of the steel truss girder; Check the lifting parameter table of the floating crane, compare the calculated reaction force with the value in the floating crane parameter table, and then determine the appropriate lifting point position; 2) Design and construction of the spreader: For the hoisting of the steel truss girder, a 30mm thick Q370qE connecting steel plate is attached to the inner and outer sides of the node by using the bolt hole group at the upper chord node, and the connecting steel plate is higher than the upper chord of the steel truss girder The top surface of the rod is 50cm, and a 720*800*30mm Q370qE cover plate is welded on it to connect the connecting steel plates on the inner and outer sides of the node; and a stiffening plate with a spacing of 20cm and a thickness of 16mm is used to reinforce the inner and outer sides. Connecting plate; when hoisting the steel truss girder, a φ426*8mm steel pipe is installed on the two hoisting nodes of the cross bridge as a cross brace, and the left and right hoisting points are connected to balance the horizontal force of the cross bridge at the hoisting point during hoisting ; 3) Overall hoisting construction process: Assemble the steel truss girders at the assembly site into a bridge state, install spreaders at the nodes at the lifting points, use 500t and 300t floating cranes for overall hoisting, move to the bridge site and erect it in place; the main construction Proceed as follows: ①Complete the construction of bridge foundation, main pier and cap beam; ② Plan steel truss girder assembly site and carry out steel truss girder assembly operation; ③Use truck cranes to assemble the steel truss girders into a bridge state at the assembly site; ④ Install the spreader; ⑤The steel truss girder is hoisted as a whole by the floating crane, and moved to the bridge position to complete the erection of the steel truss girder; ⑥ After the steel trusses are in place, install the prefabricated concrete bridge deck from both ends of the bridge to the middle, and pour the longitudinal joints of each bridge deck; ⑦ After the longitudinal joints reach 100% strength, pour the transverse joints in batches in order, with a difference of 4 days in age between each batch; ⑧ Carry out bridge deck system construction. 2. The overall hoisting construction method of large-span steel truss girders according to claim 1, characterized in that the design and construction of the spreader, the joints of the spreader are connected to the top of the cover to weld the lugs, and the lugs are 500* 420*30mm Q235 steel plate, open a hole at the position of the pin shaft, and affix a 16mm thick, 200 outer diameter, and 100mm inner diameter ring-shaped reinforced steel plate on the inside and outside of the opening. When hoisting, insert the pin shaft into the ear plate pin hole, and hang the steel wire rope on the pin shaft, the pin shaft adopts a diameter of 10cm, and the material is 40Cr.

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