A method for hoisting precast box girders for bridges and a hoisting positioning device

Abstract

This application relates to the technical field of bridge engineering, and discloses a method and positioning device for hoisting precast box girders for bridges. The hoisting of precast box girders includes the following steps: S1, the box girder is placed on a transport trailer, and the transport trailer is moved to the bridgehead; S2, a main crane and an auxiliary crane work together, with the rated lifting capacity of the main crane being greater than that of the auxiliary crane, and both the main crane and the auxiliary crane remaining at the bridgehead; S3, the main crane is used to hoist the far end of the box girder from the bridgehead, and the auxiliary crane is used to hoist the near end of the box girder from the bridgehead, so that the main crane bears the main hoisting torque, and the auxiliary crane assists in adjusting the posture of the box girder, lifting the box girder to the designated position; during the hoisting process, a total station is used to monitor the axial deviation of the box girder from the support and the height difference between adjacent box girders in real time. This application can reduce the adverse impact of box girder installation on river traffic.

Description

Technical Field

[0001] This application relates to the technical field of bridge engineering, and in particular to a method for hoisting precast box girders for bridges and a hoisting positioning device. Background Technology

[0002] With the acceleration of urbanization, the application of precast box girders in bridge engineering is becoming increasingly widespread. Traditional cast-in-place construction has disadvantages such as long cycle time and significant interference, while precast box girders can improve the efficiency of bridge construction.

[0003] Precast box girders are typically installed using a hoisting method, usually employing a crane operating on the riverbed to lift the girders to the designated location. However, for bridge projects with two spans or less, the crane on the riverbed will occupy space in the river, affecting traffic flow. Summary of the Invention

[0004] To reduce the adverse impact of box girder installation on river passage, this application provides a method for hoisting precast box girders for bridges and a hoisting and positioning device.

[0005] Firstly, this application provides a method for hoisting precast box girders for bridges, employing the following technical solution:

[0006] A method for hoisting precast box girders for bridges includes the following steps:

[0007] S1, the box girder is placed on the transport trailer, and the transport trailer is moved to the bridgehead;

[0008] S2 employs a main crane and an auxiliary crane working together. The rated lifting capacity of the main crane is greater than that of the auxiliary crane. Both the main crane and the auxiliary crane remain at the bridgehead.

[0009] S3, the main crane is used to lift the box girder at the far end of the bridge abutment, and the auxiliary crane is used to lift the box girder at the near end of the bridge abutment. The main crane bears the main lifting torque, and the auxiliary crane assists in adjusting the posture of the box girder and lifting it to the designated position. During the lifting process, a total station is used to monitor the axial deviation of the box girder from the support and the height difference between adjacent box girders in real time.

[0010] By adopting the above technical solution, the main and auxiliary cranes with different rated lifting capacities work together. The main crane bears the main lifting torque at the far end of the box girder, while the auxiliary crane is responsible for the near end and assists in adjusting the posture. Both the main and auxiliary cranes are located at the bridgehead, so that the lifting of the box girder does not require the occupation of the river channel. The torque distribution is optimized, and the risk of overturning caused by insufficient lifting capacity of a single crane or uneven force on the two cranes is not likely to occur.

[0011] Optionally, in S3, the deviation of the box girder from the support axis is less than or equal to 2mm, and the height difference between adjacent box girders is less than or equal to 8mm.

[0012] Optionally, in S3, the box girder hoisting sequence is to hoist the middle girder first, then the side girder.

[0013] By adopting the above technical solution, this sequence allows the bridge structure to develop symmetrically from the middle to both sides, making the force system more balanced and stable. It is less likely that installing the side beams first may cause the bridge piers to bear unbalanced eccentric loads, thereby causing safety hazards or structural deformation.

[0014] Optionally, the box girder is hoisted using a bottom-lifting method, and a hoisting positioning device is used to limit the position of the hoisting ropes.

[0015] Secondly, this application provides a hoisting and positioning device, which adopts the following technical solution:

[0016] A hoisting and positioning device includes: a main frame and clamping components; the main frame extends along the width direction of the box girder in the length direction, and there are two sets of clamping components that can be adjusted and moved along the length direction of the main frame, with the two sets of clamping components corresponding to both sides of the box girder along its own width direction respectively;

[0017] Each clamping assembly includes a first clamping group and a second clamping group. The first clamping group is used to clamp the box girder flange plate together with the main frame, and the second clamping group is used to clamp the lifting rope together with the first clamping group.

[0018] When hoisting the box girder, the hoisting rope is wound around the bottom plate of the box girder and passes through two sets of clamping components at the same time, so that the hoisting rope is clamped between the first clamping group and the second clamping group.

[0019] By adopting the above technical solution, a main frame spanning the box girder and two sets of clamping components are used to achieve clamping and fixing of the box girder flange plates and coordinated limiting of the lifting ropes, thereby reducing the risk of swaying caused by the slippage of the lifting ropes.

[0020] Optionally, the first clamping group of the two clamping assemblies moves symmetrically on the main frame via a first driving mechanism, and the second clamping group of the two clamping assemblies moves symmetrically on the main frame via a second driving mechanism.

[0021] Optionally, the first clamping group includes

[0022] The first movable seat moves along the length of the main frame onto the main frame;

[0023] The adjusting component moves and adjusts along the length of the main frame on the first movable seat; and

[0024] The counterweight is located on the outer periphery of the adjusting component and on the lower side of the main frame;

[0025] When the first clamping assembly is engaged with the flange plate, the adjusting member abuts against the side wall of the flange plate, and the pressing rod abuts against the lower surface of the flange plate.

[0026] By adopting the above technical solution, the adjusting component is responsible for pressing against the side wall of the flange plate from the side to determine the lateral position; the pressing rod presses against the lower surface of the flange plate, and together with the main rod, forms a three-dimensional clamping effect on the flange plate, so that the device is positioned on the box girder.

[0027] Optionally, the pressure rod is hinged to the adjusting member, and the two ends of the pressure rod that are far apart from each other are the abutting end and the pressure-bearing end, respectively;

[0028] The second clamping assembly includes a second movable seat and a limiting member. The second movable seat moves along the length of the main frame on the main frame, and the limiting member moves and adjusts along the direction perpendicular to the length of the main frame on the second movable seat.

[0029] When the adjusting member abuts against the side wall of the flange, the pressing rod can rotate until the pressing end abuts against the lower surface of the flange, and the pressure end extends out of the adjusting member on the side away from the flange; at the same time, the second moving seat and the adjusting member together clamp the lifting rope, and the limiting member presses down the pressure end.

[0030] By adopting the above technical solution, through the hinge of the pressure rod and the setting of a limiting member to press down the pressure end of the pressure rod, the pressure rod can adapt to the tilt angle of the lower surface of the flange plate, thereby making the abutment end surface fit against the lower surface of the flange plate, thus improving the clamping effect of the pressure rod on the flange plate. At the same time, combined with the height movement of the adjusting member, the main frame and the pressure rod can adapt to the thickness of the flange plate, improving the adaptability of the hoisting and positioning device.

[0031] Optional, the adjusting element includes

[0032] The main body is used to abut against the flange plate, and the main body has a mounting cavity on the side facing the corresponding second clamping group;

[0033] A rotating shaft is rotatably connected to the main body base, and is provided at both the upper and lower ends of the main body base; and

[0034] The conveyor belt is fitted with the rotating shafts at both ends of the main body, and the side of the conveyor belt facing the corresponding second clamping group together with the side wall of the mounting cavity forms a groove for the lifting rope to be inserted.

[0035] Within the space enclosed by the conveyor belt, there is an abutment that moves along the length of the main frame. A linkage component is provided between the second clamping group and the abutment. When the second clamping group moves toward the corresponding first clamping group, the linkage component drives the abutment to move toward the second clamping group, so that the conveyor belt is clamped between the suspension rope and the abutment.

[0036] By adopting the above technical solution, a low-friction structure consisting of a rotating shaft and a conveyor belt is set within the adjusting component. The linkage assembly cooperates with the abutment component, allowing the conveyor belt to move with the lifting rope during the initial adjustment stage. This reduces frictional resistance, enabling the lifting rope to slide easily into position and protecting its surface from damage. When clamping is required, the linkage assembly drives the abutment component to press against the back of the conveyor belt, supporting the belt and restricting its movement. The conveyor belt and the second moving seat together firmly clamp the lifting rope.

[0037] Optional, linkage components include

[0038] The first rack is fixed to the side wall of the contacting part;

[0039] The second rack is fixed to the second clamping assembly, and the second rack extends into the main body opposite the first rack; and

[0040] The toothed column has teeth that are distributed sequentially along its circumference and is rotatably connected to the main body. The two opposite sides of the toothed column are respectively engaged with the first rack and the second rack.

[0041] The teeth of both the first and second racks are distributed along the length of the main frame.

[0042] In summary, this application includes at least one of the following beneficial effects:

[0043] 1. By differentiating the roles of main and auxiliary cranes and monitoring in real time with total station, the torque of the box girder hoisting process was optimized, and construction was carried out on the bridge deck without occupying the river channel, thus reducing the impact on river traffic during the box girder installation process;

[0044] 2. The hoisting and positioning device clamps the box girder flange plate and the hoisting rope simultaneously, positioning the hoisting rope and the flange plate relative to each other. This eliminates the need for additional structures to connect the hoisting rope during the prefabrication of the box girder, and the hoisting points can be adjusted as needed. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the box girder installation in an embodiment of this application;

[0046] Figure 2 This is a schematic diagram of the structure of the hoisting and positioning device and the box girder in the embodiments of this application;

[0047] Figure 3 Figure 2 The left view;

[0048] Figure 4 This is a top view of the hoisting and positioning device in the embodiments of this application;

[0049] Figure 5 This is a schematic diagram of a set of clamping components cooperating with a lifting rope in an embodiment of this application;

[0050] Figure 6 This is a schematic diagram of the structure of the first clamping group in the embodiments of this application;

[0051] Figure 7 This is a schematic diagram of the structure of the first clamping group and the second clamping group cooperating in an embodiment of this application;

[0052] Figure 8 yes Figure 7 Cross-sectional view at point AA;

[0053] Figure 9 This is a schematic diagram of the structure of the contacting component and the linkage component in the embodiments of this application.

[0054] Explanation of reference numerals in the attached drawings: 1. Box girder; 2. Transport trailer; 3. Bridgehead; 4. Main crane; 5. Auxiliary crane; 6. Lifting rope; 7. Main frame; 8. First clamping assembly; 81. First moving seat; 82. Adjusting component; 821. Main body seat; 822. Rotating roller; 823. Conveyor belt; 83. Pressing rod; 9. Second clamping assembly; 91. Second moving seat; 92. Limiting component; 921. Vertical rod; 922. Horizontal rod; 10. First drive mechanism; 101. First bidirectional screw; 102. First guide rod; 103. First motor; 11. Second... Drive mechanism; 111, second bidirectional screw; 112, second guide rod; 113, second motor; 12, abutting end; 13, pressure-bearing end; 14, groove; 15, contacting element; 16, linkage assembly; 161, first rack; 162, second rack; 163, toothed column; 17, abutment; 18, pier; 19, hook; 20, moving groove; 21, adjusting rod; 22, limiting rod; 23, arc groove; 24, sliding groove; 25, travel rod; 26, first clearance groove; 27, second clearance groove; 28, pad; 29, mounting cavity. Detailed Implementation

[0055] The following is in conjunction with the appendix Figure 1 To be continued Figure 9 This application will be described in further detail.

[0056] This application discloses a method for hoisting precast box girders for bridges. (Refer to...) Figure 1 The method for hoisting precast box girders for bridges includes the following steps.

[0057] Step 1: The longitudinal center line, transverse center line and the outline of the corresponding beam need to be marked on the supports of the bridge abutment 17 and the bridge pier 18 in advance. The center line of the beam needs to be marked on the box girder 1 in advance to indicate the alignment of the box girder 1.

[0058] Step 2: At the loading position of box girder 1, the box girder 1 is lifted onto the transport trailer 2 by a truck crane, and then the transport trailer 2 takes the box girder 1 to the lifting site at the bridgehead 3.

[0059] Among them, four transport trailers 2 operate in a cyclical manner. The transport channels in the construction area must be reinforced and leveled in advance to prevent severe vibrations during transportation. The speed of transport trailers 2 is controlled within 5km / h.

[0060] Step 3: The main crane 4 and the auxiliary crane 5 work together. The rated lifting capacity of the main crane 4 is greater than that of the auxiliary crane 5. Both the main crane 4 and the auxiliary crane 5 stay at the bridgehead 3.

[0061] In this embodiment, the rated lifting capacity of the main crane 4 is 500 tons, and the rated lifting capacity of the auxiliary crane 5 is 200 tons.

[0062] Step 4: The main crane 4 is used to lift the box girder 1 at the far end of the bridge abutment 3, and the auxiliary crane 5 is used to lift the box girder 1 at the near end of the bridge abutment 3. The main crane 4 bears the main lifting torque, and the auxiliary crane 5 assists in adjusting the posture of the box girder 1, lifting the box girder 1 to the designated position on the support of the bridge abutment 17 and the support of the bridge pier 18. During the lifting process, a total station is used to monitor the axial deviation of the box girder 1 from the support and the height difference between adjacent box girders 1 in real time.

[0063] During the translation of the beam, both ends should be moved simultaneously. The deviation of the box girder 1 from the support axis should be less than or equal to 2mm, and the height difference between adjacent box girders 1 should be less than or equal to 8mm. It should also be noted that both the main crane 4 and the auxiliary crane 5 use lifting ropes 6 for bottom-lifting of the box girder 1, and the box girder 1 is equipped with a lifting and positioning device to limit the movement of the lifting ropes 6. The lifting ropes 6 are steel wire ropes, and after being wound around the bottom of the box girder 1, the two ends of the lifting ropes 6 that are far apart are hooked onto the hooks 19 of the crane.

[0064] Furthermore, the hoisting sequence of box girder 1 adopts the method of first the middle girder and then the side girder. The bridge in this embodiment has two spans, and each span is equipped with thirteen box girders 1, as shown in the figure. Specifically, during the hoisting of box girder 1, the hoisting sequence is as follows: Z1-6, Z1-5, Z1-4, Z1-3, Z1-7, Y1-1, Y1-2, Y1-3, Y1-4, Y1-5, Y1-6, Z1-2, Z1-1, Z2-6, Z2-5, Z2-4, Z2-3, Z2-7, Y2-1, Y2-2, Y2-3, Y2-4, Y2-5, Y2-6, Z2-2, Z2-1. When hoisting Z1-6 to Z1-1, the transport trailer 2 and the crane are located at one end of the bridge 3 on one side of the bridge. When hoisting Z2-6 to Z2-1, the transport trailer 2 and the crane are located at the other end of the bridge 3 on the other side of the bridge, so that the hoisting of box girder 1 does not affect the passage of the river.

[0065] This application also discloses a hoisting and positioning device for use in the above-described method for hoisting precast box girders for bridges.

[0066] Reference Figure 2 and Figure 3 The hoisting and positioning device includes a main frame 7 and clamping components. The main frame 7 is a rectangular strip. The clamping components are in two sets and move symmetrically along the length of the main frame 7. The two sets of clamping components together clamp the box girder 1 and the hoisting rope 6 so that the hoisting rope 6 wound on the box girder 1 is positioned relative to the box girder 1, thereby improving the stability between the hoisting rope 6 and the box girder 1 and making it less likely for the hoisting rope 6 to shift relative to the box girder 1 during hoisting, causing the box girder 1 to sway.

[0067] Reference Figure 3 and Figure 4 The main frame 7 has a moving groove 20 extending through its upper and lower sides along its length, and the clamping assembly moves within the moving groove 20. Each clamping assembly includes a first clamping group 8 and a second clamping group 9, which are distributed along the length of the main frame 7. The first clamping group 8 moves on the main frame 7 via a first driving mechanism 10, and the second clamping group 9 moves on the main frame 7 via a second driving mechanism 11. In the two clamping assemblies, the two first clamping groups 8 are located between the two second clamping groups 9.

[0068] Reference Figure 2 , Figure 5 and Figure 6 Specifically, the first clamping assembly 8 includes a first movable seat 81, an adjusting member 82, and a pressing rod 83. The first movable seat 81 is block-shaped and moves along the length of the main frame 7 in the moving groove 20 of the main frame 7. The first movable seat 81 has a vertically penetrating adjusting groove on the side facing the second clamping assembly 9. The adjusting member 82 is a vertically extending rod-shaped rod that slides vertically in the adjusting groove. The adjusting member 82 has a vertically penetrating groove 14 on the side facing the second clamping assembly 9, which is used for the lifting rope 6 to be inserted. Furthermore, one end of the first movable seat 81 along the width direction of the main frame 7 is rotatably connected to an adjusting rod 21, and the other end is fixed with a limiting rod 22. Both the adjusting rod 21 and the limiting rod 22 extend vertically upward. The top of the adjusting member 82 is threaded onto the adjusting rod 21 and slides vertically onto the limiting rod 22, so that rotating the adjusting rod 21 can adjust the height position of the adjusting member 82.

[0069] The lower end of the adjusting member 82 extends downward beyond the lower side of the main frame 7. The pressing rod 83 is square-shaped and hinged in the middle to the outer side wall of the lower end of the adjusting member 82. The hinge axis of the pressing rod 83 is parallel to the width direction of the main frame 7. The two ends of the pressing rod 83 that are far apart from each other are the abutting end 12 and the pressure-bearing end 13, respectively. Each first clamping group 8 has two pressing rods 83, which are respectively hinged to both sides of the adjusting member 82 along the width direction of the main frame 7.

[0070] Reference Figure 2 and Figure 5 The second clamping assembly of 9 pieces includes a second movable seat 91 and a limiting member 92. The second movable seat 91 is block-shaped and moves along the length of the main frame 7 in the movable groove 20 of the main frame 7. The second movable seat 91 has an arc groove 23 that runs vertically through the second movable seat 91 on the side facing the corresponding first movable seat 81. The arc groove 23 is used to cooperate with the lifting rope 6 so that the lifting rope 6 can be inserted.

[0071] The limiting member 92 includes a vertical rod 921 and a horizontal rod 922. The vertical rod 921 slides vertically through the second movable seat 91, and its bottom end extends downward out of the second movable seat 91. The horizontal rod 922 slides along the width of the main frame 7 through the bottom end of the vertical rod 921. Both the vertical rod 921 and the horizontal rod 922 are threaded rods, and each has two nuts threaded onto it. The two nuts on the vertical rod 921 are threaded to move to abut against the upper and lower sides of the second movable seat 91, respectively. The height of the vertical rod 921 relative to the second movable seat 91 can be adjusted by adjusting the position of the nuts on the vertical rod 921. The two nuts on the horizontal rod 922 are threaded to move to abut against the opposite sides of the vertical rod 921, respectively. After the nuts on the horizontal rod 922 are removed from the horizontal rod 922, the horizontal rod 922 can be removed from the vertical rod 921, and the length of the horizontal rod 922 is greater than the distance between the two abutment rods 83 on both sides of the adjusting member 82. In addition, a guide groove extending along the axial direction of the vertical rod 921 is provided on the side wall of the vertical rod 921, and a guide block extending into the guide groove is provided in the second moving seat 91. When the vertical rod 921 moves up and down, the guide block slides in the guide groove to limit the rotation of the vertical rod 921 relative to the second moving seat 91.

[0072] Reference Figure 2 and Figure 5When the clamping components and lifting ropes 6 are attached to the box girder 1, the main frame 7 abuts against the upper surface of the box girder 1. The length extension direction of the main frame 7 is parallel to the width direction of the box girder 1. The two sets of clamping components are located on opposite sides of the box girder 1. The lifting ropes 6 are routed around the bottom plate of the box girder 1 and extend upward from opposite sides of the box girder 1. The two sides of the lifting ropes 6 are clamped between the adjusting parts 82 and the second moving seats 91 of the two sets of clamping components. At the same time, the first moving seats 81 of the two sets of clamping components abut against opposite sides of the flange plates of the box girder 1. The abutting end 12 of the pressing rod 83 abuts against the lower surface of the flange plate of the box girder 1. The vertical rod 921 is adjusted so that the horizontal rod 922 abuts against the upper surface of the pressure end 13 of the two opposing pressing rods 83. The inclination angle of the pressing rod 83 is consistent with the inclination angle of the lower surface of the abutting flange plate. The flange plates on both sides of the box girder 1 are clamped between the main frame 7 and the pressing rods 83.

[0073] Thus, the hoisting and positioning device positions the flange plate relative to the box girder 1 by clamping it with the main frame 7 and the pressure rod 83. The hoisting rope 6 is clamped by the first moving seat 81 and the adjusting member 82, so that the part of the hoisting rope 6 wrapped around the box girder 1 is positioned relative to the hoisting and positioning device. It should be noted that the corner at the bottom of the box girder 1 is isolated from the hoisting rope 6 by a pad 28 to reduce the wear of the hoisting rope 6 on the box girder 1 during hoisting.

[0074] By adjusting the distance between the two first movable seats 81, the distance between the two second movable seats 91, the height of the adjusting member 82 relative to the first movable seat 81, and the position of the crossbar 922 pressing down on the pressure bar 83, the hoisting positioning device can be adapted to box girders 1 of different sizes.

[0075] Reference Figure 2 and Figure 5 Furthermore, the first drive mechanism 10 includes a first bidirectional screw 101, a first guide rod 102, and a first motor 103, while the second drive mechanism 11 includes a second bidirectional screw 111, a second guide rod 112, and a second motor 113. The first bidirectional screw 101 and the second bidirectional screw 111 are rotatably connected to the main frame 7, and their axes are both parallel to the length direction of the main frame 7. The first guide rod 102 and the second guide rod 112 are both fixed to the main frame 7, and their length directions are both parallel to the length direction of the main frame 7. The first motor 103 is mounted on the main frame 7 and cooperates with the first bidirectional screw 101 to drive the first bidirectional screw 101 to rotate. The second motor 113 is mounted on the main frame 7 and cooperates with the second bidirectional screw 111 to drive the second bidirectional screw 111 to rotate.

[0076] Two first movable seats 81 in the two clamping assemblies are respectively threaded onto the positive thread section and the negative thread section of the first bidirectional screw 101, and the first movable seats 81 are simultaneously slidably sleeved on the first guide rod 102, the second bidirectional screw 111, and the second guide rod 112. Two second movable seats 91 in the clamping assembly are respectively threaded onto the positive thread section and the negative thread section of the second bidirectional screw 111, and the second movable seats 91 are simultaneously slidably sleeved on the first bidirectional screw 101, the first guide rod 102, and the second guide rod 112. Thus, when the first bidirectional screw 101 rotates, it drives the two first movable seats 81 to move symmetrically on the main frame 7, and when the second bidirectional screw 111 rotates, it drives the two second movable seats 91 to move symmetrically on the main frame 7.

[0077] Reference Figure 7 , Figure 8 and Figure 9 Furthermore, in this embodiment, the adjusting member 82 includes a main body 821, a rotating roller 822, and a conveyor belt 823. The main body 821 extends vertically and cooperates with the first movable seat 81, the adjusting rod 21, and the limiting rod 22. At the same time, the pressing rod 83 is hinged to the main body 821. The main body 821 has a mounting cavity 29 extending through both ends of the main body 821 on the side facing the second movable seat 91 in the same group. The depth of the mounting cavity 29 is deeper than the groove 14 formed by the adjusting member 82.

[0078] There are two rollers 822, which are rotatably connected to the upper and lower ends of the main body 821 and enter the mounting cavity 29. The axis of the rollers 822 is parallel to the width direction of the main frame 7, and the outer wall of the rollers 822 is smooth. The conveyor belt 823 is located in the mounting cavity 29 and is simultaneously sleeved on the two rollers 822. The side of the conveyor belt 823 facing the second movable seat 91 in the same group and the two opposing inner walls of the main body 821 in the mounting cavity 29 together form a groove 14.

[0079] Reference Figure 2 , Figure 5 and Figure 8 When the lifting rope 6 is used in conjunction with the lifting and positioning device, a gap is first left between the main body 821 and the second movable seat 91 for the lifting rope 6 to pass through. Then, the lifting rope 6 abuts into the groove 14 and against the conveyor belt 823. When the lifting rope 6 moves around the box girder 1 for position adjustment, it can drive the conveyor belt 823 to move relative to the rotating roller 822, or the rotating roller 822 to rotate simultaneously when the conveyor belt 823 moves. This reduces the friction on the lifting rope 6, improves the smoothness of the initial position adjustment, and reduces the wear of the lifting rope 6. After the position adjustment of the lifting rope 6 is completed, the second movable seat 91 is moved to clamp and position the lifting rope 6 between the conveyor belt 823 and the second movable seat 91.

[0080] Reference Figure 2 , Figure 8 and Figure 9 Furthermore, the space enclosed by the conveyor belt 823 includes an abutment 15, which is square in shape. The main body 821 has grooves 24 on the inner walls of opposite sides of the mounting cavity 29. The abutment 15 enters the grooves 24 on opposite sides. A travel rod 25, which passes through the abutment 15 along the length of the main frame 7, is fixed in the grooves 24 on the main body 821. The abutment 15 can move relative to the main body 821 along the length of the main frame 7. A linkage component 16 is provided between the second moving seat 91 and the abutment 15. When the second moving seat 91 moves away from the main seat, the linkage component 16 moves the abutment 15 to the cavity enclosed by the conveyor belt 823, preventing the abutment 15 from contacting the conveyor belt 823. At this time, the position of the suspension rope 6 can be adjusted. When the second movable seat 91 moves towards the main seat 821 until the second movable seat 91 and the conveyor belt 823 clamp the suspension rope 6 together, the linkage component 16 simultaneously drives the abutment 15 to move to press against the inner side of the conveyor belt 823, so that the second movable seat 91, the suspension rope 6, the conveyor belt 823 and the abutment 15 press against each other in sequence, so that the abutment 15 supports the conveyor belt 823 and the conveyor belt 823 is clamped to restrict movement, thereby improving the clamping effect of the suspension rope 6.

[0081] Specifically, the linkage assembly 16 includes a first rack 161, a second rack 162, and a toothed post 163. The first rack 161 is fixed to the side wall of the contact member 15, and the teeth of the first rack 161 are distributed sequentially along the length direction of the main frame 7. The main body 821 has a first clearance groove 26 for the first rack 161 to move along the length direction parallel to the main frame 7. The second rack 162 is fixed to the second movable seat 91, and the teeth of the second rack 162 are distributed sequentially along the length direction of the main frame 7. The end of the second rack 162 away from the second movable seat 91 extends into the main body 821 and is opposite to the first rack 161. The main body 821 has a second clearance groove 27 vertically provided to allow the second rack 162 to move.

[0082] The toothed post 163 is rotatably connected to the main body 821 and extends vertically. The toothed post 163 is spline-shaped and has teeth distributed sequentially along its circumference. At the same time, the toothed post 163 is located between the opposing first rack 161 and second rack 162, and the first rack 161 and second rack 162 are respectively engaged on opposite sides of the toothed post 163.

[0083] When the second movable seat 91 moves away from the main seat 821, and the space between the second movable seat 91 and the main seat 821 is large enough to allow the suspension rope 6 to pass freely, the contact member 15 is located in the space enclosed by the conveyor belt 823 and is separated from the conveyor belt 823. When the second movable seat 91 moves closer to the main seat 821, and the second movable seat 91 and the conveyor belt 823 clamp the suspension rope 6 together, the contact member 15 moves closer to the second movable seat 91 and presses against the conveyor belt 823 under the drive of the linkage component 16. It should be noted that when the distance between the second movable seat 91 and the main seat 821 is at its maximum, the first rack 161 and the second rack 162 are still engaged on the toothed post 163, and when the main seat 821 moves vertically relative to the second movable seat 91, the second rack 162 moves vertically on the toothed post 163 at the same time.

[0084] The implementation principle of a hoisting and positioning device according to an embodiment of this application is as follows: First, the main frame 7 is placed on top of the box girder 1. The distance between the two sets of clamping components is adjusted by the first drive mechanism 10 and the second drive mechanism 11 to adapt to the width of the box girder 1. The first clamping group 8 is adjusted so that the adjusting member 82 laterally presses against the flange plate, and the pressing rod 83 rotates to the abutting end 12 to press against the lower surface of the flange plate. After the hoisting rope 6 passes around the bottom of the box girder 1, it is placed in the groove 14 of the adjusting member 82. At this time, the structure of the conveyor belt 823 allows the hoisting rope 6 to move with low friction for adjustment.

[0085] After the position of the suspension rope 6 is adjusted, the second clamping group 9 is driven to move towards the first clamping group 8, and the second moving seat 91 and the conveyor belt 823 clamp the suspension rope 6 together. During this process, the linear motion of the second moving seat 91 is converted into the reverse motion of the abutment member 15 through the linkage component 16, so that it presses against the conveyor belt 823 from the inside, fixing the conveyor belt 823, so that the conveyor belt 823 and the second moving seat 91 work together to form a rigid clamp on the suspension rope 6. Then the limiting member 92 is adjusted to press the pressure end 13 of the pressure rod 83, restricting the rotation of the pressure rod 83.

[0086] When disassembling the hoisting positioning device, first release the clamp on the hoisting rope 6, remove the hoisting rope 6 from the hoisting positioning device, then release the clamp on the flange plate of the box girder 1, and move the hoisting positioning device upward away from the box girder 1.

[0087] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for hoisting a precast box girder of a bridge, characterized in that , comprising the following steps: S1, the box girder (1) is placed on the transport trailer (2), and the transport trailer (2) moves to the bridge head (3); S2, the main crane (4) and the auxiliary crane (5) are used for cooperative operation, the rated lifting weight of the main crane (4) is greater than that of the auxiliary crane (5), and the main crane (4) and the auxiliary crane (5) are all stayed at the bridge head (3); S3, the main crane (4) is used for lifting the box girder (1) at the far end of the bridge head (3), the auxiliary crane (5) is used for lifting the box girder (1) at the near end of the bridge head (3), the main crane (4) bears the main lifting torque, the auxiliary crane (5) assists in adjusting the posture of the box girder (1), and the box girder (1) is lifted to the specified position; the axis deviation of the box girder (1) relative to the support and the height difference of adjacent box girders (1) are monitored in real time by using a total station during lifting; The box girder (1) is lifted by using a bottom lifting type, and a lifting positioning device is used for limiting the lifting rope (6); The lifting positioning device comprises a main frame (7) and a clamping assembly; the main frame (7) extends along the width direction of the box girder (1) in the length direction, the clamping assembly is adjusted and moved along the length direction of the main frame (7), and there are two groups of clamping assemblies; the two groups of clamping assemblies correspond to the two sides of the box girder (1) along the width direction of the box girder (1) respectively; Each group of clamping assemblies comprises a first clamping group (8) and a second clamping group (9); the first clamping group (8) is used for clamping a flange plate of the box girder (1) together with the main frame (7); and the second clamping group (9) is used for clamping the lifting rope (6) together with the first clamping group (8); When the box girder (1) is lifted, the lifting rope (6) is arranged around the bottom plate of the box girder (1), and the lifting rope (6) passes through the two groups of clamping assemblies at the same time, so that the lifting rope (6) is clamped between the first clamping group (8) and the second clamping group (9); The first clamping group (8) comprises A first moving seat (81) is moved on the main frame (7) in the length direction of the main frame (7); An adjusting part (82) is adjusted and moved on the first moving seat (81) in the direction perpendicular to the length direction of the main frame (7); and A pressing rod (83) is arranged on the outer periphery of the adjusting part (82) and located on the lower side of the main frame (7); When the first clamping group (8) cooperates with the flange plate, the adjusting part (82) is abutted to the side wall of the flange plate, and the pressing rod (83) is abutted to the lower surface of the flange plate; The adjusting part (82) comprises A main body seat (821) is used for abutting to the flange plate, and the main body seat (821) has a mounting cavity (29) on the side corresponding to the second clamping group (9); A rotating roller (822) is rotatably connected to the main body seat (821), and is arranged at both ends of the main body seat (821); and A conveying belt (823) is sleeved on the rotating rollers (822) at both ends of the main body seat (821), and the conveying belt (823) and the side wall of the mounting cavity (29) on the side corresponding to the second clamping group (9) jointly enclose a groove (14) for the lifting rope (6) to abut into. The transmission belt (823) is surrounded by the abutting piece (15) moving along the length direction of the main frame (7) in the space, and the linkage assembly (16) is arranged between the second clamping group (9) and the abutting piece (15); when the second clamping group (9) moves towards the corresponding first clamping group (8), the abutting piece (15) is driven to move towards the second clamping group (9) through the linkage assembly (16), so that the transmission belt (823) is clamped between the sling (6) and the abutting piece (15).

2. The bridge precast box girder hoisting method according to claim 1, characterized in that: In S3, the axis deviation of the box girder (1) relative to the support is less than or equal to 2mm, and the height difference between adjacent box girders (1) is less than or equal to 8mm.

3. The bridge precast box girder hoisting method according to claim 1, characterized in that: In S3, the box girder (1) is hoisted in the order of middle beam first and side beam later.

4. The bridge precast box girder hoisting method according to claim 1, characterized in that: The first clamping group (8) in the two groups of clamping assemblies moves symmetrically on the main frame (7) through the first driving mechanism (10), and the second clamping group (9) in the two groups of clamping assemblies moves symmetrically on the main frame (7) through the second driving mechanism (11).

5. The method of claim 1, wherein: The abutting rod (83) is hinged to the adjusting piece (82), and the two ends of the abutting rod (83) away from each other are respectively the abutting end (12) and the pressure receiving end (13); The second clamping group (9) comprises a second moving seat (91) and a limiting piece (92), the second moving seat (91) moves on the main frame (7) along the length direction of the main frame (7), and the limiting piece (92) adjusts and moves on the second moving seat (91) along the direction perpendicular to the length direction of the main frame (7); When the adjusting piece (82) abuts against the flange plate side wall, the abutting rod (83) can be rotated to abut the pressure receiving end against the lower surface of the flange plate, and the pressure receiving end (13) extends out of the side of the adjusting piece (82) away from the flange plate; at the same time, the second moving seat (91) and the adjusting piece (82) jointly clamp the sling (6), and the limiting piece (92) presses down the pressure receiving end (13).

6. The bridge precast box girder hoisting method according to claim 1, characterized in that: The linkage assembly (16) comprises The first rack (161) is fixed to the side wall of the abutting piece (15); The second rack (162) is fixed to the second clamping group (9), and the second rack (162) extends into the main body seat (821) opposite to the first rack (161) at the same time; And The toothed column (163) has teeth distributed along the circumferential direction of the toothed column (163) in sequence, and is rotationally connected in the main body seat (821), and the opposite sides of the toothed column (163) are engaged with the first rack (161) and the second rack (162) respectively; Wherein, the teeth of the first rack (161) and the second rack (162) are distributed along the length direction of the main frame (7).

Images