Method for hoisting large steel structure in semi-cover excavation construction of subway station

Abstract

The invention relates to the technical field of civil engineering foundation pit supporting, in particular to a hoisting method for a large steel structure in semi-cover excavation construction of a subway station. Comprising an open excavation area and a cover excavation area; the steel structure is conveyed into the foundation pit from the open excavation area through a crane and conveyed to the cover excavation area from the interval area between the middle pile bodies; the position of the walking vehicle is adjusted, and the height of the carrier roller frame is adjusted through the lifting mechanism to correspond to the position of the conveyed steel structure; after the steel structure penetrates through a steel rope ring connected with the first electric hoist, the steel structure is conveyed to the small trailer, and the left end of the steel structure is located on the left side of the small trailer; the small trailer carries the steel structure to walk leftwards for a certain distance and is lifted by the steel rope ring connected with the electric hoist, and the small trailer and the steel structure jointly convey the steel structure to the steel enclosing purlin and are manually connected; after the steel structure in the area is installed, the walking beam is started to move forwards along the hanger rail, and the chain drives the walking vehicle to move to the next construction position at the same time. The method is simple in process, convenient to operate, high in construction efficiency and small in resource waste.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support technology in civil engineering, specifically a method for hoisting large steel structures in semi-cut-and-cover construction of subway stations. Background Technology

[0002] In the field of urban rail transit construction, subway stations are mostly located in bustling urban areas, with narrow construction sites and strict restrictions imposed by surrounding road traffic. Especially for semi-cut-and-cover stations in traffic-sensitive areas, how to safely and efficiently install steel supports within confined spaces has become a key technical challenge.

[0003] Currently, there are two main methods for installing traditional steel supports. First, a truck crane is used outside the pit to lift the assembled steel supports to the installation location, which are then lowered into the pit. Two excavators are then used to work together to move the supports under the cover plate. Finally, manual labor, along with the excavators, adjusts the supports to the designed position for erection. This method requires a large investment of manpower and machinery, resulting in high resource consumption. Furthermore, after the main station structure construction, the overlapping internal operations make the movement of the steel supports extremely difficult. Second, another method uses a truck crane to lift the steel supports into the pit, and then winches and hand-operated hoists are used under the cover plate for manual traction and installation. This method is inefficient, and the stability and safety of winches and other equipment in the complex pit environment are difficult to guarantee. Summary of the Invention

[0004] The purpose of this invention is to design a method for hoisting large steel structures in the semi-cut-and-cover construction of subway stations that is simple in process, convenient in operation, efficient in construction, and low in resource waste.

[0005] This invention includes an open-cut zone and a cut-and-cover zone with a roof slab; steel walers are installed on the side piles of the cut-and-cover zone, and central piles are spaced apart on the other side of the cut-and-cover zone; a longitudinal hanging rail is fixed below the roof slab, and a traveling beam with transverse guide rails is connected to the hanging rail; a first electric hoist that cooperates with the transverse guide rails is installed on the traveling beam; traveling guide rails along the length of the cut-and-cover zone are respectively installed on the lower parts of the side piles and the central piles; a traveling trolley is installed on the traveling guide rails, and traveling wheels that cooperate with the traveling guide rails are installed at both ends of the traveling trolley; a transverse guiding mechanism is installed on the traveling trolley, and a small trolley cooperates with the transverse guiding mechanism; a set of longitudinal rollers is installed on the small trolley through a roller frame; the traveling beam and the traveling trolley are connected to each other by a chain on one side of their respective forward directions; the small trolley includes its lower base, and the roller frame is connected to the lower base through a lifting mechanism. The installation method for steel structures is as follows: (1) The crane delivers the steel structure from the open-cut area to the foundation pit and from the interval between the central piles to the cut-and-cover area. There are at least two connection points between the crane and the steel structure, and the point closest to the cut-and-cover area is spaced apart from the left end of the steel structure. (2) Adjust the longitudinal position of the traveling vehicle and adjust the height of the roller frame through the lifting mechanism so that it corresponds to the position of the steel structure being transported; after the steel structure passes through the steel rope loop connected to the first electric hoist, transport the steel structure to the small trolley and position its left end on the left side of the small trolley. (3) The trolley and electric hoist carry the steel structure a distance to the left and deliver the steel structure to the steel waler, where it is connected manually; (4) After the steel structure in the area is installed, start the traveling beam to move forward along the longitudinal rail, and the traveling vehicle will be driven by the chain to move to the next construction position.

[0006] Furthermore, an upper base is provided between the roller frame and the lower base; the lifting mechanism includes a first lifting mechanism between the upper base and the lower base and a second lifting mechanism between the upper base and the roller frame; the first lifting mechanism is a large-amplitude lifting mechanism, and the second lifting mechanism is a fine-tuning lifting mechanism; during installation, the first lifting mechanism is used to adjust the height position of the roller frame and the steel structure in step (2); the second lifting mechanism further fine-tunes the consistency of the height of the roller frame and the steel structure in step (2); and / or, the first lifting mechanism and the second lifting mechanism adjust the height of the roller frame in step (3) so that it corresponds to the position of the steel waler.

[0007] Furthermore, the first lifting mechanism includes two sets of interlocking connecting rods connected between the upper base and the lower base. The upper and lower ends of one side of the two sets of connecting rods are respectively connected to the upper base and the lower base via shafts, and the upper and lower ends of the other side are respectively engaged with the transverse elongated holes of the upper base and the lower base via sliders. The intermediate shaft connecting the hinge points of the two sets of connecting rods is hinged to the piston rod of the hydraulic cylinder via a connecting shaft. The cylinder body of the hydraulic cylinder is connected to the lower base via the connecting shaft.

[0008] Furthermore, the second lifting mechanism is a jack; or, the second lifting mechanism includes vertical guide grooves on the front and rear sides of the upper base, and guide pins located in the vertical guide grooves are provided on the front and rear sides of the roller frame; a torsion motor is fixed on the upper base, and there are two identical sprockets on the shaft of the torsion motor, which are connected to the sprockets on the two eccentric wheel shafts on both sides of the shaft by chains, the sprockets on the two eccentric wheel shafts are identical, and at least one eccentric wheel is installed on each eccentric wheel shaft, and a contact plate that mates with each eccentric wheel is provided at the lower part of the roller frame.

[0009] Furthermore, the lateral guide mechanism is a lateral guide groove installed on the traveling vehicle, and the rollers of the trolley are located in the lateral guide groove.

[0010] Furthermore, protruding baffles are provided on the left end and front and rear sides of the idler frame. The upper end of the left baffle is lower than the highest point of the idler. When the steel structure is placed on the idler and the flange at its port is placed to the left of the left baffle, the steel structure will move to the left when the trolley moves to the left. The baffles on the front and rear sides are higher than the highest point of the idler.

[0011] Furthermore, two electric hoists are installed on the traveling beam. During the transportation of the steel structure, the steel rope loops connected to the two electric hoists are located on the left and right sides of the trolley, respectively, to assist in the balance of the steel structure and to assist in positioning when docking with the steel waler.

[0012] The beneficial effects of this invention are: This invention achieves direct, efficient, stable, and precise transportation and installation of steel structures from the open-cut area to the cut-and-cover area by setting up a special transportation and installation system consisting of a traveling guide rail, a traveling vehicle, a small trolley, a hanging rail under the top slab of the cut-and-cover area, a traveling crossbeam, and an electric hoist. This effectively avoids the cumbersome process of multiple transfers within the foundation pit in traditional processes, greatly simplifies the construction process, and improves construction efficiency.

[0013] Furthermore, through the coordinated operation of the traveling vehicle and the small trolley, combined with the hoisting assistance of the electric hoist, the continuous, stable movement and precise positioning of the steel structure were achieved, which significantly reduced the intensity of manual labor and construction safety risks. At the same time, it reduced the reliance on a large number of auxiliary machines such as excavators and winches and manpower, thereby saving resources and reducing costs.

[0014] Furthermore, the first and second lifting mechanisms equipped on the trolley can make significant adjustments and precise fine-tuning to the height of the roller frame, ensuring the height matching and stability of the steel structure during reception, transportation, and final docking with the steel waler, thereby improving installation accuracy and operational safety. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the main structure of the cut-and-cover area during the construction process of this invention; Figure 2 This is a three-dimensional structural diagram of the cooperation between the traveling vehicle and the small trolley in this invention; Figure 3 This is a three-dimensional exploded view of the small motorcycle in this invention; Figure 4 for Figure 3 A three-dimensional structural diagram of the upper and middle base and the second lifting mechanism; Figure 5 This is a schematic diagram of the structure of step (1) of the present invention; Figure 6 This is a schematic diagram of the structure of step (2) of the present invention; Figure 7This is a schematic diagram of the structure of step (3) of the present invention; Figure 8 This is a schematic diagram of the structure of step (3) of the present invention; Figure 9 This is a schematic diagram of the structure of step (4) of the present invention; Among them, 1. Open-cut area, 2. Cut-and-cover area, 21. Side piles, 22. Central piles, 23. Connecting beam, 3. Top plate, 31. Suspension rail, 32. Traveling crossbeam, 33. Transverse guide rail, 34. First electric hoist, 35. Second electric hoist, 36. Steel rope ring, 37. Fixing buckle, 38. Chain, 4. Steel waler, 5. Traveling guide rail, 6. Traveling trolley, 61. Traveling wheel, 62. Transverse guide groove, 63. Fixing ring, 7. Small trolley, 71. Roller frame, 711. Roller, 712. Steel plate, 713. Contact plate, 71 4. Baffle, 715. Guide pin, 72. Upper base, 721. Vertical guide groove, 722. Hinge seat, 723. Guide seat, 73. Lower base, 731. Horizontal elongated hole, 74. First lifting mechanism, 741. Connecting rod, 742. Slider, 743. Connecting shaft, 744. Hydraulic cylinder, 75. Second lifting mechanism, 751. Torsion motor, 752. Sprocket, 753. Eccentric wheel shaft, 754. Eccentric wheel, 76. Roller, 8. Steel structure, 81. Left connection point of crane, 82. Right connection point of crane. Detailed Implementation

[0016] This invention is based on Figure 1 Define the up / down and left / right directions in this embodiment; wherein, with Figure 1 One side of the connecting chain 38 of the central traveling carriage 6 is defined as the front in this embodiment, and the opposite side is the rear.

[0017] As shown in the figure, this embodiment includes an open-cut zone 1 and a cut-and-cover zone 2 with a roof slab 3. Steel walers 4 are installed on the side piles 21 of the cut-and-cover zone 2, and central piles 22 are spaced apart on the other side of the cut-and-cover zone 2. The steel walers 4 and the central piles 22 are evenly distributed along the length of the cut-and-cover zone 2, and the central piles 22 are located on the boundary between the cut-and-cover zone 2 and the open-cut zone 1. The open-cut zone 1 is provided with steel walers 4 corresponding to the positions of the cut-and-cover zone 2, and the steel walers 4 are arranged in multiple layers according to the depth of the open-cut zone 1 and the cut-and-cover zone 2. Connecting beams 23 are provided between adjacent central piles 22, and the connecting beams 23 have the same number of layers as the steel walers 4. They are located below the fixed steel structure 8, providing reinforcement and support for the central piles 22 and the steel structure 8 of the cut-and-cover zone 2.

[0018] A longitudinal hanging rail 31 is fixed below the top plate 3 of the cut-and-cover area 2. A traveling beam 32 with a transverse guide rail 33 is connected to the hanging rail 31. A first electric hoist 34 that cooperates with the transverse guide rail 33 is installed on the traveling beam 32. Lifting rings are provided at both the left and right ends of the traveling beam 32.

[0019] The hoisting rail 31 is fixedly connected to the roof slab 3 along the length of the cut-and-cover area 2. A traveling beam 32 connected to the hoisting rail 31 is perpendicular to the hoisting rail 31. Two electric hoists are mounted on the traveling beam 32, and each hoist is located on the left and right sides of the traveling beam 32 respectively, connected to a steel rope loop 36 via a transverse guide rail 33. The electric hoist on the right is the first electric hoist 34, and the electric hoist on the left is the second electric hoist 35. The steel rope loop 36 is formed by folding the lower end of the wire rope upwards and fixing it with a fixing buckle 37, creating a loop due to the wire rope's flexibility. The fixing buckle 37 uses existing technology, which allows for easy fixing of the wire rope to form the steel rope loop 36 and also allows the steel rope loop 36 to be unfolded.

[0020] In this embodiment, the lower parts of the side piles 21 and the middle piles 22 are respectively equipped with parallel and corresponding travel guide rails 5 along the length direction and position of the cut-and-cover area 2. The travel guide rails 5 can enhance the stability of the side piles 21 and the middle piles 22. A traveling vehicle 6 is provided on the travel guide rails 5. The two ends of the traveling vehicle 6 are provided with traveling wheels 61 that cooperate with the travel guide rails 5. The traveling wheels 61 are self-locking to ensure the stability of the traveling vehicle 6 during the transportation of the steel structure 8.

[0021] The traveling vehicle 6 is a rectangular frame welded from steel, with wheels 61 at both ends of the front and rear crossbeams. A transverse guide mechanism is provided on the traveling vehicle 6, and a small trolley 7 cooperates with the transverse guide mechanism. The transverse guide mechanism is a transverse guide groove 62 on the traveling vehicle 6, and the rollers 76 of the small trolley 7 are located within the transverse guide groove 62. The transverse guide groove 62 is set along the length of the traveling vehicle 6 on its front and rear crossbeams. The rollers 76 on the bottom of the small trolley 7 on its front and rear crossbeams cooperate with the transverse guide groove 62. The rollers 76 of the small trolley 7 can be self-locking, allowing them to be fixed at any position in the transverse guide groove 62. Baffles can be provided on the outer sides of the front and rear crossbeams of the traveling vehicle 6 for limiting and protecting them.

[0022] The traveling beam 32 and the traveling vehicle 6 are connected by a chain 38 on one side of their respective forward directions. The outer sides of the crossbeams on both the front and rear sides of the traveling vehicle 6 are equipped with fixing rings 63 connected to the chain 38. The traveling vehicle 6 can connect the lower end of the chain 38 to the fixing ring 63 on either the front or rear side, depending on its forward direction. The upper end of the chain 38 is connected to the lifting rings at both ends of the traveling beam 32. This chain 38 design not only does not affect the transportation and installation of the steel structure 8, but also allows for convenient access to the next working position after installation, reducing the labor intensity of workers.

[0023] In this embodiment, the trolley 7 is equipped with a set of longitudinally arranged rollers 711 via a roller frame 71, and the trolley 7 includes a lower base 73. The roller frame 71 is connected to the lower base 73 via a lifting mechanism, and an upper base 72 is provided between the roller frame 71 and the lower base 73. The lifting mechanism includes a first lifting mechanism 74 between the upper base 72 and the lower base 73, and a second lifting mechanism 75 between the upper base 72 and the roller frame 71; the first lifting mechanism 74 is a large-amplitude lifting mechanism, and the second lifting mechanism 75 is a fine-tuning lifting mechanism. The design of the trolley 7 enables the transport of the steel structure 8 to the left without being affected by protruding structures on the object, such as flanges.

[0024] The idler frame 71 includes front and rear steel plates 712 and a pair of contact plates 713 fixedly connected to the left and right sides of the front and rear steel plates 712. The left end and the front and rear sides of the idler frame 71 are provided with protruding baffles 714. The upper end of the left baffle 714 is lower than the highest point of the idler 711. When the steel structure 8 is placed on the idler 711 and the flange at its port is placed to the left of the left baffle 714, the steel structure 8 will move to the left when the trolley 7 moves to the left. The front and rear baffles 714 are higher than the highest point of the idler 711. The left end baffle 714 is welded to the upper surface of the left contact plate 713, and the right end can also be provided with the same right end baffle 714 as the left end, which serves to reinforce the roller frame 71; the front and rear baffles 714 are respectively welded to the upper surfaces of the front and rear steel plates 712. The front and rear baffles 714 are higher than the highest point of the roller 711 to prevent the steel structure 8 from slipping during the transportation process, which serves as a limiting function. A set of longitudinal rollers 711 is provided between the front and rear baffles 714 to support the steel structure 8 and assist in the leftward transportation of the steel structure 8.

[0025] The first lifting mechanism 74 described in this embodiment includes two sets of interlocking connecting rods 741 that are hinged together between the upper base 72 and the lower base 73. The upper and lower ends of one side of the two sets of connecting rods 741 are respectively connected to the upper base 72 and the lower base 73 via shafts, and the upper and lower ends of the other side are respectively engaged with the transverse elongated holes 731 of the upper base 72 and the lower base 73 via sliders 742. The intermediate shaft connecting the hinge points of the two sets of connecting rods 741 is hinged to the piston rod of the hydraulic cylinder 744 via a connecting shaft 743. The cylinder body of the hydraulic cylinder 744 is connected to the lower base 73 via the connecting shaft 743.

[0026] The two sets of interlocking connecting rods 741 can be respectively located on the left and right sides or the front and rear sides, but the lifting height is higher when located along the length of the trolley 7. Therefore, in this embodiment, the two sets of connecting rods 741 are respectively located on the inner sides of the left and right crossbeams of the trolley 7 and their positions correspond to each other. The upper and lower ends of the front sides of the two sets of connecting rods 741 are respectively hinged to the hinge seats 722 on the left and right sides of the upper base 72 and the crossbeams on the left and right sides of the lower base through shafts. The upper and lower ends of the rear sides are respectively engaged with the guide seats 723 on the left and right sides of the upper base 72 and the transverse elongated holes 731 on the crossbeams on the left and right sides of the lower base through sliders 742.

[0027] The intermediate shaft positions of the corresponding lower cross hinge points of the two sets of connecting rods 741 are connected by the connecting shaft 743, which also provides support. The intermediate shaft positions of the sliders 742, whose corresponding lower rear ends of the two sets of connecting rods 741 mate with the transverse elongated holes 731 of the lower base 73, are connected by the connecting shaft 743, allowing the lower rear ends of the two sets of connecting rods 741 to slide against the lower base 73. Furthermore, this embodiment includes a pair of symmetrically positioned hydraulic cylinders 744. The bottom of each cylinder is connected to a hinge seat on the connecting shaft 743 at the lower rear end of the two sets of connecting rods 741, thus connecting them to the lower base 73. The piston rods are connected to hinge seats on the connecting shaft 743 at the lower cross hinge points of the two sets of connecting rods 741.

[0028] The second lifting mechanism 75 described in this embodiment is a jack; or, the second lifting mechanism 75 includes vertical guide grooves 721 provided on the front and rear sides of the upper base 72, and guide pins 715 located in the vertical guide grooves 721 are provided on the front and rear sides of the roller frame 71; a torsion motor 751 is fixed on the upper base 72, and there are two identical sprockets 752 on the shaft of the torsion motor 751. They are respectively connected to the sprockets 752 on the two eccentric wheel shafts 753 on both sides by chains. The sprockets 752 on the two eccentric wheel shafts 753 are the same, and at least one eccentric wheel 754 is installed on each eccentric wheel shaft 753. A contact plate 713 that cooperates with each eccentric wheel 754 is provided at the lower part of the roller frame 71.

[0029] The two eccentric wheels 754 are located on the front and rear sides inside the upper base 72, and their two ends are rotatably connected to the crossbeams on the left and right sides of the upper base 72, respectively. Each eccentric wheel shaft 753 has an eccentric wheel 754 fixedly installed at both ends inside the upper base 72. Each eccentric wheel 754 corresponds to and cooperates with the contact plates 713 on the left and right sides of the roller frame 71.

[0030] In this embodiment, the installation method of the steel structure is as follows: (1) The crane delivers the steel structure 8 from the open-cut area 1 to the foundation pit and from the interval between the central piles 22 to the cut-and-cover area 2. There are at least two connection points between the crane and the steel structure 8, and the point closest to the cut-and-cover area 2 is spaced apart from the left end of the steel structure 8.

[0031] The spacing ensures that when the left connection point of the crane is close to the junction of the cut-and-cover zone 2 and the open-cut zone 1, the flange at the left end of the steel structure 8 can be located to the left of the baffle 714 at the left end of the trolley 7.

[0032] (2) Adjust the longitudinal position of the traveling vehicle 6 and adjust the height of the roller frame 71 through the lifting mechanism so that it corresponds to the position of the steel structure 8 being transported; after the steel structure 8 passes through the steel rope loop 36 connected to the first electric hoist 34, transport the steel structure 8 to the small trolley 7 and position its left end on the left side of the small trolley 7.

[0033] The two electric hoists on the traveling beam 32 are, on the right, the first electric hoist 34, and on the left, the second electric hoist 35. The initial positions of the first electric hoist 34 and the second electric hoist 35 are both placed on the right. The first electric hoist 34 is located at the rightmost position of the right side of the transverse guide rail 33. The second electric hoist 35 does not need to be at the rightmost position of the left side of the transverse guide rail 33. It is sufficient to ensure that the distance to the leftmost side can assist the trolley 7 in completing the docking of the steel structure 8 and the steel waler 4. The first electric hoist 34 and the second electric hoist 35 are respectively connected to steel rope loops 36. During the transportation of the steel structure 8, the steel rope loops 36 connected to the two electric hoists are located on the left and right sides of the trolley 7, respectively, to assist in the balance of the steel structure 8 and to assist in positioning when docking with the steel waler 4.

[0034] Its trolley 7 is located between the steel rope loops 36 connected by the two electric hoists. Its initial position is on the right side of the traveling vehicle 6 and in contact with the steel rope loop 36 connected by the first electric hoist 34, which makes it easier for the crane to place the steel structure 8 on the trolley 7. The steel rope loops 36 connecting the two electric hoists are all folded upwards from the lower end of the steel wire rope and fixed to the steel wire rope itself by the fixing buckle 37. Due to the high toughness of the steel wire rope, a loop is formed at its lower end. The lowest point of the loop is lower than the roller frame 71 of the small trolley 7, ensuring that the steel structure 8 can pass through the loop. After the steel structure 8 is placed on the trolley 7, the wire rope at the connection point 81 on the left side of the crane is loosened; at this time, the trolley 7 can be manually pushed to move to the left along the lateral guide mechanism of the traveling vehicle 6 to connect with the steel waler 4.

[0035] (3) The trolley 7 and the electric hoist carry the steel structure 8 to the left for a distance and deliver the steel structure 8 to the steel waler 4, where it is connected manually.

[0036] The trolley 7 carries the steel structure 8 to the left and moves to the second electric hoist 35. The trolley 7 can be fixed in place. With the help of the crane, the rollers 711 on the roller frame 71 can move the steel structure 8 to the left and pass through the lower end of the steel rope loop 36 connected to the second electric hoist 35. When the right-side connection point of the crane has reached the boundary between the open-cut area 1 and the cut-and-cover area 2, and can no longer transport to the left, first tighten the steel cable loops 36 connected to the two electric hoists to lift the steel structure 8. Then loosen the wire rope at the right-side connection point 82 of the crane. At this time, the steel cable loops 36 can exert a lifting force on the steel structure, so the steel structure 8 does not need to be removed from the support of the idler rollers 711. Just ensure the balance of the steel structure 8. Then, the steel cable loops 36 connected to the two electric hoists and the small trolley 7 together transport the steel structure 8 to the steel waler 4. At this time, the height of the idler roller frame 71 can be adjusted by the first lifting mechanism 74 and the second lifting mechanism 75 to align the steel structure 8 with the steel waler 4, and then the connection can be secured manually.

[0037] After the steel structure 8 of the cut-and-cover zone 2 is installed, the steel structure 8 of the open-cut zone 1 is lifted by a crane and placed into the foundation pit of the open-cut zone 1 to be connected and installed with the steel structure 8 of the cut-and-cover zone 2 and the steel waler 4 of the open-cut zone 1.

[0038] (4) After the steel structure 8 in the area is installed, the traveling beam 32 is started to move forward along the longitudinal hanging rail 31, and the traveling vehicle 6 is driven by the chain 38 to move to the next construction position.

[0039] During the installation of the steel structure 8 in this area, the traveling wheels 61 of the traveling vehicle 6 are in self-locking mode, which can ensure the stability of the entire transportation process. After the steel structure 8 in the area is installed, the self-locking of the traveling wheel 61 of the traveling vehicle 6 is released, and its traveling beam 32 moves to the next construction and installation area. At this time, the traveling beam 32 is connected to the fixing ring 63 on the side of the next construction and installation area of ​​the traveling vehicle 6 through the chain 38, thus driving the traveling vehicle 6 to the next construction position.

[0040] It should be noted that during the installation of the steel structure 8, the first lifting mechanism 74 of the trolley 7 is used to adjust the height of the roller frame 71 to correspond with the height of the steel structure 8 in step (2); the second lifting mechanism 75 further fine-tunes the consistency of the height of the roller frame 71 with the height of the steel structure 8 in step (2), and makes it higher than the height of the connecting beam 23 between the middle piles 22 to prevent friction; and / or, the first lifting mechanism 74 and the second lifting mechanism 75 adjust the height of the roller frame 71 in step (3) to make it correspond with the position of the steel waler 4.

[0041] In step (2), the height of the roller frame 71 is first adjusted to correspond with the height of the steel structure 8 using the first lifting mechanism 74 of the trolley 7, so that the highest point of the roller 711 on the roller frame 71 is basically aligned with the lowest point of the steel structure 8. The two can be level or the roller 711 can be slightly lower, and the height difference between the highest point of the roller 711 and the lowest point of the steel structure 8 does not exceed 10cm. The purpose is to leave room for subsequent precise adjustment, ensuring that after the first lifting mechanism 74 is adjusted to the correct position, the height of the roller frame 71 can enter the effective adjustment range of the second lifting mechanism 75.

[0042] After completing the initial positioning, the second lifting mechanism 75 is activated for fine-tuning to further ensure the consistency of the height between the roller frame 71 and the steel structure 8. Through fine-tuning, the roller 711 is made flush with the bottom of the steel structure 8. It is important to ensure that the support height of the roller 711 is higher than the top surface of the connecting beam 23 between the central piles 22. This creates a safe clearance between the bottom of the steel structure 8 and the connecting beam 23 during the pushing or sliding process, preventing friction and ensuring a smooth and stable sliding process.

[0043] After entering step (3), for the connection between the steel structure 8 and the steel waler 4, the use of the first lifting mechanism 74 and the second lifting mechanism 75 can be flexibly selected, specifically including the following three situations, to fully cover all the operational logic included in "and / or": 1. Using only the first lifting mechanism 74: When the height adjustment requirement is large and exceeds the effective adjustment range of the second lifting mechanism 75, the first lifting mechanism 74 is driven alone to quickly raise or lower the roller frame 71 to a height range that roughly matches the steel waler 4. After the rough adjustment is completed, the docking operation can be carried out.

[0044] 2. Using only the second lifting mechanism 75: When the initial height of the roller frame 71 is close to the installation height of the steel waler 4, the second lifting mechanism 75 is used for fine adjustment to ensure that the height of the roller frame 71 is precisely aligned with the steel waler 4, thus guaranteeing the docking accuracy.

[0045] 3. Simultaneously employing the first lifting mechanism 74 and the second lifting mechanism 75: First, the first lifting mechanism 74 quickly adjusts the roller frame 71 to near the height of the steel waler 4, and then the second lifting mechanism 75 performs the final fine adjustment, balancing adjustment efficiency and docking accuracy. This is suitable for scenarios with large height deviations and high docking requirements.

[0046] By flexibly switching between the three adjustment modes mentioned above, the docking requirements of steel structure 8 and steel waler 4 under different working conditions can be adapted, which not only ensures installation efficiency but also achieves precise alignment, avoiding docking difficulties or structural damage due to height deviation.

[0047] Structures not specifically described in this embodiment are all existing technologies and will not be elaborated upon here.

Claims

1. A method for hoisting large steel structures in a semi-cut-and-cover construction of a subway station, comprising an open-cut area and a cut-and-cover area with a roof slab; steel walers are installed on the side piles of the cut-and-cover area, and central piles are installed at intervals on the other side of the cut-and-cover area; a longitudinal hoisting rail is fixed below the roof slab, and a traveling beam with transverse guide rails is connected to the hoisting rails; a first electric hoist that cooperates with the transverse guide rails is installed on the traveling beam, characterized in that: The lower parts of the side piles and the middle piles are respectively equipped with traveling guide rails along the length of the cut-and-cover area. A traveling trolley is mounted on the traveling guide rail, and traveling wheels that cooperate with the traveling guide rail are mounted at both ends of the traveling trolley. The traveling trolley is equipped with a transverse guide mechanism, and a small trolley cooperates with the transverse guide mechanism. A set of longitudinal rollers is mounted on the small trolley through a roller frame. The traveling beam and the traveling trolley are connected to each other by a chain on one side of their respective forward directions. The small trolley includes its lower base, and the roller frame is connected to the lower base through a lifting mechanism. The installation method for steel structures is as follows: (1) The crane delivers the steel structure from the open-cut area to the foundation pit and from the interval between the central piles to the cut-and-cover area. There are at least two connection points between the crane and the steel structure, and the point closest to the cut-and-cover area is spaced apart from the left end of the steel structure. (2) Adjust the longitudinal position of the traveling vehicle and adjust the height of the roller frame through the lifting mechanism so that it corresponds to the position of the steel structure being transported; after the steel structure passes through the steel rope loop connected to the first electric hoist, transport the steel structure to the small trolley and position its left end on the left side of the small trolley. (3) The trolley and electric hoist carry the steel structure a distance to the left and deliver the steel structure to the steel waler, where it is connected manually; (4) After the steel structure in the area is installed, start the traveling beam to move forward along the longitudinal rail, and the traveling vehicle will be driven by the chain to move to the next construction position.

2. The method for hoisting large steel structures in semi-cut-and-cover construction of subway stations according to claim 1, characterized in that: An upper base is provided between the roller frame and the lower base; the lifting mechanism includes a first lifting mechanism between the upper base and the lower base and a second lifting mechanism between the upper base and the roller frame; the first lifting mechanism is a large-amplitude lifting mechanism and the second lifting mechanism is a fine-tuning lifting mechanism; during installation, the first lifting mechanism is used to adjust the height position of the roller frame and the steel structure in step (2); the second lifting mechanism further fine-tunes the consistency of the height of the roller frame and the steel structure in step (2); and / or, the first lifting mechanism and the second lifting mechanism adjust the height of the roller frame in step (3) so that it corresponds to the position of the steel waler.

3. The method for hoisting large steel structures in semi-cut-and-cover construction of subway stations according to claim 2, characterized in that: The first lifting mechanism includes two sets of interlocking connecting rods connected between the upper base and the lower base. The upper and lower ends of one side of the two sets of connecting rods are connected to the upper base and the lower base respectively via shafts, and the upper and lower ends of the other side are respectively engaged with the transverse elongated holes of the upper base and the lower base via sliders. The intermediate shaft connecting the hinge points of the two sets of connecting rods is hinged to the piston rod of the hydraulic cylinder via a connecting shaft. The cylinder body of the hydraulic cylinder is connected to the lower base via a connecting shaft.

4. The method for hoisting large steel structures in semi-cut-and-cover construction of subway stations according to claim 2 or 3, characterized in that: The second lifting mechanism is a jack; or, the second lifting mechanism includes vertical guide grooves on the front and rear sides of the upper base, and guide pins located in the vertical guide grooves on the front and rear sides of the roller frame; a torsion motor is fixed on the upper base, and there are two identical sprockets on the shaft of the torsion motor. They are connected to the sprockets on the two eccentric wheel shafts on both sides of the shaft by chains. The sprockets on the two eccentric wheel shafts are the same, and at least one eccentric wheel is installed on each eccentric wheel shaft. A contact plate that mates with each eccentric wheel is provided at the lower part of the roller frame.

5. The method for hoisting large steel structures in semi-cut-and-cover construction of subway stations according to claim 1, 2, or 3, characterized in that: The lateral guide mechanism is a lateral guide groove installed on the traveling vehicle, and the rollers of the small trolley are located in the lateral guide groove.

6. The method for hoisting large steel structures in semi-cut-and-cover construction of subway stations according to claim 1, 2, or 3, characterized in that: The left end and front and rear sides of the idler frame are equipped with protruding baffles. The upper end of the left baffle is lower than the highest point of the idler. When the steel structure is placed on the idler and the flange at its port is placed to the left of the left baffle, the steel structure will move to the left when the trolley moves to the left. The front and rear baffles are higher than the highest point of the idler.

7. The method for hoisting large steel structures in semi-cut-and-cover construction of subway stations according to claim 1, 2, or 3, characterized in that: Two electric hoists are installed on the traveling beam. During the transportation of the steel structure, the steel rope loops connected to the two electric hoists are located on the left and right sides of the trolley, respectively, to assist in the balance of the steel structure and to assist in positioning when docking with the steel waler.

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