A method for overall hoisting construction of large-span double-slope trapezoidal steel roof truss

Abstract

The present invention belongs to the technical field of steel structure construction, and provides a large-span double-slope trapezoidal steel roof truss overall hoisting construction method, including: S1, transporting the left-end steel roof truss, the middle steel roof truss, the right-end steel roof truss and the connecting web rod to the construction site; S2, assembling the steel roof truss on the ground on site; S3, hoisting the steel roof truss as a whole: using a binocular camera calibration system to obtain the spatial coordinates of all targets, and then monitoring in real time whether there is a synchronization difference in the overall hoisting of the steel roof truss; S4, temporarily fixing the steel roof truss; S5, permanently fixing the steel roof truss. The present invention adopts binocular recognition machine vision technology to determine the spatial posture in the overall hoisting of the steel roof truss, timely identify and judge the coordination anomaly in the overall hoisting of the steel roof truss and timely issue an early warning, effectively control the synchronization of the overall hoisting of the two cranes, and can achieve the purpose of making the overall hoisting process of the steel roof truss convenient, saving construction period, reducing costs, and being safe and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of steel structure construction, and in particular relates to an integral hoisting construction method for a large-span double-slope trapezoidal steel roof truss. Background Art

[0002] In recent years, the application of steel structures in large-span single-story industrial plants in my country has attracted the attention of countries around the world. In the future, my country's large-span steel structure single-story industrial plants will continue to maintain a rapid growth trend for a long time. In single-story industrial plants, we usually call the transverse truss-type components in the roof structure as roof trusses. The shapes of ordinary steel roof trusses in single-story industrial plants are usually triangular, trapezoidal, and herringbone, and the slope of the roof trusses can be divided into single slope and double slope. For large-span roof trusses with a span of not less than 42 meters, double-slope trapezoidal steel roof trusses are usually used.

[0003] With the development of construction technology, more and more large-span double-slope trapezoidal steel roof trusses have begun to adopt hoisting and installation construction methods, and their hoisting and installation construction methods generally include segmented hoisting and overall hoisting.

[0004] Segmented hoisting usually involves first manufacturing the large-span double-slope trapezoidal steel roof truss in sections and then transporting it to the site. Before hoisting, a full-height scaffold is set up on site, and then a single crane is used to hoist the segmented steel roof truss to high altitude, where workers assemble the segmented steel roof truss into a whole on the high-altitude scaffold. Since segmented hoisting requires the erection of a full-height scaffold, this will greatly increase the construction workload, extend the construction period and increase costs. In addition, since construction workers are required to complete the assembly on the high-altitude scaffold, the workload of construction workers at high altitude will increase, increasing the safety risks of construction workers.

[0005] Integral hoisting generally involves assembling the large-span double-slope trapezoidal steel roof trusses made in sections into a whole on the ground. Before hoisting, multiple crane lifting points are selected on the steel roof trusses based on experience, and then the steel roof trusses are hoisted as a whole by multiple cranes. During the hoisting process, the aerial posture of the steel roof trusses is manually visually inspected, and multiple crane drivers are manually directed to control the lifting speed and synchronization of multiple cranes. Existing integral hoisting does not require the erection of a full-floor scaffolding, which can solve the problems of large construction workload, long construction period, high cost, and high-altitude operation risks for construction personnel in segmented hoisting. However, due to the need to manually visually inspect the aerial posture of the steel roof trusses, it is impossible to accurately judge the aerial posture of the steel roof trusses in a timely manner, and it is impossible to timely identify the coordination anomalies in the overall hoisting of multiple cranes, and thus it is impossible to issue a warning in a timely manner. Summary of the invention

[0006] The purpose of the present invention is to provide a large-span double-slope trapezoidal steel roof truss overall hoisting construction method, which adopts binocular recognition machine vision technology to determine the spatial posture of the steel roof truss during the overall hoisting, timely identify and judge the coordinated abnormalities in the overall hoisting of the steel roof truss and timely issue early warnings, effectively control the synchronization of the overall hoisting of two cranes, and can achieve the purpose of making the overall hoisting process of the steel roof truss convenient, saving construction time, reducing costs, and being safe and reliable.

[0007] To achieve the above object, the technical solution adopted by the present invention is to provide a large-span double-slope trapezoidal steel roof truss integral hoisting construction method, which is used to hoist the steel roof truss as a whole onto the steel column, wherein the steel roof truss comprises a left-end steel roof truss, a middle steel roof truss, a right-end steel roof truss and a connecting web, and is characterized in that the method comprises the following steps:

[0008] S1. Transport the left steel roof truss, the middle steel roof truss, the right steel roof truss and the connecting web members to the construction site;

[0009] S2. Assemble the steel roof truss on the ground:

[0010] S21. Provide a tire frame platform, which is installed on the ground at the site, and the top surface of the tire frame platform is a horizontal plane with a consistent elevation;

[0011] S22, placing the left steel roof truss, the middle steel roof truss, and the right steel roof truss horizontally on the tire frame platform, and then adjusting the positions of the three so that the bolt holes between them are aligned, and then using bolts to fix the left steel roof truss and the middle steel roof truss, and the middle steel roof truss and the right steel roof truss respectively;

[0012] S23, placing two connecting webs horizontally on the tire frame platform, one of which is fixedly installed between the left steel roof truss and the middle steel roof truss, and the other is fixedly installed between the middle steel roof truss and the right steel roof truss, so that the left steel roof truss, the middle steel roof truss, the right steel roof truss, and the connecting webs form a stable and reliable large-span double-slope trapezoidal steel roof truss;

[0013] S24. Two targets are arranged at intervals along the length direction on the lower chord of the large-span double-slope trapezoidal steel roof truss. The two targets are set at the same height and the distance between them is greater than or equal to half the length of the steel roof truss.

[0014] S3. Overall hoisting of steel roof trusses:

[0015] S31. Provide two cranes, each crane is equipped with two steel wire ropes, and select four lifting points on the upper chord of the steel roof truss;

[0016] S32, connecting two steel wire ropes of two cranes to four lifting points respectively, controlling the two cranes to synchronously lift the steel roof truss until it is lifted off the tire frame platform, and straightening the steel roof truss and then synchronously lifting the steel roof truss. During the lifting process of the steel roof truss, a binocular camera calibration system is used to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes, until the steel roof truss stops lifting after a certain distance from the ground, and then stands for a period of time;

[0017] S33, control the two cranes to synchronously lower the steel roof truss and make it not contact with the ground, and then synchronously raise the steel roof truss again, and use the binocular camera calibration system to monitor the synchronization of the two cranes in real time during the lowering and raising process of the steel roof truss to ensure the synchronization of the two cranes, until the steel roof truss stops raising after a certain distance from the ground, and then stands still for a period of time;

[0018] S34, control the two cranes to synchronously lift the steel roof truss to the top of the steel column again, adjust the steel roof truss so that the left and right ends are aligned with the connection position of the steel column, and then synchronously lower the steel roof truss to the steel column. During the lifting and lowering process of the steel roof truss, the binocular camera calibration system is used to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes;

[0019] The binocular camera calibration system is used to obtain the spatial coordinates of the two targets in real time, and compare the height difference of the two targets calculated accordingly with a preset threshold in the system. If the height difference of the two targets exceeds the preset threshold, it is judged that there is an abnormal synchronization in the overall hoisting of the steel roof truss, and the binocular camera calibration system sends an early warning signal to the crane, which makes real-time adjustments accordingly to control the height difference of the two targets below the preset threshold.

[0020] S4. Temporary fixation of steel roof trusses: When the left and right ends of the steel roof trusses touch the steel columns, the descent is stopped synchronously, and then the elevation, axis and verticality of the steel roof trusses are corrected, and then the left and right ends of the steel roof trusses are temporarily fixed and connected to the corresponding steel columns, and then the hooks of the two cranes are loosened;

[0021] S5. Permanent fixation of steel roof trusses: Weld the joints between the steel roof trusses and steel columns and use high-strength bolts to fix the connections, thus completing the overall hoisting of the large-span double-slope trapezoidal steel roof trusses.

[0022] Optionally, in step S24, two targets are symmetrically arranged on the lower chord of the steel roof truss.

[0023] Optionally, the binocular camera calibration system includes two industrial cameras and a processor, each industrial camera is used to obtain image information of two targets during the entire lifting process of the steel roof truss in real time and send it to the processor, the processor calculates the height difference between the two targets based on the image information of the two targets, and compares the height difference with a preset threshold. If the preset threshold is exceeded, a warning signal is sent to the crane.

[0024] Optionally, the left end steel roof truss includes a left end upper chord, a left end lower chord, a left end web member, a left end node plate, a left end base, a left end upper chord end plate and a left end lower chord end plate, a plurality of left end node plates are arranged on the left end upper chord and the left end lower chord, a plurality of left end web members are arranged between the left end upper chord and the left end lower chord, and both ends are connected to the left end node plate, the left end base and the left end upper chord end plate are both installed on the left end of the left end upper chord, and the left end lower chord end plate is installed on the left side of the left end lower chord;

[0025] The intermediate steel roof truss comprises an intermediate upper chord, an intermediate lower chord, an intermediate web member, an intermediate node plate, an intermediate upper chord splicing plate and an intermediate lower chord splicing plate, a plurality of intermediate node plates are arranged on the intermediate upper chord and the intermediate lower chord, a plurality of intermediate web members are arranged between the intermediate upper chord and the intermediate lower chord, and both ends are connected to the intermediate node plate, the intermediate upper chord splicing plate is installed at both ends of the intermediate upper chord, and the intermediate lower chord splicing plate is installed at both ends of the intermediate lower chord;

[0026] The right end steel roof truss comprises a right end upper chord, a right end lower chord, a right end web member, a right end node plate, a right end base, a right end upper chord end plate and a right end lower chord end plate, a plurality of right end node plates are arranged on the right end upper chord and the right end lower chord, a plurality of right end web members are arranged between the right end upper chord and the right end lower chord, and both ends are connected to the right end node plate, the right end base and the right end upper chord end plate are both installed on the left end of the right end upper chord, and the right end lower chord end plate is installed on the right side of the right end lower chord;

[0027] Step S22 specifically includes: placing the left-end steel roof truss, the middle steel roof truss and the right-end steel roof truss horizontally on the frame platform, and then adjusting the positions of the three so that the bolt holes on the right side of the left-end upper chord are aligned with the bolt holes on the left side of the middle upper chord splicing plate, the bolt holes on the right side of the left-end lower chord are aligned with the bolt holes on the left side of the middle lower chord splicing plate, the bolt holes on the left side of the right-end upper chord are aligned with the bolt holes on the right side of the middle upper chord splicing plate, and the bolt holes on the left side of the right-end lower chord are aligned with the bolt holes on the right side of the middle lower chord splicing plate, and then high-strength bolts are inserted into the bolt holes to fix the left-end steel roof truss and the middle steel roof truss, and the middle steel roof truss and the right-end steel roof truss are fixedly connected.

[0028] Optionally, a steel column base is provided at the top of the steel column, a steel column upper chord connecting flange is provided on the outer side of the top of the steel column base, and a steel column lower chord connecting flange is provided at the bottom of the steel column base;

[0029] The temporary fixation of the steel roof truss in step S4 specifically includes: when the left end base and the right end base of the steel roof truss contact the steel column base, the descending is stopped synchronously, and then the elevation, axis and verticality of the steel roof truss are corrected by using a crane in conjunction with a crowbar and a jack, and then the left end base and the right end base are fixed to the corresponding steel column base with temporary bolts, and then the left end upper chord end plate and the right end upper chord end plate are fixed to the corresponding steel column upper chord connecting flange by spot welding, and the left end lower chord end plate and the right end lower chord end plate are fixed to the corresponding steel column lower chord connecting flange by spot welding, and then the hooks of the two cranes are loosened.

[0030] Optionally, the left upper chord, left lower chord, left web, middle upper chord, middle lower chord, middle web, right upper chord, right lower chord, right web and connecting web are all made of steel, and their cross-sections are rectangular tubes, round tubes, I-beams, channels or angles.

[0031] Optionally, the bolt holes on the left end base and the right end base are enlarged bolt holes.

[0032] Optionally, the target is made of square white paper with a side length of 100 to 200 mm and is pasted on the lower chord of the steel roof truss.

[0033] Optionally, the angle between the steel wire rope and the horizontal plane is greater than or equal to 60°.

[0034] Optionally, in step S31, selecting four lifting points at the upper end of the steel roof truss specifically includes: determining four optimal lifting points based on the principle of minimizing the internal force or deformation generated by the deadweight of the steel roof truss during the lifting process of the two cranes, and the four optimal lifting points are arranged at the intersection of the left upper chord and the left end web, the intersection of the middle upper chord and the middle web, the intersection of the right upper chord and the right end web, or the intersection of the left upper chord, the middle upper chord, the right upper chord and the connecting web.

[0035] The beneficial effects of the present invention are as follows: the present invention uses binocular recognition machine vision technology to deploy a binocular camera calibration system at a suitable position on the construction site, and arranges two targets of equal height on the steel roof truss at intervals, and uses the binocular camera calibration system to perform real-time image acquisition of the two targets arranged on the large-span double-slope trapezoidal steel roof truss, and then uses parallax to perform spatial calculation and conversion, so as to obtain the spatial coordinate information of the targets on the steel roof truss, and then compares the spatial coordinates of the two targets to obtain the height difference between the two targets, and compares the height difference with a preset threshold in the system. If the height difference between the two targets exceeds the preset threshold, it is judged that there is a synchronization abnormality in the overall hoisting of the steel roof truss, and the binocular camera calibration system sends a warning signal to the crane, and the crane makes real-time adjustments accordingly to control the height difference between the two targets below the preset threshold. If it does not exceed the preset threshold, It is judged that the synchronization of the two cranes is normal, so that the synchronization difference of the two cranes in the overall lifting of the steel roof frame can be timely identified and judged. If there is a difference, an early warning signal is promptly given to the crane driver, and the crane is adjusted to ensure the synchronization of the overall lifting of the steel roof frame, so as to achieve the purpose of making the overall lifting process of the steel roof frame convenient, safe and reliable. At the same time, the present invention greatly reduces the workload of construction personnel in high-altitude operations by assembling the large-span double-slope trapezoidal steel roof frame on the ground on site and then hoisting it as a whole with two cranes, and there is no need to set up a full-house scaffolding on site, which can save construction time and reduce costs, and can reduce the safety risks of construction personnel. Finally, after the steel roof frame is hoisted into place, it is temporarily fixed first, the crane is loosened, and then it is permanently fixed, which can shorten the service life of the crane and further reduce costs.

[0036] The present invention provides a method for the overall hoisting construction of a large-span double-slope trapezoidal steel roof truss. The method adopts binocular recognition machine vision technology to determine the spatial posture of the steel roof truss during the overall hoisting, timely identify and judge the coordinated anomalies in the overall hoisting of the steel roof truss and timely issue early warnings, effectively control the synchronization of the overall hoisting of two cranes, and can achieve the purpose of making the overall hoisting process of the steel roof truss convenient, saving construction time, reducing costs, and being safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0038] Figure 1 It is a structural schematic diagram of a large-span double-slope trapezoidal steel roof truss provided by an embodiment of the present invention;

[0039] Figure 2 2 is a schematic structural diagram of a left-end steel roof truss in an embodiment of the present invention;

[0040] Figure 3 2 is a schematic diagram of the structure of the intermediate steel roof truss in an embodiment of the present invention;

[0041] Figure 42 is a schematic diagram of the structure of the right end steel roof truss in an embodiment of the present invention;

[0042] Figure 5 Schematic diagram of the structure of the steel column in the embodiment of the present invention.

[0043] In the figure: 1-left end steel roof truss, 11-left end upper chord, 12-left end lower chord, 13-left end web member, 14-left end node plate, 15-left end base, 16-left end upper chord end plate, 17-left end lower chord end plate, 2-middle steel roof truss, 21-middle upper chord, 22-middle lower chord, 23-middle web member, 24-middle node plate, 25-middle upper chord splicing plate, 26-middle lower chord splicing plate Connecting plate, 3-right end steel roof truss, 31-right end upper chord, 32-right end lower chord, 33-right end web member, 34-right end node plate, 35-right end base, 36-right end upper chord end plate, 37-right end lower chord end plate, 4-connecting web member, 5-target, 6-steel column, 61-steel column base, 62-steel column upper chord connecting flange, 63-steel column lower chord connecting flange, 7-steel wire rope, 8-hook. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] like Figure 1 As shown, the present invention provides a large-span double-slope trapezoidal steel roof truss integral hoisting construction method, which is used to hoist the steel roof truss as a whole onto a steel column 6. The steel roof truss includes a left-end steel roof truss 1, a middle steel roof truss 2, a right-end steel roof truss 3 and a connecting web 4. The method includes the following steps:

[0046] S1, transport the left end steel roof truss 1, the middle steel roof truss 2, the right end steel roof truss 3 and the connecting web 4 to the construction site;

[0047] S2. Assemble the steel roof truss on the ground:

[0048] S21. Before assembly, a tire frame platform for steel structure assembly is made at the construction site. The tire frame platform is installed on the ground at the site. The top surface elevation of the tire frame platform is controlled by a level to ensure that the top surface of the tire frame platform is a horizontal plane with a consistent elevation.

[0049] S22, placing the left steel roof truss 1, the middle steel roof truss 2, and the right steel roof truss 3 horizontally on the tire frame platform, and then adjusting the positions of the three so that the bolt holes between them are aligned, and then using bolts to fix the left steel roof truss and the middle steel roof truss, and the middle steel roof truss and the right steel roof truss respectively;

[0050] S23, placing two connecting webs 4 horizontally on the tire frame platform, one of which is fixedly installed between the left steel roof truss 1 and the middle steel roof truss 2, and the other is fixedly installed between the middle steel roof truss 2 and the right steel roof truss 3, so that the left steel roof truss 1, the middle steel roof truss 2, the right steel roof truss 3, and the connecting webs 4 form a stable and reliable large-span double-slope trapezoidal steel roof truss;

[0051] S24. Two targets are arranged at intervals along the length direction on the lower chord of the large-span double-slope trapezoidal steel roof truss. The two targets are set at the same height and the distance between them is greater than or equal to half the length of the steel roof truss.

[0052] S3, hoisting the steel roof truss as a whole, using binocular recognition machine vision technology to monitor the synchronization of the overall hoisting of the two cranes in real time:

[0053] S31, provide two cranes, each crane hook 8 is provided with two steel wire ropes 7, and select four lifting points on the upper chord of the steel roof truss;

[0054] S32, connecting the two steel wire ropes of the two cranes to the four lifting points respectively, controlling the two cranes to synchronously lift the steel roof truss until it is lifted off the tire frame platform, and straightening the steel roof truss and then synchronously lifting the steel roof truss. During the lifting process of the steel roof truss, a binocular camera calibration system is used to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes, until the steel roof truss is a certain distance from the ground (can be about 1m) and then stops lifting, and then stands for a period of time (can be 10 minutes);

[0055] S33, control the two cranes to synchronously lower the steel roof truss and make it not contact with the ground (about 0.5m from the ground), and then synchronously lift the steel roof truss again. During the lowering and lifting process of the steel roof truss, use the binocular camera calibration system to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes, until the steel roof truss is a certain distance from the ground (can be about 1m), then stop lifting again, and then let it stand for a period of time (can be 10 minutes);

[0056] S34, control the two cranes to synchronously lift the steel roof truss again to the top of the steel column (specifically, stop when the left and right bases exceed the steel column base by 0.5m), adjust the steel roof truss so that the left and right ends are aligned with the connection position of the steel column (the wind rope can be used to fine-tune the rotation of the steel roof truss so that the left and right bases are aligned with the steel column base and then synchronously lowered into place), and then synchronously lower the steel roof truss to the steel column. During the lifting and lowering process of the steel roof truss, the binocular camera calibration system is used to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes;

[0057] Among them, the binocular camera calibration system is used to obtain the spatial coordinates of the two targets in real time, and compare the height difference of the two targets calculated accordingly with the preset threshold in the system. If the height difference of the two targets exceeds the preset threshold, it is judged that there is an abnormal synchronization in the overall hoisting of the steel roof truss. The binocular camera calibration system sends an early warning signal to the crane, and the crane makes real-time adjustments accordingly to control the height difference of the two targets below the preset threshold.

[0058] S4. Temporary fixation of steel roof trusses: When the left and right ends of the steel roof trusses touch the steel columns, the descent is stopped synchronously, and then the elevation, axis and verticality of the steel roof trusses are corrected, and then the left and right ends of the steel roof trusses are temporarily fixed and connected to the corresponding steel columns, and then the hooks of the two cranes are loosened;

[0059] S5. Permanent fixation of steel roof trusses: Weld the joints between the steel roof trusses and steel columns and use high-strength bolts to fix the connections, thus completing the overall hoisting of the large-span double-slope trapezoidal steel roof trusses.

[0060] In one embodiment, Figure 1 As shown, in step S24, two targets 5 are symmetrically arranged on the steel roof frame. Preferably, the two targets are respectively installed at the two ends of the lower chord of the steel roof frame. The farther the distance between the two targets is, the more accurately the height difference between the left and right sides of the steel roof frame can be measured.

[0061] In one embodiment, the binocular camera calibration system includes two industrial cameras and a processor. Each industrial camera is used to obtain the image information of two targets in the entire lifting process of the steel roof truss in real time and send it to the processor. The processor uses parallax to perform spatial calculation and conversion based on the image information of the two targets to obtain the spatial coordinates of the two targets, and then calculates the height difference of the two targets based on the spatial coordinates of the two targets, and compares the height difference with a preset threshold. If the preset threshold is exceeded, an early warning signal is sent to the crane. The two industrial cameras are arranged at appropriate locations on the construction site so that each industrial camera can capture the entire process of steel roof truss lifting. The use of binocular recognition machine vision technology can determine the spatial coordinates of all targets in real time, thereby monitoring the synchronization of the overall lifting of the two cranes in real time and promptly issuing an early warning to the crane driver, and the crane is adjusted to make the two cranes lift synchronously.

[0062] In one embodiment, Figure 2 As shown, the left end steel roof truss 1 comprises a left end upper chord 11, a left end lower chord 12, a left end web member 13, a left end node plate 14, a left end base 15, a left end upper chord end plate 16 and a left end lower chord end plate 17, a plurality of left end node plates 14 are arranged on the left end upper chord 11 and the left end lower chord 12, a plurality of left end web members 13 are arranged between the left end upper chord 11 and the left end lower chord 12, and both ends are connected to the left end node plate 14, the left end base 15 and the left end upper chord end plate 16 are both installed at the left end of the left end upper chord 11, and the left end lower chord end plate 17 is installed at the left side of the left end lower chord 12;

[0063] like Figure 3 As shown, the middle steel roof truss 2 includes a middle upper chord 21, a middle lower chord 22, a middle web member 23, a middle node plate 24, a middle upper chord splicing plate 25 and a middle lower chord splicing plate 26, a plurality of middle node plates 24 are arranged on the middle upper chord 21 and the middle lower chord 22, a plurality of middle web members 23 are arranged between the middle upper chord 21 and the middle lower chord 22, and both ends are connected to the middle node plate 24, the middle upper chord splicing plates 25 are installed at both ends of the middle upper chord 21, and the middle lower chord splicing plates 26 are installed at both ends of the middle lower chord 22;

[0064] like Figure 4 As shown, the right end steel roof truss 3 includes a right end upper chord 31, a right end lower chord 32, a right end web member 33, a right end node plate 34, a right end base 35, a right end upper chord end plate 36 and a right end lower chord end plate 37, a plurality of right end node plates 34 are arranged on the right end upper chord 31 and the right end lower chord 32, a plurality of right end web members 33 are arranged between the right end upper chord 31 and the right end lower chord 32, and both ends are connected to the right end node plate 34, the right end base 35 and the right end upper chord end plate 36 are both installed at the left end of the right end upper chord 31, and the right end lower chord end plate 37 is installed at the right side of the right end lower chord 32;

[0065] Step S22 specifically includes: placing the left-end steel roof truss 1, the middle steel roof truss 2, and the right-end steel roof truss 3 horizontally on the frame platform, and then adjusting the positions of the three so that the bolt holes on the right side of the left-end upper chord 11 are aligned with the bolt holes on the left side of the middle upper chord splicing plate 25, the bolt holes on the right side of the left-end lower chord 12 are aligned with the bolt holes on the left side of the middle lower chord splicing plate 26, the bolt holes on the left side of the right-end upper chord 31 are aligned with the bolt holes on the right side of the middle upper chord splicing plate 25, and the bolt holes on the left side of the right-end lower chord 32 are aligned with the bolt holes on the right side of the middle lower chord splicing plate 26, and then high-strength bolts are inserted into the bolt holes to fix the left-end steel roof truss 1 and the middle steel roof truss 2, and the middle steel roof truss 2 and the right-end steel roof truss 3.

[0066] The present invention can sequentially manufacture the left end steel roof truss, the middle steel roof truss, the right end steel roof truss and the connecting web rods in a processing and manufacturing plant according to the requirements of the drawings and transport them to the construction site, and complete the overall assembly of the steel roof truss on the ground at the site. When assembling the left-end steel roof truss, first weld a number of left-end node plates on the left-end upper chord and the left-end lower chord according to the requirements of the drawings, and then weld a number of left-end web members on the left-end node plate in sequence, then install the left-end base and the left-end upper chord end plate on the left end of the left-end upper chord in sequence, and finally install the left-end lower chord end plate on the left side of the left-end lower chord. When assembling the middle steel roof truss, first weld a number of middle node plates on the middle upper chord and the middle lower chord according to the requirements of the drawings, and then weld a number of middle web members on the middle node plate in sequence, then install the middle upper chord splicing plates at both ends of the middle upper chord, and finally install the middle lower chord splicing plates on both sides of the middle lower chord. When assembling the right-end steel roof truss, first weld a number of right-end node plates on the right-end upper chord and the right-end lower chord according to the requirements of the drawings, and then weld a number of right-end web members on the right-end node plate in sequence, then install the right-end base and the right-end upper chord end plate on the left end of the right-end upper chord in sequence, and finally install the right-end lower chord end plate on the right side of the right-end lower chord.

[0067] In one embodiment, Figure 1 As shown, step S23 specifically includes: placing two connecting webs 4 horizontally on the frame platform, one of which is fixedly installed between the left-end steel roof truss 1 and the middle steel roof truss 2, and the other is fixedly installed between the middle steel roof truss 2 and the right-end steel roof truss 3, specifically welding the two ends of the connecting web to the corresponding left-end node plate, middle node plate, and right-end node plate, so that the left-end steel roof truss 1, the middle steel roof truss 2, the right-end steel roof truss 3, and the connecting web 4 form a stable and reliable large-span double-slope trapezoidal steel roof truss.

[0068] In one embodiment, Figure 5 As shown, a steel column base 61 is provided at the top of the steel column 6, a steel column upper chord connecting flange 62 is provided on the outer side of the top of the steel column base 61, and a steel column lower chord connecting flange 63 is provided at the bottom of the steel column base 61;

[0069] like Figure 1 As shown, the temporary fixation of the steel roof truss in step S4 specifically includes: when the left end base 15 and the right end base 35 of the steel roof truss contact the steel column base 61, the descending is stopped synchronously, and then the elevation, axis and verticality of the steel roof truss are corrected by using a crane in conjunction with a crowbar and a jack, and then the left end base 15 and the right end base 35 are fixed to the corresponding steel column base with temporary bolts, and then the left end upper chord end plate 16 and the right end upper chord end plate 36 are fixed to the corresponding steel column upper chord connecting flange 62 by spot welding, and the left end lower chord end plate 17 and the right end lower chord end plate 37 are fixed to the corresponding steel column lower chord connecting flange 63 by spot welding, and then the hooks of the two cranes are loosened.

[0070] In one embodiment, the left upper chord, the left lower chord, the left web member, the middle upper chord, the middle lower chord, the middle web member, the right upper chord, the right lower chord, the right web member, and the connecting web member are all made of steel, and their cross-sections are rectangular tubes, round tubes, I-beams, channel steels, or angle steels.

[0071] In one embodiment, the bolt holes on the left end base and the right end base are enlarged bolt holes.

[0072] In one embodiment, the target is made of a square white paper with a side length of 100 to 200 mm and is pasted on the lower chord of the steel roof frame.

[0073] In one embodiment, the angle between the steel wire rope and the horizontal plane is greater than or equal to 60°.

[0074] Since in the existing overall lifting, it is necessary to select the lifting points of multiple cranes based on experience, and the selection of the lifting points has not been calculated by technical personnel, there is a safety risk that the steel roof truss may be deformed or overturned during the lifting process due to unreasonable lifting point settings. Therefore, in one embodiment, in step S31, selecting four lifting points at the upper end of the steel roof truss specifically includes: determining four optimal lifting points based on the principle of minimizing the internal force or deformation generated by the dead weight of the steel roof truss during the lifting process by the two cranes, and the four optimal lifting points are arranged at the intersection of the left upper chord and the left end web, the intersection of the middle upper chord and the middle web, the intersection of the right upper chord and the right end web, and the intersection of the left upper chord, the middle upper chord, the right upper chord and the connecting web. The present invention is based on the principle that the internal force or deformation generated by the deadweight of the steel roof truss during the lifting process by two cranes is minimized. The technical personnel calculate the optimal combination setting of lifting points and finally determine four optimal lifting points. This greatly reduces the safety risks of deformation or overturning of the steel roof truss during the lifting process due to unreasonable lifting point settings, and increases the safety and reliability of the overall lifting process of the steel roof truss.

[0075] like Figure 1 As shown, the lifting points include lifting point A, lifting point B, lifting point C, lifting point D, lifting point E and lifting point F located on the left and right sides of the steel roof truss. Before lifting, various lifting point combination setting schemes of the two cranes on the steel roof truss, such as lifting point A and lifting point D, lifting point B and lifting point E, lifting point C and lifting point F, lifting point A and lifting point C, lifting point B and lifting point D, lifting point C and lifting point E, lifting point B and lifting point C, lifting point C and lifting point D, and lifting point D and lifting point E, are calculated to determine the optimal lifting point combination setting scheme. In this embodiment, according to the principle that the internal force or deformation generated by the dead weight of the steel roof truss during the lifting process of the two cranes is minimized, the four optimal lifting points are determined to be lifting point B and lifting point E on the left and lifting point B and lifting point E on the right. The two steel wire ropes of one crane are respectively connected to the lifting point B and lifting point E on the left, and the two steel wire ropes of the other crane are respectively connected to the lifting point B and lifting point E on the right.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for integrally hoisting a large-span double-slope trapezoidal steel roof truss, which is used to integrally hoist the steel roof truss onto a steel column, wherein the steel roof truss comprises a left-end steel roof truss, a middle steel roof truss, a right-end steel roof truss and a connecting web, and is characterized in that: The method comprises the following steps: S1. Transport the left steel roof truss, the middle steel roof truss, the right steel roof truss and the connecting web members to the construction site; S2. Assemble the steel roof truss on the ground: S21. Provide a tire frame platform, which is installed on the ground at the site, and the top surface of the tire frame platform is a horizontal plane with a consistent elevation; S22, placing the left steel roof truss, the middle steel roof truss, and the right steel roof truss horizontally on the tire frame platform, and then adjusting the positions of the three so that the bolt holes between them are aligned, and then using bolts to fix the left steel roof truss and the middle steel roof truss, and the middle steel roof truss and the right steel roof truss respectively; S23, placing two connecting webs horizontally on the tire frame platform, one of which is fixedly installed between the left steel roof truss and the middle steel roof truss, and the other is fixedly installed between the middle steel roof truss and the right steel roof truss, so that the left steel roof truss, the middle steel roof truss, the right steel roof truss, and the connecting webs form a stable and reliable large-span double-slope trapezoidal steel roof truss; S24. Two targets are arranged at intervals along the length direction on the lower chord of the large-span double-slope trapezoidal steel roof truss. The two targets are set at the same height and the distance between them is greater than or equal to half the length of the steel roof truss. S3. Overall hoisting of steel roof trusses: S31. Provide two cranes, each crane is equipped with two steel wire ropes, and select four lifting points on the upper chord of the steel roof truss; S32, connecting the two steel wire ropes of the two cranes to the four lifting points respectively, controlling the two cranes to synchronously lift the steel roof truss until it is lifted off the tire frame platform, and straightening the steel roof truss and then synchronously lifting the steel roof truss. During the lifting process of the steel roof truss, a binocular camera calibration system is used to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes, until the steel roof truss stops lifting after it is 1m off the ground, and then stands for 10 minutes; S33, control the two cranes to synchronously lower the steel roof frame to 0.5m from the ground, and then synchronously raise the steel roof frame again. During the lowering and raising process of the steel roof frame, use the binocular camera calibration system to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes, until the steel roof frame stops raising after 1m from the ground, and then stands for 10 minutes; S34, control the two cranes to synchronously lift the steel roof truss again to the top of the steel column, stop when the left and right bases exceed the steel column base by 0.5m, adjust the steel roof truss so that the left and right ends are aligned with the connection position of the steel column, and then synchronously lower the steel roof truss to the steel column. During the lifting and lowering process of the steel roof truss, use the binocular camera calibration system to monitor the synchronization of the two cranes in real time to ensure the synchronization of the two cranes; The binocular camera calibration system is used to obtain the spatial coordinates of the two targets in real time, and compare the height difference of the two targets calculated accordingly with a preset threshold in the system. If the height difference of the two targets exceeds the preset threshold, it is judged that there is an abnormal synchronization in the overall hoisting of the steel roof truss, and the binocular camera calibration system sends an early warning signal to the crane, which makes real-time adjustments accordingly to control the height difference of the two targets below the preset threshold. S4. Temporary fixation of steel roof trusses: When the left and right ends of the steel roof trusses touch the steel columns, the descent is stopped synchronously, and then the elevation, axis and verticality of the steel roof trusses are corrected, and then the left and right ends of the steel roof trusses are temporarily fixed and connected to the corresponding steel columns, and then the hooks of the two cranes are loosened; S5. Permanent fixation of steel roof trusses: Weld the joints between the steel roof trusses and steel columns and use high-strength bolts to fix the connections, thus completing the overall hoisting of the large-span double-slope trapezoidal steel roof trusses.

2. The method for overall hoisting construction of a large-span double-slope trapezoidal steel roof truss according to claim 1 is characterized in that: In step S24, two targets are symmetrically arranged on the lower chord of the steel roof truss.

3. The method for overall hoisting construction of a large-span double-slope trapezoidal steel roof truss according to claim 1 is characterized in that: The binocular camera calibration system includes two industrial cameras and a processor. Each industrial camera is used to obtain image information of two targets in the entire lifting process of the steel roof truss in real time and send it to the processor. The processor calculates the height difference between the two targets based on the image information of the two targets and compares the height difference with a preset threshold. If the height difference exceeds the preset threshold, a warning signal is sent to the crane.

4. The method for overall hoisting construction of a large-span double-slope trapezoidal steel roof truss according to claim 1 is characterized in that: The left end steel roof truss comprises a left end upper chord, a left end lower chord, a left end web member, a left end node plate, a left end base, a left end upper chord end plate and a left end lower chord end plate, a plurality of left end node plates are arranged on the left end upper chord and the left end lower chord, a plurality of left end web members are arranged between the left end upper chord and the left end lower chord, and both ends are connected to the left end node plate, the left end base and the left end upper chord end plate are both installed on the left end of the left end upper chord, and the left end lower chord end plate is installed on the left side of the left end lower chord; The intermediate steel roof truss comprises an intermediate upper chord, an intermediate lower chord, an intermediate web member, an intermediate node plate, an intermediate upper chord splicing plate and an intermediate lower chord splicing plate, a plurality of intermediate node plates are arranged on the intermediate upper chord and the intermediate lower chord, a plurality of intermediate web members are arranged between the intermediate upper chord and the intermediate lower chord, and both ends are connected to the intermediate node plate, the intermediate upper chord splicing plate is installed at both ends of the intermediate upper chord, and the intermediate lower chord splicing plate is installed at both ends of the intermediate lower chord; The right end steel roof truss comprises a right end upper chord, a right end lower chord, a right end web member, a right end node plate, a right end base, a right end upper chord end plate and a right end lower chord end plate, a plurality of right end node plates are arranged on the right end upper chord and the right end lower chord, a plurality of right end web members are arranged between the right end upper chord and the right end lower chord, and both ends are connected to the right end node plate, the right end base and the right end upper chord end plate are both installed on the left end of the right end upper chord, and the right end lower chord end plate is installed on the right side of the right end lower chord; Step S22 specifically includes: placing the left-end steel roof truss, the middle steel roof truss and the right-end steel roof truss horizontally on the frame platform, and then adjusting the positions of the three so that the bolt holes on the right side of the left-end upper chord are aligned with the bolt holes on the left side of the middle upper chord splicing plate, the bolt holes on the right side of the left-end lower chord are aligned with the bolt holes on the left side of the middle lower chord splicing plate, the bolt holes on the left side of the right-end upper chord are aligned with the bolt holes on the right side of the middle upper chord splicing plate, and the bolt holes on the left side of the right-end lower chord are aligned with the bolt holes on the right side of the middle lower chord splicing plate, and then high-strength bolts are inserted into the bolt holes to fix the left-end steel roof truss and the middle steel roof truss, and the middle steel roof truss and the right-end steel roof truss are fixedly connected.

5. The method for overall hoisting construction of a large-span double-slope trapezoidal steel roof truss according to claim 4 is characterized in that: A steel column base is provided at the top of the steel column, a steel column upper chord connecting flange is provided on the outer side of the top of the steel column base, and a steel column lower chord connecting flange is provided at the bottom of the steel column base; The temporary fixation of the steel roof truss in step S4 specifically includes: when the left end base and the right end base of the steel roof truss contact the steel column base, the descending is stopped synchronously, and then the elevation, axis and verticality of the steel roof truss are corrected by using a crane in conjunction with a crowbar and a jack, and then the left end base and the right end base are fixed to the corresponding steel column base with temporary bolts, and then the left end upper chord end plate and the right end upper chord end plate are fixed to the corresponding steel column upper chord connecting flange by spot welding, and the left end lower chord end plate and the right end lower chord end plate are fixed to the corresponding steel column lower chord connecting flange by spot welding, and then the hooks of the two cranes are loosened.

6. The method for overall hoisting construction of a large-span double-slope trapezoidal steel roof truss according to claim 4 is characterized in that: The left upper chord, left lower chord, left web member, middle upper chord, middle lower chord, middle web member, right upper chord, right lower chord, right web member, and connecting web member are all made of steel, and their cross-sections are rectangular tubes, round tubes, I-beams, channel steels, or angle steels.

7. The construction method for integrally hoisting a large-span double-slope trapezoidal steel roof truss according to claim 4 is characterized in that: The bolt holes on the left end base and the right end base are enlarged bolt holes.

8. The construction method for integrally hoisting a large-span double-slope trapezoidal steel roof truss according to claim 1 is characterized in that: The target is made of square white paper with a side length of 100 to 200 mm and is pasted on the lower chord of the steel roof frame.

9. The construction method for integrally hoisting a large-span double-slope trapezoidal steel roof truss according to claim 1 is characterized in that: The angle between the steel wire rope and the horizontal plane is greater than or equal to 60°.

10. The construction method for integrally hoisting a large-span double-slope trapezoidal steel roof truss according to claim 1, characterized in that: In step S31, selecting four lifting points on the upper chord of the steel roof truss specifically includes: determining four optimal lifting points based on the principle that the internal force or deformation generated by the deadweight of the steel roof truss during the lifting process of the two cranes is minimized, and the four optimal lifting points are arranged at the intersection of the left upper chord and the left web member, the intersection of the middle upper chord and the middle web member, the intersection of the right upper chord and the right web member, or the intersection of the left upper chord, the middle upper chord, the right upper chord and the connecting web member.

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