Pipe truss jacking, unloading and installing method

Abstract

The invention discloses a pipe truss jacking, unloading and installing method. The method comprises the following steps that an assembly type supporting system is installed; and a jacking and unloading device is manufactured, and the jacking and unloading device is installed on the assembly type supporting system. And hoisting the truss, and enabling the truss to fall on the jacking and unloading device. And aligning the trusses, and jacking or lowering the trusses through a jacking and unloading device. And tensioning the prestressed inhaul cable. And unloading the truss. The height of the pipe truss is adjusted through the jacking and unloading device, so that the position of a high-altitude butt joint opening is adjusted, and the hoisting and butt joint precision of the large-span pipe truss is improved.

Description

Technical Field

[0001] The invention relates to the field of metallurgical engineering, and in particular to a method for jacking, unloading and installing a pipe truss. Background Art

[0002] The closed coal shed of an open-air material yard adopts a prestressed cable-tube truss structure with a structural span of 142m. It is hoisted in three spans. The maximum single span is 107m and the hoisting weight is about 30t. During the hoisting process, the truss span is large. If effective measures are not taken, the trusses on both sides will have large sagging deflections and the high-altitude butt joints will be unable to connect. Summary of the invention

[0003] The invention provides a pipe truss jacking and unloading installation method, which can improve the hoisting and docking accuracy of a large-span pipe truss.

[0004] An embodiment of the present invention provides a method for jacking and unloading installation of a pipe truss, comprising the following steps: installing an assembled support system. Making a jacking and unloading device, and installing the jacking and unloading device on the assembled support system. Hoisting a truss, and allowing the truss to fall on the jacking and unloading device. Aligning the trusses, and jacking or lowering the trusses through the jacking and unloading device. Tensioning prestressed cables. Unloading the truss.

[0005] In some of the embodiments, during the process of manufacturing the jacking and unloading device, the jacking and unloading device includes a lower casing, a jack, an upper casing and a cross support plate, the lower part of the lower casing is used to connect with the assembled support system, the jack is arranged in the lower casing, the upper casing is arranged above the lower casing, the upper casing and the lower casing are connected in tension, the cross support plate is arranged on the upper part of the upper casing, and the cross support plate is used for setting the welding ball.

[0006] In some of the embodiments, before the truss lifting begins, the jacking and unloading device is lifted to a preset height in advance. After the truss is lifted into place, the jacking and unloading device is used to unload in advance, and the dead weight of the truss is transferred to the assembled support system through the jacking and unloading device.

[0007] In some of the embodiments, when the hoisted truss is lifted or lowered by the lifting and unloading device, the external crawler crane cooperates with the lifting and lowering work to slowly lift or lower the component.

[0008] In some of the embodiments, during the prestressed cable tensioning process, the cables are tensioned for a second time on the assembled support system, and the second tensioning is graded tensioning.

[0009] In some of the embodiments, during the prestressed cable tensioning process, each time the prestressed cable tensioning is completed, it is immediately measured and checked. If any abnormality is found, the tensioning is suspended until the cause is found and measures are taken before continuing the tensioning.

[0010] In some of the embodiments, a staged unloading method is adopted during the truss unloading process.

[0011] In some of the embodiments, during the unloading process of the truss, the lifting and unloading devices on both sides are synchronously and slowly lowered, so that all the forces of the truss are borne by the ball joint supports on both sides.

[0012] In some of the embodiments, during the unloading process of the truss, the deflection change of the truss is constantly detected during the lowering process, and the truss is lowered until the truss stops deflecting.

[0013] In some of the embodiments, during the unloading process of the truss, the deformation and stress parameters of key parts of the structure are monitored in real time. If any abnormality is found, the unloading is stopped immediately, the cause is analyzed and corresponding measures are taken.

[0014] According to an embodiment of the present invention, a method for jacking and unloading installation of a tube truss is provided, comprising the following steps: installing a prefabricated support system. Making a jacking and unloading device, and installing the jacking and unloading device on the prefabricated support system. Lifting the truss, and allowing the truss to fall on the jacking and unloading device. Aligning the trusses, and jacking or lowering the trusses through the jacking and unloading device. Tensioning the prestressed cables. Unloading the truss. The present invention adjusts the height of the tube truss through the jacking and unloading device, thereby adjusting the position of the high-altitude docking interface and improving the hoisting and docking accuracy of the large-span tube truss. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 It is a schematic diagram of a lifting and unloading device on a prefabricated support system in an embodiment of the present invention;

[0017] Figure 2 It is an elevation view of the jacking and unloading device in the embodiment of the present invention;

[0018] Figure 3 It is a cross-sectional view of a lifting and unloading device in an embodiment of the present invention;

[0019] Figure 4 It is a plan view of the lifting and unloading device in the embodiment of the present invention;

[0020] Figure 5 A schematic diagram of the exterior of a lifting and unloading device in an embodiment of the present invention;

[0021] Figure 6A schematic diagram of the upper part of the jacking and unloading device in an embodiment of the present invention;

[0022] Figure 7 A schematic diagram of an arc plate of a cross support plate in an embodiment of the present invention;

[0023] Figure 8 A schematic diagram of another arc plate of the cross support plate in an embodiment of the present invention;

[0024] Fig. 9 It is a schematic diagram of the truss hoisting completion in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] See also Figure 1-9 The embodiment of the present invention provides a method for jacking and unloading a pipe truss, comprising the following steps:

[0027] (1) Install the prefabricated support system 1.

[0028] Among them, during the installation of the assembled support system 1, a temporary support system of tower crane standard section steel is set at the location of the long-span truss 3 segmentation point, and an operating platform is set on the top of the temporary support system. The temporary support system and the operating platform need to be designed and calculated to determine the specific model and specifications. The temporary support system of tower crane standard section steel can use 3 sets of lattice column systems made of tower crane standard sections with main limbs as round tubes φ114×12mm, cross bars and diagonal bars as φ60×5mm, and its support height is 32.5m. Five 14# I-beam connecting beams are set between the standard sections, and the connecting beams and standard sections are directly connected with high-strength bolts for easy disassembly and displacement. The operating platform can be a "field-shaped" platform made of HW200*200*8*12 and HW250*250*9*14 H-shaped steel, and the surface of the platform is covered with a layer of 3mm patterned steel plate. The center of the operating platform is used to place the jacking and unloading device 2, and the platform serves as an operating platform and a conversion platform for personnel to go up and down the truss 3.

[0029] (2) Produce a lifting and unloading device 2, and install the lifting and unloading device 2 on the assembled support system 1.

[0030] Among them, during the process of making the jacking and unloading device 2, the jacking and unloading device 2 includes a lower casing 21, a jack 22, an upper casing 23 and a cross support plate 24. The lower part of the lower casing 21 is used to connect with the center position of the operating platform of the assembled support system 1. The jack 22 is arranged in the lower casing 21, and the upper casing 23 is arranged above the lower casing 21. The upper casing 23 and the lower casing 21 are connected in tension. The cross support plate 24 is arranged on the upper part of the upper casing 23, and the cross support plate 24 is used for the welding ball to be set. It should be noted that the supporting point of the truss 3 is a welding ball node (the end of the prestressed cable). The upper casing 23 and the lower casing 21 are both steel casings, such as φ159×14mm steel pipes. The lower casing 21 can be welded to the center position of the operating platform. The jack 22 can be a 20t jack 22. The steel plate is cut into three arc plates (241, 242) with the same arc as the ball node, and the arc plates are welded to form a cross support plate 24. The steel plate can be a 16 mm steel plate.

[0031] In order to realize the pulling connection between the upper sleeve 23 and the lower sleeve 21, ear plates 25 are welded on both sides of the upper and lower sleeves, and holes are opened on the ear plates 25 for passing the full-thread screw 26. The opening can be an 18mm hole, and the full-thread screw 26 can be 16mm. The full-thread screw 26 can tighten the nut. In order to realize the cross support plate 24 set on the upper part of the upper sleeve 23, a cross groove is opened at the central symmetrical position of the top of the upper sleeve 23, and a steel plate slightly smaller than the pipe diameter is welded at the bottom of the cross support plate 24, and the cross support plate 24 is placed in the cross groove of the upper sleeve 23 for full welding. The steel plate can be a 16mm steel plate.

[0032] During the installation of the jacking and unloading device 2 on the assembled support system 1, a total station is used for precise measurement. According to the three-dimensional coordinates of the installation position determined in advance, the lower casing 21 is fully welded to the center position of the operating platform to assemble the jacking and unloading device 2.

[0033] (3) The truss 3 is hoisted and placed on the lifting and unloading device 2.

[0034] Before the truss 3 is hoisted, the jacking and unloading device 2 is lifted in advance to a preset height, such as 50 mm, and then the hoisting equipment is guided to be accurately positioned. After the truss 3 is hoisted in place, the welding balls of the truss 3 fall on the cross support plate 24 of the jacking and unloading device 2. The jacking and unloading device 2 is used to unload in advance, and the deadweight of the truss 3 is transferred to the assembled support system 1 through the jacking and unloading device 2.

[0035] (4) The trusses 3 are aligned and the trusses 3 are lifted or lowered by the lifting and unloading device 2.

[0036] During the aligning process of the truss 3, if the installation nozzle is lower or higher than the nozzle of the installed truss 3, the hoisted truss 3 is lifted or lowered by the lifting and unloading devices 2 on both sides. In other words, the nozzle of the structure position is vertically fine-tuned by the lifting and unloading devices 2 on both sides to adjust the installation height of the truss 3. During the lifting and lowering process, the height of the bolts on both sides of the lifting and unloading device 2 is first adjusted to facilitate the adjustment of the internal jack 22.

[0037] When the hoisted truss 3 is lifted or lowered by the lifting and unloading device 2 , the external crawler crane cooperates with the lifting and lowering work to slowly lift or lower the component to maintain the stability of the truss 3 .

[0038] After the pipe ends are aligned, the positioning plate is welded for welding. After the pipe ends of truss 3 are butt-jointed and pass the flaw detection, the secondary truss 3 between trusses 3 is installed. After the secondary truss 3 is installed, the prestressed cable is tensioned.

[0039] (5) Prestressed cable tensioning.

[0040] During the prestressing cable tensioning process, according to the designed prestressing value of the cable, two 100t jacks 22, oil pumps and tensioning tooling and other equipment can be selected at each tensioning construction point, and the jacks 22 and oil pressure sensors are calibrated according to the actual tensioning force required by the design and prestressing process.

[0041] Each truss 3 has been pre-tensioned by 25% before being hoisted. Therefore, only the cables are tensioned for the second time on the operating platform of the assembled support system 1. The second tensioning is graded tensioning, which can be graded according to: ↘50%↘75%↘103%. The tensioning of prestressed cables adopts double control, with cable force control as the main control and deformation control as the auxiliary control. After each prestressed cable tensioning is completed, it is measured and checked immediately. If any abnormality is found, the tensioning is suspended until the cause is found and measures are taken before continuing the tensioning.

[0042] During the tensioning process, the pressure measured by the pressure sensor and the deformation of the steel structure measured by the total station are recorded to monitor the behavior of the structure during construction.

[0043] (6) Truss 3 is unloaded.

[0044] Before unloading the truss 3, carefully check whether the connection parts and welds of the steel structure are normal to ensure the safety of the structure. At the same time, check the roller frame, tensioning equipment and related support and fixing devices to ensure that they are in good condition.

[0045] During the unloading process of the truss 3, the preload force is gradually reduced by adopting a staged unloading method. The amount of unloading each time should be determined according to calculations and actual conditions to avoid excessive unloading at one time, which may cause structural deformation or instability.

[0046] During the unloading process of the truss 3, the lifting and unloading devices 2 on both sides are slowly lowered synchronously. During the lowering process, the deflection change of the truss 3 is constantly detected, and the truss 3 is lowered until there is no downward deflection, so that all the forces of the truss 3 are borne by the ball joint supports (such as 4) on both sides. Appropriate monitoring equipment (such as strain gauges, displacement sensors, etc.) can be used to monitor the deformation, stress and other parameters of the key parts of the structure in real time. If an abnormal situation is found, the unloading is stopped immediately, the cause is analyzed and corresponding measures are taken. The amount of each unloading, monitoring data, and the status of the structure and other information should be recorded in detail for subsequent analysis and evaluation.

[0047] In order to solve the difficulties of large deformation and deflection of the large-span prestressed cable tube truss 3 steel structure during installation, difficulty in high-altitude pipe joint docking, and difficulty in structural unloading after prestressed cables are tensioned, the present invention adjusts the position of the high-altitude docking interface by adjusting the height of the tube truss 3, provides a temporary support point for structural unloading, and makes the load of the truss 3 smoothly and safely transferred to the ball joint support, making the truss 3 hoisting and installation process safer, more efficient and reliable, and solving the problems of hoisting and docking accuracy of the large-span tube truss 3 and unloading after cable tensioning.

[0048] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for jacking up and unloading a pipe truss, characterized in that: The following steps are involved: Install the fabricated support system; Making a lifting and unloading device, and installing the lifting and unloading device on the assembled support system; The truss is hoisted and placed on the lifting and unloading device; The trusses are aligned, and the trusses are lifted or lowered by the lifting and unloading device; Prestressed cable tensioning; Truss unloading.

2. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: During the process of manufacturing the jacking and unloading device, the jacking and unloading device includes a lower casing, a jack, an upper casing and a cross support plate. The lower part of the lower casing is used to connect with the assembled support system. The jack is arranged in the lower casing. The upper casing is arranged above the lower casing. The upper casing is connected to the lower casing by tension. The cross support plate is arranged on the upper part of the upper casing. The cross support plate is used for setting the welding ball.

3. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: Before the truss lifting begins, the jacking and unloading device is lifted to a preset height in advance. After the truss is lifted into place, the jacking and unloading device is used to unload in advance, and the deadweight of the truss is transferred to the assembled support system through the jacking and unloading device.

4. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: When the hoisted truss is lifted or lowered by the lifting and unloading device, the external crawler crane cooperates with the lifting and lowering work to slowly lift or lower the component.

5. The method for jacking up and unloading and installing a pipe truss according to claim 1, characterized in that: During the prestressed cable tensioning process, the cables are tensioned for a second time on the fabricated support system, and the second tensioning is graded tensioning.

6. The method for jacking up and unloading and installing a tube truss according to claim 1, characterized in that: During the prestressed cable tensioning process, each time the prestressed cable tensioning is completed, it is immediately measured and checked. If any abnormality is found, the tensioning will be suspended until the cause is found and measures are taken before continuing the tensioning.

7. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: During the truss unloading process, a staged unloading method is adopted.

8. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: During the unloading process of the truss, the lifting and unloading devices on both sides are slowly lowered synchronously, so that all the forces of the truss are borne by the ball joint supports on both sides.

9. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: During the unloading process of the truss, the deflection change of the truss is detected at all times during the lowering process until the truss stops deflecting.

10. The method for jacking up and unloading a pipe truss as claimed in claim 1, characterized in that: During the truss unloading process, the deformation and stress parameters of key parts of the structure are monitored in real time. If any abnormality is found, the unloading is stopped immediately, the cause is analyzed and corresponding measures are taken.

Images