Large-span roof profile steel truss hoisting method

Abstract

A large-span roof profile steel truss hoisting method comprises the following steps that before truss hoisting, it is confirmed that site ground preparation work is completed, and hoisting requirements are met; the first crane enters the site to be assembled, the second crane enters the site to be supported, and the third crane is standby at a designated construction site; the rigging is correspondingly installed on the first crane, the second crane and the third crane; a first crane and a second crane are adopted to carry out trial hoisting on the truss, and whether the foundation, the cranes, rigging, equipment and the like are abnormal or not is checked; according to the theoretical hoisting weights of the first crane, the second crane and the third crane, the hoisting weights are rechecked, and hoisting is conducted if no abnormity exists; numbering the trusses, and sequentially hoisting according to the sequence numbers 3, 1, 2, 4, 5 and 6 of the trusses; and after the hoisting task is completed, the crane is disassembled and returned. According to the invention, the hoisting of the large-span truss is realized by adopting a three-crane cooperative hoisting mode, so that the hoisting stability and safety are ensured; and in the hoisting process, the number of people needing manpower cooperation is smaller, and the efficiency is higher.

Description

Technical Field

[0001] The invention relates to the technical field of building steel structure construction, in particular to a method for hoisting a large-span roof steel truss. Background Art

[0002] The Ningxia Great Wall Intangible Cultural Heritage Exhibition Hall construction project undertaken by the company is located in Xiaqiao Village, Linhe Town, Lingwu City, Ningxia Hui Autonomous Region, within the Shuidonggou Scenic Area. The total construction area is 20,000m 2 The building has a total height of 15.65m (including 20.15m underground), with three floors above ground and one underground. Its primary functions include an exhibition hall, a multi-purpose hall, and auxiliary facilities. The structural system is a frame-shear wall structure, the floor structure is cast-in-place concrete beams and slabs, and the exhibition hall roof is a long-span steel truss. The foundation is a flat raft foundation using a replacement cushion method, and the foundation design grade is Class B. Because this project utilizes steel trusses for the long-span roof, with a span of 68.504 meters, an installation height of 16.45 meters, and a maximum weight of 96.5 tons, the existing lifting methods are difficult to meet due to the large lifting radius, and cannot guarantee stable and safe lifting of such a long-span truss. Summary of the Invention

[0003] In order to solve the technical problems existing in the above technology, it is necessary to provide a method for hoisting a large-span roof steel truss.

[0004] A method for hoisting a large-span roof steel truss comprises the following steps:

[0005] Step S1: Before truss hoisting, confirm that the on-site ground preparation work has been completed and meets the hoisting requirements;

[0006] Step S2: The first crane is paired with the second crane, and the third crane is on standby at the designated construction site.

[0007] Step S3: Installing rigging to the first crane, the second crane, and the third crane accordingly;

[0008] Step S4: Use the first crane and the second crane to test-lift the truss and check whether there are any abnormalities in the foundation, cranes, rigging, equipment, etc.;

[0009] Step S5: Check the lifting weight according to the theoretical lifting weights of the first crane, the second crane, and the third crane. If there is no abnormality, proceed to the lower lifting.

[0010] Step S6: number the trusses and hoist them in the order of truss numbers 3, 1, 2, 4, 5, and 6;

[0011] Step S7: After the lifting task is completed, the crane is dismantled and withdrawn.

[0012] Preferably, in step S6, the following method is used when hoisting truss No. 3:

[0013] The first crane and the second crane hook the two ends of the truss respectively and slowly lift the hooks;

[0014] After the truss is lifted to a certain height, it is rotated to the installation direction;

[0015] Slowly walk forward to the crane station position when in place;

[0016] The first crane and the second crane simultaneously perform pole climbing actions to lift the truss to the top of the installation position;

[0017] Use the third crane to hook the truss at halfway point to ensure the lateral stability of the truss;

[0018] Under the cooperation of the first crane and the second crane, the hook is dropped to accurately place the truss in the installation position;

[0019] After the truss is fixed, the rigging on the first crane, the second crane and the third crane are unhooked from the truss.

[0020] Preferably, in step S6, the following method is used when hoisting the remaining numbered racks:

[0021] The first crane and the second crane hook the two ends of the truss respectively and slowly lift the hooks;

[0022] After the truss is lifted to a certain height, it is rotated to the installation direction;

[0023] Slowly walk forward to the crane station position when in place;

[0024] The first crane and the second crane simultaneously perform actions such as climbing the pole and dropping the hook to lift the truss to the installation position;

[0025] After the truss is fixed to the previously installed truss, the rigging of the first crane and the second crane is unhooked from the truss.

[0026] Preferably, the positions where the first crane and the second crane hook the truss are 8 meters away from the ends of the truss.

[0027] Preferably, in step S6, when hoisting truss No. 3, it is necessary to verify whether truss No. 3 is a rod-resistant structure.

[0028] Preferably, in step S1, the on-site ground includes a truss stacking area, a transport walking area, and a hoisting area;

[0029] The ground in the truss stacking area must be compacted and flattened in layers, and no serious water accumulation is allowed. After the ground in the stacking area is compacted, it must be able to withstand a force of 5t / m2 ;

[0030] The ground in the transport walking area must be paved with 40cm thick stones after layering and compaction, and then paved with a 20cm thick gravel layer, with a bearing capacity of 20t / m 2 ;

[0031] The ground in the lifting area is paved with a roadbed box.

[0032] Preferably, the gap between adjacent roadbed boxes should not exceed 10 cm.

[0033] Preferably, a C20 concrete surface layer, a ballast cushion layer, and a rammed earth layer are laid in sequence below the roadbed box.

[0034] Preferably, the thickness of the C20 concrete surface layer is 200 mm, the thickness of the ballast cushion layer is 500 mm, and the thickness of the plain soil rammed layer is 200 mm.

[0035] Preferably, in step S4, the lifting height of the truss during the trial lifting is 100 mm.

[0036] Compared with existing technologies, the method for hoisting large-span roof steel trusses provided by the present invention uses a dual-crane collaborative hoisting method to achieve the hoisting of large-span trusses, ensuring stable and safe hoisting. Furthermore, during the hoisting process, fewer people are required to coordinate, resulting in higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 Schematic diagram of the lifting points for lifting the C1HJ-3 truss according to the present invention.

[0039] Figure 2 This is a schematic diagram of the lifting plane for lifting the C1HJ-3 truss according to the present invention.

[0040] Figure 3 This is a schematic plan view of the hoisting and positioning of the C1HJ-3 truss according to the present invention.

[0041] Figure 4 Schematic diagram of the lifting points for lifting the C1HJ-1 truss according to the present invention.

[0042] Figure 5 This is a schematic diagram of the lifting plane of the C1HJ-1 truss according to the present invention.

[0043] Figure 6This is a schematic plan view of the hoisting and positioning of the C1HJ-1 truss according to the present invention.

[0044] Figure 7 Schematic diagram of the lifting points for lifting the C1HJ-2 truss according to the present invention.

[0045] Figure 8 This is a schematic plan view of the hoisting and positioning of the C1HJ-2 truss according to the present invention.

[0046] Figure 9 Schematic diagram of the lifting points for lifting the C1HJ-4 truss according to the present invention.

[0047] Figure 10 It is a schematic plan view of the hoisting and positioning of the C1HJ-4 truss according to the present invention.

[0048] Figure 11 Schematic diagram of the lifting points for lifting the C1HJ-5 truss according to the present invention.

[0049] Figure 12 This is a schematic plan view of the hoisting and positioning of the C1HJ-5 truss according to the present invention.

[0050] Figure 13 Schematic diagram of the lifting points for lifting the C1HJ-6 truss according to the present invention.

[0051] Figure 14 This is a schematic plan view of the hoisting and positioning of the C1HJ-6 truss according to the present invention.

[0052] Figure 15 This is a schematic elevation diagram of the hoisting of the C1HJ-3 truss according to the present invention.

[0053] Figure 16 This is a schematic diagram of the crane assembly of the present invention.

[0054] Figure 17 This is a schematic diagram of the ground layering in the transport walking area of ​​the present invention.

[0055] Figure 18 This is a schematic diagram of the ground layer compression in the hoisting area of ​​the present invention.

[0056] Figure 19 This is a schematic diagram of the calculation of the lifting weight and lifting point position of the present invention. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0058] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0059] For better explanation, take the steel structure hoisting project of the Ningxia Great Wall Intangible Cultural Heritage Exhibition Hall construction project as an example. The truss span is 68.504 meters, the installation height is 16.45 meters, and the heaviest weight is 96.5 tons. The engineering quantities are shown in the following table:

[0060]

[0061] The present invention provides a method for hoisting a large-span roof steel truss, comprising the following steps:

[0062] Step S1: Before truss hoisting, confirm that the on-site ground preparation work has been completed and meets the hoisting requirements;

[0063] Step S2: The first crane is paired with the second crane, and the third crane is on standby at the designated construction site. The first crane is a 500t crawler crane, the second crane is a 650t crawler crane, and the third crane is a 500t crawler crane.

[0064] Step S3: Installing rigging on the first crane, the second crane, and the third crane accordingly;

[0065] Step S4: Use the first crane and the second crane to test lift the truss, with the lifting height of the truss being 100 mm during the test lifting; check whether there are any abnormalities in the foundation, cranes, rigging, equipment, etc.;

[0066] Step S5: Check the lifting weight according to the theoretical lifting weights of the first crane, the second crane, and the third crane. If there is no abnormality, proceed to the lower lifting.

[0067] Step S6: hoist the trusses numbered C1HJ-1, C1HJ-2, C1HJ-3, C1HJ-4, C1HJ-5, and C1HJ-6 in the order of truss numbers C1HJ-3, C1HJ-1, C1HJ-2, C1HJ-4, C1HJ-5, and C1HJ-6;

[0068] Step S7: After the lifting task is completed, the crane is dismantled and withdrawn.

[0069] In this plan, the rigging uses φ42×16000mm steel wire rope. The rigging needs to be inspected before installation to confirm whether it is in good condition. If it is found that the steel wire rope, hemp rope, and shackle have reached the scrap level, they should be prohibited from use.

[0070] Among them, the scrapping of wire ropes meets the requirements of SH / T3536. The joints have slippage, deformation and cracks; there are concentrated broken wires near the joints or the broken wires are near the roots; the consolidation force of the pressed wire rope joints does not reach 90% of the minimum breaking force of the wire rope.

[0071] The scrapping standards for jointless rope loops are as follows: the wear of the wire rope surface and strands exceeds 10% of the nominal diameter; the total corrosion area inside and outside the entire rope exceeds 10%; the red no-hanging sign in the rope core connection area is bent and deformed; when the rope strands are severely separated, the rope strands are unevenly stressed and cannot form a combined force; the wire rope strands are pulled out.

[0072] Shackle scrapping standards: shackle body twisted more than 10 degrees; shackle body or pin deformation exceeds 15% of the nominal size.

[0073] Specifically, in step S6, the following method is used when hoisting the C1HJ-3 truss:

[0074] The first and second cranes hook the two ends of the C1HJ-3 truss respectively and slowly lift the hooks;

[0075] After the C1HJ-3 truss is lifted to a certain height, it is rotated to the installation direction;

[0076] Slowly walk forward to the crane station position when in place;

[0077] The first and second cranes simultaneously climbed the pole to lift the C1HJ-3 truss to the top of the installation position;

[0078] Use the third crane to hook the C1HJ-3 truss at halfway point to ensure the lateral stability of the C1HJ-3 truss;

[0079] The first and second cranes work together to drop the hook and accurately place the C1HJ-3 truss in the installation position. During this process, the third crane needs to maintain the lateral traction on the C1HJ-3 truss to prevent the C1HJ-3 truss from fluctuating in the lateral direction.

[0080] After the C1HJ-3 truss is fixed, the rigging on the first crane, the second crane and the third crane are unhooked from the C1HJ-3 truss.

[0081] It should be noted that in step S6, C1HJ-1, C1HJ-2, C1HJ-4, C1HJ-5, and C1HJ-6 are the same, but are different from the hoisting of the C1HJ-3 truss, which is specifically as follows:

[0082] The first crane and the second crane hook the two ends of the truss respectively and slowly lift the hooks;

[0083] After the truss is lifted to a certain height, it is rotated to the installation direction;

[0084] Slowly walk forward to the crane station position when in place;

[0085] The first crane and the second crane simultaneously perform actions such as climbing the pole and dropping the hook to lift the truss to the installation position;

[0086] After the truss is fixed to the previously installed truss, the rigging of the first crane and the second crane is unhooked from the truss.

[0087] Specifically, the first and second cranes hook onto the truss 8 meters from the end. As shown in the figure, according to the mechanical formulas: F1 + F2 = G, F1XL1 = F2XL2; the weight of F1 and F2 is distributed based on the crane's performance. The total truss length is 68.5 meters, with half of the length being 34.25 meters.

[0088] Therefore, the truss lifting weight and lifting points are calculated as follows (calculated in the order of lifting):

[0089] C1HJ-1, 2, 4, 5 trusses:

[0090] F1=30t,F2=30t

[0091] The 500t crawler hanging wire rope is selected at a position 8m from the end, so L1 = 26.25m

[0092] L2=L1, so the wire rope of the 650t crawler crane is hung 8m away from the end.

[0093] C1HJ-3, 6 trusses:

[0094] F1=48.25t,F2=48.25t

[0095] The 500t crawler hanging wire rope is selected at a position 8m from the end, so L1 = 26.25m

[0096] L2=L1, so the wire rope of the 650t crawler crane is hung 8m away from the end.

[0097] Of course, when hoisting truss C1HJ-3, its hoisting process parameters are shown in the table below:

[0098]

[0099]

[0100] When hoisting truss C1HJ-1, the hoisting process parameters are shown in the table below:

[0101]

[0102]

[0103]

[0104] When hoisting truss C1HJ-2, the hoisting process parameters are shown in the table below:

[0105]

[0106] When hoisting truss C1HJ-4, the hoisting process parameters are shown in the table below:

[0107]

[0108] When hoisting truss C1HJ-5, the hoisting process parameters are shown in the table below:

[0109]

[0110]

[0111] When hoisting truss C1HJ-6, the hoisting process parameters are shown in the table below:

[0112]

[0113]

[0114] Specifically, in step S6, when hoisting truss No. 3, it is necessary to verify whether truss No. 3 is resistant to poles. It can be seen from the hoisting plan that when hoisting the C1HJ-3 truss, the 500t crawler crane is closest to the frame and the climbing pole is farthest into the frame. Therefore, it is necessary to verify whether the C1HJ-3 truss is resistant to poles. If the 500t crawler crane does not resist poles when hoisting the C1HJ-3 truss, and both the 500t crawler crane and the 650t crawler crane have 84-meter main arms, then the 500t crawler crane and the 650t crawler crane will not resist poles when hoisting all trusses. It can be seen from the hoisting elevation of the 500t crawler crane that the anti-pole safety distance and the hoisting height safety distance both have margins, so the hoisting requirements are met.

[0115] Specifically, in step S1, the site ground includes a truss stacking area, a transportation walking area, and a hoisting area;

[0116] The ground in the truss stacking area must be compacted and flattened in layers, and no serious water accumulation is allowed. After the ground in the stacking area is compacted, it must be able to withstand a force of 5t / m 2 ;

[0117] The ground in the transport walking area must be paved with 40cm thick stones after layering and compaction, and then paved with a 20cm thick gravel layer, with a bearing capacity of 20t / m 2In addition, the roads in the transport walking area must ensure smooth access from the truss stacking area to the assembly areas inside and outside the yard. The width of the transport road must not be less than 10m. There must be at least two transport channels from outside to inside the yard, and the width and height must meet the requirements for heavy transport vehicles to pass through.

[0118] The ground in the lifting area is paved with a roadbed box.

[0119] Among them, the gap between adjacent roadbed boxes cannot exceed 10cm.

[0120] Among them, the C20 concrete surface layer, ballast cushion layer and plain soil ramming layer are laid in sequence under the roadbed box.

[0121] Among them, the thickness of C20 concrete surface layer is 200mm, the thickness of ballast cushion layer is 500mm, and the thickness of plain soil ramming layer is 200mm.

[0122] Specifically, the 500t crawler crane's maximum deadweight under superlift conditions is 570t, and the maximum equipment load is 48.25t. The roadbed boxes measure 5000×2500×200, each weighing 7t (10 total), with an uneven load of 2 times the load, and the crawler track length is 10.5m. Two roadbed boxes are laid horizontally and one vertically under each crawler track, perpendicular to the crawler track direction. The effective contact area between the crawler and roadbed boxes is 75m2. The gap between adjacent roadbed boxes cannot exceed 10cm, and the front and rear ends of the crawler track cannot stop at the joint. The remaining four roadbed boxes are laid forward or backward during the crawler movement.

[0123] Crawler crane ground pressure: [570+48.25+42]×2 / [5.0×2.5×6]=17.6t / m 2 The crawler crane's ground pressure is less than the foundation bearing capacity of the construction site by 20t / m 2 Therefore, the 500t crawler crane super-lifting condition meets the lifting requirements.

[0124] Specifically, the 650t crawler crane's maximum deadweight under superlift conditions is 610t, and the maximum equipment load is 48.25t. The roadbed boxes measure 5000×2500×200, each 7t (10 total), with an uneven load of 2 times, and the crawler track length is 11.2m. Under each crawler track, one roadbed box is laid horizontally and two vertically, perpendicular to the crawler track direction. The effective contact area between the crawler track and roadbed boxes is 75m2. The gap between adjacent roadbed boxes cannot exceed 10cm, and the front and rear ends of the crawler track cannot stop at the joint. The remaining four roadbed boxes are laid forward or backward during the crawler movement.

[0125] Crawler crane ground pressure: [610+48.25+42]×2 / [5.0×2.5×6]=18.67t / m 2 The crawler crane's ground pressure is less than the foundation bearing capacity of the construction site by 20t / m 2 Therefore, the super-lifting condition of the 650t crawler crane meets the lifting requirements.

[0126] The above disclosure is only a preferred embodiment of the present invention, and it is certainly not intended to limit the scope of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for hoisting a large-span roof steel truss, characterized by: The following steps are included: Step S1: Before truss hoisting, confirm that the on-site ground preparation work has been completed and meets the hoisting requirements; Step S2: The first crane is paired with the second crane, and the third crane is on standby at the designated construction site. Step S3: Installing rigging to the first crane, the second crane, and the third crane accordingly; Step S4: Use the first crane and the second crane to test-lift the truss and check whether there are any abnormalities in the foundation, cranes, rigging, equipment, etc.; Step S5: Check the lifting weight according to the theoretical lifting weights of the first crane, the second crane, and the third crane. If there is no abnormality, proceed to the lower lifting. Step S6: number the trusses and hoist them in the order of truss numbers 3, 1, 2, 4, 5, and 6; Step S7: After the lifting task is completed, the crane is dismantled and withdrawn.

2. The method for assembling a large-span roof steel truss according to claim 1, characterized in that: In step S6, the following method is used when hoisting truss No. 3: The first crane and the second crane hook the two ends of the truss respectively and slowly lift the hooks; After the truss is lifted to a certain height, it is rotated to the installation direction; Slowly walk forward to the crane station position when in place; The first crane and the second crane simultaneously perform pole climbing actions to lift the truss to the top of the installation position; Use the third crane to hook the truss at halfway point to ensure the lateral stability of the truss; Under the cooperation of the first crane and the second crane, the hook is dropped to accurately place the truss in the installation position; After the truss is fixed, the rigging on the first crane, the second crane and the third crane are unhooked from the truss.

3. The method for assembling a large-span roof steel truss according to claim 2, wherein: In step S6, the following method is used when hoisting the remaining numbered racks: The first crane and the second crane hook the two ends of the truss respectively and slowly lift the hooks; After the truss is lifted to a certain height, it is rotated to the installation direction; Slowly walk forward to the crane station position when in place; The first crane and the second crane simultaneously perform actions such as climbing the pole and dropping the hook to lift the truss to the installation position; After the truss is fixed to the previously installed truss, the rigging of the first crane and the second crane is unhooked from the truss.

4. The method for assembling a large-span roof steel truss according to claim 2, wherein: The position where the first crane and the second crane hook the truss is 8 meters away from the end of the truss.

5. The method for assembling a large-span roof steel truss according to claim 1, 2, 3 or 4, wherein: In step S6, when hoisting truss No. 3, it is necessary to verify whether truss No. 3 is a rod-resistant structure.

6. The method for assembling a large-span roof steel truss according to claim 5, characterized in that: In step S1, the site ground includes a truss stacking area, a transportation walking area, and a hoisting area; The ground in the truss stacking area must be compacted and flattened in layers, and serious water accumulation is prohibited. After compaction, the ground in the stacking area must be able to withstand a load of 5t / m². The ground in the transport walking area must be paved with 40cm thick stones after layered compaction, and then paved with a 20cm thick gravel layer, with a bearing capacity of 20t / m²; The ground in the lifting area is paved with a roadbed box.

7. The method for assembling a large-span roof steel truss according to claim 6, characterized in that: The gap between adjacent roadbed boxes cannot exceed 10cm.

8. The method for hoisting a large-span roof steel truss according to claim 7, characterized in that: The C20 concrete surface layer, ballast cushion layer and rammed soil layer are laid in sequence under the roadbed box.

9. The method for assembling a large-span roof steel truss according to claim 8, characterized in that: The thickness of C20 concrete surface layer is 200mm, the thickness of ballast cushion layer is 500mm, and the thickness of rammed soil layer is 200mm.

10. The method for hoisting a large-span roof steel truss according to claim 6, characterized in that: In step S4, the lifting height of the truss during the trial lifting is 100 mm.

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