In large-scale industrial equipment installation projects, gantry cranes serve as critical material handling equipment. Their construction quality directly impacts production efficiency and operational safety. Modern engineering construction imposes higher requirements on the installation precision and operational reliability of lifting machinery, necessitating systematic construction technical plans for support. Scientific construction process design can circumvent common issues in traditional installation work, such as structural deformation and positioning deviations, ensuring stable operation throughout the equipment’s entire lifecycle. From foundation construction to complete machine commissioning, each phase must strictly adhere to technical specifications, forming a complete quality control chain.
As a core logistics device in large-scale industrial production scenarios, the gantry crane plays a vital role not only in material handling and loading/unloading operations but also as a crucial link in ensuring efficient production line operation and safety. Therefore, ensuring that the installation and construction quality of the gantry crane meets preset standards is decisive for enhancing overall production line efficiency, maintaining normal enterprise operations, and preventing potential safety incidents.
This plan provides comprehensive planning and detailed management for all stages of equipment installation, from initial planning, mid-term execution to final acceptance, forming a rigorous and highly operational standardized work procedure. During specific implementation, the structural installation of the gantry crane will be precisely controlled to ensure its installation accuracy meets national code requirements—specifically, keeping the installation error of structural components within ±3mm. This measure aims to guarantee the structural stability and operational safety of the crane. Concurrently, for the installation and commissioning of the electrical system, the plan will strictly enforce high-standard quality management requirements, ensuring a first-time commissioning pass rate that leads the industry, i.e., achieving a success rate of over 98%.
The formulation and implementation of this plan will strictly adhere to the latest national technical standards, including GB/T 3811-2008 “Design Rules for Cranes” and TSG Q7015-2016 “Supervision and Inspection Rules for Installation, Modification, and Major Repair of Lifting Appliances”. Starting from the foundational aspect of ground treatment, a scientific foundation design and construction technology will provide stable foundational support for the gantry crane, effectively preventing equipment failures and safety accidents caused by foundation issues. During installation, advanced surveying instruments and technical means will be employed to precisely control the installation position and dimensions of each component, reducing performance degradation due to error accumulation. Simultaneously, critical steps in the electrical system such as wiring, connection, and commissioning will be strengthened, utilizing automation and intelligent technology to improve the reliability and stability of the electrical system. Upon completion of the full machine installation, rigorous whole-machine performance testing and acceptance procedures will be conducted to ensure the crane’s operational performance metrics under various working conditions meet both design requirements and national standards.
Before commencing formal construction, a thorough survey and preparation of the construction site is required. Firstly, ensure that the “Three Accesses and One Leveling” work for the construction area is complete—meaning road access is clear, power and communication lines are unobstructed, the site is leveled, and the measured foundation bearing capacity meets the minimum requirement of no less than 150 kPa. This forms the basis for ensuring construction safety and smooth progress.
Regarding equipment, precision instruments like total stations must be used to re-measure the positions of embedded parts, ensuring they match the design drawings. Axis deviations exceeding 5mm require secondary grouting treatment. For crane components, strict inspection is mandatory upon arrival on site. This includes key parameters such as the web plate waviness of the main girder and the torque coefficient of high-strength bolt connections. Specifically, the main girder web plate waviness must not exceed 3mm per meter to ensure its flatness and strength meet requirements. High-strength bolt connection sets must be accompanied by torque coefficient test reports to confirm their tightening level and mechanical properties comply with standards.
Table: Construction Site and Equipment Inspection Checklist
| Inspection Item | Inspection Content/Standard | Inspection Tool/Method | Permissible Deviation/Requirement | Corrective Action (if non-compliant) | Relevant Code/Basis |
|---|---|---|---|---|---|
| Site “Three Accesses and One Leveling” | Clear road access, unobstructed power & comm lines, leveled site | Site survey, measuring instruments | Foundation bearing capacity ≥150 kPa | Reinforce until compliant | Construction Code GB 50202-2018 |
| Embedded Parts Position Re-measurement | Axis position consistency with design drawings | Total Station | Deviation ≤5mm | Secondary grouting correction | Steel Structure Construction Code GB 50755 |
| Main Girder Web Plate Waviness | Flatness per meter range | Laser rangefinder, straightedge | ≤3mm/m | Replace or correct component | Crane Design Code GB/T 3811 |
| High-Strength Bolt Connections | Integrity of torque coefficient test report & mechanical properties | Torque wrench, lab testing | Within ±10% of design torque coefficient | Prohibit use and isolate/mark | GB/T 1231-2006 |
| Special Operation Personnel Qualification | Certification status of crane engineers, welding technicians, etc. | Certificate verification | 100% certification rate | Prohibit from working | “Regulations on Safety Tech Training & Assessment for Special Operation Personnel” |
| Steel Material Re-inspection | Yield strength of Q345B material | Universal testing machine | ≥345 MPa | Reject from site | GB/T 1591-2018 |
| Electrical Component Certification | CCC mark & inverter protection rating | Visual inspection, certification document check | IP54 or higher | Replace with compliant product | GB 14048.1-2012 |
Table: Construction Personnel Training and Material Management Checklist
| Category | Key Requirement/Standard | Implementation Method/Tool | Acceptance Criteria | Responsible Department | Documentation |
|---|---|---|---|---|---|
| Specialized Training Content | Portal frame lifting center of gravity calculation, emergency measures for wind speed >8m/s | Simulation drill + theoretical assessment | 100% pass rate | Safety Supervision Dept. | Training attendance sheet + assessment record |
| Material Traceability Ledger | Complete quality certificate, re-inspection reports | Electronic ledger system | 100% information completeness rate | Materials Management Dept. | Material entry acceptance form |
| Non-conforming Product Isolation | Clearly marked and physically isolated | Visual management + zoning | 100% isolation rate | Quality Inspection Team | Non-conforming product disposal record |
| Welding Procedure Qualification | Execution per GB 50661 standard | Third-party testing + procedure test piece | Weld grade ≥ Class II | Technical Dept. | Welding Procedure Qualification Report |
| Crane Daily Check | Structural members crack-free, brakes responsive | Checklist + ultrasonic flaw detection | Zero tolerance for defects | Equipment Ops Team | Equipment daily inspection record |
| Emergency Drill | Coverage of scenarios like collapse, electrocution | Quarterly practical drills | ≥2 times per year | Project Dept. | Drill evaluation report |
Regarding personnel, assemble a team comprising professional technical staff such as crane engineers, welding technicians, and electrical commissioning personnel. Furthermore, all personnel performing special operations must hold valid certifications, with a mandatory 100% certification rate. This not only ensures the professionalism and safety of the construction but also enhances overall construction efficiency and quality.
To improve the team’s professional skills and emergency response capabilities, specialized training will be conducted. Key aspects such as center of gravity calculations during portal frame lifting and emergency measures for wind speeds exceeding 8 m/s will be addressed through simulation drills. Personnel failing the training assessment will be prohibited from working, ensuring all participants possess sufficient professional knowledge and skills.
Regarding materials, main structural steel must be accompanied by quality certificates and re-inspection reports. The measured yield strength for Q345B grade steel must be no less than 345 MPa. This forms the basis for ensuring structural strength and stability. Concurrently, electrical components must be checked against drawings for CCC certification marks, and inverter protection ratings must meet the IP54 standard. A traceable ledger must be established for all incoming materials, and a clearly marked isolation area must be designated for non-conforming items. This facilitates material management and use while enhancing overall construction safety and quality control.
During foundation construction for the gantry crane, first ensure the work area is level and free of积水 (standing water). Following design drawing requirements, pour the rail foundation using high-strength grade C30 concrete. To ensure precise positioning and verticality of anchor bolts, use positioning molds to fix them, controlling deviations within 1/1000. After pouring, allow the concrete to cure for 28 days, then conduct a rebound test to confirm strength reaches 120% of design strength. If strength is insufficient, continue curing until the requirement is met. Additionally, grounding devices must be installed at a depth of no less than 0.8 meters, with a measured grounding resistance of ≤4 Ω to ensure equipment safety.
During portal frame structure installation, use a 500-ton mobile crane for main girder lifting. Lifting point locations are determined via finite element analysis to ensure structural safety and stability. Connect the portal legs to the main girder using Grade 10.9 M24 high-strength bolts. The initial tightening torque is set at 50% of the final torque value to ensure tight and reliable connections. Simultaneously, monitor the overall structural verticality using a laser theodolite, ensuring deviations remain within permissible limits. Adjustment of the mid-span camber must also strictly adhere to requirements, ensuring it falls within the range of (0.9/1000 ~ 1.4/1000)L to guarantee proper gantry crane operation.
When installing hoisting and travel mechanisms, first perform non-destructive testing on the drum assembly to ensure quality compliance. Wire rope winding must maintain a 5% safety coil count to prevent rope detachment or jamming. The wheel assembly end face levelness deviation must not exceed 1/1000D (where D is the wheel diameter). The coaxiality between the variable-frequency motor encoder and the reducer input shaft should also be ≤0.1mm. During no-load trial runs of the gantry travel mechanism, the current difference between the motors on both sides must not exceed 10% of the rated value to ensure smooth and reliable operation.
During electrical system installation and commissioning, use flame-retardant cables for power circuit routing. The bending radius of conduits must be no less than 6 times the conduit diameter to ensure installation quality. PLC program development must include fault self-diagnosis functions. The repeat positioning accuracy for the hoist mechanism’s zero-position signal should be controlled within ±2mm. To verify the electrical system’s performance and stability, conducting a 72-hour continuous load test is essential. During the test, record temperature rise data at various points. Motor bearing temperatures must not exceed 75°C. The electrical system installation is considered successful and ready for use only when all data meets requirements.
During construction, for controlling the mid-span deflection of the main girder, we employ advanced total stations for real-time monitoring. We ensure that under full load, the girder’s deformation strictly complies with regulations—i.e., not exceeding 1/700 of the girder span length—to guarantee structural stability and safety. For gantry rail installation, we strictly control joint gaps within 4-6mm, while permitting a rail gauge deviation range of ±5mm to ensure vehicle travel smoothness and rail system reliability. For high-strength bolt connections on critical components, we use torque wrenches for final tightening checks, ensuring each bolt reaches the specified torque value, with an under-tightening rate not exceeding 5%, thereby ensuring connection tightness and safety.
Quality control of the main girder web plate butt welds is a critical part of the entire construction process. We employ 100% ultrasonic testing, strictly following the Class BⅡ assessment criteria per GB/T 11345-2013. Twenty-four hours post-welding, we perform magnetic particle inspection to ensure the weld surface is free of crack-like defects. For important fillet welds, we strictly control the throat height measurement, ensuring it is no less than 90% of the value indicated on the drawings to guarantee weld quality and structural strength.
During electrical system commissioning and testing, we conducted rigorous simulated fault testing on safety circuits, performing 200 tests to ensure the system responds promptly in emergencies, with emergency stop response time not exceeding 0.5 seconds. For the hoist height limit switch, we performed three full-scale calibrations, ensuring its actuation error is within ±20mm. Insulation resistance testing is a key indicator for verifying electrical system safety performance. We use a 1000V megohmmeter for measurement, ensuring insulation resistance is ≥1 MΩ.
Establish a warning zone with a radius of 30 meters around the construction site, monitored and maintained by designated personnel to prevent unauthorized entry. To monitor on-site wind speed in real-time for timely response to potential risks like falls from height or struck-by objects, anemometers are placed at key locations, uploading data in real-time to a monitoring center. This allows managers to grasp wind speed changes and implement appropriate safety measures. During lifting operations, strictly adhere to the “Ten Do Not Lift” principles to ensure operational safety and effectiveness. Simultaneously, for sling selection, we always ensure a safety factor of 6 to handle potential unexpected situations. To further enhance employee safety awareness and hazard identification capabilities, daily pre-shift meetings are held to conduct JSA (Job Safety Analysis) for upcoming work. This analysis helps identify potential major hazards like falls from height or struck-by objects, enabling proactive preventative measures.
Personnel working at height must be equipped with five-point double-hook safety harnesses to effectively mitigate impact forces in case of a fall, reducing injury risk. Simultaneously, anchorage points for lifelines must have a load-bearing capacity of ≥15 kN to withstand potential pulling forces and prevent failure. During welding operations, personnel must wear auto-darkening helmets to protect against arc flash. In areas with excessive noise, provide hearing protection like earplugs to safeguard workers’ hearing health. Before confined space entry, conduct oxygen content testing to ensure levels are maintained between 19.5% and 23.5%. This prevents health issues or safety incidents due to oxygen deficiency.
A specialized response plan has been developed for potential structural collapse incidents. This plan defines key elements such as the emergency organization, rescue procedures, and resource allocation. A 50-ton hydraulic jacking equipment is stockpiled as critical emergency rescue gear. Multi-department joint drills are conducted quarterly, simulating main girder lifting imbalance scenarios. These simulated drills not only test the plan’s effectiveness but also improve employee emergency response capabilities. The target emergency response time is controlled within 8 minutes to ensure rapid activation of emergency mechanisms and minimize losses. The medical rescue team is equipped with first aid equipment such as AED defibrillators, and first aiders hold Red Cross certification. This professional equipment and certified personnel can provide timely and effective medical assistance to the injured, reducing casualty rates.
During construction, all technical indicators must meet preset standards to ensure engineering quality. For load capacity tests, static load testing applies 1.25 times the rated load per industry regulations to verify the main girder’s bearing capacity and stability. During this, the residual deformation of the main girder is measured, requiring it not to exceed 1/2000 of the girder length to judge structural safety and reliability. Furthermore, dynamic load testing is a key step for verifying equipment performance. Conducting combined motions of all mechanisms under 1.1 times the design load ensures no permanent structural deformation, guaranteeing stable and efficient operation under normal working conditions.
When submitting acceptance documents, they must include 28 items of technical data such as third-party inspection reports, weld inspection records, and material quality certificates. These documents comprehensively reflect the equipment’s true performance and construction quality, providing a solid basis for subsequent use and maintenance.
To ensure long-term stable equipment operation, a comprehensive condition-based predictive maintenance system must be established. Specifically, measure wheel tread wear monthly. Once wear reaches 10% of the original thickness, replace the wheel promptly to prevent safety hazards from excessive wear. For the lubrication system, employ an advanced centralized automatic greasing method to ensure adequate and appropriate lubrication of all friction pairs, effectively reducing wear. Simultaneously, inspect critical components like wire ropes weekly, taking immediate action if wire breakage is detected.
For the electrical control system, clean and dust the electrical cabinets quarterly to maintain a good electrical environment. During inspection and maintenance, if contactor contact thickness wear exceeds 50%, replacement is mandatory to ensure normal operation and safety of the electrical system.
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