Steps for Installing Xinguangzheng Steel Structures
2025-06-20 
260
I. Preparation for Installation
(A) Preparatory Work
Construction Organization Design: The construction organization design for steel structure installation shall concisely describe the project overview, comprehensively quantify the scope, correctly select construction machinery and methods, rationally sequence the installation steps, detail key installation technical measures, strictly define quality and safety standards, and carefully prepare project schedules, labor plans, and material supply plans.
Pre-Construction Inspection: Includes acceptance of steel components, inspection of construction machinery and measuring instruments, and re-surveying of foundations.
Design drawings and modification documents.
Material quality certificates or test reports for steel and auxiliary materials.
Test data for friction coefficients of high-strength bolts.
Factory inspection reports for Class I and II welds.
Geometric dimension inspection reports for steel components.
Component list. The installation contractor shall verify these and re-check component dimensions. Damaged components during transport must be repaired by the manufacturer.
Component Acceptance: Steel components shall be inspected against construction drawings and specifications. Upon delivery, the manufacturer shall provide a product certificate of conformity and the following technical documents:
Machinery and Instrument Inspection: Critical lifting equipment, tools, wire ropes, and accessories must be inspected before installation to ensure reliable performance and safety. Measuring instruments must be calibrated by authorized units to guarantee accuracy.
Foundation Re-Survey: Steel structures are fixed to reinforced concrete bases (foundations, column tops, corbels). The accuracy and strength of these bases and their anchor bolts must be re-surveyed. This includes checking the level, elevation, flatness of the base surface, and the position and embedment accuracy of anchor bolts. Results and rectification requirements shall be submitted to the foundation contractor.
Develop Installation and Component Supply Plans: Organize construction effectively.
Inspect Steel Components: Components must have certificates of conformity. Check components against drawings before installation. Transport components to the installation area in sequence, positioning them below their final location where possible for easier installation.
Steel Column Installation: Before lifting, determine the lifting points and rigging method, implementing protective measures. After lifting, when the column base is 30-40cm above the anchor bolts, align it so the base holes match the bolts, then lower slowly into position. After initial alignment (vertical deviation ≤20mm), tighten bolts for temporary fixing before unhooking.
Steel Beam Installation: Conducted after column verification. Lift beams symmetrically using two points. Lower slowly to within 100mm of the column reference surface, then adjust, align, correct, and fix. Use a theodolite for real-time correction during lifting.
Wall Purlin Installation: Due to their small cross-section and light weight, purlins can be lifted in batches or panels. Alignment focuses on spacing and straightness. Check spacing with a template bar; adjust by loosening/tightening bolts. Check straightness with string lines and steel tapes, then fix with bolts.
Installation Correction:
Steel Columns: Correct verticality using a theodolite or plumb bob; deviations are adjusted with jacks. Elevation is corrected by slightly raising the base with jacks and adjusting shim thickness. Securely tighten anchor bolts immediately after correction. Grout the base with fine aggregate concrete after final verification.
Steel Beams: Measure and correct axis position and verticality using jacks; fix immediately after correction.
(B) Wall Profiled Color Sheet Installation
Preparation:
Prepare detailed installation drawings based on design documents. Conduct technical training and safety briefings.
Verify material specifications and quantities; repair or replace damaged sheets.
Ensure all construction equipment is available and operational.
Verify the installation accuracy of related steel components. Clean weld spatter from purlins and apply anti-rust paint.
Installation Sequence: Install wall sheets starting from one end along the purlin lines. Sheets must interlock tightly and be fixed with screws. Seal joints for waterproofing. Adjust position and fix progressively during installation.
(C) Floor Deck Installation
Prepare a layout plan before installation. Lay decking from one end of the floor, adjusting position and fixing progressively. Install decking first at openings, then cut to the required size.
II. Stability During Installation (Component & Structural Stability)
Component Stability: Refers to preventing bending, torsion, or buckling of individual components during storage, lifting, handling, and positioning. Critical for large, thin-walled members.
Structural Stability: Refers to ensuring the structure remains stable during lifting stages before the full support system is erected, as it may bear loads (including self-weight). The lifting sequence must guarantee step-by-step stability. Temporary measures like guy ropes may be required.
III. Connection Methods in Xinguangzheng Steel Structure Installation
Field connections primarily use ordinary bolts, high-strength bolts, and welding.
Ordinary Bolts: Mainly used in bending/tension joints (bolts primarily in tension). With pre-tensioning, also used for shear connections (e.g., transmission towers). After tightening, exposed threads must be 2-3 pitches minimum. Anti-loosening measures (e.g., double nuts, locknuts) are required. Minor bolt hole misalignment shall be corrected with reamers/files; flame cutting is prohibited.
High-Strength Bolts (HSFG): Used in structures subject to dynamic loads. Transmits shear via friction between contact surfaces. Faying surfaces must be prepared as per specifications. Friction coefficient and torque coefficient tests are mandatory. Initial and final tightening torques must be measured during installation.
Site Welding: Inspection requirements match factory welding.
Site welding should be minimized in design.
Mitigate adverse weather (rain, wind, cold).
Minimize impact of difficult welding positions (limited access, overhead welding).
Key Checks During Lifting: For columns/beams: ensure base shims are solid/level, columns are plumb/displacement-free, beams have correct verticality and lateral sweep. After forming a stable space frame unit and passing inspection, the space between the column base plate and foundation must be grouted with expansive concrete. Finally, check overall verticality and plane straightness of the main structure.
IV. Pre-Lifting Preparation
Mark design axes on column base plates and control lines on top cover plates for alignment/plumb control during erection.
Bolt Connection Quality Control:
Ordinary Bolts: Max one washer per bolt end. No flame cutting for hole enlargement. ≥2 exposed thread pitches after tightening. Anti-loosening required.
HSFG Bolts: Focus on faying surface preparation (e.g., sandblasting), slip coefficient, tightening sequence (initial/final torque), torque values, exposed thread length, plate surface damage/deformation. Contact surfaces must be flat (>75% contact), edge gaps ≤0.8mm. Bolts must insert freely (no hammering/reaming). HSFG bolts cannot be temporary bolts. Tighten sequentially in one direction. Torque-check all bolts installed daily; replace/retighten under/over-torqued bolts.
Critical Quality Control Points:
Anchor Bolt Embedment: Quality directly impacts installation. Precise control of position, plumbness, length, and elevation minimizes rework. Methods: direct embedment or sleeve/reserved hole.
V. Winter & Rainy Season Construction Measures
(A) Winter Construction Measures
Follow relevant steel structure winter construction regulations.
Account for thermal contraction differences between fabrication (positive temp) and installation (negative temp); implement adjustment measures.
Welders must pass low-temperature welding procedure qualification.
Materials used at sub-zero temps require certificates proving compliance.
Electrodes exposed >2 hours must be rebaked (max 3 times).
Dry flux to ≤0.1% moisture content before use.
HSFG bolts require certificates and re-testing of torque coefficient/axial force at installation temp.
Prohibit water-based paints.
Include thermal contraction allowances in component cutting.
Assemble components from inside out. Determine weld shrinkage allowance via test at low temp.
Clean joint surfaces (50mm width) of rust, burrs, dirt, oil, ice/snow; keep dry.
For welding >9mm thick plates: Use multi-pass welding (bottom-up). Complete each weld pass uninterrupted. Remove defects if interrupted. Absolutely prohibit arc striking on base metal.
Erect protective shelters during snow or winds >6m/s.
Remove and re-weld defective welds using qualified low-temp procedures.
Below 0°C: Conduct paint application tests. Clean surfaces thoroughly (rust, oil, burrs) and keep dry before painting. No painting during snow/ice.
Implement anti-slip measures for transport/storage. Ensure level, solid, ice-free storage areas. Stack identical components level; place shims vertically aligned; prevent sliding.
Re-inspect components for winter conditions before installation. Repair damaged or deformed components on the ground.
Use anti-slip pads with wire rope slings. Securely lash lifting lugs and tools.
Develop and strictly follow a component installation sequence chart based on temperature.
Develop welding sequence plans; prohibit simultaneous welding at both ends of a member.
Remove ice, snow, dew before installation without damaging coatings.
Correct columns/main beams immediately after sub-zero installation; achieve permanent fixation. Ensure daily installed sections form stable systems.
Faying surfaces for HSFG connections must be free of snow, ice, dirt, oil.
Adhere to GB50250-95 ("Code for Construction and Acceptance of Steel Structures") and project specifications for quality inspection.
(B) Rainy Season Construction Measures
Erect temporary shelters. Prevent rain on hot welds. Dry damp joints thoroughly (e.g., using oxy-acetylene torches) before welding; keep joints dry.
Remove water from components before lifting without damaging coatings. Faying surfaces for HSFG must be dry, clean, and free of dirt/oil.
No painting during rain.
No roof insulation work during rain or winds ≥ Level 5.
Store electrodes dry; rebake if necessary (max twice). Maintain rebaking records.
During high winds: Immediately align and permanently fix columns, main beams, bracing to prevent instability. Ensure daily installed sections form stable systems.
