Metal Structure Installation: Technology, Stages, and Quality Control
A structure fabricated to drawings still has to be assembled correctly on site — from foundation prep to verifying the plumb of the finished frame.
Site and foundation preparation
Before erection, a survey checks foundation axes and elevations, plus the position of embedded plates and anchor bolts — deviations at this stage carry through the entire frame and are hard to correct once assembly starts. In parallel, structures are delivered to site and laid out by shipping mark per the shipping schedule.
Sub-assembly and lifting
Large members (trusses, frame sections) are often sub-assembled into larger blocks on the ground and then lifted whole by crane — this reduces at-height work and the number of field joints in hard-to-reach spots. The lifting sequence and temporary bracing before permanent connections are set is defined by the erection method statement, not improvised by the crew on site.
Field connections: bolts and welding
The main field connections on site are bolted (including high-strength bolts with controlled tensioning) and welded. Bolted connections are preferred where erection speed matters and no post-weld corrosion touch-up is needed; welded connections where a monolithic joint is required. Requirements for each connection type are set already at the KMD stage — the erection crew does not choose them arbitrarily.
Erection quality control
After each tier or section of the frame goes up, a survey verifies column plumb, beam level, and overall geometry against the design. Field welds are checked visually and, for critical joints, by ultrasonic testing — before the structure is closed in by cladding or enclosure panels.
Safety on work-at-height erection
Erecting frames and pipe racks is work at height with lifting equipment, so the crew needs certification for height and rigging work, and the site needs a cordoned danger zone, fall-arrest systems, and a lift plan coordinated with the crane. This is not a formality — most industrial customers require it before a crew is admitted to site.
Need metal structure installation on site?
UK-ZTO-AN erects fabricated structures with its own crews on site — from foundation to handover of the frame for follow-on work.