Analysis of Design Code for Steel Tubular Truss Structures

The design of steel tubular truss structures must comply with GB 50017-2017 Standard for Design of Steel Structures. Its core requirements include: width-to-thickness ratio limits for member sections (outer diameter to wall thickness ratio of circular tubes ≤ 100(235/fy)), node connection forms (intersection welding requires a ratio of bay length to section height ≥ 12), and load combination principles (internal force calculation under dead load, live load, wind load, and seismic action). The standard particularly emphasizes stability design, introduces the direct analysis method to optimize structural safety and economy, and specifies deflection limits (short span 1/250, cantilever 1/125).

During design, attention should be paid to the coordinated analysis of spatial trusses and lower support structures. Node welds should meet the requirements of full penetration and equal strength butt joints, and when steel pipes are lengthened, the longitudinal weld seams should be staggered by a distance ≥ 5 times the wall thickness and ≥ 200mm. For large-span structures (≥ 30m), cambering (≤ span 1/300) can be considered to improve the appearance. The standard also clarifies that seismic design must use the design intensity earthquake verification method and divides section types S1-S5 to guide the design of plastic energy dissipation zones.