STRUCTURAL INVESTIGATIONS ON THE PROGRESSIVE COLLAPSE OF A STEEL-TIMBER INTERMEDIATE ROOFING

Building constructions are susceptible to significant risks from numerous low probability hazards during their design lifetime. Typical examples include fire, impact, explosion, earthquake, and severe weather hazards (wind, snow). The probable risks also include a special category pertaining to unidentifiable events, such as human errors in design and construction. As such exposures and hazards are difficult to quantify, the consequences can be severe, ranging from injuries or loss of life to serious economic costs. The paper presents the results of investigations conducted in the aftermath of a partial collapse during the construction of an intermediate roof built from hybrid steel-timber trusses in an existing market. The experimental tests and numerical simulations allowed the investigators to reconstruct the chain of events and identify the local damage that triggered the progressive collapse.