Seismic and Wind Load Considerations for Temporary Structures

Reliability assessment of temporary structures using past performance information

“…As explained in Mohammadi and Zamani (2008), with the first situation, the structure performed well and passed its original intended short service life. A new (modified) risk level is obtained based on the fact that it did not experience a major load.…”

“…This is because the service life expected of a temporary structure is much shorter than a "permanent structure;" and, as a result, the probability of extreme load exposure to the temporary structure is substantially less. Thus, it will make sense to use a reduced load level proportional to the intended service life of the temporary structure as has also been suggested by Rosowsky (1998) and Mohammadi and Zamani (2008). However, the short service life does not imply less importance.…”

“…Using a reduced load level may be a reasonable assumption for a structure that is only used once. However, the decision to allow the same structure to be reused brings about certain ambiguity as to what happens to the level of risk inherent in the structure, which is now subject to repeated use and some reduction in its capacity due to periodic disassembling and reassembling (Mohammadi, 2006;Mohammadi and Zamani, 2008). The decision to whether continue or discontinue with the usage can be made by estimating the risk of failure of the temporary structure with considerations for its geometry, its resistance to withstand load and the conditions to which the structure has been exposed to.…”

“…The computation of the risk of failure of a temporary structure to seismic and wind load environment has been suggested by Mohammadi (2006) and Mohammadi and Zamani (2008). In these papers, a Bayesian updating process was adopted to use the performance record of a structure in a past usage period in estimating the risk of failure in a subsequent period.…”

“…Mohammadi then argues that this modified risk may be used as a parameter in decision-making process as to whether allow the structure to continue its service into a second usage cycle. On a follow up study to further investigate the significance of the performance record of temporary structures as a means to modify their risk of exposure to extreme events, Mohammadi and Zamani (2008) report on a method using the Bayesian updating approach to modify the risk of a temporary structure to wind and earthquake loads. The study was limited to basic development of an updating model and utilizing various levels of wind velocity and earthquake ground acceleration intensities as a means to define the resisting capacity of the structure.…”