High clearance scaffold systems during construction - I. Structural modelling and modes of failure

The highest risk to structures during their lifetime is generally during the construction phase. This is evidenced by the fact that most structural failures occur during the placement of fresh concrete in construction rather than after the structure is completed and is in service. A scaffold support system, often a combination of modular steel scaffolds and wooden shores, is typically used for temporary support during the construction of high-clearance concrete buildings in Asia. Such temporary support systems are often used because they are convenient, versatile and relatively inexpensive. No guidelines exist, however, for the design and use of these temporary structures during construction. This paper focuses on the development of a computer model based on actual construction practices which is then used to provide a description of likely causes of scaffold support system collapse during construction. An examination of the effect of combining wooden shores with modular steel scaffolds on the performance of temporary support structures then follows.