Computer-based modeling of concrete pressures on complex shaped wall formwork

The determination of concrete pressures on formwork is an important aspect of temporary works design. CIRIA provides a data sheet for easy abstraction of maximum concrete pressure values for formwork design. The data sheet cannot be used directly where complex shaped walls are encountered. A data model has been developed to describe the geometry of wall cross-sections so that the concrete pressure envelopes on complex shaped wall formwork can be computed systematically. The procedure described in CIRIA Report 108 for computing maximum pressures on non-parallel sided walls is used to implement the data model in a computer program developed to interface with a computer-aided drafting package. This allows the use of CAD techniques for describing the model geometry and associated attribute information to the computer, thereby providing a good user interface. An example is used to illustrate the application of the model to a complex shaped wall