THERMAL STRESSING OF PLAIN AND PRESTRESSED MASONRY DIAPHRAGM WALLS

Diaphragm walls constitute a structurally efficient form of masonry. T he effects of the large cross-wall temperature differentials which can develop during winter need to be examined. Finite element models of d iaphragm walls were analysed to determine if thermal stresses could po tentially cause structural distress. For validation, model walls were subjected to flexural loading and the results were compared with those from experimental tests on similar walls. Good agreement was found. T herefore, thermal analyses were performed. It was found that the resul ting stresses were heavily dependent on the structural boundary condit ions, but indicated the potential of cracking. Series of 2 and 3 m hig h walls were therefore constructed and subjected to thermal loading. T he walls were subjected to different boundary conditions. The 3 m high walls were tested both plain and prestressed. None of the walls crack ed as a result of the thermal loading. A simple method is presented fo r estimating the change in prestress force due to the temperature chan ge in the wall.