ÖNORM B 1997-1-2

This ÖNORM includes the ultimate state design for the failure mechanisms - mechanical bearing resistance failure (GEO), - sliding (GEO) and - eccentric load (tilting) as well as the serviceability limit state (settlements, settlement differences and distortions). This ÖNORM shall be applied to normal or oblique to the base loaded foundations and to central and intermittent load for spread foundations with a low foundational depth (guide value t <= 3 b). This ÖNORM is also applicable to underpinning. In addition, this ÖNORM is to be used to determine the size and the time course of settlements, in special cases also the heave, of structures with spread foundations. In addition, this ÖNORM covers settlements or heave caused by changes in the level of groundwater (eg dewatering). It does not record settlements due to the effect of groundwater currents (internal erosion), as a result of dynamic loads, frost effects, soil dehydration or mining measures. Foundations in rock are treated in this ÖNORM exclusively in the normative Annex B. Not subject to this ÖNORM are - foundations with predominantly horizontal effects of actions (eg foundations of overhead lines). For this purpose, there are separate calculation methods, which take into account a clamping of the side surfaces in the soil for the removal of the loads. These are described in ÖVE / ÖNORM EN 50341. - the failure by heave (liquefaction failure, internal erosion - HYD). - the uplift of anchored and non-anchored constructions (UPL). - the design of floorboards (eg industrial floors, high-bay warehouses). - the effect of frost on the ground at foundations. (Possible precautions against frost effects are, for example, sufficient embedment depth, protection against freezing through thin concrete components such as foundation plates or granular layer and protection against freezing of open subsoil.)