Abstract: This invention provides a method of preparing a foundation structure including the steps of forming foundation trenches in the ground; and heating the ground defining the trenches sufficiently to irreversibly change the properties of the ground defining the trenches. In the case where the ground consists primarily of clay, it is heated to a temperature above a level where the ground is baked into a brick-like consistency, wherein the structural water of crystallisation is removed and any carbonaceous material and Fe is oxidised. If the ground consists primarily of sand, it is heated to a temperature above its vitrification point wherein mullite (AI6Si2O13) begins to form. The method includes the further step of pre-treating the ground by adding an additive such as potash or slaked lime to the soil, prior to the step of heating.

Abstract: This invention provides a method of preparing a foundation structure including the steps of forming foundation trenches in the ground; and heating the ground defining the trenches sufficiently to irreversibly change the properties of the ground defining the trenches. In the case where the ground consists primarily of clay, it is heated to a temperature above a level where the ground is baked into a brick-like consistency, wherein the structural water of crystallisation is removed and any carbonaceous material and Fe is oxidised. If the ground consists primarily of sand, it is heated to a temperature above its vitrification point wherein mullite (AI6Si2O13) begins to form. The method includes the further step of pre-treating the ground by adding an additive such as potash or slaked lime to the soil, prior to the step of heating.

Abstract: This invention provides a foundation structure (10) cast from a settable material such as concrete and comprises a slab (12) having a particular generally annular non-rectangular circumferential outer profile. The foundation structure (10) is further provided with a plurality of intsecting primary beams (14) extending through a common central region of the slab (12); and a secondary annular circumferentially extending beam (16). The structure (10) is constructed by a method including the steps of forming a plurality of radially extending primary channels extending through a central foundation region of the building; forming a secondary annular circumferentially extending channel; providing a void former for defining a common central region of intersecting channels, through which the primary beams (14) extend after being cast; casting a settable material into the channels; and casting a slab of settable material integrally with the primary and secondary beams (14, 16).