ULTIMATE BEARING CAPACITY OF FOOTINGS ON COAL ASH

Abstract

Coal ash is recognized as an alternative fill material to the conventional natural soils near a coal fired thermal power station where its large deposits are available. This paper presents experimental investigations on footings on coal ash subjected to loads. A series of laboratory model tests on varying sizes of footings were conducted. The conventional bearing capacity evaluation methods applied for natural soils do not consider progressive failure. These effects are explained based on the non-linear strength behavior of the granular soil and occurrence of progressive failure. The classical bearing capacity theory was applied in relation to the relative dilatancy of coal ash to describe this phenomenon. Few novel observations presented here show that the extent of progressive failure of ash fills is a compressed function of material characteristics of the ash, size and depth of footing and the settlement ratio.