Resumen de Analysis of concrete slabs supported on soil
Joaquim A. O. Barros
A numerical model for material non-linear analysis of concrete slabs supported onsoil is described in this work. In this model, the cracked concrete is regarded as cracks withconcrete between cracks. The behaviour of the concrete between cracks is simulated by theconventional theory of plasticity. The behaviour of the cracks is defined by their constitutivelaws using the concrete fracture properties. Smeared multifixed and rotating crack modelsare available in the model.Concrete can be reinforced with sets of smeared bars of different materials and geometricproperties, as well as with discrete steel fibres. A tension-stiffening model that takes intoaccount the concrete fracture properties and the reinforcement characteristics is used for thereinforced cracked concrete.Main effects of the fibre reinforcement are reproduced in the model, introducing the materialfracture energy and a convenient softening law in the crack constitutive law, and using a newstress-strain relationship for the behaviour in compression.Soil supporting the concrete slab is simulated with springs perpendicular to the slab middlesurface. The soil non-linear behaviour and the loss of contact between slab and soil areaccounted for.Concrete slabs supported on soil are analysed with the model proposed. Safety of wire meshreinforced concrete slabs and steel fibre reinforced concrete slabs is discussed. A comparisonwith conventional design methods is performed. The influences of the soil load bearingcapacity, as well as the loss contact between soil and slab on the behaviour of slab-soilsystem are analysed.
