Assessing the suitability of evapotranspiration in the moisture control of expansive soils under foundations of buildings.

Abstract

Civil engineering is in the challenging situation of trying to discover cost effective, reliable and sustainable methods for ground improvement to meet the current demands needed for infrastructure facilities. Henceforth, getting an informed geotechnical engineer’s view of how best to place trees around our structures to keep a high dry density of the soil below foundations to limit soil deformation.

In order to achieve this, a simulation was used to mimic a real-life structure with a horizontal barrier. Two setups were organized using a tree proximity ratio(D/H) of 1 from the simulated structure and varying tree spacings of 40cm and 80cm plus varying plant species but of the same class. Moisture contents were monitored at a week’s length in the two moulds at various positions below the simulated foundation and barrier. And a comparison in results was made between the results of the setups with plants and those of a setup without plants(used as a control setup). The effect of varying tree spacing and tree specie was also assessed. Lab tests including the free swell test, sieve analysis, Atterberg limits, compaction test and the oedometer test were carried out to classify the soil and also obtain the various properties of the soil like its optimum moisture and its deformation at various moisture contents. Test results show that evapotranspiration is suitable in controlling moisture in expansive soils.