Buildings constructed on expansive soils (e.g. organic – peaty – soils and expansive clays) are observed to crack extensively within a short period of time after their construction. In case of peats, this is mainly caused by the high compressibility. For clays, the large differential movements arise due to alternating swelling and shrinkage of the soil with the variation of its moisture content.
There are many areas in world where expansive soils exist. These make construction of foundations more difficult, they may cause large differential movements in structures as a results of excessive settlement or heave. Foundation engineers must be able to identify such soils when they are encountered in the field. Although it is not possible to solve all the problems caused by such soils, preventive measures can be taken to reduce the possibility of damage to the built structures.
The research will involve – among others - the following subtasks:
- Determine the swelling pressure for remoulded samples by using physical (foundation) model.
- Study the effect of grain size of the replacement soil on the magnitude of swelling pressure and swelling percentage.
- Study the effect of depth of soil replacement on the magnitude of swelling pressure and swelling percentage.
- Determine the active zone for expansive soils with and without replacement.
- Determine the modulus of subgrade reaction for expansive soils.
- Study the behaviour of foundation on expansive soils using finite element methods.