Centrifuge modelling on performance of natural clay barrier with piles

Abstract

In this paper, the performance of natural clay barrier subjected to massive pile constructions is investigated using laboratory scale models on centrifuge. Model grounds comprising mainly either thick barrier of soft clay or stiff clay were made and pile construction, pile lateral loading were simulated besides conducting advective-diffusive transport modelling for very long prototype design period. Two types of pile namely opened end and close end steel piles were used as model piles. Deformation of the ground due to pile deflection under lateral loading and its impact on leakage, resistivity change in a pile vicinity ground due to contaminant movement were also monitored. Assessment of flow and transport around pilling area and pile free area was done on completion of centrifuge test by thorough model excavation, sampling and chemical analysis. Test results reveal that soft ground is strong enough to prevent its deterioration irrespective of the types of pile and their stiffness but stiff ground is susceptible to some amount of deterioration. However the degree of damage can be reduced by using OE piles for stiff ground under appropriate gravitational field. So the stiffness of the ground and its thickness are very important parameters to be considered for safety against possible environmental deterioration due to the mentioned activities.