Settlement Behaviour of a Cement-Stabilised Malaysian Clay

Soft clay soils often cause difficulties in construction operation with their low strength and low stiffness nature. However the engineering properties of these clay soils can be enhanced by adding ordinary Portland cement (OPC) for modification or stabilisation purposes. This paper describes the application of the cement stabilisation technique for improving the engineering properties of a soft Malaysian clay. The objectives of this study are two-fold: firstly, to study the settlement behaviour of the cement-treated clay using standard oedometers; and secondly, to explore the equal strain approach for predicting the settlement pattern of a stabilised columnar system for the clay. The quantities of cement added to the clay were 5 %, 10 % and 20 % by dry weight of the clay. The specimens were next cured in dry condition for 7, 14 and 28 days respectively to allow for investigation of the curing effect. The oedometer test results showed that cement is effective in enhancing the settlement resistance of the originally weak clay soil, and interestingly, compressibility of the clay was not markedly improved for specimens left to cure for longer periods than 7 days. In addition, settlement prediction of the stabilised columnar system using the equal strain approach showed that a columnar inclusion test in the oedometer can simulate the compressibility behaviour of a single column system with sufficient accuracy