3.2 Geotechnical Properties of Singapore Marine Clay

In Singapore, excavation in soft marine clay is a major construction problem as excessive ground movement often occurs during excavation. The marine clay is geologically termed the Kallang formation which frequently appears in two layers, the upper and lower clays, separated by a thin layer of stiff clay. Figure 2.6 shows a typical profile of the Kallang Formation. The geotechnical properties of the upper and lower marine clays are summarised in Table 3.1. The values given in the table are based on published data by Tan (1983). The upper marine clay is slightly over-consolidated with overconsolidation ratio OCR of 1.1 to 1.5 indicating that the clay has probably undergone some ageing.