Discussion on ‘A review of geology and engineering geology in Singapore’ by John Pitts

Abstract

K. Morton and P. Sayer write: Dr Pitts has presented a broad introduction to the engineering geology of Singapore. As he noted, there is considerable room for further investigation and understanding. The geology of Singapore has been well presented previously by the Singapore Public Works Department (1976) and Dr Pitts has summarized this report with comments based on his own observation. In such a review it might have been better to classify the geology into groups in a manner described, for example, by Andrews et al . (1984). This classification can be used to identify those areas where further knowledge on the engineering behaviour would be required from those where the behaviour is reasonably predictable. In particular, the superficial soils would fall into the former category and the moderately weathered to fresh basement would fall into the latter. Burnett (1984) has suggested that any deposit in the former category which can be repeatedly recognized can be broadly classified on the basis of an assessment of its origin, process of accumulation and final typical land form or shape. Natural geological deposits are divided into two environmental groups: first, sub-aerially formed regolith (essentially terrestrial, non-stratiform) and second, subaqueous stratiform. It is possible then to identify the properties of the materials on a rational scale rather than discuss the relative merits of localized deposits. A combination of the classification methods (after Andrews et al . (1984) and Burnett (1984)) together with the basic engineering properties could be proposed as shown in Table 1. Given this