Tan Wee Cheng Today Online 21 Mar 13;
Given the repeated occurrences of road cave-ins recently, we would be imprudent to dismiss them as localised coincidences. These incidents may be no more random than the “once-in-50-years” flooding that happened a few times in the past few years.
Our island was essentially formed by the interaction of currents from the estuary of the Johor River, Strait of Malacca, Java Sea and South China Sea.
The marine clay and sand that form this isle’s foundation are soft and unstable, though strengthened by small rocks deposited by ocean currents over millions of years. Will the soil continue to hold if this sandbar is overbuilt with tall building structures sitting on multiple basement levels supported by deep foundation piles?
That is not to mention the MRT tunnels, underpasses, pipes, cable installations and sewerage channels surrounding all these structures. Perhaps, there is only so much weight the land, especially soft clay, can support.
We have seen more flooding over the past few years, which some attribute to the removal of vegetation cover.
With more infrastructural projects being planned to alleviate traffic congestion and the housing crunch, as well as to cater for a rise in population, we might be testing nature’s geological tolerance.
The flooding and road cave-ins may well be Mother Nature’s warnings to our challenges of those limits. I hope the relevant agencies bear these factors in mind while implementing key projects to achieve the vision of a sustainable, dynamic Singapore.
