The report titled “Proposed Putra Heights LRT stations a great danger, says UKM geologist” by Leven Woon in Komunitikini on 28 March 2011 has been brought to the attention of The Institution of Engineers, Malaysia (IEM).
IEM notes that the issues of public safety mentioned in the article pertain to the work of Engineers and concern engineering practice. The institution would like to clarify on the technical aspects of these issues in order that the public may be correctly informed to make reasoned decisions.
Below are the relevant excerpts from the report, followed by the IEM’s clarification.
a. “Tajul said the sags and crests of the land constitute a differential settlement and hence it will be hard to estimate the length of
foundational pillars needed for the track.”
The highs and lows of a terrain can be either natural or have been re-profiled by human activities, like earthworks cutting and filling. There is no technical difficulty in building a foundation within the requisite safety standards to support any structure to be built on it. Professional Engineers would carry out investigation to characterise the subsurface conditions prior to selecting the appropriate foundation system and to determine the appropriate founding materials. There is absolutely no technical difficulty in determining the length of the foundation piles, should the necessary engineering processes be carried out properly.
b. “It’s not only about inserting pillars into the ground. The subsurfaces of some crests might be too soft to sustain the weight of a running
LRT car. The pillars will subside.”
This statement is based on presumption that the foundation is not founded on competent and stable founding materials. If the foundation is appropriately designed and founded, the subsidence of pillar would be within the tolerable limits of a safe track design, and shall not pose any technical concern.
c. “The quarry wall is sharp and the residents’ houses are built right next to it. The quarry cannot even sustain the houses, not to mention
LRT stations,” he said. Tajul’s report also mentions the existence on the site of the proposed stations of a type of soil which cracks, and
hillslopes that might not be sustainable in the a long-run.”
The stability of ground supporting any structure shall be carefully assessed and the necessary stabilisation works shall be determined.
problems technical solutions, with due consideration of buildability and financial limitations, that conform to accepted safety standards can be
designed and built. However, long term sustainability of any structure does not just depend on good engineering design alone but on other
factors such as proper maintenance, usage and other causes.
In summary, the above-mentioned works come under the purview of Engineers, and it is a normal engineering scenario for Engineers. A competent Engineer would be able to ensure the public safety as top priority in his/her proposal. With the employment of suitably qualified professional engineers and the right method of construction and technology available in Malaysia, the stations can be constructed safely at the proposed sites.
Ir. Prof. Dr. Lee Teang Shui,
The Institution of Engineers, Malaysia