Why Malaysia need to tunnel underground for the MRT?

Kuala Lumpur is a densely developed city with no pre-planned corridors for a transit network such as the MRT. Moreover, in order for the MRT to accomplish its objective, it needs to provide connections to the busiest centres in the Klang Valley, and these areas are also typically the most densely developed.

The MRT Sungai Buloh -- Kajang line will be the foremost people-mover in the region when completed catering to 1.2 million people with an estimated daily ridership of over 400,000 passengers a day by 2020.

Normally, an above --ground MRT infrastructure is cheaper to construct that the underground one. However, to build an above-ground rail route through densely built city centre would be cost prohibitive, mainly due to land acquisitions that will be needed, and would also require severe change/ alternations to the cityscape, plus putting some heritage buildings at risk of demolition. Construction of such a route would also be inefficient, and extremely disruptive to the day-to-day lives of city dwellers.

For a good understanding of these reasons, it is necessary to keep in mind certain fundamental characteristics of underground space.

• First, the underground medium is a space that can provide the setting for activities or infrastructures that are difficult, impossible, environmentally undesirable or less profitable to install above ground.
• Another fundamental characteristic of underground space lies in the natural protection it offers to whatever is placed underground. This protection is simultaneously mechanical, thermal, and acoustic.
• On the other hand, the containment created by underground structures has the advantage of protecting the surface environment from the risks and/or disturbances inherent in certain types of activities.
• Lastly, another important feature of underground space is its opacity. Thanks to the natural visual screen created by the geological medium, an underground structure is only visible at the point(s) where it connects to the surface.

Credit: www.mymrt-underground.com.my/