1. The Land Transport Authority (LTA) has begun construction of the Marina Coastal Expressway (MCE)-Singapore's first road tunnel under the sea -following today's ground breaking ceremony at Marina South. Minister for Transport Mr Raymond Lim officiated as representatives of the six MCE civil contracts pledged their commitment to safe construction.
2. Building the 5-km expressway will be one of LTA's most technically challenging projects thus far. The team will work in difficult soil conditions in marine clay as deep as 60 metres in some places. The team will also need to reclaim an additional 13.1 hectares of land at Marina Wharf and Marina East to create new land space for construction of the expressway.
3. Difficult soil conditions, coupled with the scope of excavation, will require robust temporary works for the earth retaining systems, as well as extensive ground improvement works to ensure safety. While a typical excavation is 15 metres deep and 60 metres wide (enough for more than 15 traffic lanes), work can go as deep as 25 metres and as wide as 120 metres. It is estimated that 3 million m3 of excavation spoils will be removed.
Tunnel Below the Sea
4. "The MCE will be a major engineering challenge, especially the section that has to be constructed below the sea. We successfully 'moved' a river to build the KPE and now we'll 'dam' the sea," said Land Transport Authority, Chief Executive, Mr Yam Ah Mee. "Despite the challenges, we are very excited about this important project, which would serve the new Downtown at Marina Bay, connect KPE to AYE and to support the long term growth of Singapore."
5. A 420m section of the tunnel will run beneath the sea bed across the Marina Bay connecting Marina South and Marina East (about 20 metres below mean sea level). It will be a first in tunnel construction in Singapore. Here the key challenge for the team is to ensure that the Marina Barrage, a dam for the freshwater reservoir, can continue to operate normally while work progresses.
6. As the undersea tunnel will be constructed parallel to the Marina Barrage just 130 m away, works for the undersea tunnel will be conducted in two stages to allow the discharge of water from the Marina Barrage to the sea, as well as the passage of small crafts and vessels into the Marina Bay when necessary. Please refer to Annex A for the construction sequence of the undersea tunnel.
Tunnelling Above the New MRT Line
7. Another challenge will be at the Marina South section of the MCE where the tunnel will run above the new North-South Line Extension (NSLe), which is expected to be completed by 2014. As part of the MCE works, the team will construct a 280m section of the NSLe tunnel directly under the MCE tunnel.
About the MCE
8. When completed in 2013, the MCE will serve as a key element of the strategic island-wide road network to support the long-term growth of Singapore. The MCE will enhance the current road network to support the projected increase in traffic generated by upcoming developments in the Marina Bay area.
9. The MCE's total route includes a 3.6km long road tunnel, two ventilation buildings and three interchanges with the KPE/ECP, Marina Boulevard/Central Boulevard, and the AYE/Maxwell Road. Please refer to Annex B for the alignment map for MCE.
10. To date, LTA has awarded contracts worth about $4.1 billion for the construction of the MCE, including all 6 major civil contracts and 4 major system-wide contracts.
Annex A - Construction of the Undersea Tunnel
Annex B - Map showing MCE alignment