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Tunnelling works begin for DTSS Phase 2 243 works begin for DTSS Phase 2 3/4/2019 4:00:00 PMUse of digital technologies and smart tunnel monitoring process to gather real-time information on the progress and location of the machines during tunnelling works.Issue DatePress ReleaseAbout PUB, Singapore’s National Water AgencyFind out more about us<p>​​​​ <img src="" class="border-0" alt="" style="margin:5px;" /> ​ </p><p> <img src="" class="border-0" alt="" style="margin:5px;" /> ​ </p><p> <strong>Singapore, 4 April 2019 </strong>– PUB, Singapore’s national water agency celebrates a key milestone that will bring us a step closer to the completion of the Deep Tunnel Sewerage System (DTSS) Phase 2 project. The launch ceremony of the first Tunnel Boring Machine (TBM), to mark the commencement of DTSS Phase 2 tunnelling works, was officiated by Minister for the Environment and Water Resources, Mr Masagos Zulkifli. </p><p>2 This underground superhighway is Singapore's answer to a world-class used water management system that will protect the environment, public health and water sources. When completed, DTSS - an ambitious $10 billion infrastructure project first conceived 25 years ago - will greatly enhance our water sustainability by boosting PUB's capability to reclaim and recycle water in an endless cycle.</p><p>3 The first TBM for DTSS Phase 2, named after the Jalan Bahar work site where it will be lowered into a shaft, will create a 3.5m-diameter tunnel 42m below ground. A total of 19 TBMs will be used for this project, to dig at depths of between 35m and 55m below ground and seabed, to create deep tunnels and link sewers that range from 3m to 6m in diameter. The TBM builds a tunnel by slowly cutting through layers of soil and rock. While moving forward, pre-cast concrete segments are installed and excavated material is transported to the surface where it is treated for disposal. More than 1.8 million cubic metres of soil will be excavated during the tunneling works. </p><p> <strong>Vertical Shaft Sinking Machine (VSM) – First in Asia</strong></p><p>5 Tunnel construction is a complex and challenging process that requires a tremendous amount of preparatory work. It begins with the construction of the shaft, an underground passageway that facilitates access and ventilation during construction. This is followed by the tedious and progressive assembly and commissioning of the TBM within and beyond the shaft before it starts erecting the tunnel segments. When the tunnel is completed, the secondary lining is then installed before reinstatement works is carried out to restore the site to its original condition.</p><p>6 In a first for Asia, PUB will pioneer the use of a Vertical Shaft Sinking Machine (VSM) to construct the shaft. This is an innovative method that allows for the shaft construction and excavation to be carried out simultaneously, compared to conventional methods that require the retaining wall to be installed before excavation can start. It is also safer as all operations are controlled and monitored from the surface.</p><p>7 Ng Joo Hee, Chief Executive of PUB, said: ““For us in Singapore, used water is also a source of good water. We do not waste a drop of it. In fact, we collect every drop of our sewage and turn much of it into potable water again, in the form of NEWater. The DTSS is Singapore’s very innovative way of collecting our wastewater, on a national scale, in a safe, efficient and reliable way. Because of it, we are able to reuse and recycle water endlessly.”</p><p> <strong>Smart Tunnelling and Innovative Tunnel Features</strong></p><p>8 DTSS Phase 2 deep tunnels will be a showcase of cutting edge technologies and advanced smart sensors at work. Constructed using concrete resistant to microbiological-influenced corrosion and lined with High Density Polyethylene (HDPE) to further protect the concrete from the harmful sewer environment, the tunnel will also come equipped with a waterproof membrane coating in sections where it goes under the seabed.</p><p>9 During tunnelling, PUB will employ a <strong>smart tunnel monitoring system</strong> known as the ‘Shaft and Tunnel Excavation System’ (STEMS) to act as the nerve center to provide real-time updates of the TBM locations and instrumentation readings, ensuring safe and smooth operations throughout the construction period with minimal disruption to the structures in the immediate vicinity.</p><p>10 <strong>Fibre optic sensors</strong> are embedded within the tunnel lining, to monitor structural integrity and detecting problems before they become potential risks. The installation of <strong>isolation gates</strong> at strategic points of the deep tunnel allow for sections of the tunnel to be isolated in the event where used water flow diversion is required. To mitigate odour, forced ventilation equipment called “<strong>air jumpers</strong>” will also be used in the operations of its air management system in the tunnels, a first for Singapore. </p><p> <strong>DTSS Phase 2 - Combined 100km of Deep Tunnels and Link Sewers</strong> </p><p>11 The DTSS Phase 2 conveyance system will traverse 100km across the western half of the island, including the downtown area as well as upcoming developments such as the Jurong Lake District, Tengah Town and the Greater Southern Waterfront. Comprising 40km of deep tunnels and 60km of link sewers, works on the system will be carried out through 18 contracts, including 5 design and build contracts for the deep tunnel that runs along the Ayer Rajah Expressway from Keppel Road to Tuas View Basin, and another 13 contracts for the link sewers. Tunneling works is targeted to complete by 2024. </p><p>12 When completed, used water from homes, offices and industries will be conveyed via two tunnels - the 30km-long South Tunnel (domestic use) and the 10km Industrial Tunnel (industrial use) - to the Tuas Nexus for treatment and recycling into NEWater. </p>​ <p> <a href=""><em>Annex A: Media Factsheet on DTSS</em></a> ​</p><p> <strong>For media enquiries, please contact:</strong> </p><p>Sally Toh (Ms)<br>Senior Assistant Director (Communications) <br>Tel: 8100 4781 <br>Email: <a href="" style="text-decoration:underline;"></a><span style="text-decoration:underline;">​</span></p>​​​​​​​​ <p>Dilys Quek (Ms)<br>Senior Manager (Communications) <br>Tel: 9875 3188 <br>Email: <a href="" style="text-decoration:underline;"></a><span style="text-decoration:underline;">​</span></p>​​​​​​​​​<p>​​​PUB is a statutory board under the Ministry of the Environment and Water Resources. It is the national water agency, and manages Singapore’s water supply, water catchment and used water in an integrated way.</p><p>PUB has ensured a diversified and sustainable supply of water for Singapore with the Four National Taps (local catchment water, imported water, NEWater, desalinated water).</p><p>PUB calls on everyone to play a part in conserving water, in keeping our waterways clean, and in caring for Singapore’s precious water resources. If we all do our little bit, there will be enough water for all our needs – for commerce and industry, for living, for life.</p>​<p>​<span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">Like us at </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;"></a><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> </span><br style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">Follow us on </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;"></a><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> and </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;"></a><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> </span><br style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">Subscribe to our channel at </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;"></a><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> </span><br style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">For our latest event photos​, visit </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;"></a><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> </span><br style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">Download our mobile apps: MyWaters fo</span><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">r </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;">iOS</a> ​or​​<span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;">Android</a><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"> </span><br style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;"><span style="font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;">Visit our website at </span><a href="" style="color:#2196f3;font-family:roboto-regular-webfont;font-size:18px;line-height:30.24px;background-color:#ffffff;"></a>​​</p>