By rosebell
Linking Mountbatten, Dakota and Paya Lebar stations, two Circle Line tunnels will be closed one at a time for the works, which is due to address tunnel squatting, whereas Singapore’s Land Transport Authority (LTA) is carrying out strengthening works.
Considering that due to the soft marine clay that some stretches of Circle Line tunnels are built in this phenomenon is caused, if not addressed, could lead to disruptions in train operations and structural defects in the tunnel in the long term.
Monitoring the issue for the past decade,the LTA has identified three localised sectors of the CCL tunnels between Stadium and Paya Lebar stations that are more affected by tunnel squatting.
While LTA closes each tunnel in turn at the three localised sections with a total of 450m,the train operations can continue safely in the affected tunnels as consultants have confirmed.
Installing steel plates along the circumference of the affected tunnel segments will be done during the strengthening work.
With the aim of more safety LTA says it has studied best practices in Shanghai, Taipei, Busan, Barcelona and Lisbon where similar engineering challenges were encountered. In order to establishing the conditions for tunnel safety to be maintained against long-term tunnel squatting, full-scale tunnel segments loading tests have also been conducted in some of these countries.
