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Land Transport Authority – Downtown Line 3, Singapore - Optimisation

Tunnelling works completed on schedule after switching to our custom-developed product


Leighton/John Holland JV


TBM Technology,Sprayed Concrete





The Project 

Singapore’s Land Transit Authority (LTA) awarded the Downtown Line Stage 3 (DTL3) C953 contract consisting of the construction and completion of Sungei Road station to Leighton/John Holland JV. 

The Challenge 

Ground conditions of the EPB TBM tunnel drive were in Old Alluvium (OA) and mainly made up of very stiff clay. The advance rate of the TBM was slow at 7-8 mm/min and the TBM was experiencing very high torque. 

The ideal target advance rate was to achieve 20 mm/min to meet the tight project completion schedule to avoid a heft daily LD. The advance rate had to be increased by at least two times to meet the deadline. 

Quick Facts

  • TamSoil 280AC developed and produced in under a week
  • Major tunneling works completed on schedule after switching to our product
  • Positive feedback of TamSoil 280AC leads to another customer in the same project
  • 90 tons of TamSoil 280AC supplied to C935 (Leighton John Holland JV) and 180 tons supplied to C929A (Nishimatsu)

The Solution 

The challenges faced by the contractor were clear to Normet and a solution was found, but the company did not yet have a suitable product.  

Global resources were put together and within a week’s time, Normet managed to bring in raw materials from Europe and develop a new TamSoil product locally at Normet’s factory. 

The outcome was TamSoil 280AC, a clay dispersant foaming additive for EPB TBM tunneling. It was delivered to the site for use on the TBM within a week from the first meeting with the contractor.  

Project Outcome

After using TamSoil 280AC, the advance rates improved instantly to a high of 38 mm/min. The advance rate was > 20 mm/min on average.  

The quick response from Normet’s team of TBM specialists and on-site 24/7 support on the foam settings allowed the tunnelling works to be completed on schedule.  

The news of successful completion spread, and the LTA instructed another project facing similar clay issues on their EPB TBM (C929A by Nishimatsu) to use TamSoil 280AC.  

The C929A advance rate before using TamSoil 280AC was 8-9 mm/min. After switching to TamSoil 280AC, the advance rate improved to 25-28 mm/min and tunnelling works were also completed on schedule. 

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