The first TBM breakthrough for Kuala Lumpur’s MRT Sungai Buloh-Serdang-Putrajaya (SSP) Line has taken place on 29thJanuary at the Chan Sow Lin MRT Station site, marking a major achievement in the construction of the Klang Valley MRT Project’s second Line.
The tunnel drive between Bandar Malaysia North MRT Station and Chan Sow Lin Station was excavated using a 6.6m diameter Herrenknecht Variable Density machine, taking 11 month to cover the 1.9km long distance.
The breakthrough marked the first completed tunnel drive of 16 needed to complete the 13.5km long underground section on the SPP Line.
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The TBM, S-776-VD was the same machine that completed the very first drive for the MRT SBK Line in 2014.
MRT Corp Strategic Communication and Stakeholder Relations Director Dato’ Najmuddin Abdullah congratulated MRT Corp’s tunnelling team and underground works contractor MMC Gamuda KVMRT for successfully completing the first section through challenging geology, saying the project was truly on its way to completion by 2022.
Seven more TBMs are due to be launched this year on the line, currently a total of five are in operation. A total of 12 TBMs, 10 Variable Density and two EPBMs, will be used to construct the line.
The VD TBM will now be pulled across the Chan Sow Lin Station box and restarted to excavate the second tunnel drive northwards to the Tun Razak Exchange Station. Upon completion the TBM will be disassembled.
MMC Gamuda KVMRT Construction Director Dato’ Ubull Din Om said that the profile fell within Extreme V Karstic limestone making it very challenging for TBM operations. He said in 2003 when the SMART tunnelling works were carried out in the same area numerous sinkholes had formed, leading to significant disruption. He added that tunnelling had proceeded smoothly as a result of the specially designed Variable Density machines and the experience of MMC-Gamuda’s personnel after it was used on the previous SBK Line.
The overall construction progress on the SSP Line is now 41%.