Riding on experience and lessons learned from the previous SMART tunnel in Kuala Lumpur, Gamuda collaborated with Herrenknecht (equipment manufacturer) and Ruhr University to develop a safe tunnelling method in order to tackle the challenging Karstic Limestone on the Klang Valley Mass Rapid Transit (KVMRT) Kajang Line (Line 1). Hence, the world’s first Variable Density (VD) TBM was developed. VD TBM uses high-density slurry mixes (HDSM) to provide excavation face support preventing sinkhole and blow outs. The innovative breakthrough had successfully reduced occurrence of incidents in Line 1. Overall, six VD and four Earth Pressure Balance (EPB) were used.
For the Putrajaya Line (Line 2), eight TBMs from Kajang Line were refurbished and upgraded with four additional TBMs ordered from Herrenknecht. Gamuda’s collaboration with Herrenknecht expanded vastly with the TBM refurbishment works. The refurbishment was carried out locally with the intention to grow the local industry and bring in global experts to upskill the local workers through knowledge and technology transfer. Gamuda and Herrenknecht explored and worked with local companies such as Waiko Engineering Works to manufacture and source TBM parts locally. The refurbishment works were successful as all TBMs had completed mining through various mixed geologies namely Karstic Limestone, Granite and Kenny Hill formations without major incidents or significant delays.
This paper discusses Gamuda’s collaboration efforts with the project Client, Herrenknecht (equipment manufacturer), Ruhr University (research academics) and Waiko Engineering (local industry) for the refurbishment works and actual findings from Line 2. Recommendations based on the findings were also presented for reference in future works.