Mechanized tunnelling in Kuala Lumpur, the capital of Malaysia, presents a number of challenges. Above all, the karstified limestone with changing geological conditions and difficult to predict underground cavities requires maximum performance from the mechanical engineers and tunnel builders. Herrenknecht developed and supplied an innovative solution to build a new subway to sustainably improve the efficiency of local public transport for over eight million inhabitants of the metropolitan region.
The plans for the "Klang Valley MRT" project include the construction of three subway lines with a total length of 150 kilometers. The first phase, the "Blue Line" from Sungai Buloh to Kajang, has a length of 51 kilometers. Twice 9.5 kilometers run underground through karstified limestone and the Kenny Hill Formation.
The karstic limestone is just about the most difficult ground to get through for a tunneller.
Gusztáv Klados, Project Manager MMC-Gamuda
For a total of 11.4 kilometers of tunnel, Herrenknecht supplied two EPB shields as well as six newly developed Variable Density TBMs specifically designed to handle the complex limestone karst zones. The machine design combines the principle of the EPB Shield with that of the Mixshield. A transition from one operating mode to the other can be realized quickly and without extensive adjustments. Depending on the requirements, safe tunnel face support is provided by pressurized bentonite with a connected slurry circuit or in earth pressure mode with screw discharge. Combinations of the modes are possible as well as variation of the density and thus the viscosity of the bentonite in order to be able to react flexibly when changes occur in the tunnel face conditions.
Herrenknecht Formwork supplied 160 moulds to produce a total of 100,000 concrete segments. Companies belonging to the Herrenknecht Group also provided belt conveyors (H + E), navigation systems (VMT) and multi-service vehicles (TechniMetal) for the project.
In May 2013, Malaysian Prime Minister Datuk Seri Najib Tun Razak gave the starting signal in Kuala Lumpur for S-774, the world's first Variable Density TBM. Only a little less than two years passed before the final breakthrough in April 2015 and the completion of tunnel construction for the "Blue Line". The new technology passed the baptism of fire with flying colors and showed the way for mechanized tunnelling in the most difficult unconsolidated rock.
Herrenknecht gained its first experience of Kuala Lumpur's underground in the years from 2004 to 2007. Two large Mixshields excavated the combined sewage and road tunnel SMART.
Kuala Lumpur's Blue Line was excavated by six Variable Density TBMs and two EPB Shields.
The success of the Herrenknecht technology in the construction of the Blue Line convinced all project participants and the Malaysian decision makers. The second subway line for Kuala Lumpur, the Sungai Buloh-Serdang-Putrajaya Line (SSP Line), will also be excavated by Herrenknecht's Variable Density TBMs and EPB shields. On January 2019, a first tunnelling success for the construction of the SSP Line was celebrated with the first intermediate breakthrough. The breakthrough in the parallel tunnel followed on March 15. The approx. 2 kilometer long section between Bandar Malaysia North MRT Station and Chan Sow Lin MRT Station was completed. Until March 2019, a total of 4.3 kilometers of tunnel were excavated by all Herrenknecht machines currently employed.
Projekt Highlights
Column 0 | Column 1 |
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Project | Klang Valley MRT Blue Line |
Client | MRT Corporation on behalf of the malaysian Minitry of Traffic |
Contractor | MMC GAMUDA KVMRT (PDP) Sdn Bhd |
Geology | Soft ground Heterogeneous groundKuala
Lumpur limestone, Kenny Hill Formation |
Tunnelling Length | 11,400m |
Machine Data | 6x Multi Mode TBM Diameter: 6,620 mm Lining method: Segmental lining Cutterhead power: 1,280 kW Torque: 4,239 kNm 2x EPB Shield Diameter: 6,620 mm Lining method: Segmental lining Cutterhead power: 1,280 kW Torque: 4,239 kNm |