The Klang Valley Mass Rapid Transit (KVMRT) is part of an integrated three-line transport system in the urban areas of Klang Valley, Malaysia. Line 2, the Putrajaya Line, was needed to provide greater public transport to residents in Greater Kuala Lumpur, and will help to reduce the number of cars on the roads and ease traffic congestion.

As the lead underground design reference consultant for the Putrajaya Line – the transit’s second line – we designed over 13.5km of underground rail, ten interchange stations, tunnels, and fit out design for the Tun Razak exchange station. Across all ten stations we delivered alignment design, geotechnical interpretation and design, tunnel and tunnel ventilation, civil and structural design, electrical and mechanical design, architectural design and transit-oriented development (TOD) planning, fire engineering, pedestrian modelling, costing, and geographic information systems (GIS) design.

In collaboration with MRT Corp, we supported interface coordination and land acquisition, safeguarded the railway corridor, and developed the master implementation programme. This line is an integral part of KVMRT which will cater for over 100,000 daily commuters and enhance the region’s connectivity, mobility and economic development by connecting Klang Valley’s densely populated areas and reducing congestion in Kuala Lumpur.

Complex geology and constrained urban spaces created design alignment challenges for the underground sections of the Putrajaya Line. Our team was challenged with designing a 10-kilometre-long twin bored tunnel and 3.5 kilometres of underground stations and tunnels through diverse rock formations, including karstic limestone, interbedded sedimentary rocks and granitic bedrock. Dense built-up areas, right of way restrictions, and tunnelling limitations near or beneath buildings and structures added extra complexity.

Using innovative thinking, we designed the alignment and bore tunnels in a stacked configuration, integrating with top side development and avoiding clashes with building and structure foundations. We used steel fibre reinforced concrete (SFRC) lining design for the tunnel segments for durability and stability. Using a gravity survey, we identified the boundaries between hard and soft ground and potential underground cavities. We then applied a seismic surface wave method to measure the ground’s ability to conduct electric currents – an uncommon technique allows for non-invasive and efficient geophysical urban environment surveying. This approach was vital for understanding where the proposed line design passed along or near geological boundaries and tunnelling limitations.

Collaborating with MRT Corp to create long-term value

Good transport design integrates stations with their adjacent spaces and public amenities. On completion of the Putrajaya Line, we are now working with MRT Corp on the next phase of the transit, supporting precinct regeneration projects and enabling developers to provide future affordable housing developments.