KUALA LUMPUR LRT SYSTEM 2

This article describes the construction methods used on the tunnels for the Kuala Lumpur Light Rapid Transit System 2 in Malaysia; it includes a route map. The route is 29km long and runs from the south west suburbs, through the city centre, to the north east suburbs. The section through the centre is in tunnel, and the rest of the route is on viaducts. There are 24 stations, five of which are underground. The underground section was 4.4km long, and the tunnelling works were divided into three separate design-and-construct contracts: (1) Western Cut-and-Cover Tunnel, 500m long at the western portal to the underground section; (2) Bored Tunnel Contract 1, 1.6km long; and (3) Bored Tunnel Contract 2, 1.8km long bores, with 100m of cut-and-cover at the eastern portal. The bored tunnels have twin tubes, each of 4.9m diameter. Each contract includes a 'performance specification' stating the design and construction requirements. The article discusses: (1) ground conditions; (2) bored tunnels; (3) compressed-air machines; (4) emergency intervention shafts; (5) tunnel excavation and temporary works; (6) permanent tunnel works; (7) the Kewalram Shaft in Contract 2, sunk between the two running tunnels with short links to them; and (8) cut-and-cover tunnels.