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The "Stormwater Management and Road Tunnel" or "SMART Tunnel", is a storm drainage and road structure in Kuala Lumpur, Malaysia, a major national project in the country. The 9.7 km (6.0 miles) tunnel is the longest stormwater tunnel in South East Asia and second longest in Asia.
The main objective of this tunnel is to solve the problem of flash floods in Kuala Lumpur and also to reduce traffic jams along Jalan Sungai Besi and Loke Yew flyover at Pudu during rush hour. There are two components of this tunnel, the stormwater tunnel and motorway tunnel. It is the longest multi-purpose tunnel in the world.
It begins at Kampung Berembang lake near Klang River at Ampang and ends at Taman Desa lake near Kerayong River at Salak South. The project is led by the government, including Malaysian Highway Authority (LLM) and the Department of Irrigation and Drainage Malaysia (Jabatan Pengairan dan Saliran = JPS) and also a company joint venture pact between Gamuda Berhad and Malaysian Mining Corporation Berhad (MMC).
Construction Method ;
Kuala Lumpur city is sitting on Karstic limestone geology with high ground water table. The Special Features of Karstic limestone include cliffs, pinnacles, cavities, collapsed cavities and sinkholes. Overlying these Karstic limestones is loose alluvium from previous tin mining activities.
Due to the nature of the soil condition, much thought and planning was channeled towards the selection of a construction method that would have minimal negative impact on the geological
condition of the soil.
It is known that the tunnel boring machine is the most advanced and cost effective method used in the construction of tunnel in Europe. However, TBMs come in a variety of shapes, sizes, using a variety of technology according to need. For SMART, after much research, study and survey, the Slurry Shield TBM was opted for. This machine is designed to overcome problems of groundwater drawdown which has been identified as the root cause of incidences of sinkhole appearance.
In terms of cost, the slurry shield machine is not different from any other type of TBM but unlike other types, the slurry shield machine is designed to create a pressured shield made up of bentonite and air pressure.
This pressured shield is able to counter balance the pressures of the groundwater and loose soil acting on the face of the boring machine.
Due to the nature of the soil condition, much thought and planning was channeled towards the selection of a construction method that would have minimal negative impact on the geological
condition of the soil.
It is known that the tunnel boring machine is the most advanced and cost effective method used in the construction of tunnel in Europe. However, TBMs come in a variety of shapes, sizes, using a variety of technology according to need. For SMART, after much research, study and survey, the Slurry Shield TBM was opted for. This machine is designed to overcome problems of groundwater drawdown which has been identified as the root cause of incidences of sinkhole appearance.
In terms of cost, the slurry shield machine is not different from any other type of TBM but unlike other types, the slurry shield machine is designed to create a pressured shield made up of bentonite and air pressure.
This pressured shield is able to counter balance the pressures of the groundwater and loose soil acting on the face of the boring machine.
Technical specifications ;
Stormwater Tunnel
* Construction cost: RM1,887 million (US$514.6 million)
* Stormwater tunnel length: 9.7 km (6.0 mi)
* Diameter: 13.2 m (43.3 ft) (outer diameter)
* Tunnelling method: Tunnel Boring Machine (TBM)
* TBM type: Slurry shield
Motorway Tunnel
* Motorway tunnel length: 4 km (2.5 mi)
* Structure type: Double Deck
* Ingress and egress: 1.5 km (0.93 mi) at Jalan Sultan Ismail and Jalan Imbi
* Length: 1.4 km (0.87 mi) at Jalan Tun Razak
Features ;
* Longest tunnel in Malaysia.
* 9.7 km (6.03 miles) stormwater by-pass tunnel.
* 4 km (2.49 miles) double-deck motorway within stormwater tunnel.
* The motorway tunnel is suitable for light vehicles only. Motorcycles and heavy vehicles are not allowed.
* Ingress and egress connections to the motorway tunnel linking the southern gateway to the city centre.
* Holding basin complete with diversion and tunnel intake structures.
* Storage reservoir and a twin-box culvert to release flood discharge.
Tunnel Safety ;
Ventilation or escape shafts at 1 km intervals provide ventilation within the motorway. To protect the ventilation system during floods, the system consist of a series of shafts; each containing an exhaust and fresh air injector. This design enables fans situated outside the SMART Tunnel to create a longitudinal flow in the tunnel between the shafts that permits the air in the tunnel to be continuously renewed and to enable extraction of exhaust fumes. The feature also allows smoke control in the event of a fire. The SMART Tunnel is also equipped with fire-fighting, telecommunication and surveillance equipments at 1 km intervals.
