TBM ( Tunnel Boring Machine)

TBM tunnelling

Ground conditions dictated construction by tunnel boring machine which is now under way with two slurry TBMs working in opposite directions from the middle of the tunnel alignment. We helped develop the TBM procurement strategy and produce contract documents to enable the contractor to purchase two 13.2m diameter machines – among the world’s largest in diameter. A ventilation shaft sited near central Kuala Lumpur served as the launch site for the TBMs. The ventilation facilities are located in Limestone rock, with the largest excavation being 150m in length, 20m wide and 28m deep.

The first TBM launching shaft was completed in January 2004 ready for assembly of the first TBM which commenced tunnel boring in June 2004. Shortly after this the second TBM arrived for assembly and commissioning and began tunnelling in August 2004.
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
• Links: 1.6 km (1 mi) at Kuala Lumpur-Seremban Expressway Links:City Centre
near Kg. Pandan Roundabout KL-Seremban Expressway near Sungai Besi Airport

About TBM:

How far does the TBM moves in a day? What's the furthest achieved?
The TBM moves at an average distance of 10 meters per day. The furthest achieved was about 24 meters, believed to be a world record for this type machine size.
What powers the TBMs?
The TBMs use electricity. Each machine have a connected load of 8.3MW, with incoming voltage at 22kV. This voltage is transformed to lower levels at the machines to meet requirements.
How many people are needed to operate the TBM?

There are about 16 people per shift needed to operate the TBM.
The slurry shield tunnel boring machine consists of four main parts.
The first is the Rotary Cutter Head with tungsten pick bits used for excavation of soil and disc cutters used for the excavation of rock.
The second part of the machine is the Bulkhead located immediately behind the Rotary Cutter Head. This is where the pressured bentonite slurry shield is formed to provide stability during the tunnel excavation.
The third part of this machine consists of hydraulic rams, which are used to propel the machine forward and to keep the tunnel in its right alignment.
The fourth and the last main part of the machine is the tunnel lining erector used to install the pre-cast concrete lining of the tunnel.
Other parts complementing the main Special Features are two boogies on rails that house electrical, slurry pumping, ventilation equipment
and cable and pipes.
The pre-cast concrete linings for the tunnel are transported continuously to the erector by boogies on rails. These linings are then hoisted and placed in the correct position in the tunnel with the help of vacuum pads attached to hydraulics arms. The arms are ex tended to keep the linings in place while the linings are bolted together.
The void between the excavated ground surface and the linings is immediately filled with cement mortar grout under pressurized conditions to ensure all the voids are fully filled.
For SMART, two Slurry Shield machines are used, both starting from the JKR field area in Jalan Chan Sow Lin. The first machine will head North under Jalan Tun Razak and Jalan Desa Pandan before terminating at the pond at Ampang behind
Gleneagles Hospital.
The second machine will head south under the Jalan Chan Sow Lin and the KL-Seremban Highway next to the Sg Besi airfield before terminating at the existing pond in Taman Desa.