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Technical Paper on the KL LRT2 System
Introduction The Project was awarded to PUTRA (the Operator & Client) by the Malaysian Government in 1994 for a Design, Build and Operate contract based on a 60 year Concession Agreement. The system is currently the longest automated driverless railway in the world, consisting of 29km of railway, 24 stations and a depot. The trains and system are procured from Bombardier of Canada who installed a similar system for the Vancouver Skytrain. The project was fast-track construction and became operational only 3½ years after first construction contract award with Section 1 opening on September 1, 1998. The second phase opened in June 1999 to complete the Project. This timescale is recognised to be a major achievement for a modern LRT project.
Project Structure The structure of the Project centres around the Operator – PUTRA, who are part of the Renong Group and are responsible to the Ministry of Transport by it’s Concession Agreement. The MOT’s Director General of Railways is a regulatory body with powers to stop operations or construction work affecting the safety of the railway. The DGR took an active role in overseeing the installation work and the final operational certification process. PUTRA appointed a Project Manager for implementation, another Renong company PLRT who in turn engaged Bechtel for international management expertise. The Consulting Engineer was HSSI-Halcrow-DeLeuw Cather, appointed by PUTRA to advise on all technical aspects of the Project, oversee the Systems Works, supervise the construction works and take responsibility for the design of facilities work. The majority of Civil works were tendered on the engineer’s design and awarded to the Renong construction group UEC and it’s partners. These companies constructed the elevated guideway, depot facility, 18 elevated stations, 2 underground stations and all power substations. Design Build Civil contracts were awarded for the tunneling work – to Hyundai and Hazama, 3 underground stations – SNC JV and City Properties, and also the integrated KL Sentral station – to KLSSB. For the Systems works, bids were received from Canada, France, Germany and Japan, but were eventually split and awarded to Bombardier / SNC Lavelin for the Rolling stock, trackwork and depot equipment, to the Renong company EDSB for power supply, and to Thorn Transit (now Cubic Transportation) for the fare collection system.
Alignment For all transportation projects, the alignment is the critical first stage of design and many factors contribute to establishing the route, - such as land availability, projected ridership from areas passed through, potential commercial development and obstructions or restrictions from roads, rivers, railways and major utilities. The LRT 2 alignment was established over 3 distinct sections. Section 1 commences at the Subang depot facility close to the old international airport. The route passes through the satellite city of Petaling Jaya before entering Kuala Lumpur city and consists of over 14km fully elevated guideway with 11 elevated stations. As mentioned earlier, this section was opened to the public in September 1998. One station on this section is still under construction, this being the large integrated railway station at KL Sentral that will not be completed until January 2001.
LRT Transit Integration Map LRT Underground Section The 2nd
section of alignment is underground through what they call KL’s golden triangle
district which is prime commercial area. The route follows the course of River
Klang and consists of 4.4km of twin bored tunnels, cut and cover tunnels,
entrance and exit portals, 2 tunnel intervention shafts and 5 underground
stations. These stations are located strategically at the link to Star LRT and
courthouse area at Masjid Jamek, hotel and commercial area at Sultan Ismail,
historical residential area of Kampong Baru, opposite the now famous Twin Towers
at KLCC and at Ampang Park shopping and hotel area. This section opened to the
public on 1st June 1999. The 3rd section of alignment turns north, mostly thru Malay residential areas from Damai to Gombak and consists of 8.2km elevated guideway, 2.3km at-grade track, 7 elevated and one sub-grade station. This section also opened in June 1999 to complete the Project.
Ridership To give you a general idea of the passenger capacity of the system, the initial set-up is to operate 35 No 2-car train sets that can accommodate around 150,000 passengers per day, operating from 6am to midnight. This can be expanded to the design capacity of 400,000 passengers by introducing more trains for four-car sets that can run on the guideway at a minimum 90 second headway. The 14km journey on Section 1 takes about 20 minutes and the full 29km journey takes 45 minutes. The trip through the underground section only takes about 5 minutes compared to about half an hour in normal traffic.
Transport Integration Revenue and passenger generation depends a lot on integration with other transportation systems. LRT2 connects to the Star LRT which was already operational, it connects with several bus terminals, all stations have public bus drop-offs, and car & taxi drop off parking is provided at all station entrances. PUTRA also operate their own feeder bus fleet of 60 buses to take passengers in local districts to the nearest station. There are three major Park & Ride stations on route, one at each end station and one near a main highway routing, to attract car owners from taking their car into the city centre. One of the prime revenue and passenger generators for LRT2 will be the link to KTM commuter railway services and the Express Rail Link to the new International airport from the integrated railway station at KL Sentral. However, as the ERL will only open in 2002, this is unlikely to produce the intended forecast for several years to come. Depot The first stage in any successful LRT is to ensure that there is a Depot facility constructed as soon as possible to enable trains to be fully tested and operational staff trained up before revenue service begins. This was done by constructing an integrated modern Depot Facility on a 33Ha site within 33 months.
Elevated Stations The focal point of the LRT is the passenger stations and on LRT2 there are several designs. The elevated stations have either a side platform or an island (centre) platform type defining the layout - the selection of which type is adopted depends on the initial alignment, land availability, projected ridership and site constraints. For instance where track cross-overs or pocket tracks are located near a station for operational reasons, this tends to favour island platforms. All have the passenger concourse below the platform, concourse being either above road level or at-grade. The side platform stations have the guideway running straight thru the centre, split by platforms either side and are much wider than island platforms. The guideway is split either side of an island platform station. Station lengths are defined by the platform length which is set for the future 4-car train length of 68m. Platform floors are flush with the train floor and the platforms are always straight to avoid gaps at the platform edge - these features are to provide unhindered access to the train for disabled persons. The stations are designed to International recognised transit standards, such as NFPA 130, the local Malaysian Building Codes and British design codes. The structures are reinforced concrete frames with steel roof trusses and are independant from the viaduct structure that was erected prior to the station structure being formed. Equipment rooms necessary to operate the station are located at Concourse level away from the public area. The elevated stations are naturally ventilated being open ended and open sided with rain-screen protection for the tropical storms that occur in Malaysia. Underground Stations The majority of stations are elevated, however as mentioned earlier, there are 5 underground stations in the centre of KL. All are centre platform types as the twin underground tunnels are a minimum horizontal distance apart and are naturally split either side of the platform as they connect to the station. These stations were generally in confined city centre sites, close to the Klang river and most had problems with existing underground utilities. The requirement for straight level platforms at the station area also provided a challenge for the alignment engineers to work within very tight tolerances and clear all underground obstructions such as the river walls and piling for adjacent buildings. The structures are essentially a buried concrete box some 20m wide, 90 to 120m long with base level around 20m below surface. The platform level is about 16m below ground with the concourse level some 5m above this, leaving a rise of around 10 to 12m from concourse to ground entrances, this of course being serviced by some of the longest escalators installed in Malaysia. Flood control was a major issue with the stations designed to prevent ingress from a 1 in 200 year flood level topping the banks of the adjacent Klang river. Design features of the underground stations include the use of platform screen doors that allow full air-conditioning and a complex environmental control system linked to tunnel ventilation and fire / smoke control systems for normal and emergency evacuation conditions. Design is based on the same International, Local and British Codes as the elevated stations but design life for the underground section is 120 years. The construction of the underground stations involved top-down excavation in all cases with perimeter diaphragm or secant pile walls being installed prior to excavation. On 4 of the 5 stations the Contractor cut down to roof slab level, cast the roof slab against the exposed ground with a lined surface, and used this as protection to excavate down to concourse slab, casting this level and continuing excavation to base slab, all the while removing spoil through strategically spaced openings in the slabs. These slabs provided the horizontal strutting action to restrain the perimeter walls with Masjid Jamek station requiring additional temporary steel struts due to the close proximity of adjacent multi-storey building foundations. At Dang Wangi station, the Contractor chose to excavate fully down to base slab from surface, utilising temporary horizontal struts and building upwards from base by use of a proprietary falsework system. Viaduct Construction That is the passenger stations covered. In order to get these passengers from point to point thru the city, the trainway has to be constructed. On LRT2 this consists mainly of 22.3km elevated viaduct, 4.4km of tunnels and 2.3km of at-grade trackway. The viaduct is constructed from single cell …. - see slide. The box girder precast sections were built in a covered casting yard specially set up for the project and each segment was match cast against each other. - see slide. The LRT guideway construction used elevated launching gantries to install and connect the precast segments into beam elements between pier supports. These gantries were somewhat special in that they could articulate around tight radius curves to a minimum 100m radius. Two types were used, these being a CD type for normal spans of between 18 to 36m and the SP type for special continuous structures over major roads or railways for spans upto 63m. Tunnel The LRT2 has also broken new ground in Kuala Lumpur by constructing the first underground tunnels. The ground that the tunnels went thru consisted of alluvium, limestone and volcanic rock intrusions. Apart from the bored tunnels, there were two sections of cut and cover tunnel with the 500m section at Pasar Seni being of particular interest as it rotated about itself, one over the other, due to the tight constraint of buildings and the adjacent river. The west-end had a 180m cut & cover section which was constructed to initiate the tunnel drive. Settlement monitoring was of prime concern at Masjid Jamek station where adjacent tall bank buildings were founded on rail section piles. This however, proved to be useful to the Contractor to assess the benefits of strut placement & removal. No special building protection measures were needed. This slide shows the operation of an Earth Pressure Balance tunneling machine - the head digging at front, spoil removed by conveyor to the rear and taken away by small locomotive to the access shaft where it was disposed of. All tunnel jobs
will have some problems during construction and fortunately, the LRT2 tunnels
only had minor ones with no major face losses or collapses. In fact at no point
did the ground surface above the tunnel exceed the predicted settlement
allowance of 80mm. The tunnel horizon was between 15 to 20m below ground.
Trackwork One of the more important features for construction was laying the steel trackway. This was important because if it not installed correctly to stringent tolerance, consequences may include problems with rail noise, braking and shuddering of the train and higher wear on the wheels and rails. This installation requires to be done by a specialist Contractor, in the case of LRT2 this was also the track designer. The track has 2 power rails for third and fourth rail 750V traction power operation.
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