The Rs 14,600-cr Chennai Metro Rail may help decongest roads and make commute unbelievably quicker, but the 46-km two-corridor mass rapid transit network is also going to be an ambitious engineering feat that is all set to change the skyline of the growing city.
For a city that is only familiar with flyovers and clove leaf-shaped grade separators, the metro rail is going to be special in many ways. Its elevated viaducts are going to soar over bus sheds of Chennai Mofussil Bus Terminus and also over the clove leaf-shaped grade separator at Kathipara, while the underground corridor will have to be built under the highly congested Broadway.
Deputy chief minister M K Stalin, while inaugurating the piling work for the construction of an elevated viaduct from Koyambedu to Ashok Nagar on Wednesday, said: “It has set a record among contemporary projects as the fastest in reaching financial closure, by securing Japanese government funding in 12 months and Central government funding in 14 months. The same process has taken more than two-and-a-half years in other cities. The government is committed to sustaining this pace and making the project operational by 2014-15.”
A daunting task lies ahead for engineers — different soil conditions, a high water table, construction along one of the most busiest stretches, tunnelling underneath flyovers, railway lines and others. The soil type varies in Chennai: sandy, clay type, loose soil, highly flowing clay, among others.
“Pile load test is the most important and crucial aspect of construction of elevated stretches of the corridors. This is because soil conditions are different and water table is high as is the case with Mumbai. Engineers will have to monitor the soil condition and behaviour of pile loads every couple of hours to identify the depth to which pile foundation should be sunk at each and every point of the elevated stretch,” said a senior official of Metro Rail.
Once piles are sunk, loads to the tune of two to three tons will be applied on the pile. The impact of the weight will be monitored every two to three hours. If it sinks, more digging will be done and load tests carried out. Such tests will be conducted at three or four locations. Once the depth is identified, the pile will be fixed and a pile cap installed. The column will be built over the pile cap. A concrete beam will then be constructed over the columns to hold a pre-cast viaduct, on which ballastless tracks will be laid. The Metro Rail corridor-II alignment will be along an elevated structure after Thirumangalam, up to St Thomas Mount, a stretch that will see piledriving work and piers being installed in the coming months.
Route alignment has been fixed only after carrying out a detailed soil test, but more tests are needed at every stage of building the foundation for the elevated tracks. The official also said that Chennai Metro Rail would be using the most modern technology in which the drawbacks faced in the Delhi project have been corrected.
Pile load tests are elaborate. Pile depth can go up to 27 metres at Koyembedu and less than 10 metres in the rocky terrain at St Thomas Mount and also Kathipara. As the metro rail is going to be intensely used, ballastless tracks made of longwelded head-hardened rails will be laid to minimise maintenance.
Though works on underground section will be finalised only after a general consultant carries out a detailed study, Metro Rail has decided that tracks will be 12 metre below ground level along the tube and 12.5 metre below ground level at stations.
The official said that the alignment and stations were designed to minimise disruption or displacement of existing buildings. Nevertheless, civic agencies and state government bodies have been told not to start works on subways and other facilities till Metro Rail’s final alignment is decided.
THE MAKING OF METRO RAIL WHAT Chennai Metro Rail will be a 2-corridor 46-km mass rapid transit facility. First corridor will connect Washermanpet to airport and the second Chennai Central to St Thomas Mount. Stretches of Washermanpet-Saidapet and Chennai Central-Thirumangalam will be underground WHY Chennai has grown rapidly and so has the traffic. The project aims at providing a fast, reliable, modern, convenient and economical mode of public transport which can be integrated with other forms of private and public transport including suburban trains and MRTS HOW Trial pile load tests have begun in three spots between Koyembedu and Ashok Nagar to build elevated viaducts. Soil tests will determine the depth at which pile structure should be installed. Columns will come up on it and beams fixed over them for laying of tracks WHEN The project has been scheduled for completion by 2015. When fully functional, the city will have the most sophisticated transport system that will make commute quicker and also link major railway stations to the airport. Commute from Mannadi to the airport will take just 40 minutes
US VERSUS THEM
Kolkata | The idea of building an underground railway was conceived way back in 1949. But it took more than three decades to complete the project that covers a length of 97.5 km
Delhi | Phase I of the Metro Rail project, covering 65 km, was completed in November 2006 at a cost of Rs 10,571 crore. Phase II works are on
Mumbai | Metro project will connect Versova and Ghatkopar (12 km). The project is estimated to cost Rs 2,300 crore BYPASSING CONGESTION 46 The total number of kilometres the two corridors of Metro Rail will cover. Underground tracks will be 12m deep 34The scheduled speed of the train in kmph. Busy stations will have one train every 2.5 min, others every 15 min 4 The number of coaches in each train. As many as 1,038 passengers can be accommodated in a train 19 The number of hours Metro Rail will operate in the city. Services will begin at 5 am and end at midnight
-source from PROPERTYNICE.COM
No comments:
Post a Comment