Tunnelling toward a city with no more flood woes-雷诺护垫
Tunnelling toward a city with no more flood woes
Engineer says B200bn project the only way to stop capital being swamped again
Published: 3/12/2011 at 12:00 AM
Newspaper section: News
A 100-kilometre tunnel linking Ayutthaya and Samut Prakan has been suggested as the latest solution to tackling floods in Bangkok to better direct water and avoid conflicts among residents.
Although the huge tunnel, 10 metres high and 24 metres wide,Tie Wire, would cost an enormous 200 billion baht, engineer Suchatchawi Suwannasawat, who suggested the idea, believed the project "suits Bangkok better than other alternatives".
The super tunnel has won early backing from Bangkok Metropolitan Administration's deputy governor Teerachon Manomaiphibul, who has urged the government also to get behind the project.
Advocates of the tunnel idea say conventional methods for directing water fail to do the job. Many networks of canals are illegally blocked by houses, which limits their effectiveness. Draining water from land which is densely occupied by communities can also lead to conflicts.
The varying topography of the city, with some areas higher than others,barbed mesh, makes it difficult for officials to drain and direct water to the routes they want.
But these problems can be avoided if the tunnel is built and "its construction has nothing to do with the expropriation of vast tracts of land as required by the construction of a floodway", said Mr Suchatchawi. He chairs the Thailand Underground and Tunnelling Group under the Engineering Institute of Thailand, which will take part in the 2012 World Tunnel Congress in Bangkok between May 18 and 23 next year.
The tunnel would be built near the Bang Pa-in-Samut Prakan outer ring road, extending 100km from Ayutthaya's Bang Pa-in district to Samut Prakan, which is the exit of the tunnel to the Gulf of Thailand. The tunnel will be divided into two storeys. Its upper half of 5m would be a six-lane road while its lower half would serve as a sewer to drain 130 million cu/m a day of storm water.
But in case Bangkok suffers such a large flood again, Mr Suchatchawi said,fence netting manufacturers, the upper half of the tunnel could be turned into a floodway to boost drainage to 260 million cu/m a day.
Bangkok can also earn "added value" as floodwater will be used to produce between 400 and 600 megawatts of electricity with a vertical tunnel called a "Power Generation Shaft" built as part of the project. Construction should take two years if the project is joined by many construction firms building different sections, Mr Suchatchawi said.
"We must have the government implement this tunnel project. The Bangkok Metropolitan Administration alone can't do it. It needs a huge investment," said deputy BMA governor Teerachon. "But I agree with the project."
City Hall has built its own giant tunnel linking Rama IX and Ramkhamhaeng roads. The 5km tunnel, 5m in diameter, which opened in February this year, can drain water at 60 cu/m a second.
The city also plans to build another three tunnels,不锈钢生丝, mostly 5m in diameter,Expanded Metal Meshes, as part of its flood prevention measures.
The Ratchada-Suthisan tunnel,雷诺护垫, construction of which began in the middle of this year,mesh wire, will run 6km from Ratchada-Sutthisan intersection to the Chao Phraya River. Others are the 13.5km Don Muang tunnel which will help drain water in Dong Muang, Chatuchak, Bang Khen districts and parts of the Sai Mai area and the 9.5km Suan Luang Ro 9 tunnel whose drainage will cover 85 square kilometres, including Phra Khanong.
Thailand is not the only country that is troubled by floods, Mr Suchatchawi said. Others countries face the same problem, but they have tunnels to drain water.
The US has a 174km tunnel in Chicago,石笼网, and Japan a 64km tunnel to drain stormwater.
Kuala Lumpur has also approved a new 9.7km tunnel divided into levels - a motorway on the upper stretch and a sewer on the other.
Mr Suchatchawi said he was especially upset comparing Bangkok's tunnels with Singapore's 300km tunnel network.
International body goes underground
The World Tunnel Congress is an international conference supported by the International Tunnelling and Underground Space Association.
Civil and mining engineers meet at the conference each year to present and exchange views on technologies and projects relating to underground constructions.
Thailand is among the association's 280 members, which include individuals, organisations,metal wire, companies and 58 entire countries.
Bangkok will host the World Tunnel Congress on May 18-23, after Canada and Finland held the meeting in 2010 and 2011, respectively.
Military Barriers/Hesco Bastions
Information
The QIAOSHI's Military Barriers or Hesco Bastions is a modern gabion used for flood control and military fortification. It is made of a collapsible metal wire mesh container and heavy duty fabric liner, and used as a temporary to semi-permanent dike or barrier against blast or small-arms. One of the less heralded life- and labor-saving devices of war, it is used on nearly every United States Military base in Iraq as well as on NATO bases in Afghanistan.
Originally designed for use on beaches and marshes for erosion and flood control, the Hesco Bastion quickly became a popular security device in the 1990s.
Assembly
Assembling the Hesco Bastion entails unfolding it and (if available) using a front end loader to fill it with sand,Stone Box, dirt or gravel. The placement of the barrier is generally very similar to the placement of a sandbag barrier or earth berm except that room must generally be allowed for the equipment used to fill the barrier. The main advantage of Military Barrier,Welded Box, strongly contributing to their popularity with troops and flood fighters, is the quick and easy setup. Previously,stainless steel back, people had to fill sandbags, a slow undertaking, with one worker filling about 20 sandbags per hour. Workers using Military Barrier and a front end loader can do ten times the work of those using sandbags.
The Hesco Barrier come in a variety of sizes. Most of the barriers can also be stacked, and they are shipped collapsed in compact sets. Example dimensions of typical configurations are 46" x 36" x 32 (1.4m x 1.1m x 9.8m) to 7 x 5 x 100 (2.1m x 1.5m x 30m).
A new system of Hesco Bastion developed specially for military use is deployed from a container, which is dragged along the line of ground where the barrier is to be formed, unfolding up to several hundred meters of barrier in minutes, ready for filling with soil by a backhoe.
Protection
Filled with sand, 60 centimetres (24 inches) of barrier thickness will stop rifle bullets and shell fragments. It takes 1.5 metres (five feet) of thickness to prevent penetration by a rocket propelled grenade round. Approximately 1.2 metres (four feet) of thickness provides protection against most car bombs.
Specification
