Recently, the country officially announced the "National Comprehensive Three-dimensional Transportation Network Planning Outline", which mentioned the transportation route from Fuzhou to Taipei, making the Taiwan Strait channel, a topic that has lasted for more than 20 years, become lively again.
Senior academician of the Chinese Academy of Sciences and lifelong first-class honorary professor of the Institute of Tunneling and Underground Engineering of Tongji University Sun Jun said in the article "Thoughts on Several Key Issues in the Planning Plan for the Taiwan Strait Tunnel Project": If the tunnel plan is adopted in the Taiwan Strait , which will generally take 30 years to complete.
Three route options for the Taiwan Strait passage
Building a passage across the Taiwan Strait to connect the island of Taiwan and the mainland was first proposed by Professor Wu Zhiming of Tsinghua University in 1998. Later, after many discussions by experts and scholars on both sides of the Taiwan Strait, three plans were formed. The three plans are:
(1) North line: Fuqing Xiaoshandong - Pingtan Nianggong cross-sea bridge - Pingtan Island to Taiwan Island Hsinchu undersea tunnel , about 122 kilometers long.
(2) middle line: Putian Wat Shi - Nanri Island - Taiwan Miaosu, about 128 kilometers long.
(3) Southern Line: Xiamen - Kinmen - Penghu - Chiayi, about 174 kilometers long.
Three route options for the Taiwan Strait Channel
Which route option is the best?
There are many factors that affect route selection, mainly considering geological and seismic hazards, cross-sea transportation methods, project durability, construction methods and cycles, project investment, operation and maintenance, etc. Taken together, experts believe that the northern route option is the most economical, geologically stable, and most likely option to establish a Taiwan Strait passage.
Industry experts recommend the Northern Line plan
From a seismic perspective, the Northern Line is the best
Northern Line: There have been no major earthquakes exceeding magnitude 7 in history. Current seismic activity is average, with only moderate earthquakes around magnitude 5 occurring more frequently. Not big.
center line: There have been no major earthquakes exceeding magnitude 7 in history, but moderately strong earthquakes of magnitude 5 to 6 have occurred, and the current frequency is slightly higher.
South Line: Moderately strong earthquakes of magnitude 5 to 6 have also occurred.
In terms of route length - the northern line is preferred.
The northern line scheme has a short distance and relatively small project investment; while the southern line has the longest length and the largest investment.
From the perspective of the structural method of crossing the sea - the preferred tunnel, top experts in the industry roughly estimate that it will take 30 years to repair it.
When crossing the sea by land, you can choose bridges, tunnels, seawalls, etc. The Taiwan Strait is not only the main sea route for maritime traffic between the north and south of China, but also an international waterway, so we cannot build embankments and roads by reclamation. The available solutions include bridges, tunnels and bridge-tunnel combination solutions.
(1) bridge solution : It is relatively user-friendly and has many advantages, such as wide field of vision, non-depressing driving, high driving safety, and no problems with ventilation and daytime lighting. However, because the Taiwan Strait is open to navigation, unfavorable factors such as bridge clearance and ship collision must be considered. A series of problems will also arise in the design and construction of tall bridges. And traffic is subject to adverse weather conditions.
Special long bridge scheme
(2) Tunnel scheme : The biggest advantage is all-weather traffic, basically not affected by bad weather and geological conditions such as wind, rain, fog, earthquakes, etc., and there are almost no obstacles and obstacles to offshore engineering and shipping. Influence. The tunnel is buried deep underground. Even in the event of a major earthquake, only the entrance needs to be reinforced. The main tunnel has excellent seismic resistance, and the probability of being damaged by earthquakes is much lower than that of bridges. However, the shortcomings are also very prominent. For example, long-term driving in tunnels under artificial lighting conditions can easily cause driving fatigue, increase depression and tension, thereby reducing the safety of driving in tunnels, and easily lead to driver errors and traffic accidents. Moreover, the ventilation problem of the tunnel, which is more than 100 kilometers long, is also very difficult to solve.
Suggestion of long-distance tunnel scheme
From the perspective of cross-sea transportation mode - the long tunnel railway is preferred
The northern line tunnel scheme is very long, and tunnel highway, tunnel railway and other schemes can be considered.
(1) On ultra-long tunnel roads, the speed limit for driving a car is 80 kilometers/hour, but the speed limit for railways can be doubled to 160 kilometers/hour. It seems that railway traffic is more efficient.
(2) On ultra-long tunnel highways, the probability of multi-vehicle accidents causing fires will be much greater than on railways.
(3) The ultra-long tunnel highway requires the construction of more than 10 super large ventilation shafts in the middle of the strait. However, the strait channel is frequently opened to navigation. Not only does the two sides of the strait reach agreement, but it also needs to be recognized by the international shipping community.
Look at it this way, you can use the "train to carry a car" method to cross the super long tunnel, that is, on a dedicated platform, the car is mounted on a railway flatbed, and it crosses the sea in a similar way to a ferry, except that it does not use a boat, but a car. More stable trains. This method has been successfully used in the English-French Channel channel.
The railway in the English Channel Tunnel
In terms of the difficulty of construction
(1) The special long bridge scheme is adopted, which can be constructed simultaneously in sections. Moreover, the bridge foundation construction and girder operation technology are very mature and have a high degree of industrialization, which can significantly shorten the construction period. .
Offshore bridge construction
(2) If a long tunnel plan is adopted, the working surface for excavation is limited, and the construction period will be much longer without building a bridge. According to rough calculations by top experts in the industry, it will take 30 years. The average water depth in the Taiwan Strait is 60 meters, and the maximum water depth in the central part of the strait is between 90 and 100 meters. When constructing in deep sea underground and underwater, random risks such as water penetration and landslides are much greater than when building a bridge.
Tunnel excavation construction
From the perspective of durability
(1) The long tunnel plan must consider the corrosion of the tunnel concrete and steel bars by seawater chloride ions and motor vehicle exhaust in the tunnel, so the tunnel must be considered to be usable for at least 150 years.
(2) The special bridge plan should also consider the corrosion of sea breeze, chlorine ions in seawater, etc. to the concrete and steel bars of the bridge underwater and above water.
From the perspective of daily operation and maintenance
(1) Tunnels need all-weather ventilation, day and night lighting, and internal decoration must be moisture-proof, which are expensive.
(2) adopts a long-span main bridge solution, which requires regular painting to prevent corrosion, replacement of steel beams, main cables, etc., and the price is also high.
Tunnel ventilation equipment instructions
Bridge anti-corrosion maintenance instructions in sea water
Do you think it is better to build a bridge or dig a tunnel for the Taiwan Strait Channel? Is it better to build roads or railways? Please leave a message in the comment area to communicate.
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