* Seikan Tunnel
Since this tunnel is positioned as part of an international highway project, the most desirable mode of transport is for vehicles to be able to travel under their own power. Therefore, this must be considered first. Many automobile tunnels have been built in Japan to date, and their size hasnow largely been standardized,as shown in Figure 1. When the transport demand is less than 10,000 vehicles per day, it will be a single lane in each direction, and this one tunnel will be used for both directions. When the transport demand increases, another tunnel of the same type will be added and used as a two-lane tunnel in each direction.
Also, since it is an underwater tunnel, it is necessary to provide an advance pilot tunnel and a work tunnel.Judging from the example of the Seikan Tunnel,it is likely that they will be constructed in the arrangement shown in Figure 2. The advance pilot tunnel and work tunnel will be used for ventilation or pipelines even after the tunnel opens, and will also be used for maintenance work. In the case of the Japan-Korea Tunnel, joint management of various facilities such as optical communication cables, superconducting power transport facilities, natural gas supply facilities, and drinking water transport facilities in response to future global warming can be considered in order to address future communication and energy issues.
* Honshu-Shikoku Bridge
However, the biggest problem in this case is ventilation. Since automobiles emit exhaust fumes, long tunnels require large ventilation systems.Figure 3 shows the ventilation system in the Kan-etsu Tunnel constructed by the Japan Highway Public Corporation, and it is a considerably large system (for reference,the Eurotunnelandthe Tokyo Bay Aqua-Lineare also shown).
This ventilation system uses a vertical shaft supply and exhaust system, which is slightly less expensive to construct than a horizontal flow system.
However, in the case of the Japan-Korea Tunnel, the length will be several tens of times that of the above tunnel, so the cost of the ventilation system will be extremely large. Furthermore, a critical disadvantage is that, because it is an underwater tunnel, vertical shafts and inclined shafts cannot be constructed. The total ventilation volume varies depending on the traffic volume, but 1,000 to 2,000 m³/s is required, and in land tunnels, the tunnel is divided into sections of 1 to 2 km, and vertical shafts are installed to supply and exhaust air from the surface. If we estimate that the total length is 20 times that of the Kan-etsu Tunnel and the blower horsepower per unit length is three times greater, the electricity costs alone would reach more than 10 billion yen per year, making it clear that this is an unrealistic plan.
All methods of autonomously driving vehicles through tunnels pose various challenges. However, as the tunnel is expected to open in 20 to 30 years, it is anticipated that a new intelligent transport system (ITS) will be developed during this time that will enable autonomous driving within tunnels. Furthermore, the practical application of current-collecting electric vehicles is also conceivable as a fairly realistic use. However, tunnels are enclosed spaces, and manually driving them for long periods of time is difficult due to psychological pressures and other factors.
Therefore, while driving inside tunnels needs to be automated, complete unmanned operation is not necessary. Since people are already in the vehicles, the automated driving system should be designed to assist human driving operations in coordination with human actions. For
this reason, the tunnel will need to be designed with ergonomic considerations in mind, including an Advanced Highway System (AHS), lighting, and traffic light arrangements. Thus, the previously mentioned simple guidance system for electric vehicles will serve as one aid to automated driving. In addition, the introduction of guideway signal safety equipment will be necessary to prevent collisions in the forward and backward directions. Another
problem is that while roads in Japan are left-hand traffic, roads in South Korea are right-hand traffic. When driving vehicles through the Japan-Korea tunnel, according to domestic laws, traffic will naturally be left-hand until Tsushima. Therefore, it will be necessary to switch left and right at some point between Tsushima and Geoje Island. If customs procedures are carried out at some point, that point will serve as the point of change. At this point, all vehicles stop and the occupants disembark, making the left-right reversal easy. However, if border crossings become nearly free, as is currently done in European countries, it will be necessary to create a point where vehicles can be turned left or right using an overpass. In that case, it will be essential to ensure that drivers fully understand that the left and right sides have been reversed, and to take every precaution to prevent accidents.
There is a long history of constructing railways through long tunnels. Currently, the world's longesttunnel, the Seikan Tunnel, has a total length of 53.85 km. The Japan-Korea Tunnel will have a total length of 250 km, but it will pass through the islands of Iki and Tsushima. In this case, due to the linear relationship between Iki and Tsushima, it is thought that the tunnel will not reach the surface and will be underground. However, this is the same as an underground tunnel on land, and therefore the longest distance underwater is approximately 70 km from Tsushima to Geoje Island. Thus, if we extrapolate the experience of the Seikan Tunnel and construct a railway tunnel, it is thought that there will be few technical problems.Figure 4 shows the tunnel cross-section of theSeikan Tunnel, which was constructed according to Shinkansen standards.
It would be preferable for the Japan-Korea tunnel to be constructed using almost the same standards. Note that if mechanical excavation is performed using a boring machine (TBM),the tunnel cross-section will be circular,as shown in Figure 5. However, as will be discussed later (the introduction of the French-made TGV was not intended at the survey stage, and futuresurveys will compare it with the TGV), the vehicle clearance for direct trains into Korea will be slightly smaller than that of Japan's Shinkansen, so the tunnel cross-section can also be somewhat smaller. There is also the possibility of using Japanese Shinkansen trains as far as Busan, and the vehicle clearance of the Korean National Railway above the platform is almost the same as that of Japan's Shinkansen.
Therefore, it is expected that the aforementioned cross-section will be used for the tunnel. Since the tunnel section will naturally be an electric track, as shown in this cross-sectional diagram, it will naturally be necessary to lay overhead catenary lines and supply power to them. The vehicles that will run on it will be Shinkansen trains, so the electrical system will be 25kV AC. Therefore, substations with a capacity of about 30,000kVA will have to be installed every 20 to 30 km.
Furthermore, depending on the progress of the Yamanashi Maglev (Maglev) line, which is currently in the experimental stage (see: future Japan-Korea tunnel concept diagram), it can have a significant impact on the advanced transportation network system between Japan and Korea, and indeed throughout Northeast Asia.
Regarding the linear motor car, the 8th Committee (2000) of the "Superconducting Magnetic Levitation Railway Practical Technology Evaluation Committee," which is mainly composed of academic experts, evaluated it as follows: "Although there are still issues to be considered regarding long-term durability and some aspects of economics, it is considered that the technical prospects for practical application as an ultra-high-speed mass transit system have been established." To address issues such as long-term durability, cost reduction, and improvement of the vehicle's aerodynamic characteristics, running tests aimed at practical application will continue for approximately five years from 2000 onwards in the pilot section (reference site: Ministry of Land, Infrastructure, Transport and Tourism, "Linear Motor Car" website).
For the Seikan Tunnel, since its total length is 54 km, power is supplied from substations installed on both sides of the tunnel. In the case of the Japan-Korea Tunnel, power can be supplied to the tunnel by installing substations on land between Kyushu, Iki, and Tsushima. However, between Tsushima and Geoje Island, the underwater section of the tunnel extends for 70 km, requiring the installation of one or two substations in between. Therefore, a space of approximately 20m x 15m x 30m must be secured on the seabed, and high-voltage cables must be laid to that point. Furthermore, if a railway is built, passenger service will be through, so terminals will not be necessary (however, with the introduction of the French-made TGV, there are differences in signaling and control systems, making mutual operation a subject for future consideration).
Regarding freight transport, if a tunnel were built connecting South Korean railways and the Shinkansen (bullet train) via the Japan-Korea Tunnel, freight trains passing through the tunnel could travel directly to any destination in South Korea, as both the Shinkansen tracks and South Korean railway tracks (including the TGV) are standard gauge (1435mm). However, since Japan's Shinkansen was built as a passenger-only railway, there are problems such as its unsuitability for general freight transport. Conversely, direct operation is impossible on Japan's conventional lines because the track gauge is narrow gauge (1066mm). Therefore,
since container transport will be the main mode of transport, a container transshipment base will need to be established on the Kyushu side. This will require a fairly large transshipment base, but one option is to use the surplus rail freight facilities from the Chikuhō coalfield.
Here, containers loaded on freight cars on the Japanese side would be transshipped to freight cars bound for the South Korean side. Transshipment of containers between rail freight cars is rare worldwide, but the practice carried out for international freight at the Spanish-French border can serve as a reference. Furthermore, this base also handles the transshipment of containers bound for South Korea, transported by truck from northern Kyushu and western Chugoku region, onto container railcars, and vice versa. From a freight transport perspective, this essentially means that South Korea's railway network has been extended to the base in northern Kyushu. Transporting large bulk cargo (coal, cement, ore, grain, etc.) by rail through the Japan-Korea Tunnel is not appropriate. Considering that large cargo is being transported domestically by coastal shipping, the same reasoning should be applied to transport between Japan and South Korea.
Railways can generally transport automobiles on freight cars. Therefore, it is possible to transport automobiles by rail only through tunnel sections, and then have them drive themselves to their destination once they exit the tunnel. In the case of trains (Le Shuttle) operating on the Channel Railway (Euro) Tunnel (see photo), a car train system is employed where automobiles are loaded onto two-tiered (or sometimes single-tiered, large) freight cars, and passengers generally ride in passenger cars. Loading and unloading of passenger cars onto the freight cars is done by staff, who then drive themselves. In general, what is called a car sleeper is popular in Europe. In this case, passengers sleep in sleeping cars and arrive near their destination the next morning, from where they drive themselves. The same system is applied to passing through tunnels. Of course, since railways operate through services, it is possible to extend this system to longer distances, such as using sleeping cars, not just within tunnels. Freight cars can also be transported by rail only within tunnels using a similar method. However, large trucks sometimes exceed the vehicle clearance limits when loaded onto regular freight cars, so methods such as lowering the floor of the freight car or using a "kangaroo" system where only the wheels are lowered below the floor are employed. When loading cars onto freight cars in this way, a space is inevitably needed to park the cars while waiting. This is what could be called a ferry terminal. The space required varies depending on the volume of transport, but for passenger cars, it is usually enough for 200 to 300 vehicles, requiring an area of 10,000 to 15,000 m2. Facilities for resting passengers and truck drivers are also necessary. This is similar to the service areas on highways.
The South Korean government plans to build an expressway connecting Busan and Geoje Island (total length: 8.2 km), with completion scheduled for 2009. The project will consist of two cable-stayed bridges, each 230 m and 475 m long, and a 3.4 km immersed tunnel 40 m below the surface.
A groundbreaking ceremony for the Geoga Bridge, a connecting road between Gadeokdo Island in Busan and Geoje Island in Gyeongsangnam-do (Gyeongsangnam-do), was held on November 27, 2003, in front of the Busan New Port Public Relations Center. The project is
expected to cost 1.4469 trillion won (approximately 144.7 billion yen) by 2010.
The road will be 8.2 km long with four lanes in each direction, connecting Cheonga-dong, Gadeokdo Island, Gangseo-gu, Busan, and Yuho-ri, Jangmok-myeon, Geoje Island
, Gyeongsangnam-do. Of the entire route, the 3.7 km section from Gadeokdo Island to Daejukdo Island will be constructed using the "immersed tunnel" method, the first in Korea to construct a structure on land and fix it to the seabed, while the 4.5 km section from Daejukdo Island to Jungjukdo Island to Jido Island to Jangmok will be constructed as two "cable-stayed bridges."
The construction of the project will be handled by "GK Marine Highway," a consortium formed by eight domestic companies including Daewoo Engineering & Construction, Daelim Industrial, and Doosan Engineering & Construction, with an investment of 999.6 billion won. The government, Busan City, and Gyeongsangnam-do Province will provide 447.3 billion won in support. Although the road will belong to Busan City and Gyeongsangnam-do Province upon completion, a "BOT" (Build-Operate-Transfer) system will be adopted, under which the contractor will collect tolls and manage and operate the road for 40 years.
Once the road opens, the distance between Busan and Geoje will be reduced from 140 km to 60 km, and the travel time will be shortened from 2 hours and 10 minutes to 50 minutes. In addition, it will help to distribute traffic on the Namhae Expressway and Gyeongbu Expressway, and will greatly contribute to the handling of import and export goods for Busan's new port, Mongsan's Sinho Industrial Complex, and Geoje's shipbuilding industry. Prior to this, in October 2003, Busan City held a groundbreaking ceremony for the construction of the Gadeok Bridge, which is part of the Busan-Geoje connecting road, and commenced construction.
