The development of railway is to meet the needs of transportation, especially the needs of long-distance and large-scale cargo transportation. People first laid the ground railway. Later, because the ground traffic was too crowded, the railway extended into the air, built an elevated railway, and then extended to the underground, laying an underground railway. In order to lay a railway in the mountainous area, people braved difficulties and dug a large number of tunnels to make the railway unimpeded.
As early as 1884, the world's earliest underground railway tunnel was built under the streets of Brooklyn, new york, USA. This is the earliest ventilation tunnel in the world, and it is also the first time to use the tunnel constructed in cut and cover. However, in the construction of tunnels in mountainous areas, only the underground excavation method can be used.
The longest railway tunnel in Germany (10748m)-Kassel Highland Tunnel Construction Site With the continuous development of science and technology, the tunneling technology is also changing with each passing day. Somali, an Italian, invented the percussion rock drill, powered by compressed air, which increased the speed of tunnel excavation by three times, which was a milestone in the transformation of tunnel excavation from manual to mechanized.
The United States is the birthplace of modern tunnel excavation technology in the world. Americans first invented and used electric drills and explosive blasting technology to dig tunnels. Since then, many new excavation tools and effective blasting techniques have been invented one after another, and have been used to this day.
At present, China has the largest number of tunnels in the world, and the number of tunnels built every year is also the largest, with an average of more than 20 tunnels/kloc-0. By the end of 1980s, more than 4,800 railway tunnels had been built and put into use. The number of railway tunnels is second only to that of China, with about 3,850.
Compared with building tunnels on land, in exploration, design and construction, it is more difficult to dig tunnels and lay underwater railways than to lay railways on the ground. However, in order to solve the transportation problem between the strait and the bay, there are more than 20 cross-harbour tunnels built and planned around the world, mainly distributed in Japan, the United States, Western Europe and other technologically developed countries.
Cross-harbour tunnels have one common feature. Most of them are part of railway traffic, and some of them are passages for urban subways and cars. Between Manhattan Island, Long Island and New Jersey in the United States, five undersea tunnels have been dug for automobile traffic. Three subsea tunnels have been built in Rotterdam, the Netherlands. Denmark and Sweden will build a 3.4-kilometer-long subsea tunnel, and Turkey is building a 9-kilometer-long subsea tunnel.
The Japanese-built Han Qing Tunnel is one of the longest English Channel tunnels in the world. Han Qing Tunnel starts from Ibimoto-machi, Aomori Prefecture in the south and ends at Li Tang, Zhinai-machi, Hokkaido in the north, with a total length of 5,385 kilometers, of which 233 kilometers are under the sea. The main tunnel has a diameter of 1 1 m and a height of 9 m, and two railway lines are laid. In addition, there are two auxiliary tunnels for logistics supply. High-speed rail 13 minutes can pass through the tunnel.
Han Qing Tunnel started on 1964 and was completed and opened to traffic on 1987. After 23 years, its construction cost a total of 3.7 billion US dollars, and the total number of people participating in the project construction is 1 1 10,000, which can be described as huge and unprecedented in scale. Since the start of construction, due to the influence of topography and volcanic activity, the topography of the construction site is complex and there are four obvious faults. In addition, the seabed works under special conditions of 200 meters from the sea surface and about 100 meters from the seabed, and many unexpected difficulties have been encountered in the construction.
During the construction period of 18, there were four major water accidents. An accident occurred in May 1976, with a maximum water output of 80 tons per minute and a continuous water output of 80 days. /kloc-more than 0/000 cubic meters of sand and gravel collapsed, and more than 70 meters of tunnel was flooded.
Faced with such great difficulties, Japanese engineers and technicians did not lose heart. They used advanced excavation technology to advance from the north and south sides of the Taiwan Province Strait. Every 30 cm, immediately put an arched steel frame around it and inject cement, bone potassium and masonry mixed slurry. After three minutes of solidification, the reinforced concrete slab is laid. In June, 1983, 1 1, the construction teams from the north and the south met, connecting the two largest islands in the Japanese archipelago. When 1987 was opened to traffic, a total of sand and gravel10150,000 cubic meters were excavated, and steel168,000 tons and cement 790,000 tons were used, with a cost of 70 million US dollars per kilometer.
The completion of the Qinghai-Tibet railway tunnel runs through the main artery of Japan's north and south. The traffic between Hokkaido and Honshu will no longer be affected by bad weather, and the transportation capacity will be greatly improved, shortening the through train between the Japanese capital and Hokkaido by 6 hours. The completion of the Qinghai-Tibet Railway Tunnel has given Japan confidence in building a more complex subsea tunnel. 1985, the 250km-long "Ma Haixia-Japan Cross-Harbour Tunnel" was officially started in an all-round way, with an estimated cost of USD 20 billion. If this project is successful, it can be regarded as the highest level of submarine engineering technology in contemporary times.
The undersea tunnel from Italy to Sicily is about to break ground. This is a suspended subsea tunnel. The whole building adopts reinforced concrete structure. The cross section of the pipeline is 42 meters wide and 24 meters high. Huge concrete pipes are placed in water 30 meters deep, and the concrete pipes neither sink nor float. In order to prevent tunnel swing caused by traffic, all running vehicles are controlled by computer. There are two bus routes in the tunnel, and each floor has three lanes. Trains and railways are located on the left and right sides of the tunnel. The submarine tunnel constructed by this technology is 1/2 lower than that of ordinary bridges and tunnels, and it has ideal seismic function.
A cross-harbour tunnel of 1.4 km has also been built between Hong Kong and Kowloon. The tunnel is connected by prestressed concrete pipe sections with a length of 14 100 m and a diameter of 5.4 m, forming a submarine tunnel, in which a double-track railway is laid. The construction of this tunnel is not complicated. First, the pipeline is prefabricated on land, each section weighs 700 tons, and then transported to the site for laying in sections. Dig trenches on the seabed in advance, and then lay gravel. Then use the work boat to sink the pipeline to the predetermined position. The project broke ground by 500,000 cubic meters, greatly improving the traffic between Hong Kong and Kowloon.
The English Channel is the crossroads where the Atlantic Ocean crosses the North Sea. Between Britain and France, it is bordered by the Atlantic Ocean in the west and the North Sea in the northeast. It starts from the junction of Li Si Islands and Youfante Islands in the west and ends at Dover Strait in the east, with a total length of 563km, with the widest point of 24 1 km and the narrowest point of 33km. After 10 years of argumentation and research, Britain and France started construction in an all-round way in 1987, and 1993 was completed and opened to traffic.
The project consists of three tunnels, two train tunnels with a diameter of 76 meters and a service tunnel with a diameter of 48 meters, with a total length of 53 kilometers, of which 38 kilometers will pass through rocks with a depth of 40 meters under the sea. Because the bottom strata in this sea area are Cretaceous, mudstone, marl and late Cretaceous siltstone, the construction is very difficult. In order to ensure the engineering quality and construction speed of the tunnel, Britain and France adopted the method of simultaneous excavation on both banks and used laser guidance to ensure the accurate and unbiased construction direction. A 1.200-ton super excavator was purchased from Japan for excavation. The machine body is 20 meters long, the rotating diameter of the shovel head is about 87 meters, and the bucket teeth and grinding wheel are very sharp, reaching 12 cm per minute. The whole project adopts flow operation, and the excavated rocks are transported away by conveyor belt; The main skeleton of the tunnel adopts arch stone, and the reinforced concrete arch ring wall plate is used to help the gallows to be in place. Filling mortar is 0.6m thick and riveting bolt is 0.5m long. It is planned to dig out 6.5438+0.5 million cubic meters of rock and replace it with high-quality concrete. The whole project cost $654.38+0.7 billion. By 1 990,65438+February,1,all tunnels have been completed. After the project is completed, the journey from London to Paris will be shortened from 5 hours to 3 hours, with the designed annual passenger throughput of 30 million passengers and cargo 1.5 million tons.
China has the largest number of tunnels in the world. By the end of 1999, there were 6,876 railway tunnels in China, with a total length of 3,670 kilometers, ranking first in the world. In terms of tunnel construction, from the steel hammer operation in 1960s and 1970s to the promotion of "New Austrian Tunneling Method" in 1980s, from the application of hydraulic drilling rig to the introduction of tunnel boring machine, China has opened a new era of tunnel construction again and again, and the construction records have been constantly refreshed. 1999, during the construction of Qinling tunnel, the longest tunnel in China (1846 km), China used GPS global positioning device for the first time, used V5 earth audio electromagnetic sounder for exploration for the first time, and introduced the world's most advanced roadheader for construction for the first time, with an average monthly driving ruler of 200m and a maximum driving ruler of 456m, setting a monthly driving ruler and single-ended ventilation for tunnel construction.
At present, China has mastered new technical achievements such as geological advance prediction, deep hole double liquid grouting and long pipe shed advance support, and has overcome the construction difficulties of different spans such as faults, water inrush and weak surrounding rock. In the field of urban subway and light rail, the series of construction methods of "shallow burying and underground excavation" have been popularized, ending the history of "opening the belly" in subway construction in China. The shield construction and bored bite pile technology being carried out in the subway field have solved the problems that have plagued the subway construction in coastal areas of China for many years. On May, 2000 1 1, the longest "light bulb" tunnel in China-neijiang-kunming railway Huangtupo No.3 Tunnel was successfully completed. Through the construction, China has further mastered the new technological achievements such as the geological technology of weak surrounding rock, the one-step molding technology of large section, the ventilation and smoke exhaust technology of "light bulb" tunnel, and the transportation of large slope orthogonal frequency conversion high-power battery locomotive, which indicates that the tunnel construction technology in China is gradually maturing.
The cross-harbour tunnel connects human life with the ocean, making the railway transportation industry go out of the land and extend to the ocean, marking a new level of human transportation technology development.