毕业设计外文翻译--隧道工程docx-公路隧道(编辑修改稿)

毕业设计外文翻译--隧道工程docx-公路隧道(编辑修改稿)内容摘要：

e have been more than 5300 railway tunnels with a total length of 2500km, ranking first in the world up to now. Although the extensive construction of highway tunnel started rather late pared with that of railway tunnel in China, the number of highway tunnels has increased rapidly in the recent years due to the new tide of construction of high class highways or expressways. At present, there more than 500 highway tunnels with a total length of over 1km each and 6 tunnels over 4km each. The longest highway tunnel in China now is the of Huayinshan Tunnel in Sichuan Province. Besides those tunnels already built or under construction, several extra long highway tunnels are under design or planning. For example, one is the long Xingkui Tunnel in Fujian Province. It is well worth mentioning that three immersed highway tunnels, which are located in Guangzhou, Yongjiang and Shanghai respectively also have been designed and built by Chinese panies. There has been more than 100km of metros built in five cities, namely Beijing, Shanghai, Guangzhou and Nanjing. The construction techniques of tunnels and stations have got great advances in the Shanghai metro and Guangzhou metro, where the shield tunneling method has been successfully used. In the respect of hydraulic tunnels, there are now more than 400 tunnels with a length of more than 400km and more than 40 underground powerhouses. For example, the diversion tunnel in Ertan hydropower station is 1100m length, 23m in width and in height, 附录一 中英文翻译 7 which is the largest tunnel in China. In the construction of hydraulic tunnels and expressway tunnels, international of advanced technology and equipment, for example, wet shotcrete, TBM and DOT have been widely used in tunnels and metros in China. Tunnels are one of the greatest projects in engineering and construction. It is also one of the most expensive projects. For this reason, extensive planning and surveying goes into the preexcavation stage of the project. 2. Tunnel Types and Tunnel Structures Tunnel Types The response of the ground to the excavation of an opening can vary widely. Based on the type of ground in which tunneling take place, four principal types of tunneling may be defined: . Cutandcover tunneling shown in . In such tunneling the。