英语翻译After the general dirction for a tunnel has been determined,the next steps are a geological survey of the site and a series of borings to obtain specific information on the strata through which the tunnel may pass.The length and cross sec

英语翻译After the general dirction for a tunnel has been determined,the next steps are a geological survey of the site and a series of borings to obtain specific information on the strata through which the tunnel may pass.The length and cross sec
英语翻译
After the general dirction for a tunnel has been determined,the next steps are a geological survey of the site and a series of borings to obtain specific information on the strata through which the tunnel may pass.The length and cross section of a tunnel generally are governed by the use for which it is intended ,but its shape must be designed to provide the best resistance to internal and external forces.Generally,a circular or nearly circular shape is chosen.
In very hard rock,excavation usually is accomplished by drilling and blasting.In soft to medium-hard rock,a tunnel-boring machine typically does the excavating work.In soft ground,excavation usually is accomplished by digging or by advancing a shield and squeezing the soft material into the tunnel.In all cases the excavated rock or earth,called muck,is collected and transported out of the tunnel.In underwater tunneling,a shield is used to advance the work.Another method of building an underwater tunnel is to sink tubular sections into a trench dug at the bottom of a river or other body of water.

英语翻译After the general dirction for a tunnel has been determined,the next steps are a geological survey of the site and a series of borings to obtain specific information on the strata through which the tunnel may pass.The length and cross sec
在普通方向为隧道已经被确定,下一个步骤是一个地质调查的网站和一系列的一些钻孔可获得特定的信息所通过的隧道上覆岩层的可以通过.长度和断面隧道一般是由那些事情原本的使用,但是它的形状必须设计成提供最好的抵抗内部和外部力量.通常,一个圆形的或近圆形的被选中.
在非常坚硬的岩石,开挖通常花了凿岩爆破.在软岩石,一个tunnel-boring medium-hard机器通常禁赛的挖掘工作.在软土地基、开挖通常是挖洞或提前完成一个盾牌,轻轻地捏软物质进入隧道.在所有情况下,出土的岩石或地球,称为粪,收集和传播出去的隧道.在水下隧道,一个盾牌是用来发展工作.另一种方法,建立了一种水下隧道是沉管状部分挖一条沟河的底部或身体的其他的水