精选优质文档-倾情为你奉上附录二 外文参考文献及翻译NATM tunnel design principle in the construction of major and Construction TechnologyW.BroereI.The NATM Design Principle1.Tunnel design and construction of two major theoretical and development process Since the 20th century, human space on the ground floor of the growing demand, thus the underground works of the study of a rapid development. In a large number of underground engineering practice, it is generally recognized that the tunnel and undergrou