英语翻译The design of tunnel support has always been considered

英语翻译
The design of tunnel support has always been considered a highly complex matter from the point of view of engineering and has largely been reduced to empirical formulations ([Barton et al.,1974] and [Bieniawski,1974]) that have provided good results under similar geological conditions.
Many site engineers think that empirical analysis of convergence is sufficient to manage the excavation of a tunnel and do not care much about more sophisticated analysis methods ([AFTES,2002] and [Graziani et al.,2005]).However,models may prove very useful in obtaining a better understanding of the interaction between the rock mass and the support,in order to optimize the design.
The difficulty of designing the support of tunnels is a consequence of the following aspects:
• Insufficient knowledge of the behavior of the ground under conditions associated with the excavation of the tunnel.
• Insufficient data on the natural stress state of the ground.
• It is a three-dimensional problem.
• It is necessary to analyze the interaction between the support and the ground near to the advancing face.
• The time-dependent response due to the rheological properties of the ground must be taken into account.

设计巷道支护一直被视为一个非常复杂的事情,从的角度来看,工程,并已在很大程度上已沦为实证配方（ [巴顿等人,1974年]和[ bieniawski ,1974年] ）表示,已提供了良好的效果下类似的地质条件.
许多工地工程师认为,实证分析的收敛性是足够的管理挖掘一条隧道,不那么在意更精密的分析方法（ [ aftes ,2002年]和[ graziani等人,2005年] ） .不过,模型,可证明是非常有用的,在取得更深入的了解的互动关系岩体和支持,以优化设计.
难度设计的支持隧道是一个后果是以下几个方面：
•知识不足的行为,在地面条件下与开挖隧道.
•数据不足,对自然应力状态的地面.
•它是一个三维问题.
•它是有必要予以分析的互动关系,支持和地面附近向前进面子.
•时间依赖的反应,由于流变学特性的地面必须加以考虑.