Abstract Drill and blast method is mostly used method for excavation of tunnels throughout the world. This tunneling method involves the use of explosives. Compared with bored tunneling by Tunnel Boring Machine, blasting generally results in the development of a blast-induced damaged zone around the tunnel boundary. Theoretically, the presence of this zone, with its reduced strength and stiffness, will affect the overall performance of the tunnel, as well as its construction and maintenance. In fact, the extent of the damaged zone is finite. However, the effect of this zone is traditionally considered by a damage factor D applied to the entire rock mass surrounding the tunnel. This is a common modeling method which can greatly underestimate the strength and stability of the overall rock mass. In this paper, a semi-analytical solution is proposed for analysis of tunnels considering the damaged zone. The solution is presented for circular tunnels excavated in rock masses obeying a new proposed non-linear strain-softening behavior and the non- linear Hoek–Brown failure criterion. The damaged zone is assumed to have a cylindrical shape with reduced strength and deformability parameters.

中文翻译：

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考虑爆破损伤区的 Hoek-Brown 应变软化岩体中开挖圆形隧道弹塑性分析新半数值方法

摘要 钻爆法是目前世界范围内隧道开挖最常用的方法。这种隧道挖掘方法涉及使用炸药。与隧道掘进机掘进隧道相比，爆破通常会导致隧道边界周围形成爆破损伤区。理论上，该区域的存在及其强度和刚度的降低，将影响隧道的整体性能，以及隧道的建设和维护。事实上，损坏区域的范围是有限的。然而，该区域的影响传统上是通过应用于隧道周围整个岩体的损伤系数 D 来考虑的。这是一种常见的建模方法，会大大低估整体岩体的强度和稳定性。在本文中，提出了一种半解析解决方案，用于分析考虑损坏区域的隧道。该解决方案适用于在岩体中开挖的圆形隧道，该隧道遵循新提出的非线性应变软化行为和非线性 Hoek-Brown 破坏准则。损坏区域被假定为具有降低的强度和变形参数的圆柱形状。