中文摘要：

从不同围岩类别出发，对3车道小间距隧道采用典型双侧导坑法的开挖施工过程进行了数值模拟研究。给出了不同围岩类型下的3车道小间距隧道在施工过程中的围岩破坏特征及其变形规律和变形规律的相似件，获得了洞周最大变形量值之间的相对比值关系。通过中隔墙的变形与塑性破坏规律分析，比选出了3车道隧道中隔墙最小间距的工程设计参考值。分析表明：Ⅱ类围岩合理间距不应小于0．45B，Ⅲ类围岩应在0．35～0．45B之间，Ⅳ，Ⅴ类围岩可在0．2～0．35B之间选择，对信息化反馈施工，指出了必须重点监控与关注的位置。为小间距隧道的发展和施工设计提供了较确切的参考数据和理论依据。

英文摘要：

Based on different classes of surrounding rocks, the numerical simulation of construction process is studied for three roadway tunnels with small spacing, adopting the typical method of double side excavation. The damage characteristic and the deformation law of surrounding rocks are given in the construction process for the different classes of surrounding rocks of three driveway tunnels. The comparability of the distributive law of deformation along the tunnel boundary is indicated for different classes of surrounding rocks; and the relative ratio of maximum displacement is obtained. By comparing the deformation and the plastic damage law in the interval wall between tunnels, the minimum spacing is selected for engineering design reference in three roadway tunnels. It is shown from analysis that the reasonable spacing is more than 0.45B for surrounding rock class Ⅱ and between 0.35B and 0.45B for surrounding rock class Ⅲand between 0.20B and 0.35B for surrounding rock classification Ⅳ and Ⅴ. The key locations of measurement and control are given for the feedback information construction, and these provide the reference data and the theoretical basis for the development and construction design of highway tunnels with small spacing.