水平泥岩砂岩互层隧道超欠挖控制技术

水平泥岩砂岩互层围岩的地质特点导致围岩在施工爆破后易沿结构面及软弱破坏面破坏，形成较难人为控制的超欠挖现象。以大梁峁特长公路隧道为工程背景，提出了相应的超欠挖控制措施：采用科学合理的控制爆破技术和施工措施，经此处理后，超欠挖值明显减小，开挖面基本平整、光滑，隧道施工过程中未发生塌方事故，拱顶掉块也明显减少。

On the Overcut-and-Undercut-Controlling Techniques for Tunnels in Horizontally-Bedded Sandstone and Mudstone Interbed

The characteristics of the horizontally-bedded sandstone and mudstone interbed often cause the post-explosion damage to the surrounding rock along the interbed and the soft interface,which results in either overcutting or undercutting beyond human control. With the Daliangmao super-long highway tunnel as the engineering background, the corresponding overcutting- and-undercutting-controlling measures for the construction of a tunnel are put forward in the paper：applying the scientificallyrational explosion-controlling technology and other construction measures to the excavation for a tunnel, the value of either the undercutting or overcutting is apparently decreased,with the excavated surface being plain and smooth. There is no collapse happening and landslides are also obviously decreased during the tunnel construction.