Abstract: In order to solve the serial engineering problems caused by the third series argillaceous weak cementation rich water silty sand in the construction process of Lan-Yu and Ningxia Wangwa railway, the surrounding rock characteristics of the third series argillaceous weak cementation rich water silty sand rock systematically were elaborated, the main auxiliary technical measures and engineering plans were introduced, and the design measures and the key construction technology of this stratum were put forward, in the consideration of the engineering and scientific difficulties in construction of Tao Shuping, Hu Maling, Cheng’er Shan tunnels, et al. The major principle that “major precipitation, concentrated catheters, strong supporting, assistant grouting, fast digging, fast supporting, fast closing” was determined, and the horizontal jet reinforcement in tunnel was adopted when it was necessary. The proposed whole set construction method of such stratum conditions was explored and applied to the engineering practice successfully, which solved the rarely encountered engineering problem in the world.

Key words: tunnel engineering, the third series, argillaceous weak cementation, rich water, fine sandstone, surrounding rock features, horizontal jet

摘要： 为解决兰渝铁路、宁夏王洼铁路在建设过程中所遇到的第三系泥质弱胶结富水粉细砂岩所带来的系列工程问题，结合桃树坪、胡麻岭、程儿山等隧道建设中的工程难点和科研攻关，系统阐述了第三系泥质弱胶结富水粉细砂岩的围岩特性，介绍了适应该围岩的主要辅助技术措施和工程方案，提出了针对该地层的设计措施和施工关键技术。确定采用以“重降水、密导管、强支护、辅注浆、快挖快支快封闭”为主的工程原则，必要时洞内水平旋喷加固，摸索出一整套此类地层条件下隧道的施工方法，并成功的应用于工程实践中，解决了一个世界罕遇的工程难题。

关键词: 隧道工程, 第三系, 泥质弱胶结, 富水, 粉细砂岩, 围岩特性, 水平旋喷