Abstract: To ensure the smooth construction of Yingrenshi-Jiuwei ecological drainage tunnel, it is necessary to investigate and evaluate the geological conditions. Study result shows that the main geological problems of the tunnel are tunnel collapse, water gushing, quicksand and mud inrush. Strata of the tunnel body are mainly soft in the upper part and hard in the lower part, and the tunnel top is V type surrounding rock which is extremely unstable. The following construction methods are listed from highest suitability to lowest: mining method, shield tunneling method and TBM. The optimal method should be determined after comprehensive comparison. By evaluation of the influence from underground structures, underground pipelines, geostress and environment to tunnel construction, important guidance for engineering practice is provided.

Key words: tunnel, geological condition, evaluation

摘要： 为保证应人石-九围生态排水隧洞的顺利施工，亟需对地质条件进行调研和评价。研究认为，隧洞主要工程地质问题为隧洞塌方、涌水、流沙和突泥等。隧洞洞身多为上软下硬地层，大部分洞顶为极不稳定的V类围岩，隧洞施工工法适宜性由高到低为：矿山法、盾构法、TBM法，应综合比较后确定最优方案。同时对地下构筑物、地下管线、地应力及环境对隧洞施工的影响进行了评价，为工程实践提供指导。

关键词: 隧洞, 地质条件, 评价