全断面开挖技术在特大断面洞室开挖中的应用

APPLICATION OF FULL SECTION EXCAVATION TECHNOLOGY IN THE CONSTRUCTION OF THE FIRST LAYER EXCAVATION OF EXTRA LARGE SECTION CAVERNS

某水电站工程的泄洪放空与生态放水洞无压段属于特大断面地下洞室,共分3层进行开挖支护施工。该泄洪放空与生态放水洞无压段第一层开挖支护施工时,前期采用中导洞先行两侧扩挖技术,后期采用全断面开挖技术,经比选上述2种开挖技术可知,特大断面地下洞室第一层施工时采用全断面施工技术是可行的,有利于提高效率、节约成本、保证安全,同时质量也能满足要求。

The The non pressurized section of the flood discharge and ecological drainage tunnel in a certain hydropower station project belongs to a super large section underground cavern,which is divided into three layers for excavation and support construction.During the excavation and support construction of the first layer of the non pressure section of the flood discharge and ecological water release tunnel,the middle guide tunnel was first expanded on both sides in the early stage,and the full section excavation technology was adopted in the later stage.After comparing the above two excavation technologies,it can be concluded that the full section construction technology is feasible for the first layer of the super large section underground tunnel,which is conducive to improving efficiency,saving costs,ensuring safety,and also meeting the quality requirements.