The Excavation Procedure of Super-Large Underground Chambers and the Surrounding Rock Stability

During the construction of a group of super-large chambers, the most critical problem is the stability of the surrounding rock. So it’s necessary to analyze the excavation sequence and the stability of the underground chambers. In this paper, three main chambers of an underground hydropower station are excavated according to three different schemes. The stability of the underground chambers constructed in accordancewith the three excavation schemes are analyzed and compared by employing three-dimensional nonlinear finite method, supplying a reference for the construction design and field construction. In addition, some relevant comments and suggestion are put forward for the revealed problems in the surrounding rock stability.