The surrounding rock of underground powerhouse of Xilongchi pumped storage power station in Shanxi is horizontal thin layered

the project has been completed and in operation for many years

it is safe during construction and operation

but before the project starts

there was no successful example for excavation of underground cavern with large span and high side wall in horizontal thin layered. In view of this

this paper based on the project of Xilongchi pumped storage power station

studied the horizontal thin surrounding rock from the view of engineering geology

such as lithology characteristics

structure characteristics of rock mass

mechanical characteristics of rock mass

rock classification of underground cavern with large span and high side wall

deformation characteristics of surrounding rock and so on; according to the research results

excavation and supporting of cavern construction and deformation monitoring of surrounding rock was analysized; mechanics parameters of surrounding rock are inverted on the basis of deformation monitoring results. It verified the previous investigation results and made valuable experience of large underground cavern excavation in horizontal thin bedded geological environment

and provided more technical support for construction of large span underground cavern in the horizontal thin layered geological bodies

has an important guiding significance for large underground caverns construction under this kind of adverse geological conditions.