Stress calculation of unlined pressure tunnel surrounding rock in hydraulic engineering

In hydraulic engineering, the running state of pressure diversion tunnel directly affects the normal use and economic benefit of the whole project. This paper bases on the deep-lying circular tunnel and analyse stress distribution in the unlined hydraulic tunnel surrounding rock by using the finite element method, respectively study the stress after the completion of the tunnel excavation, additional stress produced by the internal water pressure, stress distribution produced during water filling operation. These research results provide some references of design and construction for unlined pressure tunnel.