Study on Construction Mechanic Principles and Construction Technology of Shallow-buried Mined Tunnels with Large Spans

Regarding mined large span Metro station tunnels in soft ground,the mechanisms of displacement control in the sequential excavation of the tunnels,the mechanisms of advance reinforcement of the ground and the loading transfer between the primary reinforcement structure and the secondary lining structure are studied.Proper construction methods and assistant construction methods are established for mined large span Metro station tunnels on basis of the study results.The technology has been applied in the engineering practice and satisfactory effects have been achieved.In this way,systematic key construction technologies for mined large span Metro station tunnels in soft ground are established.