The Loess Area Shallow Buries And Digs Secretly The Third Company To Arch Subway Tunnel The Structure Stress System Transformation And The Characteristic Studies

Based on three-arched subway tunnel of the K17+095 section of the Second Subway Line of Xi'an, Through embedding pressure cell between primary support and surrounding rock, secondary lining and primary support, welding the reinforcement meter on design position of grille arch and anchor bolt, embedding concrete strain meter in secondary lining, analysis the field test, and compared with the results of numerical calculation,research the structural changes of other parts caused by each excavation of the three-arched subway tunnel, the middle wall of left and right line transfer load of tunnel arch and the inhibition to the deformation of the supporting system of side hole of left and right line. Specific research results:1. Analysis the effect on the structural stress transition of the supporting system caused by different hole excavation of the three-arched subway tunnel.2. Research the structural stress characteristics of primary support after the three-arched tunnel excavation completed.3. Definitude the bias effects on the middle wall of left and right line in the tunnel excavation and after the secondary lining completed; Analysis the unloading effect of the middle wall on the tunnel vault,especially the vault area of the middle drift of left and right line and middle hole; Also draw the middle wall of left and right line suppress the stress and deformation of primary support of the side hole caused by the deformation of surrounding rock of the side hole of left and right line.4. Computing the effect of system anchor bolt on the stress of primary support.5. Come to the load distribution ratio of secondary lining and primary support which as a whole bear the tunnel load.6. Summarize the length of time of rock deformation and space effect caused by tunnel excavation.