Inverse Analysis of Internal Forces in Shield Tunnel Segments for Water Conveyance in Deep-Buried Soft Soil
Leveraging the shield tunnel's test ring within the Dianzhong water diversion project,two rows of concrete strain gauges were embedded at the entrance and exit in the excavation direction.Additionally,reinforcing bars were em-bedded as a control group.On-site experimental monitoring was conducted to analyze the internal force distribution of the test ring.Based on the extensive on-site monitoring data,the study investigated the strain discrepancy between concrete and steel reinforcement in the monitored test ring and performed an inverse calculation of internal forces in the tunnel lin-ing segments.The analysis included variations and safety assessments of internal forces.The results indicate that the steel reinforcement strain is greater than or equal to concrete strain.Influenced by the shield tail effect,the discrepancy between steel reinforcement strain and concrete strain at the entrance is significantly smaller than at the exit.The arch top and bottom experience small positive bending moments,while the sides are subjected to negative bending moments.The axial force values show a continuous increasing trend,and the axial force in the F-type segment is significantly greater than in other segments,indicating structural weakness in the F-type segment,avoid placing block F on the spandrel as much as possible.The internal forces are within the enveloping diagram of a safety factor of 1.3,indicating that the structure is suitable for the geological conditions of this test ring.
shield tunnelon-site experimental monitoringstrain discrepancyinverse of internal force
万方数据
维普
