单护盾 TBM 施工阶段围岩荷载与管片受力研究

Segment failure and leakage phenomena often appear in the construction process of TBM，which directly affect the safe operation of metro. In view of this，this paper based on Chongqing Metro Loop Project，conducted onsite monitoring of segment forces during segment assembly，and explored the surrounding rock load of tunnel segments in the actual construction environment. The evolution law of segmentstratum interaction during single shield TBM tunnel construction was found out through onsite monitoring.Using ANSYS threedimensional finite element analysis software，a numerical model considering the interaction of shield segmentbolt，segmentsurrounding rock and segmentshield tail was established，the force of the segment under the action of surrounding rock in the construction process was analyzed，the deformation of the segment under the action of normal propulsion load and additional torque was compared，and the eccentric jack effect on the mechanical behavior of segment was obtained. The analytical results indicate that，the pressure behind the segment of single shield TBM tunnel is the combined action of pea gravel，slurry and surrounding rock. The surrounding rock pressure behind segment of single shield TBM construction in sandstone stratum in Chongqing area is slightly higher than the theoretical calculation value，and the actual surrounding rock pressure at the top，bottom and waist of segment is 150～160kPa，165～200kPa and 45～52kPa，respectively. Excessive additional torques may cause partial segment breakage.