Abstract:

The construction and monitoring technologies for earth pressure balance (EPB) shield closely crossing underneath existing tunnel in unconsolidated confined water silty sandy soil strata are studied by taking shield section of Wangjiadun North StationFanhu Station section on Line No. 3 of Wuhan Metro for example. The supplemental consolidation system and related parameters are presented; meanwhile, shield boring parameters and control points of EPB shield crossing underneath existing Metro tunnel in soft and weak strata are presented as well. The monitoring technologies for existing Metro tunnel are carried out so as to guarantee the tunnel safety.

Key words: shield tunnel, soft and weak strata, earth pressure balance (EPB) shield, closely underneath crossing, existing tunnel, boring parameter, settlement and deformation, monitoring