Abstract:
Taking the engineering of a station underground passageway of Suzhou Rail Transit Line 5 as example, by adopting site monitoring and comparative analysis methods, the variation law of ground subsidence induced by urban shallow-buried rectangular pipe jacking construction is studied. Results show that during the shallow-buried rectangular pipe jacking process, the ground surface deformation consecutively undergoes four phases: slight disturbance and subsidence, dramatic subsidence, grouting uplift and consolidation subsidence. In the direction along pipe jacking axis, ground subsidence is observed in an area within 7.5 m around the excavation face. Pipe jacking construction causes the ground subsidence width to be about three times of the pipe section width. By comparing existing theoretical prediction formula and in-situ monitoring data, results show that both Peck formula and stochastic medium model can be used to predict the ground subsidence induced by shallow-buried rectangular jacked tunnels. By comparative statistics of existing cases, the subsidence trough distribution patterns are concluded with normalization analysis.