Study on construction interaction of shield tunnel with overlapping curves of small turning radius
[Objective]Due to the restriction of the subway network planning and surrounding environment,overlapping shield tunnel with small turning radius is widely used.The uplift law of the adjacent lower tunnel lining induced by the construction of upper tunneling is extremely complicated in overlapping shield tunnel.Furthermore,the reinforced measures need to further stud-ied.[Methods]Based on the project of shield tunnels,running from Shangqingqiao Station to Qinghe Station,the effect of the grouting into soils and steel support reinforcement on the uplifted deformation and the stress characteristics of steel support are in-vestigated by method of numerical simulation and field measures.[Results]The main findings are as follows:The uplifted de-formation induced by a single reinforced measure exceeded the control value,whereas the result induced by combined measures was 4.87 mm.The grouting into soils improved the strength of soils and restrained the uplifted deformation.The steel support helped to control the deformation of segments.The vertical and horizontal support restrained the uplifted deformation and clear-ance convergence,respectively.The maximum uplift occurred at the first segment.The uplift decreased with the increase of the space of tunnel.The simulated maximum uplift was 1.15 times as much as the measured value.The measured maximum stress of the vertical support was 5.78 MPa.[Conclusion]The installation of support was the main reason for the difference.The fixed bolts between the circumferential support and segments and the optimization of longitudinal supports were proposed.It provides reference for engineering design and safe construction of similar small turning radius overlapping shield tunnel.
small turning radiusoverlapping shieldsreinforced measureuplift of tunnel liningsteel support stressdeformation
万方数据
维普
