Influence of Metro Construction on Underground Pipeline

The influence of metro construction on the underground pipeline at Huangzhuang station of No.4 line in Beijing is analyzed with 3D finite element calculation of supporting construction of tunnel and soil and combining with the monitoring and measuration of construction.The safety of underground pipeline is analyzed and predicted according to related criterion for safety assessment of pipeline.The steel frame and bolt are simulated by equivalent method.The preliminary bracing and temporary construction are simulated with space iso-parametric shell element that can bear axle bending.The secondary lining and surrounding rock are simulated with space iso-parametric solid element that follows constitutive equations of finitude deformation ideal elastic-plasticity and yield criterion of Drucker-Prager.Calculation result shows that the maximum ground subsidence predicated is 121.63 mm after construction,which cannot overrun the safety request of pipeline,which is 127.27 mm.The differential subsidence is also not overrun the control criterion.Since there are many cavities in the stratum at Huangzhuang station,at the same time there is also much water in the stratum and leakage water of pipeline,we must take measures to control the ground subsidence so as to guarantee the normal use of pipeline.