Study On Effect Of Subway Shield Tunnel Construction On Adjacent Buried Pipelines

Estimating the effect of shield tunnel construction on adjacent buried pipelines in soft soil areas, Giving a study on this research subject has important theoretical significances and utility value. the method of theoretical analysis and numerical simulation were adopted respectively to research the displacement and force of adjacent buried pipelines effected by shield tunnel construction. The research also analysed the influencing factors of displacement of pipelines. The main research results are as follows:(1)Adopting the elastic foundation beam theory, by Peck modified formula and Attewell empirical formula, using the method of initial parameter, the solution formulas of vertical displacement and mechanics properties of rigidly jointed pipelines effected by shield tunnel construction were derived in two different cases (pipeline transverse to the tunnel and pipeline parallel to the tunnel).(2)In the two different cases (pipeline transverse to tunnel and pipeline parallel to the tunnel), the effect of shield tunnel construction on the displacement and rotation angle of flexible jointed pipelines was analysed. Then the relationship of relative rotation angle in every joint and displacement in adjacent joints was given.(3)Direct relation between pipeline deformation index and maximum ground surface displacement is established and a new deformation control method is put forward based on empirical formula to overcome the weakness of previous damage evaluation method, which only take ground displacemen as assessment index. Ground surface allowable deformation is attained by using allowable deformation value of pipelines to achieve the goal of controlling pipeline deformation through ground surface displacement and protect the pipeline.(4)Using Plaxis 3D Tunnel finite element software, 3-D numerical models were established to simulate the effect of shield tunnel construction on rigidly jointed buried pipelines in the two different cases (pipeline transverse to tunnel and pipeline parallel to the tunnel).(5)In the two different cases (pipeline transverse to tunnel and pipeline parallel to the tunnel),the change laws of displacement of rigidly jointed buried pipeline effected by shield tunnel construction were studied under different factors(soil,buried pipeline,construction).