Research On The Effects Of Shield Tunnelling On Adjacent Large-diameter Pipelines

In the next decades, urban metro construction will gain rapid development in our country. The shield tunnelling method will also become a common method in metro construction. At the same time, the problem about the effects of shield tunnelling on underground pipeline should be paid more and more attention and making further study has more important practical significance.In this paper, mainly combined theoretical analysis with numerical simulation, for one thing, the interaction between the large rigid pipeline and soil has been studied; for another, the effects of shield tunnelling on the stress and deformation of underground large rigid pipeline has also been researched. Besides this, the correctness of the conclusion that mentioned obove is proved according to practical engineering.1.Based on theory of Winker elastic foundation beam, according to Beam—spring Model and Shell—spring Model, with the difference of forced settlements (the settlements of soil surrounding with pipeline), modulus of subgrade, elastic modulus of pipeline, the depth of pipeline and tunnel, the condition about the separation between the pipeline and soil has been studied. The relationship between pipeline deformation and ground surface displacement is established. Once the ground surface displacement has been gotten, the deformation of the pipeline will also been evaluated, which may be used to taking appropriate measures to protect the pipeline.2.With 3D numerical simulation software, MIDAS GTS, taking two cases—pipeline transverse to tunnel and pipeline parallel to the tunnel, considering different distance between the excavation face and the pipeline, different modulus of subgrade, different elastic modulus of pipeline, different depth of pipeline, different vertical distance between pipeline and tunnel, different horizontal distance between pipeline and tunnel, different shield pressure and grouting strength, the discipline of stress and deformation of large rigid pipeline has been studied.3.According to practical engineering, the correctness of the conclusion attained has been proved. Furthermore, monitoring measures and technical measures of shield machine traversing has also been raised.