Study On The Deformation Of Pile Foundation Induced By Shield Tunneling

Compared with traditional excavation method of subway tunnel, shield method has its unique advantages so that which has become the main method of excavating subway tunnel.Because of the complexity of urban underground environment, it is inevitable that we encounter the building structures and the pile foundations in the process of the excavating of subway.The excavation brings adverse effects on pile foundations because of its disturbance of surrounding rock and strata which causes a change of stress field and displacement of the groud.Therefore,it is necessary to make a thorough inquiry on the deformation of pile foundation induced by shield tunneling.Based on the comparative analysis approach, the paper discusses the relationship between the influence degree of pile foundation induced by shield tunneling and the relative space position between them.The influence zone is divided into four parts on the basis of the discussion above. The piles located in the different influence zone also are divided into four categories.To ensure the excavation of the tunnel safety, economy and reasonable, reasonable countermeasures are raised in accordance with different categories of pile foundations.The Thesis mainly finishes the following achievements:1. With FLAC3D numerical simulation method, the thesis discusses the deformation of single pile induced by shield tunneling, and achieves the deformation law of single pile.2. The paper finishes the calculation of settlements of the piles induced by the excavating of subway tunnel based on the settlements of the pile foundation of Xiaojiejiao Bridge induced by Taiping tunnel which goes through the pile foundations.The influence zone is divided into four parts on the basis of the calculation. The piles located in the different influence zone are accordingly divided into four categories.3. The paper finishes the calculation of settlements of the piles of Xiaojiejiao Bridge induced by the excavating of Taiping tunnel. Reasonable countermeasures are raised in accordance with different categories of pile foundations. It is very effective to take measures to control the final settlement of pile foundation in the settlement concentration zone.