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Nowadays, subway develops fast in our country, which promotes experience accumulation and technical development in subway construction. Subway lies in flourishing city, and its surrounding environment is complex. Confined by the tendency of lines and underground space, the subway construction is inevitably near current structure and pile foundation, As to have bad effect. Although adopted advanced construction method and assistance measure, But subway construction still remains unavoidable disturbed rock round , causes geologic stress field to change and brings distortion and displacement to around soil, breaks the force balance between close pile foundation and soil body , changes load ability of pile foundation , causes displacement of pile and will also produce disadvantageous influence to the upper part of bridge. The influence will closely connect with the position relation of tunnel and pile, therefore according to the position of tunnel and pile and influence size, divided close pile into different gradation, put forward reasonable countermeasure scope to different gradation of pile and reduced influence to near pile due to tunnel excavation. it is important to ensure the construction to be safe, economical and reasonable, this is also the main purpose of this thesis.In the text adopted as theory analysis, the number simulation, the spot measure, researches on the influence of subway construction upon pile. Firstly, studied that near piles influenced by excavation are connected with position parameters , according to this , the zone rounding tunnel is cut into 4 zones, with these , near piles are divided into 4 types: A piles, B piles, C piles and D piles. Studied the space position parameters influences piles stability, tunnel excavation influencing on the displacement of pile and put forward the influence relation with space position parameters. The close extent of near pile is divided into four grade: I, II, III, IV on base these. According to the grade of each near pile put forward adopting countermeasure scope, notice scope and no influence scope.Secondly, researched the effect on the west village station near pile adopted as countermeasure, drawn a conclusion that the effect relates of the near grade, and the different near pile should be adopted as different countermeasure, and it is very effective that adopting as countermeasure in the concentrate area of pile settlement to control the final settlement of pile.Finally , adoption as the spot measurement technique, the result of measurement corroborates the conclusion from the theory analysis and the number simulation, brings forward the special countermeasures adapting to the pile of the biggish settlement to guarantee the construction safety.
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