Study on Stability of Bridge Pile Foundation in Permafrost Area along Qinghai—Tibet Railway
MI Wei-jun1,LI Yong1,SHI Gang—qiang2,QU Yao—hui1
1.Northwest Research Institute Co.Ltd.of China Railway Engineering Corporation,Lanzhou,Gansu 730000,China;2.Lanzhou University,Lanzhou,Gansu 730000,China
Abstract:Research purposes: The uncertainties in the strength,homogeneity of pile and refreezing and deformation of soil around the pile existed to the pile foundation in permafrost area.To ensuer the smooth construction and the safe operation of the Qinghai—Tibet Railway,the bearing capacity test of the bridge pile foundation was carried out and the long—term monitoring for the ground temperature and deformation were conducted.In order to evaluate the stability of the bridge foundation of Qinghai—Tibet Railway,based on the long—term monitoring system for the bridge pile in the Qingshuihe experimental section and the bridge pile foundation of Qinghai—Tibet Railway,this paper studies and analyzes the homogeneity,static elastic modulus,compressive strength,static load and the characteristics of monitored ground temperature and deformation of the bridge foundation cross—section.
Research conclusions: The study results showed the integrality and homogeneity of concrete pile were rather perfect and there was no major quality defects like segregation.The majority of the compressive strength of concrete pile was between 28—33 MPa.and coe侬cient of variation of compressi。ve strength was only 0.14. and the static modulus of elasticity was 2.40×104 MPa.All these met the technical requirements.The artificial upper table for soil around the pile was between 0.08-0.2 m.and deformation of pile foundation in permafrost area was less than 10 mm,which satisfied the post— construction deformation demands for the ballasted deck piers.It was concluded the bridge foundation of Qinghai—Tibet Railway was stable.
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MI Wei-jun,LI Yong,SHI Gang—qiang,QU Yao—hui. Study on Stability of Bridge Pile Foundation in Permafrost Area along Qinghai—Tibet Railway. 铁道工程学报, 2010, 27(9): 15-19.
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