复杂地质条件下铁路桥梁桩基通用计算方法OA北大核心CSTPCD

To ensure the structural safety of railway bridge pile foundation in complex geological environments and further improve the design quality,a general calculation method for pile foundation under complex special geological conditions is proposed.Selecting static water,negative skin friction,expansive soil,and seismic liquefaction soil as the four basic special geological conditions,based on the m-Method and single pile bearing capacity calculation formula in the Standard Code for Design of Bridge Pile Foundation,this paper proposes the calculation method for each of the four basic special geological conditions when acting separately and the coupling effect algorithm when working together.The results show that the seasonal frozen depth line,the upper limit depth line of permafrost,the neutral point depth line,and the sharp layer depth line can serve as the boundary lines for ice,liquid water,frozen soil,negative skin friction,and expansive soil.The calculation steps,calculation parameters,and external load increments added to this method on the basis of the specifications can be transplanted into the general design program of pile foundations,and is suitable for calculation under any complex and special geological conditions.It can provide support for achieving safe,efficient,and refined calculation of railway bridge pile foundations under those conditions.The application of the research results in railway bridge design saves about 5％in pile length and about 4％in pile reinforcement.