基于土拱效应的CFG桩复合地基承载力设计方法-《高速铁路技术》

文章信息/Info

Title:: Design Method for Bearing Capacity of CFG Pile Composite Foundation based on Soil Arching Effect

Author(s):: JIANG Lei; China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China

Keywords:: CFG pile|composite foundation|bearing capacity of soil between piles|vertical bearing capacity of the single pile|soil arching effect|design method

摘要:: 现行规范CFG桩复合地基承载力设计主要基于半经验半理论的方法，设计者对经验系数取值随机性较大，导致不同设计者的设计结果可能偏差较大。在实际工程中，设计者对经验系数的取值也往往偏于保守，从而导致设计结果偏于保守。本文基于土拱效应理论，探讨了全新的CFG复合地基承载力设计方法，并给出了算例。基于土拱效应的设计方法，对桩间土承载力和单桩竖向承载力分别进行验算并作为判定复合地基承载力是否满足设计要求的依据，使其更符合CFG桩与土相互作用实际规律，较好的解决了因经验系数取值的随机性可能导致设计结果偏差较大的问题。本文研究成果可为铁路路基CFG桩复合地基承载力设计方法的改进和完善提供一定的借鉴。

Abstract:: The design of bearing CFG pile composite foundation in current code is mainly based on a semi-empirical and semi-theoretical method, for which the designers take the values of empirical coefficients randomly, so that different designers would obtain different design results. In practice, the values of empirical coefficients chosen by the designers are often conservative, which leads to conservative design results. Based on the theory of soil arching effect, this paper discusses a new design method for bearing capacity of CFG composite foundation with examples. For the purpose of the design method based on the soil arching effect, checking calculations are made separately for the bearing capacity of the soil between piles and the vertical bearing capacity of a single pile, and the results are used as the basis to determine whether the bearing capacity of composite foundation meets the design requirements, which makes it more in line with the actual law of interaction between CFG pile and soil, and better solves the problem that the design results may deviate greatly due to the randomness of empirical coefficient. The results of this paper may provide some reference for improving and perfecting the design method for bearing capacity of CFG pile composite foundation of railway earthworks.