基于欧标的硅藻土地层中桩基负摩擦计算

Negative friction calculation of pile foundation in diatomaceous soil based on Eurocode

纳米比亚某港口项目建于20余米厚的硅藻土层上,后方陆域回填导致的地基沉降给码头桩基带来严重的负摩擦问题。针对此工程中的负摩擦问题,研究了欧标规范的相关条款并计算负摩擦影响下的桩基承载力,提出多种工程应对措施以降低负摩擦的不利影响,如延后桩基施工时间、打设钢护筒穿过硅藻土层、增加桩径、增加入土深度和采用扩底桩等。延后桩基施工时间是综合成本最低的解决方案。该计算方法可为类似地基中的桩基的负摩擦计算提供参考。

A port project in Namibia was built on diatomaceous soil more than 20 meters thick,thus the settlement of the foundation caused by backfilling in the rear land area brings serious negative friction problems to the pile foundation of the wharf.Aiming at the problem of negative friction in this project,the relevant clauses of the European Standard Code are studied and the bearing capacity of pile foundation under the influence of negative friction is calculated.The varieties of engineering countermeasures are proposed to reduce the adverse effect of negative friction,such as delaying the construction time of pile foundation,driving steel casing through diatomaceous soil layer,increasing the diameter of pile,increasing penetration depth and enlarging pile base.Among these measurements,delaying the construction time is the lowest comprehensive cost solution.The calculation method adopted in this paper can provide a reference for the negative friction calculation of pile foundation in similar foundation.