软基中大型深沉井使用阶段侧壁摩阻力探讨

Side Friction of a Deep Caisson in Soft Soils under Service Loads

结合珠海市某软基工程中大型深沉井的设计施工实例,分析了侧壁摩阻力的特点,提出了使用阶段侧壁摩阻力采用的模式,分别讨论了大型深沉井在不采取抗浮措施、配重抗浮以及利用侧壁摩阻力来抗浮的三种方案,论证了在使用阶段考虑侧壁摩阻力来抗浮的合理性。经过工程实践证明,按照建议模型考虑使用阶段的侧壁摩阻力,在保证安全的同时能够有效的减小井体的壁厚、底板厚度及配重设置,取得了良好的经济效益,可供类似工程参考。

This paper presents the analytical results of the side friction of a deep caisson in Zhuhai soft soils under the service load conditions.The segmental side friction estimation method was proposed based on the characteristics of the side friction distributions.The buoyancy design approaches can be divided into three different methods：No uplift approach;additional dead weight approach and side friction approach.Among these methods,side friction approach is the most effective one.The project practice indicates that the side friction model proposed in this paper can effectively reduce the side and bottom thickness of the caisson,as well as the additional dead weight.