摘要
规范[1,2]中对低桩承台基础基桩竖向抗压与抗拔承载力进行验算时,均以单桩作为验算对象,有关验算准则未考虑"群桩-承台"结构体系的整体抗力效应与结构体系可靠度问题,所得出的结果可能存在一些问题。针对低桩承台基础"群桩-承台"结构体系,利用工程结构可靠性设计原理,验算群桩承台结构体系的竖向承载力和可靠度;分析表明:群桩承台结构体系的可靠度与所有构件密切相关,任何单一构件的可靠度不能代替整个结构体系的可靠度;任何一根基桩的失效不一定导致整个结构体系的失效;承台失效将会导致整个结构体系失效。针对基桩数量较多的桩基础,当承台本身具有足够高的可靠度时,规范[1,2]中的设计方法偏安全;当承台本身的可靠度不够高时,规范[1,2]中的设计方法偏于不安全。当承台下方的基桩数量较少时,按照规范[1,2]进行设计偏于不安全。
In the code,when checking the vertical compressive and uplift bearing capacity of the foundation pile of low pile cap is checked,the single pile is taken as the object to be checked.The overall resistance effect and the reliability of the structural system of"pile group cap"are not considered in the relevant checking criteria,and some problems may exist in the results.According to the"group pile cap"structure system of low pile cap foundation,the vertical bearing capacity and the reliability of group pile cap structure system are checked by using the reliability design principle of engineering structure;the analysis shows that the reliability of the group pile cap structure system is closely related to all components,and no single component can replace the reliability of the whole structure system;the failure of any foundation pile may not lead to the failure of the whole structural system;the failure of the bearing platform will lead to the failure of the whole structural system.For the pile foundation with abundant piles,the more reliable the bearing platform is,the more conservative the design method in the code becomes;if the reliability of the bearing platform is not high enough,the design method in the code will be unsafe.If there’s a small number of the piles under the bearing platform,it will be unsafe to design according to the code.
作者
卢红前
LU Hongqian(Jiangsu Power Design Institute Co.,Ltd.,China Energy Engineering Group,Nanjing 211102,China)
出处
《武汉大学学报（工学版）》
CAS
CSCD
北大核心
2020年第S01期103-110,共8页
Engineering Journal of Wuhan University
关键词
群桩承台
竖向承载力
表决系统
结构体系可靠度
蒙特卡罗法
group pile cap
vertical bearing capacity
voting system
structural system reliability
Monte Carlo method
