大面积填土下深厚软土中桩基负摩阻力分析  

Analysis on negative friction of pile foundation in deep soft soil under large-area filling

作　　者：张静 ZHANG Jing(SGIDI Engineering Consulting(Group)Co.,Ltd.,Shanghai 200093,China)

机构地区：[1]上海勘察设计研究院(集团)有限公司,上海200093

出　　处：《工程建设》2022年第1期18-23,共6页Engineering Construction

摘　　要：舟山某石化基地二期工程场地软土厚度达50 m,堆土面积超过400万m^(2),填土厚度达4~12 m,在超载预压-卸载后施工桩基。由于影响桩土相互作用的因素复杂,本文通过指数曲线法预测卸载后不同时刻的工后沉降及沉降速率,建立单桩有限元模型,并与实测数据对比验证模型的合理性。基于验证后的数值分析模型,研究不同工后沉降及沉降速率对负摩阻力的影响。结果表明:指数曲线法可有效预测工后沉降及沉降速率,负摩阻力在上部结构竣工后对桩基承载力最为不利,但桩侧承担的负摩阻力远小于规范提出的极限值。本文研究成果可为大面积填土下深厚软土中桩基设计提供借鉴与参考。The thickness of the soft soil of the second phase project of a petrochemical base in Zhoushan is up to 50 m, the piled area exceeds 4 million square meters, and the filling thickness is 4~12 m under the construction of pile foundation after pressing-unloading.Due to the complex factors affecting the pile-soil interaction, the exponential curve method is used to predict the post-construction settlement and settlement rate at different times after unloading, a single pile finite element model is established, and the rationality of the model by comparing it with the measured data is verified.Based on the validated numerical analysis model, the effect of different post-construction settlement and settlement rates on the negative friction resistance is studied.The results show that the exponential curve method can effectively predict the post-construction settlement and settlement rate, and the negative dynamic resistance is most unfavorable to the pile foundation bearing capacity after the completion of the superstructure, but the negative dynamic resistance borne by the pile side is much less than the limit value proposed by the code.The results can provide references for the design of pile foundations in deep soft soil under large-area filling.

关 键 词：负摩阻力 工后沉降 沉降速率 大面积填土 深厚软土 

分 类 号：TU473.1[建筑科学—结构工程]