摘要
以长春龙嘉机场T2航站楼为工程依托,采用现场土层沉降观测、桩基承载力测试和室内数值模拟相结合的方法研究了粉质粘土在回填堆载时桩基负摩阻力中性点的确定问题。通过土层沉降观测和桩基载荷试验,得到了回填土累计沉降量、填土加载与时间关系曲线及拟合公式以及单桩的Q-S曲线、桩身内力和桩侧负摩阻力与土层深度的变化关系;采用Midas有限元软件对桩基的沉降变形进行计算,以实测的桩侧摩阻力来模拟桩土之间的相互作用,桩端土层采用弹性支撑模拟,弹簧的刚度根据"m法"进行计算;采用改进高木俊介法计算了不同固结时间下桩周土层的残余沉降量。通过理论计算和现场试验的对比分析,确定了不同固结时间下桩基负摩阻力中性点的位置,并对该类场地地基土的沉降修正系数进行了修正。
Research about the location of neutral point of negative friction in pile foundation when silty clay is backfilled is carried out at T2 terminal of Longjia Airport, Changchun. Soil settlement observation, bearing capacity test of pile foundation and numerical simulation are adopted in the research. By observation and experiment, the accumulative settlement of backfill, the relation curve and fitting formula between the soil filling load and time and the Q-S curve of a single pile, the effects of soil depth on the internal force of pile body and on the pile side negative skin friction are obtained. Finite element software, Midas, is applied to compute the settlement deformation of the pile foundation. The actually measured pile side friction is used to simulate the interaction between the pile and surrounding soil. In the experiments, the pile bottom layer soil is simulated by elastic support, and the stiffness of the spring is calculated by “m” method. The residual settlement around the pile under different consolidation time is calculated by modified Takagi Shunsuke method. The negative skin friction neutral points under different consolidation times are located by comparative analysis of the results of theoretical calculation and field experiment. Then, the settlement correction coefficient of the foundation soil in this kind of field is modified.
出处
《吉林大学学报（工学版）》
EI
CAS
CSCD
北大核心
2017年第4期1075-1081,共7页
Journal of Jilin University:Engineering and Technology Edition
基金
国家自然科学基金项目(51508223)
关键词
土木建筑工程施工
桩基础
固结沉降
中性点
civil engineering construction
pile foundation
consolidation settlement
neutral point
