基于桩端和桩侧阻力相互作用的超长桩承载力研究

对于超长桩顶部受力承载水平临近极限情况时，会出现桩端位置附近的摩阻力陡增的现象，且不同桩体周围的土体强度和桩—土接触面特性差异，产生该效果的力度也不尽相同。以超长摩擦型单桩承载性能分析为基础，构建了复杂介质环境下超长摩擦型单桩的桩—土受力模型，并将广义弹性原理和优化反分析理论进行结合，以此来计算复杂介质中的超长桩摩擦型单桩的承载机能和测试静载试验的沉降曲线。通过测试得到的桩周和端土力学数据，结合有限单元法对超长桩桩端和桩侧阻力的Mindin解进行修正计算，以此提高抗滑桩的桩端和侧阻力相互作用的计算精度。算例结果表明，考虑桩体附加侧摩阻力修正后的计算结果和测试值吻合程度很高，说明该方法对提高超长桩的桩端和侧阻力相互作用的计算精度、对指导工程施工具有较好的借鉴价值。

Research on bearing capacity of super-long piles based on interaction between pile end and pile side resistance

When the force bearing level of the top of the super-long pile approaches the limit，the frictional resistance near the position of the pile end will increase sharply，and the soil strength and the characteristics of the pile-soil contact surface around the different piles will produce this effect.The strength is not the same.Based on the analysis of bearing capacity of super-long friction single pile，the pile-soil stress model of super-long friction single pile in complex medium environment is constructed，and the generalized elastic principle and optimized back analysis theory are combined.To calculate the bearing capacity of the super-long pile friction type single pile in the complex medium and the settlement curve of the static load test.In addition，through the test of the pile circumference and end soil mechanics data，combined with the finite element method，the Mindin solution of the super long pile end and the pile side resistance is corrected and calculated，so as to improve the calculation accuracy of the pile end and side resistance interaction of the anti-slide pile.The results of the example show that the calculation results of the modified side friction resistance of the pile are in good agreement with the test values，which explains the accuracy of the method described in this paper to improve the interaction between the pile end and the side resistance of the super long pile.It has a good reference value for guiding the construction of the project.