描述抗拔挤扩支盘桩Q-s曲线的修正双曲线模型研究

Modified Hyperbolic Model Describing Q-s Curves of Squeezed Branch Pile

为计算和预测抗拔挤扩支盘桩上拔承载力和研究其承载性状,对8个场地中共22根现场试验桩的实侧上拔荷载、上拔位移资料进行了优化拟合分析,针对抗拔挤扩支盘桩的特性,构造了一数学模型,即修正双曲线模型,该模型是在普通双曲线模型的分母中增加一起"调节器"作用的cs0.3项.对22根现场试验桩的拟合表明,该修正双曲线模型的拟合精度高,相关系数R达0.9821以上,平均0.9956;该模型对抗拔挤扩支盘桩的拟合效果比普通双曲线、某调整双曲线模型的都要好;基于该修正双曲线模型的挤扩支盘桩上拔荷载的计算值与实测值的误差在±2.81974%.结果表明,本文构造的修正双曲线模型针对抗拔挤扩支盘桩上拔荷载—上拔位移曲线的拟合是较为精确和可靠的.

In order to calculate and forecast the ultimate bearing capacity and to study its bearing behaviors of squeezed branch pile,optimized fitting analysis was carried out for field uplifting load and uplifting displacement data of 22 squeezed branch pile in 8 field testing sites.Aiming at the bearing characteristics of uplifting squeezed branch pile,a mathematical model,that was to say,modified hyperbolic model was put forward,and the model add cs0.3 which acting as adjuster in the denominator of general hyperbolic model.The fitting results of 22 field testing piles with the model showed that the fitting precision was high,the correlativity coefficients R was over 0.9821,the average value was 0.9956.The fitting effect with the model was better than general hyperbolic model and certain adjustment hyperbolic model.The error between calculation value and field measure value of uplifting load of squeezed branch piles based on fitting equations was ±2.81974%.The following conclusions can be drawn that the modified hyperbolic model is accurate and credible for describing squeezed branch pile Q-s curves.