基于灰色理论和Usher曲线的PHC管桩单桩竖向极限承载力预测

The single pile vertical ultimate bearing capacity prediction of PHC pipe piles based on the grey theory and Usher curve

针对利用现行规范公式计算PHC管桩的竖向极限承载力值存在结果偏低的问题,根据竖向静载荷文献资料,基于灰色理论GM(1,1)模型和Usher曲线模型预测单桩的极限承载力,并采用MATLAB软件实现预测模型算法.工程实例分析表明:灰色预测模型的预测精度与竖向静载试验数据级数选取、预测距离有密切关系;Usher曲线模型对桩极限承载力的预测精度大大高于灰色模型,此结果可为类似工程地质条件下PHC管桩单桩竖向极限承载力的预测提供借鉴.

In view of the current specification formula for calculating the ultimate bearing capacity of PHC pipe piles vertical value is generally low,according to the literature data of vertical static load,using the theory of grey GM（1,1）model and Usher curve model for predicting ultimate bearing capacity of single pile,to realize the predictive model algorithm by using MATLAB software.The analysis of proj ect instance shows that：the prediction accuracy of grey forecasting model is closely related to the selection of vertical static load test data series and prediction distance;Usher curve model has higher precision than the grey model for the forecast of ultimate bearing capacity of pile,which can provide appreciation for the similar engineering geology PHC pipe piles under the condition of the single pile vertical ultimate bearing capacity prediction.