管桩单桩竖向极限承载力的沉降预估研究

为了更加精确地预估预应力管桩路基地基的沉降变形，基于慢速维持荷载理论，进行了路基预应力管桩的静载试验和试桩的Q-S曲线拟合，给出单桩沉降预估公式。同时，对拟合数据和实测数据进行了对比。研究结果表明:桩身完整性程度对单桩竖向极限承载力影响十分明显；指数函数模型对桩基的Q-S曲线具有较高的拟合精度；在保证成桩质量的前提下，给出的预估公式对桩基的沉降量具有较好的预测能力，且相对误差较小。

The Settlement Prediction Based on the Test of Vertical Ultimate Bearing Capacity of Single Pipe Pile

In order to accurately estimate the foundation settlement of subgrade with the prestressed pipe pile, based on the theory of slow maintenance loading method and combined with practical engineering, the static load test of prestressed pipe pile and the fitted Q-S curve with exponential function were conducted. The prediction formula of single pile settlement is given. At the same time, the fitting data were compared with the measured data. The results showed that the integrality of piles has a significant impact to the vertical ultimate bearing capacity. The functional model of exponential with a higher fitting precision for the Q-S curve. On the premise of guaranteeing the quality of piles, this fitted Q-S curve has a preferable predictive ability with smaller relative errors. The conclusions mentioned above can offer a reference to the design and construction of prestressed pipe pile in this region.