龙门黄河大桥超长桩静载试验研究

为了研究黄河地区大直径超长桩的承载特性,采用自平衡测试法进行2根试桩静载试验,并采用钢筋计测试元件进行了桩身轴向应力测试。基于实测数据,对桩总承载力、桩侧摩阻力、桩端阻力以及承载性能进行了分析,并将桩端阻力实测值和《公路桥涵地基基础规范》计算值进行了对比。研究表明,SZ9桩桩侧摩阻力地勘报告值基本大于实测值,SZ10桩桩侧摩阻力地勘报告值与实测值基本接近,公路桥涵地基基础规范对砂土类的桩端阻力深度修正系数取值偏大,导致桩端阻力计算值远大于实测值。研究成果对黄河特殊地质条件下超长大吨位桩基础设计具有参考价值。

Study on Static Load Test of Super-long Piles of Longmen Yellow River Bridge

To obtain the bearing characteristics of super-long piles with large diameter in Yellow River area,the self-balanced load test on two single piles in compression and the axial stress test along the shaft based on strain gauges embedded in piles were conducted.Based on the test results,bearing capacity,side friction,tip resistance and load bearing properties of the piles were analyzed.The results indicate that the friction values of investigation report are almost larger than the test value of pile SZ9 while the friction values of investigation report are equal to the test value of pile SZ10.Furthermore,the comparison between the test values of tip bearing capacity and the calculation values based on the Code of Design Ground Base and Foundation of Highway Bridges and Culverts was carried out.It indicates that the deepness correction factor of tip resistance in sands determined by the Code is greater than the test results,which results in the calculation of tip resistance is greater than the test results.The research results are beneficial to the design of the super long large bearing capacity piles under the special geological conditions in Yellow River area.