矩形槽壁桩承载力原位试验研究

Research on load test of rectangle grooved pile

采用特制的矩形荷载箱对南京某高层建筑地下连续墙的槽壁桩基础进行现场足尺自平衡竖向承载力测试,实测单幅槽壁桩竖向极限承载力高达320000k N。自平衡测试结果表明该工程槽壁桩基础的侧摩阻力占竖向承载力的70%左右。通过采用桩基规范和南京基础规范计算槽壁桩承载力,计算结果表明,两种规范计算得到的承载力比实测结果偏大18%~23%,且两种规范方法和实测得到的桩端阻力约为桩端岩层单轴抗压强度的0.4~0.65倍。

According to the full-scale field test of the grooved pile of a high-rise building in Nanjing,the self-balanced bearing capacity test is carried out by using a special rectangular load cell.The vertical ultimate bearing capacity of the single diaphragm wall is nearly 320000 kN.The self-balance method shows that the total friction resistance of the grooved pile foundation is about 70% of the vertical bearing capacity.The bearing capacity of the grooved pile is calculated by using the pile foundation and the Nanjing foundation specification.The calculated results show that the bearing capacity calculated by the two specifications is 18%~23% larger than the measured results.The base resistance obtained by standard method and load test method is about 0.4~0.65 times of the uniaxial compressive strength of the bearing rock.