DX桩抗拔承载力机理的现场试验研究

通过大比例尺的现场模型DX桩静荷载试验 ,对DX桩的抗拔性能和荷载传递机理进行了研究。结果表明 ,DX桩的抗拔承载力明显大于同等条件下的等截面桩 ,且DX桩的荷载 -上拔位移关系呈缓变形 ;DX桩的承力盘发挥的端承阻力在总抗拔承载力中占有较大比例 ;由于DX桩承力盘发挥了挤压效应 ,DX桩桩身的平均单位抗拔侧阻力值也明显大于等截面桩。对等截面抗压桩、等截面抗拔桩和DX抗拔桩的侧阻力进行了比较 ,对承压和上拔两种加载方式下的侧阻力差异进行了分析

FIELD FULL-SCALE TEST STUDY ON TENSION BEARING MECHANISM OF DX PILES CAST-IN-SITU

Based on a series of loading tests of full-scale model DX piles cast-in-situ, the bearing behaviour and load-transferring mechanism of tension DX piles are studied. The results show that the tension bearing capacity of DX pile is apparently higher than that of the pile with constant section, and the curve of load-displacement of DX pile is slowly varying. The enlarged disks bear the most of all tension bearing capacity. It is found that the unit frictional resistances of DX pile is also higher than that of the pile with constant section because of squeezed efficiency of disk. Then, the lateral resistance of tension DX pile, tension pile and compression pile with constant sections are compared. The difference of lateral resistance under tensile and compressive loadings is also analyzed.