根键桩抗拔承载特性分析及变形预测

根键桩现场足尺试验表明,根键的植入不仅使基础承载力大幅提高,根键阻力的稳定发挥还能有效抑制桩体位移.但由于试验条件所限,并未对根键桩多种根键组合模式下极限承载力进行量测,仅凭现有成果无法系统预测根键桩荷载位移发展规律.故采用ABAQUS软件对足尺试验进行模拟分析,通过对比不同根键密度、位置下的Q-S曲线,确定不同根键组合对承载力的影响规律以及根键承载特性的变化情况,进而基于荷载传递理论提出考虑根键密度以及间距影响的根键桩非线性变形计算方法,结果表明理论计算与实测及模拟结果具有较高吻合度,能够正确反映不同根键组合模式下基础的变形规律.

Analysis of uplift bearing characteristics and deformation prediction of root pile

The full-scale field test of root pile shows that implantation of roots not only greatly improves the bearing capacity of foundation, but also effectively restrains the displacement of pile attributed to the stable exertion of root resistance. However, due to the limitation of test conditions, the ultimate bearing capacity of root piles has not been measured under various combination modes, and the existing results alone can not systematically predict the ultimate bearing capacity of root piles. Therefore, ABAQUS software is used to simulate and analyze the full-scale test mentioned. By comparing Q-S curves under different root densities and locations, the influence rule of different root combinations on the bearing capacity and the change of the bearing characteristics of the roots are determined. Based on the load transfer theory, a nonlinear deformation calculation method of the root pile considering the influence of the root bond density and the spacing is proposed. The results show that the theoretical prediction highly agrees with the simulation results, which correctly reflect the deformation law of the foundation under different root bond combination modes.