水平荷载对支盘桩抗拔承载力的影响分析

Analysis on Influence of Horizontal Loads on Uplift Bearing Capacity of Piles

采用数值模拟方法深入研究了水平荷载对支盘桩抗拔承载力的影响,补充了现有仅对单荷载条件下支盘桩承载性状的研究分析。通过对支盘桩在上拔荷载、水平+上拔荷载作用下的桩顶位移、荷载传递特征、抗拔承载力等方面进行对比分析,得出水平荷载对支盘桩抗拔承载力的影响规律。研究表明:水平荷载的存在使支盘桩的桩顶上拔位移有所增大,使桩周土体提前达到承载极限,直桩段的摩阻力值有所减小;同时使桩身轴力曲线的台阶状特征提前显现,支盘的承载效率和承载量有所提高。水平荷载的存在虽然总体上对支盘桩的极限抗拔承载力影响不大,但却较大幅度的改变了支盘桩的荷载承担机理,对支盘桩在复合荷载作用下的实际应用有一定参考价值。

Numerical simulation method was used to deeply study the influence of horizontal load on the bearing capacity of the anti-pull bearing capacity of the branch pile,with the supplementing the existing research and analysis of the bearing behavior of the branch piles under single load conditions.Through comparison and analysis of the pile top displacement,load transfer characteristics,and pull-out bearing capacity under the action of uplift load and horizontal + uplift load,the effect of horizontal load on the anti-pull bearing capacity of the branch pile was obtained.The study shows that the existence of the horizontal load increases the uplifting displacement of the pile top of the branch pile,so that the soil around the pile reaches the bearing limit in advance,and the friction resistance value of the straight pile decreases;at the same time,the step-like characteristics of the axial force curve of the pile body are displayed in advance,and the bearing efficiency and bearing capacity of the support plate are improved.Although the existence of the horizontal load has little effect on the ultimate pull-out bearing capacity of the branch piles,it greatly changes the load bearing mechanism of the branch piles,which has certain reference value for the practical application of the branch pile under the composite load.