桩靴抗拔承载特性模型试验及理论研究

Model test and theoretical research on uplifting bearing characteristics of spudcan

为了研究桩靴抗拔承载特性,通过自行设计桩靴抗拔模型试验装置,测量桩顶向上位移量和桩身不同截面处的应变,研究了桩靴的抗拔承载特性和荷载在桩身的传递规律.以及对桩靴上拔过程中的弹性变形进行理论分析,并与模型试验结果进行对比.结果表明:在上拔荷载作用下,桩靴的轴力沿着桩身先递减,最后在桩端处仍有部分轴力;随着上拔荷载的逐渐增加,桩靴在桩端处的阻力缓慢增加,当上拔荷载达到一定阈值后,突变为指数增长;弹性理论分析方法预测的桩体上拔位移可适用于上拔荷载较小的情况.

In order to study the uplifting bearing characteristics of spudcan,the uplifting model test device for spudcan was designed.By measuring the upward displacement of the pile and the strain at different sections of the pile,the uplift bearing characteristics and the load on the pile were studied.The theoretic analysis of the elastic deformation in the process of pulling up the pile shoe was carried out,and it was compared with the results of the model test of the pull-up resistance of the spudcan.The results show that:under the action of uplifting load,the axial force of the spudcan decreases first along the pile and remains even at the end of the pile.With the gradual increase of the pull-up load,the resistance of the spudcan increases slowly at first,while turns to increase exponentially when approaching a certain threshold.The uplift displacement of the pile can be predicted by the elastic theory analysis method when the uplift load is small.