土工袋扩底抗浮锚杆承载机理现场试验分析

Field Tests on Uplift Capacity of Anti-Floating Anchor with Enlarged End from Post-Grouting in Soil Bag

为充分发挥锚杆的抗拔承载性能,提升软土地区锚杆的抗浮潜能,提出了一种具有扩底截面的小型抗浮锚杆,其中扩底截面通过向预留土工袋内二次注浆挤土实现。同时,引入光纤光栅测试技术,对该装置的抗拔承载性状进行了现场测试,得到了扩底抗浮锚杆的轴向应力和剪应力随荷载水平和锚固深度的变化规律。试验结果表明,土工袋扩底抗浮锚杆在软土地区中的承载性能显著优于普通抗浮锚杆,扩底截面的端阻力可承担上拔荷载的近40%。

This research presented a new type of anti-floating anchor with an enlarged end owing to the post grouting into the soil bag placed in the end of the anchor.This paper introduced the features of this anchor and the corresponding construction method.Then,a full-scale test had been carried out to obtain the uplift capacity and mechanical characteristics of the anchor with the aid of the fiber sensor.The distribution of the axial force and the shear resistance along the shaft under various loadings had been summarized in this paper.The testing results showed that the uplift bearing capacity of this anchor was significantly promoted by the enlarged end which could bear up to 40%of total uplift capacity more than the anchor without the enlarged end.