充气锚杆循环荷载作用下的位移规律试验研究

Experimental Study on Displacement Law of Inflatable Anchor under Cyclic Loading

充气锚杆是一种新型扩大头锚杆,在软弱地基区域工程建设以及海洋资源的利用过程中,有其特殊的优势。笔者设计自制了充气锚杆实验槽,利用该实验槽开展了砂土中的充气锚杆循环荷载试验,揭示了砂土充气锚杆循环荷载作用下的位移变化规律。结果表明:(1)充气锚杆抗拔过程分为3个阶段:弹性位移阶段、弹塑性位移阶段和塑性位移阶段,前2个阶段,充气锚杆的塑性位移与荷载成指数函数关系;(2)随着循环荷载峰值的增加,充气锚杆在循环荷载下的位移发展速度增加,单次循环下的残余位移量与总残余位移量增加,最终的位移量也相应地增加。(3)极限抗拔承载力随着循环次数的增加而变小。

Inflatable anchor is a new type of expanding head bolt with special advantages in soft foundation area,construction and utilization of ocean resources in the process.This paper designed a home-made inflatable anchor experiment groove.The experiment is carried out by cyclic loading test of inflatable anchor in sandy soil to reveal the displacement law of the inflatable anchor in sandy soil under cyclic loading.Indoor model test is carried out to study the displacement law of inflatable anchor under cyclic loading in sandy soil.The results show that the uplift process of inflatable anchor bolt can be divided into three stages:elastic displacement,elastic-plastic displacement and plastic displacement.In the first and second stages,the plastic displacement of the pneumatic anchor bolt is exponentially related to the load.With the increase of cyclic load peak,inflatable anchor under cyclic load displacement speed increases,the residual displacement of single cycle and the total residual displacement increases,the displacement of the corresponding increase.The ultimate pullout capacity decreases with the increase of the number of cycles.