考虑锚固体不均匀及杆体脱黏效应的GFRP抗浮锚杆杆体荷载分布函数

基于荷载传递理论及Kelvin位移解,推导得出理想条件下GFRP抗浮锚杆杆体与锚固体的剪应力、轴力沿锚固深度的分布函数,并通过对2根同型号GFRP抗浮锚杆的拉拔试验进行验证。试验结果表明:试验锚杆杆体轴力及剪应力分布曲线与理论值形式相似,证明提出理论方法应用于求解GFRP锚杆杆体荷载分布函数的可行性。但由于锚固体成型后的不均匀性及杆体的脱黏效应,导致试验剪应力值低于理论值且实际曲线主要分布范围较深,同时造成轴力下降较慢,消失深度较深的现象。通过固定脱黏长度下的平均剪应力衰减法及下移弹性段起点的方法对理想条件下的杆体剪应力分布函数进行修正,并利用杆体轴力分布与剪应力分布之间的函数关系,对理想条件下的轴力分布函数进行修正,修正后剪应力及轴力分布曲线精度大大提高。

Load distribution function of GFRP anti-floating anchors considering the anchorage body unevenness and the anchor debonding effect

On the basis of the load-transfer theory and Kelvin displacement solution,distribution functions of the axial force and shear stress of the GFRP anti-floating anchor rod body along the bolting depth under ideal conditions were deduced and verified through a pullout test for 2 GFRP anti-floating anchors with the same type. The test results show that the distribution curves of the axial force and shear stress are similar to the theoretical curves,which proves the practicability of the developed theory in solving the load-distribution function of the GFRP anchor rod body. Due to the unevenness of the anchorage body and debonding effect of the anchor,however,the test shear stress value is lower than the theoretical value and the main distribution range of the test shear stress is deeper. At the same time,the unevenness of the anchorage body and debonding effect of the anchor contribute to the phenomenon that the axial force decreases slowly and its disappearance depth is larger than the theoretical value. The theoretical distribution function of the shear stress was corrected by using the average shear stress attenuation method under the fixed debonding length and the method of moving down the elastic section,and the distribution function of the shear force was also amended through the functional relationship between the axial force and shear stress distributions. It is shown that the accuracy of the revised load-distribution curves is enhanced obviously.