全长黏结GFRP抗浮锚杆荷载分布函数模型研究

Load distribution function model of full-length bond GFRP antifloating anchor

基于荷载传递法理论与Kelvin问题的位移解,进一步推导全长黏结GFRP(glass fiber reinforced plastics)抗浮锚杆在轴向拉拔荷载作用下轴力沿锚固深度的分布函数。为验证该理论应用于GFRP抗浮锚杆的合理性,借助植入式光纤光栅传感技术,对2根同型号GFRP抗浮锚杆进行现场拉拔破坏性试验。研究结果表明:根据荷载传递法与Kelvin位移解得到锚杆轴力与剪应力分布函数曲线形式与试验结果相近,说明该理论合理;孔口锚固体的开裂导致锚杆轴力及剪应力分布曲线试验值主要分布范围比理论值的更大;由于试验过程中岩土体位移较小,锚杆的剪应力分布曲线形式较理论值呈现"矮胖"的特点。此外,对锚杆轴力、剪应力理论分布函数曲线进行修正后的结果与试验结果吻合度显著提高。

Based on the load-transfer method and Kelvin’s displacement solution, the distribution function for the axial force of full-length grouted anchor under the pullout load was deduced. In order to prove the rationality that the present theory applies to the GFRP(glass fiber reinforced plastics) anti-floating anchor, an in-site pullout test was conducted with embedded bare fiber sensing technology, for the two same type GFRP anti-floating anchors.The results show that the curve form of the anchor axial force and shear stress, on the basis of the load-transfer method and Kelvin’s displacement solution, is similar to the test results, which indicates the rationality of the theory mentioned above. Due to the concrete cracking near the anchor hole port, the main distribution range for the experimental curve of the axial force and shear stress is deeper than that of the theoretical value. Because of a smaller displacement of the rock-soil body during the test process, the form for the distribution curve of the shear stress presents a "short and fat" property, compared with the curve form of the theoretical value. Additionally, the test-theory conformity is improved obviously after corrected the theoretical distribution curve of the axial force and shear stress.