光纤光栅传感技术在GFRP抗浮锚杆现场拉拔试验中的应用

光纤测试技术是将光纤布拉格光栅（FBG）传感器用光纤连成一串，通过构建多点光栅测试系统实现传感，它具有精度高、抗干扰能力强、空间分辨率高和连续数据采集等特点。将光纤光栅传感技术应用到原型玻璃纤维增强复合材料（GFRP）抗浮锚杆受力测试中，同步测试了锚杆杆体-锚固体界面、锚固体-周围岩土体界面以及锚固体内的应变，实现GFRP抗浮锚杆多界面全长受力测试。测试结果表明，光纤光栅传感技术能准确记录拉拔过程中GFRP抗浮锚杆各界面的应变变化，揭示锚杆杆体-锚固体界面、锚固体内、锚固体-周围岩土体界面的轴向应力和剪应力分别随荷载水平和锚固深度变化的分布规律，但不同界面处荷载的传递深度和剪应力沿深度的影响范围有所差异。该测试技术和传感器埋设工艺有众多优势，在岩土工程科学研究与工程应用领域具有广阔的前景。

Application of fiber grating sensing technology in pull-out test on glass fiber reinforced polymer anti-floating anchor

The optical fiber testing technology is stringing the fiber Bragg grating (FBG) by naked fibers in order to construct the multi-point sensing testing system, which has the advantages such as higher precision, stronger anti-interference ability, higher spatial resolution and continuous data acquisition. In this paper, the fiber grating sensing technology was applied to monitor the glass fiber reinforced polymer (GFRP) anti-floating anchor, and the strains at the interfaces of anchor-anchorage body, anchorage body- surrounding rock, and within anchorage body were measured, achieving the multi-interfacial and full-length measurement of GFRP anti-floating anchor. The results showed that the fiber grating sensing technology was able to accurately record the strain change of GFRP anti-floating anchor in the entire duration of the pull-out test. Additionally, the results revealed the distribution law of axial force and shear stress within the anchorage body and at the interfaces of anchor-anchorage body, anchorage body-surrounding rock with the change of applied load and depth. The transfer depth of the load and the influenced range of the shear stress were different at different interfaces. Generally, the measurement technology and sensor embedding method have many advantages, showing broad prospects in geotechnical engineering research and applications.