Abstract: As a kind of vertical anchoring technique, the anti-float anchor has been widely used in China, whose performance has begun to receive more attentions from researchers. However, steels may be eroded easily by groundwater or chemical solutions, which will cause the reductions of mechanical strength and service life, especially in subway engineering the steel anti-float anchor is forbidden. Glass fiber reinforced polymer (GFRP) anti-float anchor is a new kind of material which is composed of resin matrix and glass fiber. Compared with steel anchor, the GFRP anti-float anchor has higher strength, corrosion-resistance and light weight behavior. The field tests show the feasibility of GFRP anti-float anchor through embedded bare fiber optics sensor technique. According to the test results, the GFRP anti-float anchor stress-strain behaviors, load transfer mechanism and failure mechanism are considered. The test indicates that GFRP anti-float anchor is basically about shear failure and pullout capacity of anchors with ? 28 mm are 250 kN, which can be satisfied with engineering demands. The axial forces of anchors fall gradually with depth, and it will not bear load beyond certain length. Results show that the effect distance of axial forces is about 3.7 m when the length of bond part is in range of 3.95~6.95 m in moderately weathered granite，which indicates that GFRP anti-float anchors also exist critical anchorage depth. The shear stress on interface of anchor is not evenly distributed, which peak value is being driven down, and so as to the zero value. The research results can provide evidence for application of GFRP anti-float anchor.

Key words: non-metal, glass fiber reinforced polymer, anti-float anchor, bare fiber, shear failure