GFRP筋及钢筋抗浮锚杆承载特性现场试验及荷载-位移模型

玻璃纤维增强聚合物(Glass fiber reinforced polymer，GFRP)锚杆是从非金属锚杆中发展出的新型复合材料锚杆，具有自重轻、抗拉强度高、造价低、抗腐蚀性能好、抗电磁干扰能力强等优点。基于某中风化花岗岩场地的GFRP筋及钢筋抗浮锚杆的破坏性拉拔试验，对抗浮锚杆在拉拔过程中锚杆杆体及锚固体的位移进行测量，分析了不同材质、不同锚固长度的抗浮锚杆的承载性能及杆体、锚固体相对滑移量的差异，对比不同荷载-位移模型并获得了最适宜岩石抗浮锚杆的荷载-位移模型。试验结果表明:在中风化花岗岩中，相同锚固长度下的GFRP抗浮锚杆比钢筋抗浮锚杆的破坏荷载增加13%~14%，GFRP抗浮锚杆更易发生杆体拔出破坏，锚固系统仍有残余承载力未发挥，使用GFRP锚杆代替钢筋锚杆具有可行性；与锚固长度为4.5 m的GFRP抗浮锚杆相比，锚固长度为6.5 m的锚杆杆体相对于锚固体的滑移量更大，增大GFRP抗浮锚杆的锚固长度可有效增加其相对滑移量，但提升钢筋抗浮锚杆的锚固长度对其破坏形态无明显影响；双曲线函数及幂函数荷载-位移曲线模型与实测值吻合度较差，指-幂函数曲线模型对本次试验锚杆的破坏荷载预测精度最高，曲线整体走势较一致。 

Field tests and load-displacement models of GFRP bars and steel bars for anti-floating anchors

Glass fiber reinforced polymer (GFRP) anchor is a new type of composite anchor developed from non-metallic anchors. It has the advantages of light weight, high tensile strength, low cost, good corrosion resistance and strong electromagnetic interference resistance. Based on the destructive pull test of GFRP anchors and reinforced anti-floating anchor conducted on a medium-weathered granite site, the displacement of the anchor body and anchor solid during the drawing process of the anti-floating anchor was measured. The bearing capacity of anti-floating anchors with different materials and different anchoring lengths and the relative slip between anchor body and anchor were analyzed. The different load-displacement models were compared and the most suitable load-displacement model for rock anti-floating anchors was sought. The test results show that: In medium-weathered granite, the GFRP anti-floating anchors at the same anchoring length increase the failure load by 13% to 14% compared with the reinforced anti-floating anchors. GFRP anti-floating anchors are more prone to pull-out and failure of the anchor body, and the residual bearing capacity of the anchoring system is still not exerted. It is feasible to use GFRP anchors instead of steel anchors. Compared with the GFRP anti-floating anchor with an anchoring length of 4.5 m, the anchor body with an anchoring length of 6.5 m has a greater slippage relative to the anchor solid. Increasing the anchoring length of the GFRP anti-floating anchor can effectively increase its relative slip, and increasing the anchoring length has no obvious effect on the failure mode of the reinforced anti-floating anchor. The hyperbolic function and power function load-displacement curve models are in poor agreement with the measured values, while the finger-power function curve model has the highest accuracy in predicting the failure load of the anchors in this test, and the overall trend of the curve is more consistent.