土遗址加固中GFRP锚杆锚固性能现场试验研究

为揭示GFRP锚杆在土遗址加固中的性能，进而克服现有竹、木、复合锚杆锚固的局限性，拓展该新型材料在古遗址加固中的应用，选择直径22mm和25mm的GFRP锚杆开展了现场锚固测试试验。通过单级和循环两种加载模式，获取了两种杆体的破坏模式与极限锚固力； 在杆体砂浆界面布设应变片，获取了受荷过程中界面监测点剪应变的变化特征与分布规律。结果表明：两种锚固系统均失效于砂浆土体界面，22mm GFRP杆体极限锚固力50kN，而25mm GFRP杆体超过120kN； 从加载端到末端监测界面剪应变呈衰减分布，在较大荷载下由于加载方向与杆体轴向微弱偏离导致局部出现受压现象，试验过程中监测界面未出现脱黏现象。研究表明GFRP锚杆可以部分替代复合锚杆，在土遗址载体加固中具有良好的应用前景。

FIELD EXPERIMENTAL STUDY ON ANCHORAGE PERFROMANCE OF GFRP AT CONSERVATION EARTHEN SITES

This paper reveals the performance of GFRP bolt at earthen sites. It attempts to overcome the limit of bamboo, wood and composite bolt. Furthermore it expands its application on the conservation. GFRP bolts with the diameters of 22mm and 25mm are chosen to do field anchorage experiments. The failure mode and maximum anchorage force are gotten by single and cycle loadings. Meanwhile, the variation and distribution of interface shear strain during the loadings are obtained by adding strain gauges along the bolt-mortar interface. The result shows that mortar-soil interface is the failure interface in both anchorage system, and GFRP bolt with the diameter 22mm can gain the maximum anchoring force of 50kN while GFRP bolt with the diameter 25mm can gain more than 120kN.The interface shear strain attenuates from the loading point to the end of the bolt, with the appearance of compressive strain at some points. Debonding never happens along the interface. In conclusion, GFRP bolt owns huge prospect in conservation of the carriers of earthen sites by replacing composite bolt.