路基填土挤扩锚杆现场试验研究

Field Text Study on Squeeze⁃expansion Anchor Rods for Subgrade Filling

以汕湛(汕头—湛江)高速公路揭博(揭西—博罗)段的水毁边坡应急抢险工程为依托,开展了路基填土挤扩锚杆现场试验,对比研究了普通锚杆、单盘挤扩锚杆和双盘挤扩锚杆结构力学特性。结果表明:普通锚杆其锚固段前3 m(自锚杆自由段与锚固段接触点起向锚固段延伸至3 m)承受的拉力占比为33.35%;单盘锚杆锚固段前3 m承受的拉力占比为56.65%,双盘锚杆锚固段前3 m承受的拉力占比为61.50‰;单盘锚杆实测极限抗拔承载力为普通锚杆的1.89倍,双盘锚杆为普通锚杆1.73倍;单盘锚杆、双盘锚杆与普通锚杆相比塑性位移占比较低,变形控制效果良好;单盘挤扩锚杆和双盘挤扩锚杆具有良好的工作特性,适合于承受较高荷载的工程应用。

Based on the emergency rescue project of the water damaged slope in the Jiexi-Boluo section of the Shantou-Zhanjiang Expressway,field tests were conducted on the subgrade filling and squeeze-expansion anchor rods.The mechanical characteristics of ordinary anchor rods,single-plate squeeze-expansion anchor rods,and double-plate squeeze-expansion anchor rods were compared and studied.The research results show that the proportion of tensile force borne by ordinary anchor rods in the first 3 m of the anchorage section(from the end point of the free section of the anchor rod to the anchorage section to 3 m)is 33.35%.The proportion of tensile force borne by the first 3 m of the single-plate anchor rod anchorage section is 56.65%,while the proportion of tensile force borne by the first 3 m of the double-plate anchor rod anchorage section is 61.5‰.The measured ultimate pull-out bearing capacity of single-plate anchor rod is 1.89 times that of ordinary anchor rod,and the measured ultimate pull-out bearing capacity of double-plate anchor rod is 1.73 times that of ordinary anchor rod.Compared with ordinary anchor rods,single-plate anchor rods and double-plate anchor rods have a lower proportion of plastic displacement and good deformation control.Single-plate anchor rods and double-plate anchor rods have good working characteristics and are suitable for engineering applications that can withstand high loads.