基于PSB钢筋的高强度锚杆精细分区抗浮及受力分析

随着建筑物地下室的埋深增加、地下水位升高以及极端恶劣天气的影响，对抗浮锚杆的性能提出了更高的要求，传统抗浮锚杆的局限性日益明显。为了解决建筑物因不同区域结构自重和地下室底板埋深差异带来的抗浮难题，本文通过精细分区抗浮设计，采用精轧螺纹钢筋代替普通钢筋的高强度扩大头抗浮锚杆解决了抗浮问题，其单根抗浮锚杆的抗拔承载力为560 kN，在最大试验荷载840 kN作用下锚头最大位移仅为5.25~9.97 mm，平均值为7.91 mm，卸荷后回弹率为18.09%~46.26%，未出现破坏，展现了优越的性能。高强度扩大头抗浮锚杆存在3种类型的应力-应变模式，（压密）-预应力抵消-扩大头端压是抗浮锚杆的理想应力-应变模式，其在1120 kN荷载作用下仍能保持正常维持收敛，且抗拔承载力为560 kN时仅处于预应力抵消阶段，仍具有很大的承载潜力。

Detailed zoning anti-floating using PSB-based high strength anchors and their mechanical behaviors

With the increasing depth of building basement, rising groundwater level, and the influence of extreme weather conditions, higher requirements have been put forward for the performance of anti-floating anchors, and the limitations of traditional anti-floating anchors have become increasingly apparent. In order to address the anti-floating problem of the building with differences in structural self-weight and basement depth, we conducted detailed zoning anti-floating in different areas with high strength anchors using prestressing screw-thread steel bars instead of ordinary steel bars. The pullout capacity of a single high strength anchor can reach at 560 kN and the maximum displacement of the anchor head under a maximum test load of 840 kN is only 5.25~9.97 mm, with an average value of 7.91 mm. After unloading, the rebound rate is 18.09%~46.26%, and no damage occurred, demonstrating excellent performance. The underreamed high strength anti-floating anchor has three types of stress-strain patterns, of which (compression) - prestressing compensation - enlarged head end compression is the ideal stress-strain pattern for anti-floating anchors. It can still maintain normal convergence under a load of 1120 kN. When the pullout capacity is 560 kN, it is only in the prestressing compensation stage, which still has a great bearing potential.