论文部分内容阅读
为分析基坑开挖过程中桩锚支护结构的锚杆受力机理,结合西宁火车站综合改造工程的深基坑支护结构,对不同工况条件下锚杆的受力进行现场综合动态试验与监测。结果表明:在未施加预应力阶段,随着基坑的开挖,锚杆的锚固作用逐渐发挥,锚杆轴力沿锚固长度呈现先增大后减小的变化趋势,而摩阻力的分布则存在“中性点”;对锚杆进行单循环加载时,锚头施加的荷载有所损失,锚杆轴力和摩阻力均沿锚固段长度逐渐减小;在施加预应力之后,锚杆轴力沿锚杆长度逐渐减小,随开挖深度的增加而逐渐增大,摩阻力沿锚固长度逐渐减小。所得结论可进一步完善锚杆的受力理论,为基坑支护的优化设计及施工提供参考性建议。
In order to analyze the mechanism of the bolt supporting the pile and anchor during the excavation of the foundation pit and to combine with the deep foundation pit supporting structure of comprehensive reconstruction project of Xining Railway Station, the force of the bolt under different working conditions is comprehensively synthesized Test and monitoring. The results show that with the excavation of the foundation pit, the anchoring effect of anchors gradually develops in the stage of no prestressing, and the axial force of anchors first increases and then decreases along the anchorage length, while the distribution of frictional resistance There is a “neutral point”; when the anchor rod is subjected to single-cycle loading, the load applied by the anchor head is lost, and the axial force and the frictional resistance of the anchor rod both decrease along the length of the anchor section; after the prestressing, the anchor The axial force decreases along the length of the anchor rod, increases with the excavation depth, and the frictional resistance decreases along the anchorage length. The conclusion can further improve the stress theory of anchor rod and provide reference for the optimal design and construction of foundation pit support.