Accurate deformation monitoring of geotechnical infrastructures using distributed fiber optic sensing requires a strong interfacial bond between strain sensing cables and surrounding soil. Micro-anchors provide a straightforward solution to enhance the interlocking effect at the cable–soil interface, but their anchorage mechanism remains unclear. This paper presents an experimental study on the interfacial behavior of anchored strain sensing cables embedded in soil. A series of pullout tests were conducted to investigate the effect of various factors on interfacial performance, including anchor spacing, anchor diameter, and confining pressure. The test results indicate that the anchor spacing and confining pressure substantially influenced the pullout resistance of anchored cables, while the anchor diameter had a minor effect. In contrast with unanchored cables, anchored cables exhibited strain hardening behavior during the pullout process instead of strain softening. The micro-anchors on cables played a reinforcing role sequentially with increasing pullout displacements, and those closer to the cable head exerted reinforcing effect earlier. Due to the pullout resistance of micro-anchors, the anchored cables have unique step-like strain profiles throughout the pullout tests, and they are not prone to interface decoupling under large deformation conditions. However, for closely spaced micro-anchors, the overlapping of interfacial shear zones led to a loss in the pullout resistance, which becomes insignificant with increasing anchor spacing. This study not only provides improved insight into the interpretation of fiber optic strain measurements but also sheds light on soil–inclusion interaction mechanisms in geotechnical analyses.

使用分布式光纤传感对岩土基础设施进行精确变形监测需要应变传感电缆与周围土壤之间具有牢固的界面结合。微锚提供了一种简单的解决方案来增强索土界面的联锁效果，但其锚固机制仍不清楚。本文对嵌入土壤中的锚定应变传感电缆的界面行为进行了实验研究。进行了一系列拉拔试验，以研究各种因素对界面性能的影响，包括锚杆间距、锚杆直径和围压。试验结果表明，锚杆间距和围压对锚索抗拔力影响较大，锚杆直径影响较小。与无锚索相比，锚索在拉拔过程中表现出应变硬化行为，而不是应变软化。随着拉拔位移的增加，索上的微锚逐渐发挥加固作用，距离索头较近的微锚更早发挥加固作用。由于微锚的抗拉力，锚索在整个拉拔试验中具有独特的阶梯状应变分布，并且在大变形条件下不易发生界面解耦。然而，对于间距紧密的微锚，界面剪切区的重叠导致拉拔阻力的损失，随着锚间距的增加，拉拔阻力变得微不足道。