水电能源科学

分布式光纤应变传感(DFOSS)技术为滑坡失稳的一种有效监测手段，光缆-土体变形协调性是该技术能否准确获取滑坡变形监测数据的关键，其中土体含水率对光缆-土体变形协调性的影响十分显著。因此，通过光缆-土体界面耦合特性试验仪，探究不同含水率下黄土土体试样中光缆-土界面的破坏机制。结果表明，光缆应变监测结果准确地反映出缆-土界面渐进性破坏特征，试验特征参量(拉拔力、应变、界面剪应力)随着拉拔位移的增大而增加至峰值后缓慢减小；应变软化模型能够较好地描述力-位移关系；采用考虑拉拔力的光缆-土体变形耦合系数K定量描述光缆-土体之间的耦合性能，当K=90%～100%、60%～90%、30%～60%、0～30%时，两者的耦合性分别为强、较强、较弱、弱。

Distributed optical fiber strain sensing(DOFSS) technology is an effective tool for monitoring landslide instability. The accuracy of DOFSS in capturing landslide deformation data largely depends on the deformation coordination between the fiber optic cable and the soil, with soil moisture content playing a critical role in this coordination. This study investigates the failure mechanisms at the cable-soil interface in loess soil samples with varying moisture content, using a specialized test apparatus for evaluating the coupling characteristics of the cable-soil interface. The results indicate that strain monitoring by the fiber optic cable accurately reflects the progressive failure features at the cable-soil interface. Test parameters, including pullout force, strain, and interface shear stress, increased with pullout displacement up to a peak and then gradually decreased. The strain-softening model effectively describes the force-displacement relationship. Additionally, a deformation coupling coefficient K was introduced to quantitatively evaluate the coupling performance between the cable and the soil, considering pullout force. Based on four K values of 90%～100%, 60%～90%, 30%～60%, and 0～30%, the coupling performance was classified into four levels: strong, moderately strong, moderate, and weak.