Figure 2
From: Microanchored borehole fiber optics allows strain profiling of the shallow subsurface

Interaction between soil and microanchored fiber-optic cable, illustrated with an example of disc-shaped microanchors. (a) Resistive force components for cable pulled out from soil. (b) Modified punching shear failure mechanism of microanchor (after ref29). (c) Force diagram of a single microanchor.