Study of the interface friction between mesh and rock surface in drapery systems for rock fall hazard control

• A new test procedure to study mesh–rock interaction
• Mesh with a larger opening size and PVC coating produces greater friction.
• Interface friction and interlocking increase the mesh's resistance to sliding.

Although drapery systems are commonly used to control rock fall hazard on steep slopes, some elements of their design such as the interface friction between the mesh and ground surface are still difficult to quantify in practice. This technical note presents a new test procedure designed to study the mechanism of rock–mesh interaction in the laboratory. A series of tilt tests and tests with increasing loads were performed to study the effects that number and type of rock–mesh contacts, slope angle, and mesh characteristics had on mesh–rock interaction. The obtained data indicated that the process of interlocking between the mesh and rocks could increase the mesh's resistance to failure as well as decrease the force acting on the anchors during accumulation of rock debris or snow. Some changes to the current guidelines regarding the selection of interface friction angle are also suggested.