Geosynthetics in roads and pavements

HARD ARMOR SYSTEMS 

 

Introduction to the Problem 

Soil banks or slopes exposed to constant 

concentrated flows, currents, or waves cannot 

support vegetation so they must be protected 

from erosion by hard armor systems. Hard 

armor systems include fabric formed 

revetments, geocellular confinement systems, 

gabions, articulating concrete blocks, and, of 

course, riprap. 

 

When a hard armor system is in place, water can 

seep in and out of the bank or slope, but the 

force of the water is resisted by the armor. As 

the water seeps, it can gradually carry soil 

particles with it. The resulting voids cause 

armor support to be lost over time. This process 

is called 

piping

. Piping can culminate in 

shifting, rolling, or other instability in the hard 

armor system.