ABSTRACT
The paper presents the results of tests on a family of products for erosion control on river/channel banks: geomats reinforced with double twisted steel wire meshes or with polypropylene geogrids; and reinforced geomats combined with geocontainer mattresses. The allowable resistant shear stress and allowable water velocity have been evaluated by testing in a flume according to ASTM D6460. Two different experimental campaigns have been carried out, to evaluate the performance of products both in unvegetated and vegetated conditions, both at short and at long flow duration. The analysis of test results allowed to define the surface of allowable shear stress vs the elapsed time t (years) from installation and the duration of flow D (hours). The procedure for getting the design curves of allowable shear stress vs flow duration at different times t is illustrated. The obtained charts allow the design according to the principles set in ISO 18228-8.
