Experimental investigation of parameters affecting the stability of articulated concrete block mattress under wave attack

Revetment is a protective structure for a shoreline with stony material, usually natural stone or concrete, with a thickness of only one layer of elements and of which the elements are placed in a pattern. Various conditions of designing and implementing coastal protection structures such as implementation speed and construction cost; cause the use of Articulated Concrete Block Mattress (ACB Mat). ACB mattresses have an appropriate flexibility that can be installed on different conditions of slope revetments. ACB mat system includes a filter layer that allows infiltration and exfiltration to occur while providing particle retention of the soil subgrade. To determine the extent of the effect of hydrodynamic, structural and non-structural factors as well as presenting dimensionless relations and design charts of ACB Mats, experimental data are needed which can be achieved by an appropriate laboratory scale model (λ=1:10). In the present study, the effect of various parameters was investigated to improve existing formula by adding effects of mattress length, construction slope, filter layer, ACB mat thickness and friction coefficient. Accordingly, new modified equation was obtained by adding parameters; stability shifting factor, stability course factor and stability shape factor which can be presented as “1.8 < a < 5.4”, “7 < b < 12” and “c ≈ 1” respectively. At the end, six design charts will be presented which can be helpful to determine minimum length of mattress for different wave's characteristics and construction's slope on two type of filter layer.