Volume and Strength of a Dolos

Precise formula for computing the block volume of dolos, a concrete armor stone for protection of breakwaters and marine structures, is presented with particular emphasis for a heavier dolos. A dolos is first treated as a solid concrete body falling by rotating under its own weight. An energy approach is followed and total external energy due to fall is compared with the total internal ultimate energy capacity of the dolos as a solid concrete body. A dolos is then treated as a solid concrete element of defined shape in a particular position and then hit by another dolos. Theories of failure of engineering mechanics are applied to determine maximum principal stresses and principal strains. These are then compared with concrete rupture stresses and strains. An attempt is made to indicate the usefulness or otherwise of steel fibers as reinforcing admixtures. Three different sizes of a dolos are compared and two mixes of concrete are considered.