PROTOTYPE TESTING OF DOLOSSE TO DESTRUCTION

Abstract

The Dolos, a type of armor unit, has been used widely for breakwater and shore protection works in the world. However, it has been reported that the armor layers of several breakwaters have been damaged by wave action, and it is probable that the breakage of Dolos has been the cause of that failure. In this paper, static and dynamic tests using Dolosse units are described. 4t reinforced units and 4t, 0.4t and 0.04t unreinforced units were used. In these tests, concrete surface and reinforcing bar stress of Dolos, and impact load were measured. The results of these tests were as follows: (1) From the both tests i.e. the static load test and the drop test, stress was greatest in the corner between the chamfer and the stem. Cracks occurred at this point. (2) In the static load test, comparing the results of both units with reinforced and unreinforced chamfer, it became clear that the reinforcement of the chamfer could reduce the magnitude of the stress concentration. (3) In the drop test, the drop height which made cracks was almost constantly independent of the weights of the units. And it could be considered that there was little influence of increasing the concrete strength as to the breakage of Dolos.