WAVE TESTS OF REVETMENT USING MACHINE-PRODUCED INTERLOCKING BLOCKS

Abstract

Continued demand for relatively low-cost shore protection, in bays, estuaries, and comparable bodies of water has resulted in accelerated investigation in this area. Further, there is a great demand for a system that can be constructed by the individual property owner without recourse to a contractor or special construction equipment. Work along these lines gained impetus through the successful installation of a light-weight concrete-block revetment in 1962. This paper reports on the further development of light-weight block revetments through tests in the Large Wave Tank at Coastal Engineering Research Center (CERC). Two types of blocks were tested on a 1 on 2 slope, one a machine-produced tongue-and-groove type weighing 75 pounds, and the other a hand-produced shiplap type weighing 150 pounds, the latter having twice the surface area of the former. In all, ten tests were made with wave heights ranging from 1.5 to 6.2 feet and wave periods ranging from 3.0 to 6.0 seconds. During the tests observations were made regarding the displacement of blocks and the vertical movement of the face of the slope when attacked by waves. Data derived from the tests have provided information which has resulted in the development of a machine-produced block which remained stable under the continuous attack of 4.7-second 4.8-foot breaking waves. Comparative tests showed that the machine-produced tongue-and-groove blocks have greater stability than the hand-produced shiplap type.