The Evaluation of Bed Protection as Placing Methods of Mortar

This study was to compare the protection abilities of an SPF through ground or underwater casting. A mat of 1/10 scale was made and then mortar was placed on the ground and submerged conditions. A limit velocity of each mat was estimated with this experiment. As a result of the test, the mat failed because of the decrease of bearing power in the center of the waterway. On the one hand, the edge of the mat, where the velocity is slow, secures stability. The result of the limit velocity analysis suggests that a velocity of ground placement with 6.51m/s and underwater casting with 9.80m/s is the minimum to ensure stability. When SPF mat with a thickness of 0.50m is replaced with a concrete block, it is calculated to need a maximum thickness of 2.21m. Key Words : Ground casting, Limit velocity, Scour protection, SPF, Underwater casting, (12 C02) . * Corresponding Author : Chang-Sung Kim(KICT)Tel: +82-54-843-1815 email: csckim@kict.re.krReceived December 19, 2013 Revised January 24, 2014 Accepted February 5, 2014