In order to form a shielded water area and keep out the wave in Dongying Port extension engineering, precast reinforced concrete wave boards were adopted in the rear platform.
东营港扩建工程为形成掩护水域和挡浪，后方承台采用预制钢筋混凝土挡浪板遮帘。
2
So, if ultrasonic wave is used to determine SIF, only the first one passing through the front (or rear) surface of the specimen can be used.