PURPOSE: To prevent the intrusion of small gravels into the joint portion of slope frame blocks by a method in which the end faces of the slope frame blocks are butted vertically and bilaterally and slopes are formed on the lower end faces of the joint portion of the blocks.

CONSTITUTION: Slope frame blocks 1 having extended hexagonal joint portions on their angular both ends from a planar view are butted vertically and bilaterally. A pile 7 is driven into the space 6 formed by the butted end faces 2 of the blocks 1, and reinforcing bars 8 projected from the pile 7 are fixed with the reinforcing bars of the blocks 1, where the slope 4' formed on the lower end face of the joint portion 4 of the blocks 1 is flattened by trowels. Even when small gravels on the slope are agitated on the downside of the blocks 1, the small gravels are housed into the space 9 formed by the inclined faces, and the intrusion of small gravels into the joint portion 4 can be avoided.