| 摘要 |
PROBLEM TO BE SOLVED: To provide a parallel cross frame that can easily make a concrete block with a frame in situ, and executes a bed protection construction method while making the concrete block with the frame.SOLUTION: A bed protection construction method comprises the following step: a step of damming a flowing water and exposing the ground at the bottom of the flowing water; a step of laying water-permeable cloth on the exposed ground; a step of installing a parallel cross frame having square timbers 1 assembled stepwise on the water-permeable cloth in parallel crosses, and formed by fitting weir plates 2 between upper and lower square timbers 1, 1 forming each side of the parallel crosses; a step of making a concrete block with a frame by pouring ready-mixed concrete into the parallel cross frame and hardening it; and a step of releasing the damming of the flowing water and returning the flowing water on the surface of the ready-mixed concrete of the concrete block with the frame. Also, the parallel cross frame with upholstered back side formed by providing the water-permeable cloth 4 in a tensioned condition at the lowest stage of the parallel cross frame may be used as the parallel cross frame. |
