In recent years, the use of anisotropic materials such as CLT has been increasing, but there is no slab design formula when anisotropic materials are used. Therefore, in this paper, we propose a design formula for orthogonal anisotropy slabs. When the boundary condition of the slab is fixed all around, the formula obtained from the cross-beam theory is used in the normal RC slab, but this formula calculates a value smaller than the FEM solution. In this paper, in order to maintain continuity with this standard formula, a design formula for orthogonal anisotropic slabswith safety similar to this formula is proposed. The proposed formula is expressed by multiplying the formula obtained from the cross-beam theory by a correction function, and shows that the error is within about 10%.
