What steps should I take to place a wall on top of a berm?
When placing a wall on top of a berm, you must have the same number of segments, going in the same direction with the exact x-y coordinates, or TNM will output an error message and stop sound level calculations. The Z-bottom of the wall barrier must equal to the Z-bottom of the berm plus the berm Height at each point. When a wall is placed on the berm, the berm cannot be perturbed. Also, when putting walls on top of berms, type in coordinates (do not use snap tool). To include the berm of the berm/wall combination in the “no barrier” case (i.e., the berm is not part of the abatement feature), set all of its perturbation parameters (increments, up and down) to zero, making it a fixed-height barrier. If the berm of the berm/wall combination is going to be part of the abatement, leave the up and down perturbations at zero (making it a single-height barrier), but include a non-zero number in the increment box; the berm’s noise reduction will not be included in the “no barrier” results. How
