Why are through-joints not allowed in the wall when building a wall?

For traditional masonry, if there is a through seam (longitudinal), the longitudinal force structure performance of the wall is greatly reduced, the longitudinal resistance to shear force is greatly reduced, when encountered in earthquakes and other external forces, the wall is very easy to crack, collapse. The actual masonry project, the longitudinal seam there are data restrictions, longitudinal staggered gap is not less than a certain percentage of the length of the block itself, the specific value is measured by the percentage of the block. Traditional blocks composed of masonry structure for seismic, crack resistance, etc. itself does not have the advantage of not allowing through the seam is helpless, had to be implemented.