Consider a large shopping mall with a geometrically complex building structure. This complex is subdivided into small, geometrically compact, independent units using building separation joints. These joints are classified as volume change joints, settlement joints, and seismic separation joints. Volume change joints are placed at horizontal or vertical discontinuities in the building to relieve the effects of expansion and contraction of the building units. Generally, these joints are located at intervals of 150 to 200 feet. The tower and the adjoining low-rise wing of the building are separated using settlement joints designed to avoid distress due to different rates of settlements anticipated for the different types of foundation provided. Seismic separation joints are provided between building segments to allow individual units to move independently during an earthquake, preventing damage to one another. Lastly, the individual units existing on either side of the plane of the building separation joint can have their distinct foundations, columns, and slabs, making them independent structures that can move as a unit in response to the forces acting on them.