The structure transfers vertical loads from the top to the bottom of the structure using several different aspects. The primary way that the Burj al-Arab transfers the vertical loading is through the large spine. This is the most direct way for the vertical loads to reach the ground. Another way that the vertical loads transfer to the ground is through the curved edge where the concrete superstructure is located beneath the membrane (see Vertical Load Transfer 2 for steel structure beneath membrane). The third way, which also helps deflect horizontal loads, is the steel trusses running alongside the structure. Once the load reaches the sand of the artificial island, the vertical load goes down the foundation walls of the basement (see Vertical Load Transfer 3, white arrows) down to the piles underneath the structure and down the piles (black arrows). The piles provide an upward frictional force (red arrows) to help keep the structure standing.