Question

An element constructed at intervals along the length of a wall to stabilize it against overturning is

Answer 1

Supporting pillars are erected at regular intervals, to prevent a length of wall from falling over.

These are usually sturdy, concrete pillars, with appropriate base, that are constructed to support the wall. It is normal practice to create a concrete belt at the base, for the wall, along with the pillars and then fill the wall space with bricks and cement.