Heave/settlement points are used to monitor settlement in the ground beneath surcharges or embankments. They are also used to monitor heave (uplift) resulting from excavation or grouting. The Borros-type anchor is suitable for soft clays. It is difficult to extend the prongs of the anchor in other types of soil, such as stiff, over-consolidated clays, shales, dense sand, or sand and gravel.
A heave/settlement point consists of a three-pronged anchor, an inner pipe and an outer pipe, both steel. The inner pipe is attached to the anchor and is free to move inside the outer pipe. An optical survey is used to determine the elevation of the top of the inner pipe. Changes in its elevation indicate an equivalent amount of settlement or heave at the anchor.