Hotels in the Pamporovo resort

The resort site is a case where averages are of no use. The geology is complicated by vertical karst features filled with soft plastic clay and by tectonised zones whose bearing capacity differs sharply from the surrounding rock.

Two cores ten metres apart can tell entirely different stories. The investigation was therefore concentrated where preliminary data showed anomalies, rather than following an even grid.

The result underlines what a properly conducted engineering-geological survey is worth: on ground like this it is the difference between safe foundations and deformations that appear years after the buildings are in use.