The 2016 Hans Cloos lecture: Geo-engineering aspects on the structural stability and protection of historical man-made rock structures: An overview of Cappadocia Region (Turkey) in the UNESCO’s World Heritage List

Abstract

Underground space has been used throughout history by humankind for the purposes of human accommodation, religious ceremony, defence, food storage etc. There are a number of man-made underground rock structures in different areas all over the world. Today the interest in utilisation of underground space continues. The Cappadocia Region of Turkey was included in the World Heritage List by UNESCO in 1985. In this area, there exist significant historical underground settlements such as rock cut dwellings, cities, churches, and semi-underground cliff settlements, and modern man-made, multi-use cavities. Easy carving and thermal insulation properties of the soft Cappadocian tuffs are the main reasons for the extensive multi-purpose underground use in the region from the past to the present. In addition, short- and long-term behaviours of these rock-hewn structures and the surrounding soft tuffs are also important data sources in terms of underground geo-engineering. This paper attempts to point out some issues including short- and long-term geo-engineering characteristics of the soft Cappadocian tuffs, in which historical underground openings have been carved, a critical overview on their geo-engineering aspects, particularly their stability and implications in geo-engineering based on some typical rock-hewn structures selected from the region, and possible measures of protection and mitigation.