Paper contribution

Long-term performance of the rock-hewn structures in the Zelve Valley, Cappadocia, Türkiye

Nazlı Tunar Özcan; Reşat Ulusay; Ömer Aydan

Proceedings
EUROCK 2026
Pages
1217-1224
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

Mankind has built rock engineering structures in the Cappadocia region of Türkiye going back to at least 3000 years. However, the region experienced the excavation of many semi-underground settlements in deep valleys and underground cities in relatively flat areas. The Zelve Valley is one of the deep valleys where many semi-underground structures were excavated into soft rock. The semi-underground structures were excavated in tuffs formed during different sedimentation epochs and constructed about 1200-1500 years ago in the valley. The mechanical properties of the tuff are quite vulnerable to water content variation and exhibit time-dependent behaviour. The failures of the semi-underground structures have been increasing in recent years. Within the valley, a semi-underground structure was selected, and instruments were installed to monitor the displacement response of cracks, environmental parameters such as rock and air temperature, humidity and air pressure. In addition, the authors have already installed a multi-parameter monitoring station to monitor electrical potential variation, temperature and humidity and rain-fall in the valley since 2006. The authors also installed a triaxial accelerometer in one of the semi-underground structures first time in the world. Laboratory experiments were conducted to investigate the influence of water content on the mechanical properties of the surrounding rock. The authors present some of the recent outcomes of the integrated studies and discuss their implications in rock engineering and heritage conservation practices.

Contributors

Authors

  1. Nazlı Tunar Özcan Hacettepe Üniversity, Geological Engineering Department, Ankara, Turkiye ORCID 0000-0002-8629-4198
  2. Reşat Ulusay Hacettepe Üniversity, Geological Engineering Department, Ankara, Turkiye ORCID 0000-0003-1930-7611
  3. Ömer Aydan University of the Ryukyus, Department of Civil Engineering, Okinawa, Japan ORCID 0000-0002-7304-6486

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References

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