Latest revision as of 14:49, 30 November 2021

Abstract

This paper highlights the main objectives and some of the results of an extensive structural health monitoring (SHM) project begun in Khiva, Uzbekistan. The research team consists of experts from the University of California, Berkeley (Berkeley, USA) and Urgench State University (Urgench, Uzbekistan). According to archaeological data, the city of Khiva was established approximately 1500 years ago. The project started from Itchan Kala, the walled inner town of the city of Khiva. This paper describes results obtained for the Juma Mosque located inside of Itchan Kala. A continuous SHM became essential to ensure its preservation for humanity because a few structural anomalies were reported in the past. The ongoing project consists of three major phases. First, a terrestrial laser scanning (TLS) was deployed to capture and monitor anomalies of the monument’s geometry in 3D. A laser scanner was used, and the monument’s geometry was captured as a collection of points, which is called a “point cloud”. Second, there is a plan to monitor the monument by in-situ measurements conducted by accelerometers, position transducers and thermocouples in the next phase. The high-sensitivity accelerometers will be used to study the resonant frequencies due to the ambient vibrations. The position transducers and thermocouples will be used for measuring the thermal expansion and retraction of the monument’s minaret. They will also be used for monitoring the crack openings. Third, a finite-element (FE) model based on the as-found geometry of the point cloud will be generated. Its calibration will be based on the collected data to ensure acceptable correlations with the results of the conventional measurements. The FE model will be used for future restoration efforts to evaluate the performance and efficiency (if any) of the proposed restoration measures. This paper focuses on the results obtained for the Juma Mosque’s minaret. It discusses the major findings of the laser scanning project and estimates the minaret’s residual inclination and its taper. The paper shows that the minaret can be approximated by a truncated cone. A preliminary FE model of the minaret was developed, which will be updated based on the results of the upcoming ambient vibration study.

Full document

References

[1] Mankovskaya, L., Bulatova, V. Monuments of the architecture of Khorezm. Uzbekistan: Gafur Gulyam Publishing House. 162 p. 1978 (in Russian).

[2] Durdieva, G., Davletov, B. Results of Technical Condition’s Monitoring Conducted in Itchan Kala: Juma Mosque. 2008 (in Uzbek).

[3] Abdurashidov, K., Kabulov, F., Rakhmanov, B. Engineering Problems of Architectural Monuments. "Fan" publishing house of Academy of Sciences of Republic of Uzbekistan, Tashkent, 2011 (in Russian).

[4] Leica Geosystems AG (2011). Leica ScanStation C10. https://w3.leica geosystems.com/downloads123/hds/hds/ScanStation%20C10/brochuresdatasheet/Leica_ScanStation_C10_DS_en.pdf.

[5] Leica Geosystems (2018). Cyclone Version 9.2.1.

[6] MathWorks (2016). Matlab Version R2016b.

[7] Takhirov, S., Rakhmonov, B., Nafasov, R., Samandarov, A., Sultanova, S., Musurmanov, J. and Takhirov, B. Structural Health Monitoring of Juma Mosque in Itchan Kala, Uzbekistan by Laser Scanning. Submitted for publication in proceedings of the 10th International Conference on Structural Health Monitoring of Intelligent Infrastructure. 30 June - 2 July, 2021, Porto, Portugal.

[8] Takhirov, S., Mosalam, K., Moustafa, M., Myagkova, L., and Quigley, B. (2015). LASER SCANNING, MODELING, AND ANALYSIS FOR DAMAGE ASSESSMENT AND RESTORATION OF HISTORICAL STRUCTURES. COMPDYN 2015. 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering. M. Papadrakakis, V. Papadopoulos, V. Plevris (eds.). Crete Island, Greece, 25–27 May 2015.

[9] Takhirov, S., Gilani, A., Quigley, B., and Myagkova, L. (2018). Structural Health Monitoring and Assessment of Seismic Vulnerability of Historic Monuments on the Great Silk Road Based on Laser Scanning. The International Conference on Structural Analysis of Historical Constructions (SAHC 2018). 2254-2263. September 11-13, 2018, Cusco, Perú.

[10] Rakhmanov, B. Engineering analysis of the design features of the Islom Khoja minaret. A paper in preparation for publication.

[11] Computers and Structures, Inc. (CSI), 2014. SAP2000. Ultimate Version 16.1.1. Structural Analysis Program.

[12] Sayari Arash. MECHANICAL PROPERTIES OF MASONRY SAMPLES FOR THEORETICAL MODELING. 15th International Brick and Block Masonry Conference Florianópolis , Brazil, 2012.

[13] Dogangun, A, Acar, R, Sezen, H, Livaoglu R. Investigation of dynamic response of masonry minaret structure. Bulletin of Earthquake Engineering, August 2008, DOI 10.1007/s10518-008-9066-5