Time dependent changing of dynamic characteristics of laboratory arch dam model

• Published in: KSCE journal of civil engineering Vol. 19; no. 4; pp. 1069 - 1077
• Main Authors: Altunişik, Ahmet Can, Sevİm, Barış, Bayraktar, Alemdar, Adanur, Süleyman, Günaydin, Murat
• Format: Journal Article
• Language: English
• Published: Heidelberg Korean Society of Civil Engineers 01-05-2015; Springer Nature B.V; 대한토목학회
• Subjects: Aging (natural); Arch dams; Civil Engineering; Concretes; Dam construction; Damage; Damping; Damping ratio; Domain decomposition methods; Dynamic characteristics; Engineering; Environmental effects; Frequency; Frequency domain analysis; Frequency domains; Geotechnical Engineering & Applied Earth Sciences; Industrial Pollution Prevention; Prototypes; Reservoirs; Resonant frequencies; Resonant frequency; Rigidity; Structural Engineering; Time dependence; Vibration; Vibration tests; Vibrations; 토목공학; ambient vibration test; prototype arch dam-reservoir-foundation model; enhanced frequency domain decomposition method; dynamic characteristics; damage scenarios
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-014-1080-3

This paper investigates the time dependent changing of dynamic characteristics of laboratory arch dam models using ambient vibration test. For this aim, a prototype arch dam-reservoir-foundation model is constructed in laboratory conditions. The first experimental measurement tests are performed after the poured concrete aged for 10 months for some damage scenarios such as undamaged, minor-damaged and severely damaged of dam body in November 2009. To extract the experimental dynamic characteristics such as natural frequencies, mode shapes and damping ratios, a small impact effect is used as a source of ambient vibrations. Experimental measurements tests are repeated using same excitations considering severely damaged conditions with and without reservoir water in February 2014, and the dynamic characteristics are obtained, experimentally. Enhanced Frequency Domain Decomposition Method in the frequency domain is used to extract the experimental dynamic characteristics. At the end of the study, experimentally identified dynamic characteristics are compared with each other and time effects are investigated in detail. Maximum differences between the natural frequencies obtained as 15.36% and 14.38% in the third mode for empty and full reservoir conditions, respectively. It is thought that the increase of the natural frequencies is resulted from gaining of rigidity of the concrete, ageing, temperature and different environmental effects.