Author(s): M. Klun; D. Zupan; A. Kryzanowski

Linked Author(s): Andrej Kryžanowski

Keywords: Dam monitoring; Laser Doppler Vibrometer; Structural health monitoring; Hydropower dams; Dynamic loading

Abstract: Hydropower dams are, due to their operation on turbines and hydrodynamic effects of water, continuously subjected to dynamic loading. In this paper, we present an ongoing study of structural vibrations using a Laser Doppler Vibrometer. A detailed study to monitor vibrations on a concrete gravity dam is conducted on HPP Brezice. Laser Doppler Vibrometer (LDV) is introduced as a new experimental equipment to be used for structural health monitoring of dams. Dams are regularly subjected to several types of time-dependent loads due to operation on turbines, water flow or even earthquakes. These loads are a source of excitation of the structure. Each transient load has a unique frequency notation that consists of various dominant frequencies. From the structural point of view, those excitations close to the eigenfrequencies of the structure are of major concern. Nowadays hydropower plants due to the variable demand for power do not operate continuously as provided for in their design. There are many stops and starts of the turbines, sometimes even several times a day. These changes can lead to a decrease in structural and operational safety of dams. This study focuses on operational loads that are constantly present on HPP but considered to have a much smaller magnitude than seismic loads. We aim to present that the operational dynamic effect on dams should be given serious attention in dam design, especially concerning structural health monitoring of aging dams. Dynamic monitoring of dams implemented as part of regular monitoring on dams enables detection of latent conditions prior to the triggering event and visible structural damage.

DOI: https://doi.org/10.3850/978-981-11-2731-1_061-nm2-cd

Year: 2018