Investigation of the dynamic properties of roller compacted concrete dams by experimental and numerical methods

The dynamic behavior of civil engineering infrastructure is an essential factor in determining their structural stability, life span and reliability. Therefore, it has become an important issue in many engineering applications to identify dynamic characteristics of such structures and monitor the structure in operation. Operational Modal Analysis (OMA) is a procedure which allows for the extraction of modal parameters of a structure in service. In this study ambient vibration tests were conducted on a 101 meter high concrete gravity dam, Beydag Dam,Izmir, to measure its modal properties for validating a finite element model of the dam system. The dam height is 101 m, and the crest length is 800,335 m. Excitation was provided by wind. Vibrations of the dam were measured using accelerometers, and 45 minutes data records were acquired from each location. Decades ago, a major concern of structural engineers was the development and application of new and powerful numerical methods for the static and dynamic analysis of large civil engineering structures. The rapid development of finite-element techniques accompanied by tremendous technological progress in the field of personal computers allowed structural designers to use software packages for accurate simulation of structural behavior. The continuous aging and subsequent structural deterioration of a large number of existing structures have encouraged the development of efficient vibration-based damage detection techniques supported by structural health monitoring systems. The natural tendency of civil engineering researchers was to utilize well established input-output modal identification techniques to identify the main dynamic properties of civil structures. The finite element model calibrated based on field observations was been run and the stress and deformation values throughout the dam body have been obtained. It is possible touse such models to check the performance of existing concrete dams and make strenghtenings where possible.