METHOD FOR DETERMINING DYNAMIC CHARACTERISTICS OF BASE AND BODY OF DAM AT HYDROELECTRIC POWER STATION BY MEASURING PULSES BUILT UP WHEN STARTING HYDROPOWER UNITS Russian patent published in 2000 - IPC

FIELD: hydraulic engineering. SUBSTANCE: method for determining dynamic and elastic characteristics of the base and body of dam at hydroelectric power station involves nondestructive engineering and seismic inspections of their physical condition by measuring equipment vibrations under the action of shock pulses produced in starting hydropower units. For the purpose use is made of group of three-component vibration transducers sequentially displaced within the body of dam while recording vibrations by similar three-component vibration transducers at two reference points; one of the latter is located in the body of dam; shock pulses built up in the base when starting hydropower units are recorded at other reference point. As a result, records made at first reference point are used as basis for determining dynamic characteristics of dam including amplitudes and frequencies of natural waveforms of free damped vibrations of dam, logarithmic damping decrements, and power correlations of free damped vibrations of dam at natural waveform frequencies. Records made at second reference point are used as basis to obtain elastic wave field, dynamic moduli of elasticity and shear of base rock and body concrete, wave amplitude damping with increase in distance from source, as well as base-to-body transient characteristics. EFFECT: enlarged range of characteristics determined. 5 dwg