Evaluating structural stability: Measuring small deformations induced by dynamic and environmental loads

This work studies the measurement of slight and periodic deformation of structures under various cyclic loading conditions, such as live dynamic loads, diurnal variations of temperature, and tidal wave effects. Its purpose is to contribute to a better understanding of cyclic deformation and better measurement techniques in structures. Three experiments involving the application of high-precision quartz tiltmeters were conducted on an aerial cableway, a retaining wall, and a tunnel to determine their deformation. Real-time measurement of the tilt of the tilting anchor block of the aerial cableway was carried out during dynamic testing, six-month continuous measurement of retaining wall tilt, and measurement of tilt every hour in the tunnel for one month. With the results, 0.37 seconds of maximal tilt at 128 KN load were demonstrated by the aerial cableway to be stable and elastic. Outputs of tilt variation of the retained wall were demonstrated to be a function of diurnal variation of temperature, and tilts of less than 4 seconds in the x-component and less than 10 seconds in the y-component were observed after removing thermal effects. Tidal wave effects were demonstrated by tunnel measurement to produce oscillations due to earth tides with 0.013 seconds amplitude in the EW direction and 0.005 seconds amplitude in the NS direction. In conclusion, the application of the method of quartz tiltmeters proves to be efficient for recognizing measurement of slight cyclic deformation, which is helpful for a better structural stability for a variety of loading conditions. Its application plays a role in structural health monitoring, demonstrating the importance of advanced measurement methods for structural integrity.