Imprints of vibratory signals induced by road construction in strain and seismic records: A case study of Yichang station

One of the crucial issues in the field of earthquake forecasting and prediction is the reasonable identification of the tilt, strain, and seismic signals induced by road construction. During March to May 2018, some special disturbances induced by road construction were observed at Yichang station. With the goal of uncovering the impact on the records of the water-tube tiltmeters, vertical pendulums, extensometers, and seismometer, we analyzed the signatures of this disturbance using the signal processing method. The study produced several important results: In particular, the water-tube tiltmeters were more capable of detecting the vibratory disturbances than the vertical pendulums and extensometers, and the main feature of the disturbances was dominated by high-frequency tremors. Furthermore, the primary frequencies of high-frequency tremors for the water-tube tiltmeters in the NS and EW directions were 0.07 and 0.059 cpm, respectively. The vertical pendulums and extensometers were less sensitive to vibratory disturbance excited by the road construction. The high-frequency tremors in the seismic data occurred mainly at frequencies of approximately 2.2～4.6 Hz, and their whole waveform was analogous to the shape of two connected beads. The vibratory disturbance excited by onset of road construction was recorded at 08:00 and had a duration of approximately 12 h. The results of this study can be used to identify the noise generated by road construction in tilt, strain, and seismic data. Moreover, the method used in this work may contribute to traceable diagnosis.