# Experimental Study on the Features of Infrasonic Waves of Sandstone under Shear Load
###### Abstract  
The shear failure of rock is a major cause of rock slope instability and consequent landslides. To determine the forming mechanism of infrasonic waves during the loss of stability of sandstone slopes, experiments were carried out using a shear loading device and an infrasonic monitoring device. In the experiments, infrasonic wave events were identified, and the characteristic parameters of infrasonic waves were extracted to analyze the features of the infrasonic wave response during the shear failure of sandstone. The study results show that: (1) the whole process of shear failure was associated with infrasound events. A normalized energy cumulative coefficient of over 0.6 and a normalized infrasound rate of over 0.89 are the key time nodes for alarming landslide; (2) with an increase in sample size, the shear resistance of the sample increases logarithmically, the total energy of infrasound events increases exponentially, and the average dominant frequency of infrasound events decreases linearly; and (3) with an increase in axial pressure, the shear of the rock increases almost linearly, the number of infrasound events increases linearly, and the average dominant frequency of infrasound events increases exponentially. The research results provide important guidance for the dynamic monitoring and evaluation of the stability of sandstone slopes and can provide a theoretical reference for landslide alarming of sandstone slopes using infrasonic waves. s +
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stability. [PERSON] et al. [6; 7] monitored the infrasonic wave signals during the whole loading process of six typical kinds of rock samples in real time and processed and analyzed the infrasonic wave signals to figure out the range of characteristic frequencies of infrasonic waves generated during rock failure. [PERSON] et al. [8] analyzed the energy features of infrasonic anomalies generated during failure of rock, and the study results provide an important basis for early warning of rock failure. To monitor and warn of coal dynamic hazards by infrasonic waves, [PERSON]. [9; 10; 11; 12; 13] and [PERSON] [14] carried out a significant body of research. Through uniaxial loading experiments on coal samples, they collected infrasonic signals, analyzed the relative energy and frequency of the signals, and found that the relative energy and frequency of the infrasonic signals have obvious stage features. This laid the foundation for the stability monitoring of coal mine shafts based on infrasound. As the study went on, the team led by [PERSON] of Jiangxi University of Science and Technology [15; 16; 17; 18] examined the effects of loading path, cementation and rock grain size on the infrasonic signal features, analyzed the features of infrasonic signals before and after peak uniaxial stress, and described the destruction process of granite by using the variation features of fractal dimension of infrasonic waves' energy rate. In addition to an experimental study on infrasonic waves in lab, [PERSON] [19], [PERSON] [20], [PERSON] [21], and [PERSON] [22] monitored the infrasonic arrays of rockfalls of Mount St. Helens in Washington, the side wall of Dagurangbao landslide, Yosemite Valley and Bingham Canyon, and analyzed the basic features of the infrasound of rockfall and the falling trajectory of rock. [PERSON] [23] investigated the effects of different sizes, spaces, and types of volcanoes on the infrasonic signal and envisioned that the infrasonic waves would be a new means for monitoring the surface movement of volcanoes. The above study results have provided a theoretical reference for the infrasonic wave monitoring of rocky landslides. Rocky landslides come mainly from shear destruction mechanically. At present, without systematic studies on the features of infrasonic waves during rock shear destruction, the features of infrasonic waves during rocky hill destruction remain unclear, and the forming mechanism of infrasonic waves in rocky landslides is not understood well, hindering the identification and prediction of rocky landslides.