Experimental Hazardous Rock Block Stability Assessment Based on Vibration Feature Parameters

Abstract

This paper explores a new approach for assessing the stability of a hazardous rock block on a slope using vibration feature parameters. A physical model experiment is designed in which a thermally sensitive material is incorporated into the potential failure plane of the hazardous rock, and the complete process of hazardous rock collapse caused by strength deterioration is simulated by means of constant-temperature heat transfer. Moreover, the vibration response of the hazardous rock is monitored in real time by laser vibrometry. The experimental results show that five vibration feature parameters, including the mean frequency, the center frequency, the peak frequency, the mean frequency standard deviation, and the root mean square frequency, are well-correlated with rock stability. Furthermore, through principal component analysis, the five vibration feature parameters are synthesized into a principal component factor (PCF) as a representative assessment parameter. The results of the analysis demonstrate that the variation in the PCF exhibits three characteristic stages, i.e., “stationary-deviation-acceleration,” and can effectively identify the stability evolution trend and collapse precursor behavior of hazardous rock block.

Method to Realize the Tilt Monitoring and Instability Prediction of Hazardous Rock on Slopes

“…A concrete block is used to represent unstable rock. e weak structural plane is constructed using a material with heat-sensitive strength; specifically, sand and gypsum are used as the aggregates, and paraffin is used as the gelling agent [5]. An electric heating element is embedded in the material to control the strength to the weak structural plane.…”

“…e essential cause of collapse of hazardous rock is the strength degradation of the weak structural [5]. In the conducted test, the concrete material ensures that the block has sufficient weight.…”

“…To date, strength theory has generally been used to identify the stable state of hazardous rock at a certain instance [2][3][4]. When the tensile (or shear) stress on the control fissure of the hazardous rock exceeds the tensile (or shear) strength, the rock mass is expected to collapse [5]. However, conducting regular and detailed investigations of the geological characteristics, structural features, and mechanical properties of hazardous rocks is highly labor and cost intensive.…”

The Evaluation Method of Rock Mass Stability Based on Natural Frequency

“…To solve this problem, Ma et al [15,16] and Xie et al [17,18] proposed some simple mechanical models of rocks and investigated the quantitative relationship between the natural frequency of rocks and their stability. In their study, the rock was simplified as a rigid sphere, and the connection between the rock and the slope was simplified as a spring.…”