Earthquake-induced collapse mechanism of two types of dangerous rock masses

Abstract

As the economy of China develops, an increasing number of key traffi c projects have been undertaken in the west of China, where there are high, steep rock slopes. The collapse of dangerous rock masses, especially following a strong earthquake, is one of common geological disasters known in rock slope engineering. Therefore, it is important to study the collapse mechanism of dangerous rock masses induced by an earthquake and the analysis approach of its stability. This study provides a simple and convenient method to determine the collapse mechanisms of two types of dangerous rock masses (i.e. cantilever and upright) associated with the defi nition and calculation of the safety factor, which is based on the fl exure theory of a constant-section beam by combining with the maximum tensile-stress criterion to depict the process of crack propagation caused by seismic waves. The calculation results show that there are critical crack depths in each form of the dangerous rock masses. Once the accumulated depth of the crack growth during an earthquake exceeds the critical depth, the collapse will occur. It is also demonstrated that the crack extension amount of each step is not a constant value, and is closely associated with the current accumulated crack depth. The greater the cumulative crack depth, the more easily the crack propagates. Finally, the validity and applicability of the proposed method are verifi ed through two actual engineering examples.

A study on the Stability of Dangerous Rock Mass under Blasting Vibration Considering Size Effect

“…Their calculation example demonstrated that the criterion could quantitatively reflect the instability of dangerous rock mass. Wang W et al (Liu et al, 2008;Wang et al, 2016) concluded that the crack extension of dangerous rock mass is closely associated with its size and initial crack length. Amitrano D (Amitrano et al, 2010) examined the stability of rock slope affected by climate change, concluding that microseismic monitoring system plays an essential function in predicting and evaluating dangerous rock hazards.…”

Study on the Dynamic Stability and Spectral Characteristics of a Toppling Dangerous Rock Mass under Seismic Excitation

“…The collapse of dangerous rock masses is a common geological disaster in the western mountainous area of China, which threatens the environment and causes the loss of human lives and property, and also has adverse effects on engineering construction [1,2]. China is a country that experiences severe earthquake disasters, and earthquakes became a major cause of dangerous rock mass collapse in the western region [3,4]. Therefore, it is of great significance to study the dynamic stability analysis methods of dangerous rock masses under seismic action.…”