Numerically investigation on blast-induced wave propagation in catastrophic large-scale bedding rockslide
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Meng Wang I Guotao Ma I Fei Wang
Numerically investigation on blast-induced wave propagation in catastrophic large-scale bedding rockslide
Abstract Large-scale landslides as a common geological hazard can be easily triggered by natural factors, while it is extremely difficult to be activated by anthropolical blasting operations. The paper presents a comprehensive analysis of characteristics of stress wave propagation in a blasting-triggered large-scale rockslide, termed Wangshan–Zhuakousi Landslide, to investigate the effect of blasting wave on multi-layer interface condition. A detailed analysis of the propagation of P wave in the filling joints was conducted to verify the reliability of the analytical model and the deterioration characteristics of the weak interlayer. The results indicate that the reflection tensile wave can be formed when P wave propagates from the basalt across the tuff interlayer. The theoretical equation for damage assessment of soft rock interlayers is proposed, which can be adopted in calculating the additional stress of soft rock mass in blasting operation. It is found that the material density is the most influential factor in attenuation rate. Besides, the longitudinal wave velocity of materials and the period of incident waves perform the identical effect on the attenuation rate. It is demonstrated that the cumulative failure of tuff layer plays a crucial role in triggering successive sliding. According to the modelling, the tuff interlayer appears to be in a compressed state before the complete damage under P-wave propagation. The locally tensile behaviour can be observed after the complete damage of the tuff. The underlying tuff interlayer forms a discontinuous cumulative damage zone, which significantly triggered major ruptures and destabilized the original bedding rock slope. This paper could prove new insight towards the enforcement of risk assessments and mitigation countermeasures for blasting-induced landslide. Keywords Wave propagation . Production blasting . Landslide failure . Weak intercalation layer . Numerical simulation
Introduction Large-scale landslides as a common geological hazard can be easily triggered by natural influencing factors such as tectonic activity or heavy precipitation in flood season, while it is extremely difficult to be directly provoked by anthropolical blasting operations (Cruden et al. 2009; Xu and Huang 2013; Yin et al. 2013). It is commonly admitted that local collapse or small-scale earth slide in slopes can be influenced by excation engineering or explosive blasting. However, forming such large-scale landslide involving millions of cubic meters of sliding mass is not easy in valleys. In particular, compared with seismic effects of tectonic activity, the shaking effect of production blasting is negligible. However, the cumulative damage from blasting operations can be considerable in rock mass of slopes under unfavourable conditions, such as
bedding plane with internal weak layers, the strata of a massif dip into the slopes, which is signific
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