China
Africa
Explore chapters and articles related to this topic
Characteristics and mechanisms of earthquake-induced landslides according to recent events and studies
Published in Ömer Aydan, Takashi Ito, Takafumi Seiki, Katsumi Kamemura, Naoki Iwata, 2019 Rock Dynamics Summit, 2019
In this paper, earthquake-induced landslides of rock slopes are classified into rockfalls and rockslides based on the principles and terminology of Varnes (1978). Rockfalls are defined as rock descending of individual boulders or disrupted masses on slopes by bounding, rolling, free fall or toppling. Whereas rockslides are defined as rock mass movements by rotational slump, translational slide including deep-seated block slide, and lateral spread.
Progressive destabilization and triggering mechanism analysis using multiple data for Chamoli rockslide of 7 February 2021
Published in Geomatics, Natural Hazards and Risk, 2022
Wenfei Mao, Lixin Wu, Ramesh P. Singh, Yuan Qi, Busheng Xie, Yingjia Liu, Yifan Ding, Zilong Zhou, Jia Li
The Chamoli area, as a part of the the high Himalaya, mainly consists of high-grade metamorphic rocks (Valdiya 1980) and the area around the Tapovan-Vishnugad hydropower station about 20 km downstream is dominated by amphibolite facies, psammitic schist and gneisses (Heim and Gansser 1939; Valdiya and Goel 1983), of which the non-tectonic joints are usually much developed (Nichols 1980) and their stratified structure are easy to be affected by glaciation, deglaciation and neotectonic process (Sahoo et al. 2000; McColl 2012). The elevation range of the rockslide body is about 5,600 masl (Figure 2a), which is of high potential energy for mass movement and landslide. The actual bergschrund was close to the mountain ridge (with distance of about 273 m), which illustrates the sheard nature of the source rocks to likely condition of the faliure (Shugar et al. 2021). There were many glacier spurs existing on the slope (Figure 2b), where the permafrost degrades usually faster and deeper compared to a straight slope (Noetzli et al. 2007). Longterm changes of air temperature had impacted significantly the permafrost layer along the slope.
Machine learning driven landslide susceptibility prediction for the Uttarkashi region of Uttarakhand in India
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2022
Poonam Kainthura, Neelam Sharma
The landslide study area contains several rocks like phyllite, quartzite, argillaceous, dolomite, etc. The presence of structural discontinuities in the stones like faults, joints, bedding, and thrusts to slope inclination and direction greatly influences slope stability. As per the recorded data, the state of the rock for the selected study area is categorised as massive, sheared, fractured, and jointed. The massive rock not only describes the size but also includes the disintegrating rock mass. Hence, it can be involved in an initial rockslide and subsequent rock avalanche. The shear strength of rock is the function of bonding called cohesion and internal friction angle. Fractures are mechanical breaks in rocks involving discontinuities in displacement across surfaces or narrow zones. A fractured rock have consistently high permeability (Pradhan and Siddique 2020). The coefficient defines the strength of the jointed rock called the joint factor and depends upon the tangent modulus of the mass (Singh, Rao, and Ramamurthy 2002).
Physical modeling of tsunamis generated by subaerial, partially submerged, and submarine landslides
Published in Coastal Engineering Journal, 2020
Tomoyuki Takabatake, Martin Mäll, Dawn Chenxi Han, Naoto Inagaki, Daichi Kisizaki, Miguel Esteban, Tomoya Shibayama
As many landslides in the past are known to have occurred as a deformable debris flow (Grilli et al. 2017; Varnes 1978), it would be reasonable to have used a deformable material in the present physical model experiments. However, in some cases (a typical example would be the tsunami generated by a subaerial rockslide in Vajont reservoir, Italy in 1963), the landslide could fall into the water as a solid block (Müller 1964). Ataie-Ashtiani and Najafi-Jilani (2008) showed that tsunamis generated by a rigid submarine landslide are up to 15% higher than those produced by a deformable slide. Thus, when the predictive equations developed in the present study need to be applied to a rigid block sliding, it is necessary to keep in mind that the predictive values are likely underestimating the potential tsunami amplitudes that could be generated.