Abstract
Substrate entrainment can greatly influence the mass movement process of a debris avalanche because it can enlarge the landslide volume and change the motion characteristics of the sliding masses. To study the interaction between debris avalanches and erodible substrate, physical modeling experiments varying in the mass of granular flow and substrate thickness were performed. The experimental results show that both the entrained materials and the maximum erosion depth are increased with increasing mass of the debris avalanche and decreasing substrate thickness. During the experiment, several tests were recorded using a high-speed digital camera with a frequency of 500 frames per second, so that the process of entrainment could be clearly observed. Combined with the experiment result and results of previous studies from predecessors, the entrainment mechanism during debris avalanches are analyzed and discussed. The entrainment effect of the sliding masses on the loose bed materials include basal abrasion and impact erosion of the avalanche front, the latter of which can contribute to the former by failing or yielding the erodible bed.
Highlights
In recent years, the occurrence frequency of catastrophic landslides has significantly increased because of human activities and changes in global climate, causing a tragic loss of lives and properties (Crosta et al 2009; He et al 2010; Monjez et al 2011; Zhou et al 2013; Singh et al 2014; Umrao et al 2015)
Because the entrainment effect is critical to the motion process of debris avalanches, considerable attention has been given to this topic over a long time span, and many cases involving this phenomenon have been well documented
Mass of debris avalanche and thickness of bed materials are the key factors affecting the entrainment process of debris avalanche discussed here
Summary
The occurrence frequency of catastrophic landslides has significantly increased because of human activities and changes in global climate (e.g., rising temperature and heavy rainfall), causing a tragic loss of lives and properties (Crosta et al 2009; He et al 2010; Monjez et al 2011; Zhou et al 2013; Singh et al 2014; Umrao et al 2015). Most catastrophic landslides are triggered by strong earthquakes (Ding et al 2012; Wu et al 2012; Zhou et al 2016a), e.g., the 2008 Wenchuan earthquake directly caused more than 15,000 geohazards in the form of landslides, rockfalls and debris flows, which resulted in approximately 20,000 deaths (Yin et al 2009; Xing et al 2015). The 2000 Yigong landslide, with an initial volume of approximately 1 × 108 m3, increased its volume to more than 3 × 108 m3 because of the entrainment of a large amount of bed materials The Val Pola rock avalanche entrained approximately 8 × 106 m3 of bed materials, which was approximately 20 % of the initial volume (Crosta et al 2004). Crosta (1994) reported a rock slide/avalanche with an original volume of 0.15 × 106 m3 entrained approximately 0.25 × 106 m3 of materials while moving along a 35° inclined slope covered with deposit. Based on a large number of reported landslide cases, the entrainment effect is a common phenomenon in many large-scale landslides
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
