Deformation characteristics and failure mechanism of a reactivated landslide in Leidashi, Sichuan, China, on August 6, 2
- PDF / 18,506,099 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 103 Downloads / 227 Views
Weile Li I Bo Zhao I Qiang Xu I Fan Yang I Hao Fu I Cong Dai I Xinxin Wu
Deformation characteristics and failure mechanism of a reactivated landslide in Leidashi, Sichuan, China, on August 6, 2019: an emergency investigation report
Abstract At approximately 2:00 p.m. (Beijing time) on August 6, 2019, the previously controlled Leidashi landslide was reactivated near group 7 of Zhangjiagou village, Jianyang County, Sichuan Province, China. The 2019 Leidashi landslide damaged two main roads and 44 antisliding piles and posed a threat to another main road. This landslide was a reactivation of the 2010 Leidashi landslide and had an accumulation zone of 2.2 × 106 m3. To explore the deformation characteristics and failure mechanism, detailed field investigations, unmanned aerial vehicle photogrammetry, airborne LiDAR surveys, borehole drilling and inclinometer installation were carried out, and the collected data were analyzed. The results show that the 2019 Leidashi landslide could be divided into main slipping zone and activated zone according to movement state, and the main slipping zone could also be divided into main scarp area, main deposit area, climbing area, uplift area, and local landslide area according to the local movement and geomorphic features. The rapidly increasing landslide thrust caused by shortterm but continuous heavy rain caused the failure of the antisliding piles and ultimately reactivated the 2010 landslide. Keywords Leidashi landslide . Rainfall . Reactivated landslide . Deformation and mechanism Introduction Rainfall-induced landslides are common, and catastrophic natural hazards that occur worldwide can result in considerable loss of life and damage to infrastructure, especially large rainfall-induced landslides, which are generally larger than 106 m3 (Glade 1998; Dai et al. 1999; Lee and Pradhan 2007; Li et al. 2016; Lin et al. 2018; Ouyang et al. 2018; Wang et al. 2018; Cui et al. 2019). The rainfall infiltration may increase the pore water pressure and reduce the effective stress of a slope and thus greatly weaken the shear strength; in particular, intensive rainfalls that occur prior to slope failure have a considerable effect on the shear strength of the slope (Lee et al. 2011; Wu et al. 2015, 2017a, b; Zhao et al. 2018; Hu et al. 2019). At approximately 2:00 p.m. (Beijing time) on August 6, 2019, a catastrophic landslide (the 2019 Leidashi landslide) occurred near group 7 of Zhangjiagou village in Danjing town, Jianyang County, Sichuan Province, China (N30°19′ 50″, E104°14′ 20″), as shown in Fig. 1a and b. This landslide occurred at the interaction of 3 main roads (Fig. 1c) and posed a threat to 0.25 billion properties (SIGEIG 2019). After the occurrence of the Leidashi landslide, airborne LiDAR (light detection and ranging) was adopted to obtain highresolution images and a digital surface model (DSM). Engineering information of the 2010 Leidashi landslide, multitemporal satellite images, and a digital elevation model (DEM) were collected. Detailed field investigations and borehole dril
Data Loading...
