The catastrophic landfill flowslide at Hongao dumpsite on 20 December 2015 in Shenzhen, China

Abstract

Abstract. A catastrophic flowslide occurred at the Hongao dumpsite on 20 December 2015 in the Guangming New District of Shenzhen, China. The flowslide caused 77 causalities and damaged 33 buildings. In the absence of extreme weather conditions and seismic activity, the causes of the failure were analyzed on the basis of multi-temporal remote-sensing images, site investigation, in situ tests, laboratory tests, and numerical analyses. Site investigations showed that the volume of the displaced material was 2.32 × 10 6 m 3 and the volume of the pre-failure waste filling was 6.27 × 10 6 m 3 . The flowslide was characterized by high travel velocity and long runout distance. The displaced material was primarily a mixture of silty soil and construction and demolition waste with water content of 17.3-42.4 %. The primary causes of the failure were concluded to be the following: (1) groundwater flow had stagnated in the dumpsite due to drainage system failure and the underlying impermeable granite stratum; (2) the accumulation rate and total volume of the waste filling was in exceedance of the design capacity. The flowslide may be ascribed to the development of excess pore-water pressure as evidence of liquefaction was observed at several locations, and it is postulated that such phenomena were related to the surcharge loads imposed by the unregulated disposal activities.

Numerical Simulation of the Erosion Effect Caused by the Impact of High-Velocity Landslide

“…A landslide occurred in the Guangming New District of Shenzhen (China) on December 20, 2015, which was caused by the instability of a large artifcial landfll [30]. Approximately 2.73 × 10 6 m 3 of construction spoil was mobilized with an impact area of 0.38 km 2 in this landslide (Figure 3 How the sliding body avalanches such a long distance on such relatively fat terrain and obtains such a high velocity is the main focus of the researchers [15,19,[30][31][32].…”

“…Studies have shown that the high-velocity and longrunout distance characteristics of the Shenzhen 2015 landslide are mainly due to the high-water content and high initial pore pressure in the source area of the landslide [15,30,31,33]. Te low permeability of soil results in a signifcant increase in pore pressure during the sliding [15].…”

“…Terefore, a density value higher than the landslide density and lower than the concrete density is assigned to the obstacle, that is, ρ o � 2000 kg/m 3 . Based on previous feld surveys and analyses [30,31], the solid volume fraction of the soil in the landslide source area is taken as 0.58 in this study.…”

From dumpsites to engineered landfills: A systematic review of risks to occupational and public health

“…Meteorological conditions were scored medium-low risk, however the evidence is lacking to assess the prevalence of harm from these hazards. (Blight, 2008;Jayaweera et al, 2019;Lavigne et al, 2014;Nikulishyn et al, 2020;Xu et al, 2017;Yin et al, 2016).  These incidents impact local area swamping land, destroying houses and ruining communities.…”

Warning: soil erosion and land degradation caused by productive and constructive engineering during construction period.

“…For example, a catastrophic landslide occurred at Hongao dumpsite on Dec 20, 2015, in Shenzhen, Guangdong, Southeast China. The landslide caused 69 causalities with 8 missings, damaged 33 buildings and caused near 800 million RMB economic loss (Xu et al, 2016), related soil and water conservation engineers were arrested. For the safe operation of the principal part of the project, the implementation of soil and water conservation projects is essential for constructive and productive engineering.…”