Recent catastrophic landslides and mitigation in China

Journal of Rock Mechanics and Geotechnical Engineering.2011,3(1):10–18

Recent catastrophic landslides and mitigation in China

Yueping Yin

China Geological S urvey,B eijing,100035,China

Received 13January 2011;received i n revi sed form 5February 2011;accepted 10February 2011

Abstract:Increasing population density and development of mountainous terrain have brought human settlements within

reach of landslide hazards.In recent years,due to the shortening of return period for severe natural events such as heavy rainfall,snowline retreating,great earthquake together with human activities,catastrophic landslides happened more frequently than before,resulting in large-scale casualties due to the increasing occurrences of rapid long-runout rock avalanches,especially in China.This paper presents some typical case histories related to the catastrophic landslides,including the Guanling rock avalanche,the Yigong rockslide-debris avalanche,the Wenchuan earthquake-induced landslides and the Danba landslide.They occurred in the last decade.Moreover,taking the Jiweishan catastrophic rockslide-fragment flow and the Yuhuangge landslide located in the new Wushan Town for examples,early-warning system and risk management on landslides are discussed in detail.

K ey words:catastrophic landslides;rainfall;snowline retreating;earthquake;human activities;mitigation

1Introduction

Recently,numerous landslide disasters occurred due to the increasing population density and development of mountainous terrain.Perhaps the most serious threat arises from small,high-frequency landslides such as debris flows and debris https://www.wendangku.net/doc/d315015679.html,rge and relatively low frequency rock avalanches also contribute to a significant hazard due to their immense capacity for destruction assessment of rapid long-runout events.It is a significant and crucial problem to be solved [1].

Studies show that in recent years,rapid and long-traveling catastrophic landslides happened greatly for the shortening of return periods for severe weather events such as heavy rainfall and snowline retreating,as well as for the occurrence of great earthquake and human activities,especially in China [2–7].For example,thousands of landslides were triggered by the devastating Wenchuan earthquake.They caused great casualties and property loss.

As for the studies on catastrophic rockslide,lots of achievements have been gained.But in fact,the dynamic mechanism of such geohazards often includes

D 3S 35*T +6555;y y @qq more than one important factor.So it is very difficult to explain or describe the whole dynamic process from its start-up to stop only with any one of the factors.Based on the current researches and engineering examples,the author presents some cases related to catastrophic landslides.The main types include:(1)rainfall-induced landslide;(2)snowline retreating-induced landslide;(3)earthquake-triggered landslide;and (4)human activity-induced landslide.In addition,a failure case study and a successful one on early-warning and mitigation are discussed.

2Rainfall-induced landslide

On June 28,2010,a catastrophic rock avalanche occurred after an extreme rainstorm at Guanling,Guizhou,China (Fig.1).This rock avalanche has a long-runout distance of 1.5km and a debris volume of 1.75×106m 3.It instantly buried two villages and resulted in a death toll of 99.

Guanling rockslide-debris flow was originated in the coal strata.Its upper part was limestone and dolomite.Its middle part was sandstone with gentle inclination.Its lower part was shale and mudstone and locally coal seam (Fig.2).This kind of unique geological structure,y f ,

f oi :10.724/P.J.12.2011.00010

Corresponding author.el:8-10-88428E-mail:i n https://www.wendangku.net/doc/d315015679.html,

with hard resistant caprock overl ing so ter ductile rocks coupled with the central out low region at the