Preliminary analysis for the triggering of soil flowslide that occurred in Zhongchuan Town following the 2023 Jishishan MS6.2 earthquake in Gansu Province
On Dec.18th,2023,a magnitude 6.2 earthquake hit Jishishan Town of Linxia City in Gansu Province,and caused an unusual mud sliding disaster in Jintian Village and Caotan Village of Zhongchuan Town in Qinghai Province.The mud flowslide resulted in catastrophic consequences as casualties and demolishing and burying of residential houses.Such large mud sliding phenomenon has not been frequently reported in historical earthquakes.Through field investigation,it is confirmed that the underlain soil liquefied and triggered the disastrous phenomenon which has already been termed liquefaction-induced flowslide.Nevertheless,the massive liquefaction-induced flowslide is the first time been reported and verified by field evidence in recent 70 years.The investigation and analytical results demonstrate that the underlain soil layer in the upstream area liquefied,triggering instability and catastrophic flowslide,and the soil and water conditions in the flowing channel potentially accelerated the sliding.It is deduced that liquefaction possibly occurred in many a place,that is,the sliding channel was suspected of liquefying in various spots.The ground shaking intensity in the sliding area maintained relatively high,and that the peak ground-motion acceleration was estimated around 0.4(±0.1)g.The findings and investigation results are useful to help understanding the mechanism and process of the uncommon flowslide disaster.
万方数据
维普
