Forming Mechanism Analysis and Characteristic of Especial-huge Rock Landslide at Tiantai Village of Xuanhan County in Sichuan Province

Huge landslide which had astounded China and foreign countries had taken place in Tiantai countryside of Xuanhan county in Sichuan Province on Sept.5,in 2004.The landslide destroyed a village,jammed a river way,formed a barrier lake which had 58×106 m3 in reservoir cubage and flooded upriver Wubao town and 8 villages along the river,resulted in losing homes for19.36 thousands peoples and economic damage of 200 million yuan.Tiantai landslide which is 1.2 km2 in acreage,2 500×104 m3 in all cubage,has 210×104 m3 accumulations in river way and belongs to especial-huge and retrograde style rock landslide,is a national geological disaster which has been induced by huge rainstorm in 300 years and is an oversize landslide disaster which scope and possession losing is the largest at the red stratum in Sichuan basin.The landslide had not made any casualty because of forecasting betimes,measuring suitable and advantageous organizing.The landslide governance had created a miracle of decreasing and preventing geological disaster in Sichuan Province.