Study On Mechanism Of Airblast Created By High-Speed Landslide

Since October 9, 1963 in Italy, Vajont landslide occurred, geological scholars started to pay attention to high-speed landslide, particularly the airblast. caused by it. People recognized that there were essential differences between high-speed landslide and general ones, in its forming conditions, the form of movement, speed and mechanism etc.Dashuijing landslide happened at 9: 00, on 14th of August, 2002, was located in Xinping country, Yunnan Province. The landslide destroyed the village of Dashuijing, with 7 died, 8 lost and more than 100 houses destroyed. Based on locale geological survey we know that the high-speed landslide in the structure can be divided into the source region, the flight zone, landslide and airblast region and the accumulation of debris-flow areas. The destroyed houses and plants which beyond the both sides of the high-speed landslide showed that during each phase of high-speed landslide's movement, a great deal of airblast was created, which is powerful.In this paper, Dashuijing landslide was studied, based on locale geological survey and analysis of geological data, engineering geological conditions for forming Dashuijing landslide, its characteristics of structure and dynamics are expatiated, a 2D-model of a viscous and incompressed flow is founded by aerodynamics theory, considering the related materials get from locale survey and the characteristics of flow field caused by air-blast created by the rocklandslide, a numerical simulation of mechanism of high-speed landslide with airblast is carried out by using a software for numerical hydrodynamics, CFD,FLUENT solver. Then, the range in which potential imperil of airblast exists is obtained.The results of numerical simulation in this paper showed there are some relationship between the pressure of airblast formed in Dashuijing landslide with speed of 50.4m/s and the slid bodies. The larger obliquity of walls is, the greater pressure of airblast is. The destroy energy caused by airblast in the area of vertical wall of slid body in distance of 500m corresponds to one of wind power of 11-12 degree, the pressure of air-blast caused by the wing-type slid body is the least, in distance of 100m, the destroy energy for buildings is less, corresponding to wind power of 6 degree.The study of this program gives benefit for raising the technical level of monitoring and warning the serious geological disaster, provide the scientific bases for reducing and preventing the disaster.