REGIONALIZATION OF ENGINEERING GEOLOGICAL STABILITY AND DISTRIBUTION OF ENGINEERING DISTURBANCE DISASTERS IN TIBETAN PLATEAU

The successive implementation of national strategic deployments(e.g., the Western Development) and the gradual launch of some giant engineering(e.g., Sichuan-Tibet Railway) have been increasing the engineering activities on the Tibetan Plateau. Affected by rapid uplift, the tectonic movement in the plateau is active and the engineering geological conditions are complex. Reasonable site selection becomes the key for safe construction and operation of giant engineering. In this paper, the distance from the Holocene active fault and the relief amplitude are selected as evaluation factors, and the membership method is used to classify the engineering geological stability of the Tibetan Plateau. The results show that the whole region can be divided into five zones based on the engineering geological stability, namely poor, relatively poor, medium, relatively good and good. And the corresponding proportions in the regional land area are 22.48%, 18.01%, 28.79%, 22.72% and 8.00%, respectively. By interpreting the giant engineering and their disturbance disasters in the Tibetan Plateau, a total of 2176 giant engineering projects(e.g., railways, highways, hydropower stations, mines) are identified. And 6562 disturbance disasters are identified and mainly distributed in the poor and relatively poor zones. They take accounts of 69.66% in the total. Preliminary analysis shows that the result of engineering geological stability zoning has great significance for guiding the site selection of giant engineering in the Tibetan Plateau. Engineering disturbance disasters mainly occur in the high occurrence areas of nature disasters. The slope-cutting disturbance disasters mainly occur in the areas where landslides, thick colluvial slopes and strong unloading slopes exist. The main types of reservoir-induced disasters are landslide revival and slump in loose deposits, and the number of these disasters decreases rapidly after water storage.