Study on the Calculation Method of Water Inflow Velocity of Loose Rock Landslide

Abstract

Landslide surges pose a serious threat to the ecological environment and human life safety. Based on rock structure mechanics and water sediment dynamics, considering the additional resistance caused by the interference of loose landslide particles on flow structure, this paper deduces the resistance calculation formula of loose-rock landslide particles when entering water. It modifies the landslide velocity formula (ASCE) recommended by the American Society of Civil Engineers. The acceleration calculation formula and velocity calculation formula of bulk-rock landslides entering water are obtained, and the determination method of the main parameters in the formula is given. Based on the data of the Xintan Landslide into the Yangtze River, the rationality of the calculation results of this formula and the ASCE formula are compared and analyzed. It shows that the ASCE formula calculates the average velocity of landslide movement on land, and there will be a noticeable deviation from the actual situation when it is used to calculate the water entry velocity of a loose-rock landslide. The formula given in this paper is more practical and can be used to calculate the velocity of loose-rock landslides entering water.