The Study On Mechanism Of Set-Out Of Touzhai Rock Avalanche

Mount Emei basalt in the Yunnan province is more common, and the geological structure of the Yunnan area, the stress is complex, creating a high mountain valley. Mountain and Ravine Region of rock avalanche hazards occurred at higher frequencies rockslides is occurs in the alpine and gorge region has a strong destructive power of rock material special slope shift phenomenon, destructive strong, difficult to monitor, involving a wide range, the sudden outbreak of, of rock avalanche starting mechanism with a strong scientific and practical significance, but so far did not a detailed system theory to explain the startup mechanism of rock avalanche. Zhai tou rock avalanche is very typical examples of rock avalanche. In this paper, Zhai tou rock avalanche to rely on, start mechanism of Touzhai rock avalanche has strong scientific significance, research contents and conclusions are as follows:(1) Through inversion landslide initial impact the impact velocity of the bottom of a valley or valley slope are key factors to determine the rock avalanche transport distance and the harm. Are derived according to the principle of impact dynamics contains slump geometry parameters, landslide and its impact the calculation formula of the physical and mechanical parameters of impact velocity, which is calculated to Yunnan Zhaotong Touzhai rock avalanche landslide initial impact around the valley slope or weathering residual soil impact accumulation rate was obtained 80.21 m/s. Based on the principle of conservation of energy, impact velocity and collapse sliding body bomb punch velocity relationship, according to the calculation of Touzhai rock avalanche bomb punch velocity 5.2 m/s. Comprehensive analysis shows that the landslide hit the bottom or the valley slope after produce rock avalanches and debris flow of migration velocity by the landslide body mass, density, elastic modulus, impact direction and the slope angle, slope residual plot soil density, slip bottom surface length and other factors influence.(2) Survey and specific understanding of the Touzhai rock avalanche where the regional tectonics and regional tectonic and hydrogeological distribution of basalt layer structures similar sedimentary rock bedding structure, analysis between basalt similar sedimentary rock bedding and bedding weak structural plane influence on rock avalanches start to do full range of understanding. Occurrence in North East to the linear folds the flanks of the P2β is tilted state is the massive bedding instability of the premise and foundation; roughly along the direction of the short axis of the syncline development of longitudinal River tributaries in stripping the P2β cover layer, for P2β instability create airport environment at the same time, the channel for P2β downward migration and accumulation provides channel and places. Linear folds is the occurrence of P2β the main structural form; Emeishan basalt formation mechanism of magmatic eruptions have the potential rule, before each eruption should in the original eruption condensation and level between the two eruptions is relatively weak. It is easy to convert to slide easily slip surface.(3) When the lock solid rock thickness and by the hard rock composition, in the first half of the rock mass of large thrust slope build-up large shearing property, when the lock solid rock is suddenly cut off, the rock avalanche system at startup moment release the large amount of energy. This energy is far greater than the energy needed for broken rock, over part, will be transformed into rock avalanches start when the kinetic energy, and obtain high departure bomb punch speed. According to the theoretical analysis, it is calculated that the release of the energy transferred to the kinetic energy when the locking section of the rock mass of the lock is in obvious displacement, and the impact velocity is 5.6 m/s.(4) From the microscopic point of view to consider composed of basalt mineral crystals in cut crystal fracture release energy and the mineral crystal cut crystal fracture by the release of internal energy and shear elastic deformation energy, and preliminary calculate the internal energy and the energy conversion for the kinetic energy and obtain the higher speed.(5) Survey of Touzhai rock avalanche start early rainfall, the analysis of the influence of rainfall of rockslides start, and put forward the rainfall not Zhai tou rock avalanche induced direct factors, but to play the increase lock solid section of the sliding body gravity effect.