Instability Mechanism Of High Steep Dangerous Rock Body And Law Of Motion Of Rolling Stones

As the development of economy and technology, the investment of our country to infrastructure is becoming more and more. And the difficulty and risk of the construction is becoming larger and larger. However, the expectation to the quality of the project is becoming higher and higher. Dangerous rock body and rolling stones seriously threaten the safety of roads, railways and hydropower projects in the southwest of China. How to reduce the loss caused by engineering disasters keep the construction smooth is the responsibility of every engineer. Hence, the research for the dangerous rock body and law of motion of rolling stones is significant to reveal the occurring conditions and mechanism of rolling stones and supply theoretical direction for protection of engineering disasters.Numerical simulation and physical model test are used to investigate the instability characteristics of dangerous rock body and law of motions of rolling stones. Based on a real project the trajectory of rolling stones is predicted by numerical software.The numerical models of inclined slip dangerous rock body, vertical falling dangerous rock body, rotary dumping dangerous rock body are established based on discontinuous deformation mechanics method. The failure processes of different dangerous rock body are analyzed and the displacement evolution characteristics during failure are revealed.A three-dimensional physical model test system of law of motion of rolling stones is developed. The trajectory of rolling stones is recorded by a high-speed camera. The model test system can simulate the influence of different factors (different slope angles, rolling height, rolling angle, starting mode and block shape) to the trajectory and the variation of energy of rolling stones.The test material used in the experiment is mould gypsum. This owns the advantages of fast solidification and rapid prototyping. The moisture content of the test block is40%. And the compressive strength is tested. Three different kinds of test blocks are chosen:lump (5cmx5cm×5cm), tabular (5cm×5cm×2cm) and strip (5cm×5cm×10cm).The physical model test of law of motion of rolling stones is launched.81different experimental conditions are designed. The influence of slope angle (15°,20°,30°), rolling height (60cm,75cm,100cm), block shape (lump, tabular, strip), rolling angle (15°,35°,50°) are considered in the experiment. As for one experimental condition the test is repeated for several times. The influence of different factors to coefficient of restitution and kinetic energy loss rate are analyzed.Based on a real project field test of rolling stones is carried out. The influence of the characteristics of rolling blocks (structural surface, shape of block and quality of block), slope surface and slope shape are investigated. And the trajectory of blocks is predicted by numerical software. Nine conditions are designed in the numerical simulation. Final distribution of the rolling stones, height over the slope and kinetic energy variation of rolling stones are analyzed.The research is important to deepen the recognition to rolling stone disasters and significant to the protection design of rolling stone disasters.