The Research Of Stability Of Rock Slope Based On Statistics And Particle Flow Code

Rock mass is a heterogeneous and discontinuous media composed of rocks and structural planes.Rock slope consists of numerous discontinuities like joints,fissures,fault,etc.Failure of these discontinuities will lead to instability or damage of rock slope,making it an essential issue in rock engineering.The stability and safety factor of the rock slope largely depend on the strength and distribution of joints.However,the distribution and the development of the joints are affected by many factors.The development of joints is affected by the regional geological tectonic and shows a strong predominance of the structural plane characteristics.At the same time,the joints show a strong randomness and uncertainties within the dominant structure group.A nondeterministic probability model named Monte Carlo Method is used to simulate the random joint distribution in the main slide plane.A series of simulations are performed using the particle flow code(PFC2D)accordingly to get the sliding surface,the safety factor and the stacking pattern after slope failure.The modified gravity increasing method is introduced to the safety factor calculation.Numerical simulation tests are performed to investigate the relationship between the micro parameters of the particle and the macro properties of the specimen.The gravity is gradually reduced until the rock slope fails and the discontinuities coalesce,using the ratio of average unbalance force as the failure criteria of the slope.The effect of the increased normal stress is reduced by decreasing the friction coefficient.The current particle velocity or displacement vector pattern is thus the corresponding sliding surface.The assessment of the safety factor,the sliding surface,the stacking and flow range and rolling distance of falling rocks are discussed from the point of statistics by using the function of probability statistic,which turns an issue of uncertainty to a statistic problem.