Numerical Simulation Of Landslide Based On The Locking Effect Of Spoon-Shape

The Spoon-shape locking landslide is a type of landslide affected by two factors,which are the terrain and the mechanical properties of the soil.The stability of landslide is controlled by natural soil arch effect and anti-slip effect to a certain extent.The natural soil arch effect is prone to occur at the shrinkage section of the landslide because of soil compaction.The soil in this part and the bedrock are the locking section of this type of landslide,which is compressive and has high mechanical strength.The stress distribution of the landslide body,affected by above two factors,is like arch.Under natural conditions,the soil particles in the landslide interact strongly and the landslide is relatively stable.Stress is transferred to the bedrock via arch to form a stable system finally.However,under the conditions of prolonged rain soaking and heavy rainfall,the interaction between soil particles is obviously weakened,and landslides are prone to occur,then the geological disaster may be formed.The Maijianwo landslide is chosen as the example in this research.The main results are as follows:(1)The landslide stability and failure mode are influenced by the unique topographical conditions based on the engineering geological analysis of the Maijianwo landslide.The positive effect of the locking effect of the Spoon-shape on the stability of the landslide is explained by analyzing the historical background of the occurrence and failure of this landslide.(2)the landslides are analyzed under different working conditions of natural and rainfall based on the finite-difference method of continuous media.The results show that the distribution of large principal stresses at the leading edge is "small in the middle and large on both sides".The mechanism of soil arch effect is explained.(3)A numerical model of the Spoon-shape locking landslide based on the digital elevation model was established by particle flow code method.The characteristics of the arch distribution of the contact force and the landslide evolution characteristics are explained on the meso scale.The calculation results of landslide model by discrete element method and continuous element method are compared.The similarities and differences of these two methods are also compared.The characteristics of the Spoon-shape locking effect are analyzed from different scales.(4)There are two factors affecting the natural soil arch,which are the nature property of the landslide soil and the topographical conditions.On the one hand,the effect of different parameters of viscous materials on the stress distribution is explained on the meso-mechanical scale.The contact stress distribution between 400 kPa and 600 kPa is arched obviously,and the high or low meso parameters are not suitable.On the other hand,the topographic condition is an important factor affecting soil arching.In the case where the shear outlet is narrow,the locking effect of the Spoon-shape is obvious while the wide is not.