Analysis Of Mechanical Properties Of Root Stone Under Water Flow

It is significance to take measures of scattered rubble to protect roots in maintaining the safety of embankment protection works.The erosion loss of the root stone surface is closely related to the hydrodynamic characteristics,the size of the root stone and the contact friction between the root stones.At present,in the study of the theory of root-stone loss,the relationship between the starting force of the block and the velocity of the flow is mainly considered.Moreover,the lack of research on the definition of complex hydrodynamic boundary and the simulation method of the loss process restricts the analysis of the effectiveness of the root stone reinforcement technology.In this paper,the basic flume is used to carry out flow scouring test and mechanical calculation and analysis.The influence factors such as Reynolds number,block shape,impact time and impact frequency are taken into account.The spherical flow force formula is improved,and the process characterization functions of rock-moving force,uplift force and eddy force affected by flow fluctuation are established.The paper proposes the hydraulic boundary formula of the root-rock discontinuous material affected by water flow erosion.Based on the comprehensive evaluation theory of shear strength of rock mass discontinuities,the correlation between shear strength of underwater blocks and friction angle of discontinuities,wall rock strength and roughness coefficient is analyzed,and the discrete failure model of saturated blocks is established.The paper makes coefficient corrections to the JRC-JCS model formula.At the same time,the dam shore model test of the typical Yellow River dam was carried out,and the root stone lost process was simulated.A set of root rock discrete body instability theory and physical test verification method were established.The research results are helpful to reveal the mechanism of rock loss along the dam bank,improve the theory of discrete mechanics of underwater discontinuous media,enhance the effectiveness of rock reinforcement technology,and provide theoretical basis for river regulation design and flood control and emergency plan formulation.