Effect of Wall Roughness and Concentration of Clay on Erosion in the Hole Erosion Test | Science Publications

American Journal of Engineering and Applied Sciences

Khamlichi Abdellatif¹  Bezzazi Mohammed¹  Dubujet Philippe¹  El B. Larbi¹  Parron V.M. Angel¹  Kissi Benaissa¹  Rubio C.M. Dolores¹ 

关键词: Piping;    hole erosion test;    turbulence;    k-ε model;    wall roughness;   

DOI  :  10.3844/ajeassp.2010.734.739

学科分类：工程和技术（综合）

来源: Science Publications

【 摘 要 】

Problem statement: Internal soil erosion is a real threat for hydraulic infrastructures. Inits final stage it develops in piping involving the formation and progression of a continuous voidinside the soil between the upstream and downstream sides. The hole erosion test was introduced tocharacterize kinematics of piping in terms of the time left to rupture. Actual modeling approaches ofthis test are essentially one dimensional. The wall shear stress generated by the flow is assumed to beuniform, so that erosion rate is also uniform along the hole length. Experimental observations showhowever an irregular profile of the eroded hole. Approach: In this study an axisymmetric extensionrepresentation of the hole erosion test was performed. The biphasic flow at the origin of surfaceerosion occurring in the porous soil sample was modeled by means of the renormalization groupbased k-ε turbulence equations. Fluent software package was used to perform the numericalmodeling. Results: This had enabled to estimate the wall shear stress which was found to be nonuniform along the hole length. Erosion rate was then estimated by using a classical law. Its variationsas affected by the applied gradient pressure, fluid density as well as the actual fluid/soil interfaceroughness were analyzed. In particular, wall roughness and clay concentration were found toincrease noticeably the erosion rate. Conclusion/Recommendations: Predicting erosion rate at thestart of piping formation can be done by the proposed model. Flow features are however verycomplex in the real HET configuration. In particular, clay concentration does not vary equally alongthe hole length. The erosion law coefficients are variable. Transport phenomenon of some soilsparticles that detach is present in the problem. Further investigations including these aspects shouldbe performed in order to render more profoundly the complex physics involved in this experiment.

【 授权许可】

Unknown