Study On The Mechanism Of Drain Blockage In Road Slopes Based On Discrete Element Particle Flow Analysis

The rapid development of highway construction in China has provided strong support for social modernization.However,current highway construction often passes through regions with complex hydrogeological conditions,such as mountains and hills,which presents highly demanding technical requirements.The phrase “ten slides,nine waters” fully illustrates the significant impact of water on slopes,which has already been confirmed by engineering practice.The built-in drainage pipes within slopes lose drainage capacity with increased use,leading to potential failures and directly affecting slope stability,resulting in serious safety hazards.Therefore,draining excess water from slopes is an indispensable method to maintain slope stability.Currently,most solutions regarding the blockage of drainage holes remain theoretical,and there is a significant lack of relevant research conducted in the micro-scale field of seepage blockage.In this paper,based on the PFC discrete element particle flow software,a unit drainage structure under the seepage field was constructed,and the blockage patterns and mechanisms were systematically analyzed,and validated through indoor simulation.The main research contents are as follows:(1)A refinement of the microscopic parameters was conducted to achieve basic consistency between the indoor experiments and numerical simulations of triaxial tests using PFC software based on collected indoor triaxial test data of red clay.These microscopic parameters were further utilized as data support for subsequent construction of unit drainage structures.This approach was based on a thorough review of relevant literature.The results of this study are of theoretical and practical significance for improving the rationality of slope drainage design and reducing the risk of slope disasters.(2)A drainage unit structure model was developed in PFC software under seepage conditions,and parameters such as particle displacement,changes in force chains,and particle loss rate were analyzed.Furthermore,a thorough investigation was carried out on the three major factors that affect blockage: friction coefficient,fluid factors,and the number of geotextile layers.Incorporating the simulation results,a novel,replaceable drainage pipe structure hierarchy was proposed for in-depth research on the blockage mechanism at a microscopic level.(3)The anti-blockage capability of the new,replaceable drainage pipe structure was effectively improved as compared to traditional drainage pipes,as verified through indoor experiments conducted under different conditions.This new structure enables timely drainage of water from within the slope,which is beneficial for maintaining the stability of the slope project.In addition,its easy-to-clean and replace features substantially extend the service life of the drainage pipes for highway slopes.These results were based on a combination of numerical simulations and indoor experiments undertaken through constant head tests.