Experimental Study On Waterproofing Embankment Model Of Geotechnical Materials

Water is inevitably encountered in the construction and operation of highways.Under the action of water,highway subgrades often cause many diseases,which seriously affect the normal use of highways,and due to the wide distribution of expansive soils in China,expansive soils For water sensitivity,the poor foundation soil of expansive soil is more important for the treatment of water.The paper studies the geotechnical and composite geomembrane from the model test of the enhanced waterproof embankment of embankment using geosynthetics.The effect of using it in highway embankments.The paper first carried out the basic physical parameter property test of the test fill,and then carried out a series of embankment model tests.Through the influence of rainfall or groundwater,whether to carry out reinforcement and whether to carry out waterproofing,comprehensive research and expansion The basic physical parameters of the soil were numerically analyzed and fitted.The specific research results are as follows:(1)The expansive soil and red clay were tested,and the basic physical parameters such as the natural density,water content,specific gravity,liquid-plastic limit,optimum water content,cohesive force and internal friction angle of the soil were obtained.The numerical analysis provides some necessary parameters.(2)In the embankment model test,the displacement of the embankment changes with the increase of the height,the smaller the horizontal displacement will change,and the vertical settlement will be larger.When it is at the same height,the closer to the horizontal displacement of the embankment slope The larger it will be,the smaller the vertical settlement is,and the deformation settlement of the expansive soil embankment model is significantly larger than that of the red clay embankment model.The influence of groundwater on the embankment deformation and settlement is greater than that of rainfall.(3)In the embankment model test,when the geogrid is used alone for reinforcement,the lateral horizontal deformation of the embankment will have a significant improvement effect,but the settlement improvement in the vertical direction is not significant.When using composite geomembrane for waterproofing,and then using geogrid for reinforcement,the horizontal displacement and vertical settlement of the embankment have a significant improvement,such as the level of the expansive soil embankment model in the groundwater condition.The displacement is reduced by 37.8%,and the vertical settlement is reduced by 13.1%.The combination of composite geomembrane and geogrid reduces the vertical settlement of the expansive soil embankment model by 81.2% and the horizontal displacement of the slope top by 80.3%.(4)In the embankment model test,the rainfall will cause the earth pressure of the embankment soil to decrease first and then increase.The groundwater will cause the earth pressure of the expansive soil embankment model to decrease first and then increase,and the increase of earth pressure will lead to The load on the embankment is increased,which is unfavorable for the stability of the embankment.The soil is softened by water,the cohesion and the internal friction angle are reduced,which makes the shear strength drop sharply,which is even more deadly for the embankment.(5)The results of numerical simulation show that the physical model test can accurately reflect the actual deformation of the embankment filling,and also verify that the restraining effect of the geogrid in the horizontal direction is more obvious than the improvement effect on the vertical settlement.Much more,the combination of physical model tests and numerical simulations can provide a reference for future work.