Research On Anti-uplift And Drainage Performance Of Drainage Screw Anchor And Its Application In Slope

Anchor rod is a commonly used reinforcement material in contemporary slope management projects.It can be connected to the engineering structure at one end to anchor the slope surface and deep soil together to improve the slope stability.The application of anchor bolts has a history of more than 100 years,and various forms have been derived,including wooden anchors,reinforced mortar anchors,pipe joint anchors and so on.Among them,in recent years,a new type of anchor rod,a spiral anchor rod with drainage function,has emerged.It has the characteristics of convenient construction regardless of the stratum and soil conditions.Not only that,spiral bolts also have the advantages of simple manufacturing,short construction period,low cost,recyclable,clean and environmental protection.Functionally,this type of spiral anchor with drainage function,as the name suggests,has a good drainage effect,which can effectively prevent the effective stress reduction of the slope caused by heavy rain.Not only that,the spiral anchor also has good pull-out performance,It can tightly combine with the surrounding soil through the spiral blade to improve the integrity and stability of the soil.First of all,this paper analyzes the pull-out performance and related pull-out mechanism of the spiral anchor through the field pull-out test.A variety of spiral anchors with a diameter of 48 to 76 mm and a spiral blade width of 50 mm were tested in 12 different fields on 5 different slopes.The relationship between the force and displacement and the ultimate pullout force were obtained..Through the analysis of these data,the influence of the angle of anchor setting,the thickness of overburden,the shear strength of the soil and the squeezing effect against the pull-out force were studied.Subsequently,related formulas for calculating the pullout resistance were also proposed.Next,the indoor model test of drainage using the drainage pipe instead of the spiral anchor was carried out,and the drainage performance of the drainage pipe and the factors affecting its performance were analyzed.In the model test of drainage,by calculating the drainage speed and measuring the pressure head,the corresponding curve of the drainage speed with time and the decline of the pressure head are obtained.From the comparison of the two groups of experiments,it is found that there is weak water permeability around the drainage pipe Relevant conclusions.Later,in order to verify the conclusion of the model test,the relevant data of the drainage test of the large slope model was also quoted and compared with the conclusion of the numerical simulation,thus confirming the relevant conclusion.In this paper,the effect of screw bolt in slope treatment is studied by two related tests of uplift resistance and drainage,which provide theoretical and experimental basis for the application of screw bolt in slope treatment.