Study On The Variation Law Of Prestress Loss Of Anchor Cable In High Slope Of Muddy Dolomite In Moda Village,Guizhou

This article takes the 4# bedding high rock slope on the south side of the "Guizhou Sinopec Polyolefin Project" site in Moda Village,Guizhou Province as the research object.Through the systematic analysis of the loss factors of anchor cable prestress,the anchor cable prestress is carried out indoors.The reinforcement model test explored the change law of the loss of prestress with the length of the free section of the anchor cable.Finally,the indoor model test was verified by numerical simulation,and the stability of the slope and the loss of prestress were analyzed,and it was concluded that the argillaceous dolomite was high.The basic law of the change of slope anchor cable prestress loss,so as to provide a certain reference and basis for the formulation and implementation of slope prevention and support measures in the later stage of the "Guizhou Sinopec Polyolefin Project" and in the infrastructure construction.The specific content includes:(1)Conduct on-site exploration and collection of related data,including regional geological background,topography,stratum lithology,geological structure,hydrogeological conditions,etc.(2)From the tension system of the anchor cable,the tension method,the porosity of the anchor cable,the retraction of the anchor head fixture and the steel strand,the length of the anchor cable,the creep of the rock and soil,and the creep of the grouting material Analyze the loss of prestress under blasting construction,group anchor effect and external factors(rainfall,temperature).(3)Through a large number of indoor shear,compression and pull-out tests,it is determined that the rock mass material is made of barite powder,quartz sand,gypsum,and cement according to the weight ratio of 189:84:20:10.The cable material is a nylon rope with a diameter of 2mm,a modulus of elasticity of 2.3GPa,and a tensile strength of 450.5N.Through indoor reinforcement model tests,it is found that the loss of anchor cable prestress increases with the length of the free section.Increase and decrease.(4)Carry out the viscoelastic three-dimensional numerical simulation analysis.First carry out the simulation of the indoor model test.Corresponding to the measured prestress value in the previous chapter,it is concluded that the loss of the 1# anchor cable(the free section is 155mm)is small,and the loss rate is 20.6 %,2# anchor cable(free section is 95mm)loss rate is 22.8%;then the sensitivity analysis of the surrounding rock strength and prestress value.(5)Finally,the ideal slope model is used to perform FLAC3 D simulation analysis from anchoring angle,anchor spacing,anchor cable length and different prestress values to observe the displacement of rock and soil and analyze the loss of anchor cable prestress value.;Under comprehensive consideration and analysis,the anchor cable spacing is selected as 4m,the length of the anchor cable free anchoring section is 4m,the free section should be embedded 2m below the sliding surface is the best,and the anchoring angle is 20° as the best choice.Reasonable prestress applied by the anchor cable It is 1000 kN.