| As an important part of transmission line,the stability of HV transmission tower is related to the safe operation of power network system.Because of the vast territory and complex terrain in our country,the high voltage transmission tower is inevitably set up on the ridge and steep slope edge.These areas are prone to landslide geological hazards induced by external factors,thus threatening the stability of the power tower,leading to power tower tilt,broken line and tripping and other power network accidents.The engineering practice proves that the external inducing factors including excavation,snow load and rainfall will threaten the stability of the power tower foundation to varying degrees.Based on this problem,this paper takes the State Grid 500 The displacement and landslide safety factor of the tower foundation under the action of excavation,wind load and rainfall are studied by using GeoStudio 2012 software and soil parameter test based on the large-span 200# tower of the Yangtze River in the Badong section of Binjin and Fufeng.Through specific systematic studies,the following conclusions have been drawn:(1)Through literature statistics and collation,the spatial and temporal distribution of different induced landslides in the transmission line route provinces and their proportion are obtained,and it is preliminarily determined that rainfall and engineering excavation are the key factors to induce landslides.(2)The parameter test of landslide soil layer was carried out,in which the large straight shear test was carried out,and it was found that the cohesive force was positively linear related to the compactness layer,while the internal friction angle was negatively linear related to the compactness,and the cohesive force and internal friction angle were negatively linear related to the moisture content,and the correlation fitting linear equation was obtained.The triaxial unconsolidated undrained soil was tested and the optimum moisture content(11%)was found.(3)Based on GeoStudio software,the influence of different excavation position and size on the stability of landslide is analyzed.(4)The influence of wind load change and lower road excavation on landslide safety factor and displacement of tower foundation is analyzed,and the influence of road excavation on local landslide safety factor is obtained.(5)The stability of tower foundation landslide under different rainfall intensity,rainfall type and rainfall duration is analyzed.(6)Compare the influence of wind load,highway excavation and heavy rainfall on landslide of tower foundation.It is found that heavy rainfall has a significant effect on the horizontal displacement of tower foundation and the safety factor of ancient landslide.The influence of highway excavation on vertical displacement and local landslide safety factor of tower foundation is significant. |
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