Application And Finite Element Analysis Of Large Diameter Anchor Rope In Sand Layer

In the Pearl River Delta region, due to the impact and influence of river silt deposits, there is a lot of soft soil. Soft soils usually have low intensity, high compressibility, low shear strength, relatively large pores and other unfavorable nature. Therefore, when the use of prestressed anchor as the retaining structure of foundation pit excavation in soft soil area, weak soil layer will bring a lot of trouble to anchor hole drilling, hole collapse, sticking, drill burying accidents after another. Also in the soft soil usually need to increase the anchorage length to improve the pulling force, however after anchorage length exceeds a certain value, the pulling force of prestressed anchor cable is not obvious increase, at the same time long anchorage length will affect the underground space around of the foundation pit. To solve this problem, the large diameter anchor cable can be used in engineering. Which increase the hole diameter of anchor cable, the anchoring the entire large diameter is 500 mm ~ 800 mm, which can improve the uplift bearing capacity. What we studied in this paper are the force analysis and the engineering application of the large diameter anchor cable.The main research work includes as followed:(1) Introduced the development history and research status of prestressed anchor cable from the theoretical research, experimental analysis, finite element simulation, and analyzed the problems and deficiencies of prestressed cable research, indicated the direction for further study.(2) Made a brief state on finite element theory, introduced the cell type and the constitutive mode of the soil, prestressed anchor, retaining piles, and then introduced the finite element software Midas GTS.(3) Built up a single prestressed anchor FEM model in Midas GTS, analyzed the distribution of axial force and shear stress in anchoring section, and discussed the factors of prestress, the elastic modulus of soil, the anchor diameter change, influence on anchorage section stress. And finally compared the difference between ordinary anchor and large diameter anchor in stress.(4) Combined with practical engineering, chose the reasonable parameters, made a comprehensive analysis on the application of large diameter anchor cable in foundation pit supporting, by changing the parameters of the anchor cable structure, considering parameters change the influence on large diameter anchor supporting effect, and draw some useful conclusions for future similar engineering.