Study On Special Space Truss Steel Structure Under Complex Supporting Condition

Recently, holding pole is used increasingly widely in hoisting construction of civil engineering because of its hoisting advantage. Strength and stability are critical to holding pole. However, there are various calculation methods, still is short of uniform standard. Even some methods are not adequately accurate and not coincident with fact. The application of holding pole in civil engineering is usually based on previous experience. Set on "500kV Jiang Yin Great Crossing Engineering'", this dissertation sets forth a kind of effective means of strength analysis, and applies a reasonable deflection curve to carry out primary stability computation , for the holding pole used.Applying the finite element analysis software, SAP2000, the analysis model of holding pole is established, and the static performances are discussed here. Compared with three-moment method in common use, this analysis means is more predominant. At the same time, a simulation test is performed for part of holding pole, it is proved that the finite element software, SAP2000 is rational and feasible to analyze holding pole.The holding pole's section and bending rigidity are varied, and there are multiple axial concentrated loads and uniform distributed load acting simultaneously on it, this dissertation makes primary study on stability of perfect holding pole with energy method. Introducing displacements of every supporting point and the peak, Lagrange polynomial is obtained for deflection curve of holding pole. Using this expression, the dissertation analyzes the effect of supporting stiffness (cables and hoops) on stability of holding pole, by means of the numerical software, Matlab.Considering that the actual holding pole usually is "imperfect structure", this dissertation father does some research on initial imperfection, including initial bending, initial inclination, and initial eccentricity. Some useful conclusions are drawn out.This dissertation aims to accelerate holding pole's application in civil engineering, and can supply some references to relating design and construction personnel. This dissertation is of academic sense and of engineering value.