Reliability Analysis Of Tensional Cable Element And Study On The Design Value For Prestressed Steel Structure

Prestressed steel structure is one of the most advanced, scientific and active structural system among all the engineering structural systems. Cable is the most important element in prestressed steel structures. The reliability degree of the cable is rarely studied in and abroad. The safety factor method is adopted for the design of cable and the design value is decided by engineering experiences. The paper aimed to transfer the safety factor method to the probability limit condition design method which is based on the reliability degree theory.The paper simply introduces the prestressed steel structure, discusses the fundamental theory of structure reliability degree, and specifies the composition, classification, design value of cable.The paper collects experiment datum of steel wires and cables. The resistance uncertainties and the probability distribution of the cable are discussed from the aspects of material properties uncertainty, section geometrical parameter uncertainty and calculation model uncertainty.Three kinds of load effect combinations are considered, statistical parameters of dead load, live load, wind load effects and the resistance of the cable obtained in this paper are adopted, and the JC method in the specification are adopted to conclude the reliability index of the cable.The probability limit condition design method is adopted to design the cable. The target reliability index is decided with calibration method. Load partial factor, resistance partial factor, design value of the cable and the importance factor are gained through analyzing. With an engineering example, the calculation procedure adopting partial coefficient method is displayed to design the prestressed steel structure. At the end of the paper, research results are summarized, and some problems in this field to be deeply studied are proposed.