Abstract:

In order to obtain the high-accuracy solution for control tension of each strand of stay-cables during construction, this paper studied the nonlinear relationships among the parameters describing the static state of cables and proposed a high-accuracy and non-iteration solving method for control tension of each steel strand. Based on the exact solution of the catenary of the cable shape, the high-precision and approximate solution of the stress-free length of the cable was solved by the Taylor expansion method. Based on the two basic principles of forward assembly analysis and equivalent tensioning method, the equivalent static state of steel strands during the construction process was obtained by recursive calculation when different steel strands were tensioned. The high-precision solution for the control tension of each steel strand was solved by approximating the unstressed cable length, the equivalent cross-sectional area and the projected length of the diagonal cable.Taking the stay-cables of the main bridge of the Honghe Bridge (a composite girder cable-stayed bridge with a main span of 500 meters) in Zhuhai city, the Jitimen Bridge (a prestressed concrete cable-stayed bridge with a main span of 210 meters) in Zhuhai city and cables mentioned in two literatures as examples, the error between the approximate solution of the method in this study and the exact solution of the catenary of iterative solution was calculated. The results show that the calculated error of the stress-free cable length between the method proposed in this paper and the catenary solution is less than 0.002%, and the tension error of each strand is less than 2%, which fully meet the accuracy requirements of construction. The method presented in this paper has the advantages of high precision and low calculation cost, so it has a high value of popularization and application.

Key words: parallel-strand, stay cable, control tension, catenary