An application of a multi-objective programming technique to construction accuracy control of cable-stayed bridges

Cable-stayed bridges are gaining much popularity in Japan due to their beautiful shape. During and after construction, this kind of bridge needs to have the cable length adjusted in order to attain errors of cable tension and camber within some allowable range. This problem becomes a multi-objective optimization, and its solution has been attempted by traditional goal programming with a squared sum of objective functions as a scalarization function. Several authors, including one of the authors of this paper, reported, however, that it is not so easy to obtain a desirable solution by adjusting weights as in goal programming. On the other hand, the aspiration level approach to multi-objective programming problems is now widely recognized to be effective in many practical fields, because it is very simple and easy to implement, and does not require any mathematical consistency for the judgment of decision makers, and moreover uses the aspiration level of decision makers as a probe rather than weights for objective functions. The authors developed user-friendly software for construction accuracy control of cable-stayed bridges using a multi-objective programming technique, called the satisficing trade-off method, and applied it to some real bridges. In this paper, we report our experiences of real applications of the multi-objective programming technique to construction accuracy control of cable-stayed bridges.