In order to acquire the knowledge required in an expert system for preliminary design of cable-stayed bridge, a database regarding to 137 cable-stayed bridges which are now under service and erection has been constructed. Then, an attempt has been made to develop its expert system, into which the information and knowledge obtained from the constructed database and the existing resear ches related to the cable-stayed bridges are incorporated. If only total length and width of the bridge are input into this system, then the appropriate types of cable system, pylon and main girder are suggested. And the rough total steel weight, axial force of pylon, non-linear bending moment of main girder, critical wind speed for flutter, etc. are indicated. A schematic perspective of the suggested cable- stayed bridge can be also shown on a display if the user requests it.
