Cost Analysis of Partially Earth anchored Cable stayed Bridge

Abstract:

The equations for material amounts of all structural parts in partially earth anchored cable stayed bridges were derived, including the stay cables, pylons, girders, anchorages, and foundations. The cost of both the entire bridge and per unit area of the deck was obtained by introducing the cost of per unit weight of each material. Then, parametric studies were performed from an economic behavior perspective, and the proposed parameter values were obtained as: the ratio of the earth anchored girder length to the main span length is 0.3 to 0.4; the ratio of the side span length to the total self anchored girder length in the main span is 0.40 to 0.45; and the ratio of the height of the pylon above the girder to the main span length is 0.15 to 0.2. The comparison of results shows that the partially earth anchored cable stayed bridge is more economical than the fully self anchored cable stayed bridge with a main span length over 800~1 600 m, of which the threshold depends on the geological conditions at the anchorages.

Key words:partially earth anchored cable stayed bridge; cost analysis; material amounts; parametric; earth anchored part length