Pylon Inclination Optimized Analysis of One Single Inclined Pylon Earth-anchored Prestressed Concrete (PC) Cable-stayed Bridge

In order to study the pylon inclination’s appropriate range of single inclined pylon earth-anchored prestressed concrete (PC) cable-stayed bridge, an approximate formula about minimum inclination of pylon was obtained by the nonlinear regression analysis methods and stress analysis of inclined pylon. The equations for material amounts of the cables, anchor, main beam and pylon were derived. The approximate formula about economical inclination of pylon was obtained by introducing the cost of per unit weight or volume of each material and the relationship between the cost of the entire bridge and the factors (the inclination of pylon and the inclination of earth-anchored cables) was analyzed. Results show that firstly, as for single inclined pylon earth-anchored cable-stayed bridge, the minimum inclination of pylon increases when the inclination of side cables at main span increases, and decreases when the allowable compression stress absolute value under the action of axial force increases. Secondly, the economical inclination of pylon is influenced by the inclination of earth-anchored cables and the allowable compression stress under the action of axial force. The economical inclination of pylon increases when the inclination of earth-anchored cables and the allowable compression stress absolute value under the action of axial force decrease. Thirdly, when the inclination of earth-anchored cables is within a given range, the cost of the entire bridge initially decreases, but then turns to increase with the decline of inclination of pylon. Decreasing the inclination of earth-anchored cables is beneficial to reducing the cost of the entire bridge. Finally, the inclination of pylon should be greater than 60° and the inclination of earth-anchored cables should be greater than 43°.