部分地锚斜拉桥经济性能分析

Cost Analysis of Partially Earth anchored Cable stayed Bridge

摘要:

将部分地锚斜拉桥分为拉索、主塔、主梁、锚碇、基础等五部分,分别推导了其材料用量计算公式,引入材料单价系数，得到了全桥总造价和单位桥面面积造价.据此开展了该桥型经济性能参数研究,得到了主要结构参数的最优取值,即地锚与中跨跨径之比为0.3~0.4,边中跨比为0.40~0.45,塔跨比为0.15~0.20.对比结果表明,随锚碇处地质条件不同,在主跨跨径超过800~1 600 m后,部分地锚斜拉桥的经济性能优于全自锚斜拉桥.

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.