A method for constructing a main cable line shape of a three-tower suspension bridge with unequal main spans

Abstract

The invention discloses a method for constructing a main cable line shape of a three-tower suspension bridge with unequal main spans. The method comprises the following steps of firstly, calculating suspender force by utilizing a rigid support continuous beam method; secondly, calculating the line shape of the main span main cable according to the tower top height difference closing condition of the main span two-bridge and the bridge tower top and main cable midspan height difference closing condition; according to the principle that the horizontal forces of the main cables on the two sides of each bridge tower are equal and the principle that the shortest suspenders of the main span and the secondary main span are equal, deducing the line shape of the main cable of the secondary main span and the elevation of the low tower; secondly, according to the principle that the horizontal forces of the main cables on the two sides of each bridge tower are equal, the height difference betweenside towers and cable saddle IP points is known, and deriving the main cable shapes of left and right side spans; and finally, deriving the main cable line shapes of the left and right anchor spans according to the known main cable tension at the splay saddle, the bending moment balance of the splay saddle by the dead weight of the splay saddle and the known height difference between the splay saddle IP points and the anchoring points. The structural system is attractive in appearance, clear in stress, and is economical and reasonable.

Description

technical field [0001] The invention belongs to the field of bridge design, and in particular relates to a method for constructing main cable lines of a three-tower suspension bridge with unequal main spans. Background technique [0002] The spanning capacity of the traditional two-tower suspension bridge is the best among common bridge types, while the three-tower suspension bridge has increased the spanning capacity of the suspension bridge. As early as the last century, foreign countries attempted to construct multi-tower suspension bridges, such as the Oakland Bay West Bridge in San Francisco, the Kuroshima Kaikyo Bridge in Japan, and the South and North Bisan Seto Bridge. A two-tower suspension bridge, realized by connecting the anchors in the middle, is still a double-tower suspension bridge in essence. Later, for the first time in my country, a continuous system of large-span three-tower suspension bridges was realized, such as the Taizhou Yangtze River Bridge, the M...

AI Technical Summary

Problems solved by technology

In addition, if the height of the pylons of the secondary main span is equal to that of the main span pylons, the mid-elevation of the main cable span of the span will be increased, resulting in a longer suspender of the secondary main span, resulting in higher construction costs and unsightly bridge shapes. The problem

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