A method for identifying the internal force of a large-span suspension bridge main cable

Abstract

The invention discloses a method for identifying internal force of a main cable of a large-span suspension bridge, and relates to the technical field of maintenance of the main cable of the suspensionbridge. The method comprises the following steps: acquiring an unstressed radial load set q per unit length, an equivalent elastic modulus E of a main cable strand, a net area A of the main cable, acable force Pi of a sling, and vertical and longitudinal relative coordinates of a lifting point during blanking of the main cable; Due to the fact that the bending rigidity of the cable is very small, and no fixed shape exists, for cable structure calculation of the suspension bridge, the following assumptions can be adopted: (1) the cable is ideal and flexible, cannot resist pressure, and cannotresist bending; 2, the cable material conforms to Hooke's law; And (3) the acting direction of the cable unit load and the cable curve are in the same vertical plane. By deducing the relationship between the internal force of the main cable and the structure system parameters, the internal force of the bridging main cable can be accurately obtained only by actually measuring the structure systemparameters of the main cable, and the problem that the internal force of the main cable of the existing large-span suspension bridge is huge and inconvenient to identify is solved.

Description

technical field [0001] The invention belongs to the technical field of maintenance of main cables of suspension bridges, in particular to a method for identifying the internal force of main cables of long-span suspension bridges. Background technique [0002] The main cable of the suspension bridge is the main and most important component of the suspension bridge structure. It bears the heavy responsibility of transmitting the self-weight load and live load of the main girder to the main tower and anchorage. The main cable composed of prefabricated parallel high-strength steel strands can not only be elastically deformed by itself, but also affect the balance of the system through the change of its geometric shape, showing the characteristics of large displacement nonlinear mechanics. The shape of the main cable is mainly determined by the horizontal tension of the main cable, the force of the sling and its own load concentration, that is, it is not a parabola or a pure cate...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for identifying the internal force of the main cable of a large-span suspension bridge. By deriving the relationship between the internal force of the main cable and the structural system parameters, the main cable of the bridge can be accurately obtained only by actually measuring the structural system parameters of the main cable. The internal force of the existing long-span suspension bridge solves the problem that the internal force of the main cable of the existing long-span suspension bridge is huge and inconvenient to identify

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