Method for accurately computing unloaded cable shapes of suspension bridges with spatial cable planes

Abstract

The invention discloses a method for accurately computing unloaded cable shapes of suspension bridges with spatial cable planes. The method includes steps of setting preliminary deviation quantities;solving tangent points and horizontal force of various span main cables at main cable saddles at the moment; solving the difference delta H of horizontal force of mid-span and side span of the main cables under the preliminary deviation quantities; outputting the preliminary deviation quantities and the unloaded cable shapes under the preliminary deviation quantities if the delta H is smaller thanpermissible error values, or correcting the preliminary deviation quantities of the main cable saddles by the aid of influence matrix processes according to difference values and repeatedly carryingout the first, second, third and fourth steps until errors are smaller than the permissible error values. The method has the advantages that the method actually includes internal and external double-layer circulation, the tangent points of the various span main cables and the main cable saddles under the preliminary deviation quantities are solved by means of the inner-layer circulation, the preliminary deviation quantities are solved by means of the outer-layer circulation according to unbalanced force under the preliminary deviation quantities, only a single unknown number is available in each layer of circulation, and the method is excellent in solving efficiency and precision by the aid of the influence matrix processes under the condition that completed bridge tangent points are selected by initial values; correct results can be quickly solved by the aid of the method regardless of suspension bridges with parallel cable planes or the suspension bridges with the spatial cable planes.

Description

technical field [0001] The invention relates to an accurate calculation method, in particular to an accurate calculation method for the empty cable shape of a space cable surface suspension bridge, and belongs to the technical field of engineering construction. Background technique [0002] From the stress characteristics of the main parts of the suspension bridge and the main technical characteristics of the construction process, it can be seen that once the main cable is installed in place during the construction of the suspension bridge, the internal force and deflection of the main cable depend entirely on the structural system, structural weight, construction load and temperature changes. , it is not possible to adjust the cable force and elevation in the later stage like a cable-stayed bridge. Therefore, the calculation and analysis of the empty cable shape of the main cable under the action of its own weight has become the key to ensure the smooth and safe constructio...

AI Technical Summary

Problems solved by technology

The virtual intersection method is generally used to solve the empty cable alignment of the parallel cable plane suspension bridge, which needs to solve eight nonlinear equations. There are too many unknowns and the solution is very difficult

In addition, because the virtual intersection method only considers the correction of the vertical curve of the main cable saddle, it cannot consider the correction of the plane curve of the main cable saddle, so it cannot be applied to the solution of the empty cable alignment of the space cable surface suspension bridge

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