A Method for Reducing Negative Bending Moment of T-Frame Bridge

Abstract

The invention discloses a method for reducing the negative bending moment of a T-type rigid bridge. The method comprises the steps that in the design stage, an upward jacking load design value is calculated according to a counter force design value of side pier supports and a set reducing value of the negative bending moment of a main beam arranged at a main pier, and an upward jacking displacement design value sdesign is calculated according to the upward jacking load design value; in the construction stage, the upward jacking displacement design value sdesign is corrected according to a construction error of the height of the cantilever end of the T-type rigid bridge to obtain an actual upward jacking displacement value sactual, an actual upward jacking load F is determined according to the actual upward jacking displacement value sactual, then a jack is adopted to apply the actual upward jacking load F at the cantilever end of the T-type rigid bridge, and the T-type rigid bridge is made to meet the requirement of a bridge line. According to the method, the negative bending moment of the main beam arranged at the bridge pier is reduced, stress is reasonable, and materials are saved; the counter force of the side pier supports is appropriately increased, and disengaging and dropping of the side pier supports can be effectively prevented; main beam drooping deformation generated during construction is effectively solved, and the driving comfort is improved.

Description

technical field [0001] The invention relates to a construction method of a T-structure bridge, in particular to a method for reducing negative bending moments of a T-structure bridge. Background technique [0002] T-frame bridge is a type of rigid-frame bridge, which has the characteristics of cantilever force, and cantilever construction method can be used, that is, the upper beam body of the structure is constructed segment by segment from the top of the main pier to both sides by using a balanced cantilever construction method to form a " T”-shaped double cantilever structure, and then the construction of the bridge closing section. The T-frame bridge can also use the construction support to carry out the construction of the cantilever of the main beam. [0003] After the cantilever method construction of the T-structure bridge or the removal of the construction support of the main beam, the main beam at the main pier will produce excessive negative bending moment, and t...

AI Technical Summary

Problems solved by technology

If no measures are taken, the excessive negative bending moment of the main girder at the main pier will result in a large amount of steel used and a large beam section, which is uneconomical, and the excessive sagging deformation does not meet the requirements of the bridge alignment, which also affects the driving comfort

In addition, it will also cause the reaction force of the side pier to be too small, causing the support of the side pier to be empty or even fall.

Images