Based on `reduced section',the thesis develops a method to rectify the strength and rigidness of the main bearing components in which an example is illustrated.

Equations and relative analytical procedure were developed to predict short and long-term deflection of cracked concrete beams strengthened with FRP laminates based on transformed section method.

So in the analysis model of frame structures,the rigid region should be set on all rigid ends of the beam,as a result the more reasonable calculation span of frame beam can be used for structure analysis to make the control section consistent with the calculation section of the beam.

It takes the south bank bridge of the Hubei Suiyuezhong Hanjiang bridge as the engineering background,applies the finite element software to calculating and analyzing the principal tensile stress of the control section of the box girder web plate in the construction stage and using stage.

The flexibility and strain of control section are measured.

In design of concrete frame structures,the actual control section of a beam end is located at the interface of the beam end with an adjacent column,not at the position of column axis.