Taking the reinforced concrete and prestressed concrete works in one expressway as example from two aspects: camber and lower flexibility setting of simple beam the differences between the lower flexibility of reinforced concrete simple beam and the camber deformation of presstressed concrete simple beam are presented.

According to theoretic analysis, computing the bending deflection of every roller is enabled to ignore the effect of the web and only allow to the rectangular section made up of flange plates.

Genetic analysis of large span beam bridges long downwarping and controlling downwarping;

Research on the safety of pre-stress T beam down warping of one railway bridge;

Discussion on the prevention of reinforced concrete beam in down warping in engineering practice;

On the causes of beam bridge continuous down-warping and its control measures;

Research purposes:The post down-warping is a common disaster for large span concrete beam bridge,which can cause serious danger to bridge,so it is urgent to find out the main cause for down-warping for the purposes of prevention of it and finally control of down-warping.

This paper describes in details the principle, the operation and the experience for modifying the down deflection of a fixed-girder for bucket wheel stacker/reclaimer and keeping its pre-designed up deflection by means of firing and pre-tension method.

Which is used to correct the down deflection on the gir der of 20 t bridge crane under longitudinal shear.

The main reason of the main beam down deflection was that the most complex stress exceeded the admissible value and achieved the yield limit value.