and ribbed;  bending bearing capacity;  Reliability

It is more difficult to arrange steel bars in a single section in a small section, and most foreign regulations use parallel reinforcement to solve it, but the influence of reinforcement on the bearing capacity after merging is not clearly stipulated, and the bearing capacity and stiffness of parallel reinforcement beams in China are less studied. Through the test of the bending bearing capacity of 10 reinforced beams and 3 control beams, the influence of the reinforcements on the bending bearing capacity of the beams was analyzed, and the test was loaded at three points, and the results showed that compared with the control beams, the bending bearing capacity of the reinforced beams was reduced, and the reduction was between 10%~15%, through statistical analysis, the recommended formula for the bending bearing capacity of the reinforced beam was given, and the reliability analysis of the suggested formula was carried out.