Starting with the calculation method of ultimate bearing capacity of rectangular section beam with double layer steel-bar in concrete structure design joints and general design principle,construction method of upper longitudinal steel-bars of primary beam is analyzed in theory.

This paper gives a detailed analysis and study on the affecting factors on the bearing capacity of the cross section of the concrete beam with single reinforcement,and draws a conclusion that how much each factor affects the bearing capacity,which provides theoretical basis for solving the practical questions in works.

Analysis of the affecting factor of single-steel rectangle section beam bearing capacity;