Study On The Mechanical Behaviors And Design Of Steel Reinforced Concrete Beam-Type Transfer Story

Based on the engineering experiences and theoretical analyses, the characteristics of transfer story in the complicated building are introduced. Some fundamental properties of the Steel reinforced concrete (SRC) transfer beam are discussed. The mechanical transition through the SRC transfer beam is distinct and direct The depth of the transfer beam can be decreased, and the seismic behaviors can be improved by using SRC transfer story, instead of using the RC one. Analysis on the differences in bending capacity, shear capacity, crack and bending stiffness of SRC beam between the two codes of (YB 9082-97) and (JGJ138-2001) are carried out, and the related detail measures for SRC beam are proposed. It is shown that the calculation according to YB 9082-97 code is simple, which can be used in the preliminary design of the transfer beam section, while the prescription in JGJ138-2001 code is more accurate, which can be used in the further design or strength checkout of the transfer beam section.This paper deals with the mechanical behaviors, design of the section, choice of the calculating programs, and the related parameters of the two types of SRC transfer beam, including wall-bearing transfer beam and column-bearing transfer beam. On the basis of the study of a 32-story wall-bearing transfer beam building and a 9-story column-bearing transfer beam building, the transfer beams are designed in forms of RC and SRC structures respectively by SATWE program(Space Analysis of Tall-Building with Wall-Element).The relationships between the bending moment, shear force and the span-depth ratio are discussed. The results indicate that the bending moment and shear force increase as the span-depth ratio of the transfer beam increases. Under the sameconditions, the span-depth ratio of the SRC transfer beam is larger than that of the RC transfer beam in a certain extent. It is suggested that the span-depth ratio of wall-bearing transfer beam should be less than 8 in seismic design, 10 in static design for SRC structure. The allowable span-depth ratio of SRC column-bearing transfer beam should be lower than that of SRC wall-bearing transfer beam. Therefore the span-depth ratio of column-bearing transfer beam should be less than 6 in seismic design, 8. in static design for RC structure. The height of the transfer story is decreased, and the stiflhess of transfer story is increased hereby the seismic behaviors of the structure are improved by using the SRC transfer beam. The detailing requirements and the related proposals of SRC transfer beam are also given for the guidance of engineering design and practical application.