Research On The Structural New Type Of The Precast Shear Wall At The Connection Between Foundation And Superstructure

Precast concrete structure is a kind of structural type which is assembled with the precast component,it can effectively shorten the construction period,and possesses a certain effect of environmental conservation.Currently,the majority of the domestic precast building sets up the transformation story in the second～third floor over the foundation,dividing the construction into the two parts: the in-situ one below the transformation story,and the precast one above the transformation story.This practice can ensure the bottom’s energy dissipation capacity is larger than the upper,the shortcomings,however,are obvious: not only delay the construction period,but reduce the assembly level,so that make the precast’s name does not match its reality.Based on these,the paper will develop the research on the structural new type of the precast shear wall at the connection between foundation and superstructure.The specific work is as follows:1.The conceptual design(1)Propose the three kinds of the structural new type of the precast shear wall at the connection between foundation and superstructure,on the basis of the comprehensive analyses,the type of the section steel’s disposition in the embedded column(PSWS)is filtered out as the most rational one,and it is selected as this paper’s research object.(2)The monotonic curve and the hysteresis curve are achieved,through the numerical simulation,the theoretical analyses,and comparison with the study on the ordinary reinforced precast shear wall(PSWB),so are the derivate indexes,including the strain and the stress,the yield displacement and the yield load,the frame curve,the damage process,the ratio of ductility,the energy dissipation capacity,the rigidity degradation,the energy dissipation mechanism,and the ratio between the behavior and the cost,from the conceptual design,it is presented PSWS possessing the larger load capacity,the stronger energy dissipation capacity,and the more convenient construction than PSWB.(3)The study on the numerical simulation exhibits that the failure of PSWS and PSWB is all the coupling one from the eccentric compression plus the oblique shear plus the direct shear at the connection between the shear wall and the foundation.2.The model study(1)On the basis of the conceptual design,the test device design is carried out,so are the specimen design of the two kinds of the comparative models belonging in PSWS and PSWB,respectively.(2)The comparative studies on the comparative models are carried out under the monotonic load and the low-cycle load,through the more careful numerical simulation and the theoretical analyses,the rationality of the proposed new type of the shear wall is validated once more.(3)It is verified again the failure of PSWS and PSWB being all the coupling one from the eccentric compression plus the oblique shear plus the direct shear at the connection between the shear wall and the foundation,by the comparisons of the normal section bearing capacity,the oblique section bearing capacity,and the direct shear capacity,in conjunction with the analyses on the bearing capacity from the finite element and the related documents.3.The study on the direct shear bearing capacityThe calculative formulae of the direct shear bearing capacity is derived,by the strut-and-tie model,with the evolutionary structural topological optimization(ESO-TO)software developed by the project group and the distribution of the principal stress vectors acting as the configuration tool,it agrees well with the test data here and abroad,verifying the rationality of the derived formulae.