| Since the application of two-stage casting concrete is inevitable in concrete structural engineering, the affection of pre- and post-casting concrete interface on structure entire capability has caused comprehensive attention., Although lots of experimental researches have been done about the shear strength of pre- and post-casting concrete interface under lateral unconfined conditions, few reports about lateral confined have been seen until now in lateral confined conditions, which frequently occur in actual engineering.Based on a large number of home and aboard literatures concerned, the thesis summarizes the findings in this field, does experimental researches on 32 samples by confining strength, concrete strength and ratio of shear steel parameter, and analyses the shear transitive mechanism on lateral confined pre- and post-casting concrete interface.This paper brings forward the method of simulating pre- and post-casting concrete interface and shear steel and concrete interface through thin layer element whose material mechanical parameters are altered, which are determined by the tests. And emulation analyses of the lateral confined pre- and post-casting concrete interface shear test are made by large-scale FE software. The results reveal that the emulation analyses agree with each sample test result. FE emulation analyses show the deformations and stresses from load to destruction of typical samples, compliment and validate the test results.On the basis of the above achievements and consideration of many interface shear stress influential factors, the calculative model of interface shear stress is constructed to resolve the difficulty in pre- and post-casting concrete interface shear stress calculations. After this, a semi-theoretical and semi-statistical formula is established in which the calculative coefficients are determined by regression analysis of a large number of test results. By comparison, the formula is matches well with test results.Analysing the pre- and post-casting concrete structural performance of vertical tensioned prestressed concrete (VTPC) beam, the above formula is introduced to calculate the interface shear stress in VTPC beams, which provides the way to design and calculate lateral confined pre- and post-casting concrete interface shear stress. |
