Experimental Study On Mechanical Properties And Seismic Performance On The Staggered Floor Slab-Column Structure

With the rapid development of Chinese urbanization process, the dramatic increase in the quantity of cars, the car park has gradually become a social problem. The construction of efficient, economic and secure parking building has very important economic value and social significance. The application of staggered flat plate structure in parking buildings, can not only fully bring the capacity of slabs into play, but also can use the space reasonably, achieve economic and social benefits.The staggered flat plate structure, as a new type of structure, its unique mechanical properties determined that its capacity and seismic design can not be carried out based on the existing design methods. To understand failure mechanism, energy dissipation mechanism, seismic capacity, series of multi-level test research. FE simulation and theoretical analysis have been carried out on the seismic performance of the staggered flat plate structure from the nodes, space model and optimization model. The main work and achievements are as follows:First, by collecting, summarizing and assessing the research result of the staggered flat plate structure obtained by the research group, the conceptual design method can be given out from the two aspects of joint and structure. The conceptual design of the joints is based on constraining conditions and influence rules of staggered column caused by beam and slab. The seismic conceptual design of the structure is put forward from the three aspects of the overall seismic arrangement of the staggered component, the conceptual design of the structural elements and structure conceptual design requirements.Second, the low cyclic loading tests of two staggered structure joints specimens are carried out. Results show that the force mode of staggered structure joints under low reversed cyclic load changes from the diagonal compressive model to truss model with concrete as diagonal strut, stirrups as horizontal rod and longitudinal reinforcement of column as vertical rod, finally short column shear failure as the failure mode; Hysteresis curve shows the S type, pinch effect is obvious, ductility coefficient is low, the energy dissipation is not ideal; In engineering design, the reinforcement design and structural measures of short column should be strengthened and given special attention, as well as the steel anchor of core area node and the edge beam design.Third, put forward the proposed staggered flat plate structure joints’ destruction theory based on joints mechanical test results and the truss model theory. By comparing the frame joints sectional seismic checking formula in the current code for seismic design of buildings, put forward the proposed staggered structure joint core section seismic checking formulas, including a horizontal cross-section of the staggered joint core shear formula and horizontal shear capacity formula.Fourth, a shaking table mode prototype 1/7 test is carried out to research and analysis its overall seismic performance. Results show that if the structural calculation parameters, such as the displacement, torsion, have been under control, the split slab-column structure can be used in the 7-degree area, which is not recommended for use in 8-degree and above area without taking effective measures to strengthen. The lateral stiffness on both sides of the split column is not equal because of the split; there is a big difference of the dynamic response; maximum strain of the model happened in slab-column column and the column of Node location which should be attached importance in structural design.Fifth, for experimental research results and features of the staggered flat plate structure, the seismic optimization of general staggered structure is carried out by using Q235 soft steel ramp stays to strengthen the staggered position, in order to realize the deformation coordination between the floor and the column, and by which way to increase the energy dissipation capacity of the system. Elastic-plastic analysis is studied of the optimization model and the original model by ABAQUS. Results show that section parameter values of energy component can be based on cross-section bearing capacity equivalent theory and dissipative elements yield before the structure; the seismic performance of slab-column system has increased by using energy component and energy dissipation capacity increases by 20% than the original model.Sixth, according to the research results above, the structure measures and design recommendations of staggered structure are given out.As a new structure, this dissertation discussed and researched the staggered joints’ mechanical properties and system seismic performance. Before putting into engineering applications, there are still many problems to be solved. The dissertation gives an outlook on the problems.