Study On Flexural Experiment Of Multi-ribbed Composite Wall And Calculation Model Of Multi-ribbed Slab Structure

Multi-ribbed slab structure is a new economic and practical structural system, characterized by lightweight, good seismic behaviors, highly industrialized level, fast construction and excellent energy-saving effect. However, as a new structural system with a broad developing prospect, there are still some problems to be further studied and perfected.This dissertation is devoted to studying on the multi-ribbed composite wall, which is the main bearing member in multi-ribbed slab structure. Based on previous research achievements, experiments of moderate-high storied multi-ribbed composite walls are carried on. Combine with the mechanical and construction characteristic of multi-ribbed slab structure, a simplified mechanical model of the structure is put forward.The main content is described as follows:(1) In order to simulate the mechanical behavior of the bottom wall in a 12 storied moderate-high storied multi-ribbed slab structure, two 1/2-scaled model monotone experiments of the walls with two spans and two stories under vertical load, horizon load and bending moment are presented. Based on the test data, the wall's failure mode, bearing capacity, deformation performance and flexural stiffness degeneration are analyzed, which provide an important support for compression-bending capacity calculation and design method of the moderate-high storied multi-ribbed composite walls.(2) Combined with previous oblique section shear-bearing capacity tests of multi-ribbed composite walls, the walls' two typical failure modes and failure mechanisms are contrastively analyzed. The bearing capacity, deformation performance and other seismic performances of the walls with two different failure modes are studied. And the strain distributions of steel bars in the walls with the two different failure modes are especially analyzed. (3) According to the failure characteristic of the specimens and the steel bars' strain distributing disciplinarian in the bottom section of them, a calculation model for the bearing capacity of cross section of multi-ribbed composite wall is put forward by using a homogeneous concrete panel to simulate multi-ribbed composite slab. Moreover, based on plane-section assumption, the cross section compression-bending capacity formula for multi-ribbed composite wall is deduced, which is suited to the coupled walls with T-shaped out frame columns. And the determination method for large-small eccentric compression is also proposed.(4) A mechanical model, called frames-elastic composite panel model, is put forward to calculate the internal force and deformation of multi-ribbed slab structure during the elastic stage. In the elastic stage, the multi-ribbed slab structure can be considered as a framework system that composed of concealed beams, connecting columns and end frame columns filled with equivalent elastic composite panel. At the same time the validity of the model is verified by the two groups of previous experiments of multi-ribbed composite walls and a 1/10-scaled model shaking table test of 10 stories multi-ribbed slab structure.(5) By using the frames-elastic composite panel model that has been verified, the internal force and deformation calculation and the elastic time processing analysis of a completed multi-ribbed slab structure are presented.