A steel Vierendeel sandwich plate used as a large-span lightweight floor structure for vibration comfort during crowd gatherings was considered. Taking the steel Vierendeel sandwich plate in Guizhou Museum as an example, through finite element transient analysis, the effects of the structural damping, pedestrian self-weight, floor span, surface concrete slab thickness, and structural parameters on the floor’s acceleration response distribution were deeply studied. According to the distribution characteristics of the acceleration response, a distribution model function was constructed, and a distribution Gauss model of the relationship between the peak acceleration response and the position of the steel Vierendeel sandwich plate was established. A field test of the sandwich plate under human-induced fixed-point excitation was carried out, and the model fitting results were compared with the actual test results. The results showed that the Gaussian model could effectively estimate the peak acceleration response at different positions on the floor. In addition, according to the distribution model, a comfort evaluation method based on the comfort assurance rate was proposed that could greatly reduce the representative value of the acceleration evaluation. The research results provide a reference for the comfort evaluation and corresponding vibration-reduction design of long-span steel Vierendeel sandwich plates.

In this paper, a new type of structure was introduced. The spatial steel grid structure was composed of the top layer, lower layer H-shaped steel ribs and square steel tubes. The shear key is the key part of the structure.Based on the real dimensions of a practical prototype,two sets of full-scale shear key specimens were made, one of which has vertical stiffening ribs. The loading tests of two groups of specimens were carried out to simulate cases under pure shears and the experimental results were compared with the simulations from the finite element analysis. The effects of vertical stiffeners on failure modes, ultimate loads, strength-yield ratio and ductility of shear key were studied through experiments. By parametric analyses in the present article, relations of the stiffening plates width and thickness was recommended.

Steel open-web sandwich floors (SOSFs) have been applied in several pioneering industrial and public buildings. The traditional square tube shear key (STSK) is changed into a flanged cruciform section shear key (FCSK) to further improve the bearing capacity of SOSFs. A half-scale test model is designed. A graded static loading test is performed to measure deflection and strain. The calculation formula of the intersection beam analogy method (IBAM) considering the influence of shear stiffness is proposed. A finite element (FE) analysis was also performed. The results of the test, IBAM and FE method are compared. The maximum deviation of the deflection obtained by them is less than 5%, and the maximum strain error is less than 7%. These figures prove that all three methods have high precision in the elastic range. Compared SOSFs use a different shear keys with the same grid size and chords, the maximum Mises stress is reduced by 55.9% and the maximum displacement is reduced by 36.1%. The new shear key imparts the structure with improved bearing capacity and safety margin.

The gymnasium of Fule International School in Mianyang, Sichuan are multi-storey large-span buildings with a maximum span of 36 m and use a new system-steel grid cassettle structure. In this paper, the structure form, prefabricated construction method and support unloading process of the gymnasium are introduced in detail. To ensure smooth construction unloading, the deflection deformation of the large span floor and the field splicing node are monitored. Results show that the prefabricated construction method of the Mianyang Fule International School Gymnasium and the steel column-scaffold combination support system are affordable. After unloading, the floor has the traits of plates and relatively greater rigid reserve. Thus, it is applicable for large-span and high-load floor structure. The stress in the splicing node in the inflection point (L/2, L is the size of the grid) is relatively small, the bolt and the shearing-resistance plate have no slump, and the field splicing node is safe and reliable. The findings provide a certain reference value for the research and innovation in the process of assembly construction of multi-storey and large-span building.

For the new type of steel-concrete inclined column transfer structure (NSCICTS) with better lateral stiffness and ductility, the existing damage model and hysteresis model are difficult to accurately express the asymmetry of its test restoring force curve and the serious pinching phenomenon of the hysteresis curve, respectively. In this paper, an asymmetric damage model is firstly established according to the asymmetry of the curve, and the comparison with the existing symmetric damage model shows that the asymmetric damage model proposed can reflect the actual damage of the component or structure. Then, a simplified hysteresis loop model with a longer slip segment is established, and the damage formulas of the stiffness and residual deformation are established. Finally, the hysteresis rules are given, and the comparison with the test hysteresis curve shows that the proposed model can better simulate the structural mechanical properties. The model provides a theoretical basis for the overall nonlinear seismic analysis of the NSCICTS and other similar structures.