Pre-stressed steel structures with large space are widely used in stadium, exhibition hall, theater and other buildings today. In order to study the fire-resistance behavior of suspended steel lattice shell of a stadium, the method of performance-based fire resistance design is used. First of all, the stadium physical model is established and the software FDS is used to determine the heating curves of the measuring points of the large space structure for two fire scenes. Compared with international standards heating curve, the heating curves of the large space structure obtained here has characteristic of local high-temperature. The finite element software MSC.MARC is further used to simulate the fire behavior of the pre-stressed steel structure with large space, in which the fire scene with 10MW design power of fire source and 30 minutes duration of fire are considered and two loading ways that overall non-uniform temperature field loading and the local high temperature components loading are accepted. The results show that the pre-stressed steel structure with large space has good fire resistance behavior, and the overall failure will not take place for the fire scene suggested here during 30 minutes duration of fire.

Mechanical behavior and bearing capacity of ordinary concrete filled steel tubular short column (NCSSC) and ceramsite concrete filled steel tubular short column (CCSSC) subjected to fire load are experimentally investigated. Effect of the parameters, such as the maximum value of fire temperatures, fire duration on the strength and ductility of the two types of specimens were especially discussed. The test results show that both of the specimens of NCSSC and CCSSC after fire have higher bearing capacity and better ductility, there was no descent segment in load-displacement curves of the most specimens after the fire load was subjected, and even the case that bearing load increased again after descent segment arose. It was concluded that the maximum response temperature of specimens and fire duration time has great effect on the axial bearing capacity of concrete-filled steel tubular short columns subjected to fire, and there is a turning point of temperature for the influence.

To study rupture mechanism of structural steel, fracture experiments were tested on 12 notched plates with different thickness. The results of experiments indicated that the first crack initiated at the notched edge and expanded rapidly along the width of the plates after running through the thickness. Finally, the specimens fractured at the critical section, the fracture ductility decreased with the thickness. By numerically simulating the fracture stress field of the notched plates at initial cracking based on generalized yield model, the applicability and accuracy of the suggested fracture criterion were comparatively verified.

Referring to an egg shaped yield function for geotechnical materials, a failure criterion for light-weight aggregate concrete is put forward, in which the tensile and compressive meridians are egg shaped curves and the failure envelopes in deviated plane is smooth elliptic curves. The suggested failure criteria could describe the failure characteristic of lightweight aggregate concrete at different stress state. The precision of the suggested egg shaped failure criteria is verified by comparing with experiment data of lightweight aggregate concrete.

In order to look into the causes of fire response and post-fire bearing capacity of the steel tubular columns protected with different materials, the fire test was conducted for a set of circular steel tubes protected with different materials such as gypsum fireproof panel, bamboo plywood and the ordinary lumber core plywood, and the steel tube without any protective material. The fire response temperature of surface of steel tubes is measured and the axial compressive bearing capacity of the specimens after fire are tested and analyzed. The test results show that gypsum fireproof panel has the best fire protection characteristics, the ordinary lumber core plywood and bamboo plywood can also retard rising of the surface temperature of the steel tubes during the initial 35min although they are combustible materials. It is found that the post-fire bearing capacity of the steel tubes protected with different materials varies evidently, and the maximum value of response temperature has the greatest effect.