Experimental study on the effect of floor slab on the progressive collapse resistance of RC spatial frame structure
Du Ke1,2 Teng Nan1,2 Yan Deng1,2 Sun Jingjiang1,2
1. Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China;
2. Key Laboratory of Earthquake Engineering and Engineering Vibration, China Earthquake Administration, Harbin 150080, China
Abstract：To study the effect of floor slab on the progressive collapse of reinforced concrete (RC) spatial frame, three one-story two-by-two bays 1/3 scaled models with the Xuankou middle school building collapsed in Wenchuan earthquake taken as the prototype structure were constructed. Among them, two models incorporate floor slab sub-structures and one is a pure framed sub-structure. The progressive collapse procedure of RC frame after removing the middle columns under the quasi-static loading can be experimentally studied. The experimental results show that the pure framed sub-structure may first exhibit the beam mechanism, with the occurrence of the “compressive arch” due to the axial compressive forces in the frame beams. Once the flexural capacity in the beam ends is lost, and the pure framed sub-structure goes into the stage of catenary mechanism with the tensile force of steel in beams to resist the loads from upper structure. Based on the comparison of experimental results between floor slab sub-structure and pure framed sub-structure, it is found that the peak capacities of beam mechanism and catenary mechanism are increased by 145% and 75%, respectively, due to the “membrane effect”, indicating that the slabs can significantly enhance the progressive collapse capacity of beam mechanism and catenary mechanism. Increasing the slab thickness increases the “compressive arch’’ of beams and slabs, and hence significantly enhances the capacity of beam mechanism. However, beams and slabs fail to work together under large deformation, leading to the punch failure of slabs and the decrease of the capacity and ductility of catenary mechanism.
杜 轲 滕 楠 燕 登 孙景江. 楼板对RC空间框架结构抗连续倒塌性能影响试验研究[J]. 土木工程学报, 2019, 52(6): 14-23.
Du Ke Teng Nan Yan Deng Sun Jingjiang. Experimental study on the effect of floor slab on the progressive collapse resistance of RC spatial frame structure. 土木工程学报, 2019, 52(6): 14-23.
