Analysis On Progressive Collapse Resistance Of RC Step-terrace Frame Structure

At present,the application of mountainous buildings more and more widely in many mountainous cities.The mechanical properties of the mountain structure are significantly different from those of the general structure from the structural point of view.However,there are few studies on mountainous structure,especially the continuous collapse performance of mountain structure.China has not yet put forward the guidance on the anti-continuous collapse of the provisions,so this article refers to the United States regulate the GSA and will use the alternate path method to study the number of layers,drop layers and spans,layer and height,energy consumption of the impact of RC step-terrace frame structure.The main work is as follows:(1)According to the GSA and the particularity of the step-terrace frame structure,the parameters such as the plane position,elevation position and evaluation index of the column to be removed are determined and the anti-continuous collapse of the step-terrace structure was studied by using the alternate path method.(2)Based on the test results,the static linear,static nonlinear,dynamic linear and dynamic nonlinear analysis methods based on the demolished component method are verified and compared with the reliability of the study.(3)Explore the similarities and differences between the anti-continuous collapse performance of the RC step-terrace frame structure and the common ground frame structure.(4)Taking the SAP2000 software as the calculation platform,the effects of number of layers,drop layers and spans,layer and height on the anti-continuous collapse performance of the step-terrace frame structure are discussed by using the three methods of static linearity,static nonlinearity and dynamic nonlinear analysis based on alternate path method.The main conclusions are as follows:(1)The results show that the static and static nonlinear and dynamic nonlinear analysis methods are reliable,and the results of static analysis are relatively conservative.The results of dynamic nonlinear analysis are in good agreement with the experimental data.(2)Due to the existence of slope in the mountain structure,the redundancy of the remaining structure after the failure of the column is less,and its anti-continuous collapse performance is worse than that of the ordinary RC frame structure.But the effect of the failure column from the slope is less affected by this.(3)Under the condition that the total number of layers is constant,the anti-continuous collapse performance of the layered structure decreases with the increase of the number of layers.Under the condition of constant total span,with the increase of the span of the barrier,the anti-continuous collapse performance of the falling frame structure is gradually improved.(4)The slight change of the height of the layer structure has little effect on the continuous collapse performance of the layer structure.The larger the span structure is,the weaker the anti-continuous collapse ability.However,when the limit state is reached,the effect of the catenary is more obvious as the span increases,so the later carrying capacity decreases more slowly.(5)Reasonable setting of viscous dampers is helpful to improve the anti-continuous collapse performance of the layered frame structure,and can improve the ability of the structure to resist the dynamic effect and make the deformation of the structure stabilize as soon as possible.(6)After the corner column,the side pillar and the inner column are destroyed,the load transfer paths of the three remaining structures are increased in turn,and the equilibrium of the force increases in turn,and the dynamic response shock duration decreases...