Progressive Collapse Analysis Of Rc Frame Structures

The progressive collapse may cause heavy property loss and casualties, and may alsohave a badly social impact. In recent years, more and more research effort has been focusedon the method for structural design and analysis to prevent progressive collapse. Progressivecollapse of building structures has become a research hotspot in structural engineering.Design codes for the prevention of progressive collapse are available in some countries.However, there are no detailed design methods to resist progressive collapse in Chinese codes.There are various problems need to be solved, e.g., the capacity of structures designedaccording to the codes to resist progressive collapse is still inconclusive.In this thesis, some basic problems of design and analysis for resisting progressivecollapse are discussed. The capacity to resist progressive collapse for RC frame structures,designed according to the codes for seismic design of buildings, is analyzed using a specificstructure model. The main work of this thesis is as follows:(1) Some of the main foreign design codes and standards of progressive collapse arereviewed. Methods of design and analysis and measures are discussed, providing a referencefor developing design standard of progressive collapse in our country;(2) The theory of fiber model and finite element flexibility method is illustrated; ascheme for fiber division in fiber model and the number of integration points in the beamelement are studied. Based on this, a nonlinear static analysis program is developed forprogressive collapse of RC frame structures, which is a foundation of progressive collapseanalysis for such structures;(3) With the nonlinear static analysis program, progressive collapse analysis of a RCframe structure which is designed according to Chinese design codes is performed for twocases: including or ignoring the effect of stiffness contribution of the floor slabs. The capacityof resisting progressive collapse for RC frame structure is studied in this way. The analysisresults show that: if the effect of floor slab is ignored, the capacity of resisting progressivecollapse is inadequate, extensive damage of the structure may occur after a bottom column isremoved. If the effect of floor slab is included, the capacity of resisting progressive collapseis adequate when the middle column in the short direction is removed for the case that the structure is designed for 8 and 9 seismic intensity. However, the capacity of resistingprogressive collapse is inadequate under other load conditions, and extensive damages to thestructural are possible after a bottom column is removed;(4) Some measures for preliminary design are proposed to prevent structural progressivecollapse.