Experimental Study On The Dynamic Effect For RC Frame Structures To Resist Progressive Collapse

Due to the failure of supporting members, progressive collapse is adynamic loading process and unbalanced gravity load was induced. On theother hand, unbalanced gravity load triggers the movement of the structurewhich produces kinetic energy. The kinetic energy then transforms into elasticand inelastic strain energy and slows down the downward movement of thestructure. Thus, to prevent progressive collapse induced by the dynamicloading, the structure should accumulate adequate energy to sto p themovement before limit state of collapse. For the complexity of dynamiccharacteristics, equivalent static loading is commonly used to simulate thedynamic loading process. And experiments should be carried out to verify thevalue of dynamic increase factor (DIF) of progressive collapse phenomena.1. Pseudo-static tests are conducted to study the collapse-resistantbehavior of RC frames by removing the column. Research focus on catenaryaction, spatial interaction, force mechanism and failure modes. In addition,static parameters are obtained through tests, providing the basis for theresearch on the dynamic effect in the progressive collapse phenomenon,further design requirements and numerical simulation details.2. The automatic decoupling device is used in the experiment to simulatecolumn-removing in the RC frame. Failure process of column, timing anddifferent unbalanced load cases have been studied for the dynamic responseand performance as well. Elastic phase, elastic-plastic phase and plastic p haseare studied through testing results. Dynamic behavior of progressive collapseis fully discussed after mid-column removing, moreover, summary of dynamicbehavior has been made.3. Based on the tests conducted in the previous chapters and one moreexperiment example, numerical analysis results obtained from FEM softwareATENA matching well with the experiment results. Through n umericalsimulation of a3-bay frame model, research has been carried out on theinfluence factors in the progressive collapse s uch as floor level4. Dynamic testing results verify the estimation methodology ofprogressive collapse based on the energy equilibrium principle. Estimation methodology is then used for the progressive collapse vulnerabilityassessment of the5-bay frame model mentioned before.