Shaking Table Test Of RC Frame Structures With The Participation Of Cast-in-place Slabs In Consideration

In order to ensure the reinforced concrete frame structures can not occur the overall collapse due to "column hinge failure mechanism" in the earthquake disaster.China's"code for seismic design of buildings"(GB50011-2010)provisions proposed seismic design using "strong column-weak beam" design principle,which is to ensure beam end damage prior to the destruction of the column end.However,through the survey of earthquake disaster occurred in the past,we found that Situ reinforced concrete frame structures is mostly exhibited "strong beam-weak column" failure mode,which is in contrast to current seismic design codes.The research results show that the cast-in-place slabs improve the actual bending capacity of frame beam end,which is one of the main reasons for the failure mechanism of "strong beam weak column.In view of this,author performed a reinforced concrete frame structure shaking table test.The main research work carried out as follows:(1)Under the current design codes,a five-story reinforced concrete frame structure is designed as a prototype structure background.According to Improved design recommendations,we adjusted the initial structure and verify the effect of improving the optimized RC frame structure.(2)Select the test materials which meet the test requirements to perform preliminary material test,learn shaking-table system parameters and associated test equipment in laboratory.Determine the similarity relationship between optimized initial structure and test model structure,to obtain the size and reinforcing bars program of test model structure through the conversion and to determine the shaking table test program.(3)Product shaking-table test model structure.According to the model size,combining with the existing facilities to choice appropriate template material,using reasonable construction technology,processing foam board,making galvanized wire cages,in accordance with codes requirements place beam,slab and column bars,the final completion of the model structure from the base to the upper frame.(4)According to the test purpose,we designed the test conditions of this shaking table test,arranged the sensor and calculated the added weight.Observed experimental phenomena,analyze failure modes of model under seismic effects;Collected test data,researched and analyze dynamic characteristics,acceleration response and displacement reactions.Test results show that under the earthquake,the frame beam damage before the frame column and plastic hinge appeared on the beam end at first,the "strong column weak beam" seismic requirement was more easily achieved;Crevices on the cast-in-place slabs reflect directly floor bars in the scope of the effective flange width enhance the bending ability of frame beam end;The maximum story drift angle of model meet the requirements of the restrictive number in construction seismic code;When confronted with the rare earthquake of 2.0 g,the model structure didn't occur the overall collapse still;After adjusted by the improved design suggestions,the model of the prototype structure showed good seismic performance.