A Research Of Shaking Table Test Of The Concrete Frame Unit With Staircase

The concrete frame structure is an important building structure system. However,the concrete frame unit with staircase were seriously damaged or even collapsed inWenchuan and Yushu earthquake, which made the staircase loss of function of thevertical channel of escape and relief. Studies have shown that ladder board may bringabout impact of bracing, which make ladder board involved earthquake action. Buttraditional staircase is not taken seismic design and it is in a state of insecurity.Nevertheless, research about the staircase have not much, and there is only theoreticalanalysis lack of experimental data research. The newly revised seismic code proposesome requirments about seismic design of the staircase in concrete frame structure,and national standards design atlas also proposed some new structural measures. Theimprovement of seismic performance of staircase has aroused the concern of themajority of engineering and technical personnel.This article takes the common concrete frame unit with staircase as researchobject, and proceeds the shaking table test of frame unit with staircase for the firsttime at home and abroad, in which we takes the sliding bearingof PTFE in order tostudy its impact of the seismic performance; finaly we do some finite analysis. Themain contents are as follows:1. According to dynamical similarity relation, we build a1/3model of the concreteframe unit with the slide bearing staircase, then test the vibration characteristicsof the model and shaking table test subject to different seismic acceleration toinvestigate its dynamic characteristics, dynamic response, failure mode, failurefeature and sliding effect, etc.2. The analysis shows that the model with the ladder board in a sliding state displayswell seismic performance. The final damage is mainly in the frame componentsof the unit and there is not obvious damage in the staircase components, whichcan make the staircase as the vertical channel of escape and relief and make thestaircase safe before the damage of the frame. Furthermore, the sliding effect isquite obvious and the sliding displacement is large, whith have good performanceof energy dissipation.3. On the basis of tests, a finite element model of the experimental model isproposed using the software ABAQUS, and the seismic performance is simulated. Then we creat two models with three storeys accoding to the bottom of the ladderboard in both fixed and sliding state. The failure charateristics in muti-storeyframe with the staircase is analyzed through the time-history analysis.4. Based on the experimental and finite element analysis, the design proposals ofconcrete frame unit with staircase is provided for the actual project.