Research On Poles Of Formwork Support System Interacted With Structure During Construction Stage

With the development of economy, increasingly rapid urban development, innovativeconstruction technology, building construction cycle is becoming shorter and shorter,the construction period is normally5days or7days. Due to the construction of fasterand time-varying characteristics of concrete materials, the design and erection offormwork support system gets more and more attention. Because of the low initialstrength of concrete, when the formwork support system subjected to a greater force itwill crack or even collapse, causing accidents. Researching the force of formworksupport system is particular significance.Now multi-layer formwork supporting system is often used in building construction,the three formwork support system is most used in common. An increasing number ofstudies show formwork supporting system is not a single system, but a comprehensivesupporting system working with structure. Template interaction with the structure aspart of the comprehensive support system, involved in stress redistribution process oftime-varying structure. Newly poured concrete without any strength, but only asconstruction load on the support system. As the low bearing capacity of early-ageconcrete, it likely to lead to support pole high pressure, and a threat to the supportsystem security.The supporting poles were analyzed in this paper based on interaction with structureand time-varying characteristics of the concrete in construction using MIDAS Gen FEMsoftware for analysis of construction stages. Depending on whether support erect on theground or not, the analysis of formwork support pole divided into two kinds of model,completely unload model without support and completely load model with support. Andchanges in the construction cycle, beam section dimensions, beam span of420modelshave been analyzed, and the pole axial force variation during construction wasdiscovered.Based on summary and analysis of the computational models resulting data, foundthat in construction period of5days,7days and10days changes, the longerconstruction period, formwork supporting frame pole axial force more evenly and theeffect of construction period on the maximum axial force of pole is not obvious. Withthe increase in beam and column section, the pole vertical strain and the maximum axialforce decrease. Beam spans increase, due to increased pass paths to the column, when the stress redistribution occurs in the entire support system and load increases to thecentral pole, through to420all vertical poles in the model force observation, foundone-second span beam following central pole is larger than the calculated on a scaffoldstandard pole axial forces. And found that in certain cross-ratio range, the ratio betweenpoles calculates maximum axial force and scaffold specifications constant. And on thebasis of model results to make recommendations for future design and erection offormwork support.