Previsione della risposta di pareti in CA multipiano tramite analisi ad elementi finiti non lineari statiche e dinamiche condotte con il modello fessurativo PARC_CL2.0

The main results obtained during the phase 2 of the CASH benchmark are reported in this paper. Phase 2 of the CASH benchmark was dedicated to the response prediction, under increasing levels of seismic intensity, of multistory RC walls characterizing the seismic resisting system of nuclear power plan. Nonlinear static and dynamic analyses have been carried out to check the reliability of NLFEA to assess the seismic capacity of reinforced concrete walls, composed of four floors and two bays, to withstand strong earthquakes considered for beyond design situation. The behavior of a “regular” wall and an “irregular” wall 12m width and 16m high have been investigated. The irregular wall differs from the regular one by removing the shear wall on the third floor of the second bay. Authors attended the benchmark by modelling RC walls using multi-layered shell elements and by adopting PARC_CL2.0 crack model implemented in UMAT.for user subroutine of Abaqus software. The paper describes modelling strategies, the results of pushover analysis and the results of dynamic analyses carried out by imposing increasing values of the coefficient  used to scale the reference accelerogram. Furthermore the paper illustrates the critical issues of the actual Italian code prescription for the shear resistance assessment of RC walls.