Analysis and validation of a seismic design method proposed for precast jointed wall systems

Abstract

<p>Following the satisfactory response of the unbonded post-tensioned precast concrete wall system tested for seismic performance as part of the PREcast Seismic Structural Systems (PRESSS) test building, a set of design guidelines was published. The primary objective of this research is to evaluate the adequacy of the design guidelines and make appropriate recommendations so that the guidelines can be adopted for design of jointed walls in seismic regions. The test data to date on such systems are those collected during the wall direction testing of the PRESSS test building. Hence, this data set has been employed in the validation process. Furthermore, in order to validate the design guidelines over a range of lateral drift levels, an analytical procedure was first developed by reversing the suggested guidelines. Additionally, because of the shortcomings associated with the use of the equivalent stress block concept in design, an alternative analysis method was also considered, which was based on the monolithic beam analogy recommended for jointed systems. The analytical results from monotonic loading were compared to experimental response of the wall established from the PRESSS test building. It was found that both the analysis methods based on PRESSS and MBA predicted the moment response of the wall adequately. However, utilizing the PRESSS guidelines it was found that the neutral axis depth was overestimated by over 100% and the post-tensioning elongation was underestimated by 26%. It was also revealed that the frame contributed to the moment resistance in the wall direction by as much as 25%.</p>