Dr. Núñez-Castellanos, Eduardo

The incremental dynamic analysis is procedure highly used in the evaluation of structural systems and seismic design parameters for the linear design methods traditionally used in current building codes. The use of this methodology has been extended to industrial structures; however, in the case of steel racks subjected to subduction earthquakes such as the one in Chile, the procedure presents limitations in the post MCE scaling stage due to the high seismic demand, which does not allow its use. In this research, the seismic evaluation of steel storage racks is studied using a dynamic decremental analysis (DDA). The numerical research aims at a methodology proposed to evaluate seismic damage in steel storage racks, considering operational continuity, life safety and collapse prevention levels. A total of 4840 nonlinear models were performed to establish the performance levels, supported by the principles of the IDA according to FEMA P695. The MCE is used to scale the seismic records, however, a decremental scaling process is applied to identify the performance gap between the design intensity and the MCE intensity. The results obtained showed that the archetypes with lower load levels and lower height exhibited higher performance levels in the down-aisle direction compared to the transverse direction. In addition, the proposed methodology allows obtaining a performance level considering the seismic forces scaled to the MCE level through a methodology on steel racks, which had not been possible to evaluate using the IDA. Finally, the main problem in the study of steel racks design is to ensure the stability in the cross-aisle direction and stability of the stored goods in that direction.

BIM models are seldom used for the energy certification of buildings. This paper discusses the advantages of linking two important fields: building information modeling (BIM) and building environmental assessment methods (BEAM), presented as a rating system and a proposal for the Chilean context. The state of the art in both fields around the world is discussed, with an in-depth examination of current BIM software and related applications, followed by a discussion about previous research on integrating them. A lack of interoperability and data losses between BIM and BEM were found. A new tool is presented that addresses these challenges to ensure accurate rating system data, and this new framework is based on database exchange and takes crucial information from BIM to BEAM platforms. The development of the method includes BIM programming (API), database links, and spreadsheets for a Chilean building energy certification through a new tool, also applicable to multiclimactic zones. This new semi-automatic tool allows architects to model their design in a BIM platform and use this information as input for the energy certification process. The potential and risks of this method are discussed. Several improvements and enhancements of the energy certification process were found when incorporating this new framework in comparison to current methodologies.

Concrete strength assessment is an important topic in evaluating existing structures. Formerly, only destructive tests were employed, limiting the number of tests due to their complexity and cost. Nowadays, the application of non-destructive tests has been booming to determine material strength, offering a more accessible and cheaper strategy than its counterpart. Non-destructive strategies are based on two steps: (1) the identification of the correlation between the concrete strength and another parameter that is easy to measure in situ, and (2) the use of this easy-to-measure parameter to infer the concrete strength in any desired element of the structure. The most common parameter adopted for this purpose is the Ultrasonic Pulse Velocity (UPV). However, the correlation between concrete strength and UPV must be determined via destructive experiments. From the research perspective, attention has focused on determining the correlation coefficient and the range of credibility for estimating the inferred concrete strength. Despite it, this strategy has remained elusive in the fundamental understanding and accounting of the joint dispersion of the concrete strength and the UPV. The present work addresses this knowledge gap by proposing a new correlation method based on probability interpretations to infer the compressive concrete strength from in-situ UPV measurements and including the dispersion evidenced in UPV measurements in both steps mentioned. The results demonstrated that it is possible to determine the confidence interval for the concrete compressive strength given a certain percentile of the UPV measured in situ. Finally, the application of the proposed method is illustrated through a case study, which is representative of different building pathologies. This novel proposal is a foundation to deal with the uncertainties involved in non-destructive tests, inspiring future advances in this field.