Description:

SIMPLIFIED PROCEDURES FOR ESTIMATING EARTHQUAKE-INDUCED DISPLACEMENTS

This seminar will present performance-based probabilistic procedures for the estimation of 1) seismically-induced slope displacements applicable to earth/waste systems and natural slopes located in different seismic tectonic settings and 2) liquefaction-induced settlements on buildings with shallow foundations. The procedures to be presented are well suited to be used within a risk assessments framework.

To estimate seismic slope displacements, the current state of practice separates the estimation of the ground motion intensity measure (IM) from the seismic displacement (D) estimation, given the selected IM hazard level. Thus, D is estimated based on a single IM value. A performance-based procedure is proposed which considers the full range of potential IM values and the uncertainty in the slope properties, to estimate slope displacements that are consistent with the design hazard level.

The state of the practice for the estimation of liquefaction-induced building settlements, still largely involves the use of empirical procedures developed for free-field conditions, which cannot possibly capture shear-induced deformations in the soil beneath shallow foundations. Nonlinear effective stress soil-structure interaction analyses are performed to identify the key parameters controlling liquefaction-induced building settlements. A simplified procedure is then developed based on the analytical results. Finally, the proposed procedure is validated with results from centrifuge test and several field case histories.

Biography:
Dr. Jorge Macedo is a Postdoctoral Researcher at UC Berkeley with expertise in the areas of performance-based design and risk assessment, assessment and mitigation of seismically-induced hazards, and advanced numerical modeling of geosystems. Dr. Macedo earned his Ph.D. from the Geosystems department at UC Berkeley in 2017. In his research at UC Berkeley, he developed analytical/numerical tools and performance-based procedures to improve the resilient design of geotechnical systems (i.e. natural slopes, earth dams, heap leach pads, buildings on liquefiable soils); and to contribute to advance the state of the practice towards a proper risk and hazard assessment, which can lead to a more sustainable design of intelligent geotechnical systems. Moreover Dr. Macedo spent several years in the industry working in a global geoengineering firm on big challenging geotechnical and geo-environmental multi-disciplinary projects for the infrastructure, mining and oil & gas sectors. He was involved in major projects in South America (Peru, Brazil, and Argentina); projects that go from due-diligence and basic engineering to detailed engineering design.