Milad Roohi

University of Nebraska at Lincoln | NU · Charles W. Durham School of Architectural Engineering and Construction

Bridges are critical transportation infrastructure components, serving as vital links for mobility and evacuation during and after hazard occurrences. Ensuring their reliability and safety is of paramount importance. Traditional reliability assessment methods for bridge net- works rely on complex mathematical models, often resulting in time-consumi...

Communities can face devastation from earthquakes, including loss of lives, destruction of infrastructure, and damage to buildings. By implementing rigorous standards, communities can ensure that both new and existing structures are designed and retrofitted to withstand seismic forces. While current building codes prioritize life safety during eart...

Bayesian filtering techniques involve recursively combining a mathematical model and a system's response measurements to enhance the model's estimation and prediction capabilities. These techniques rely on reduced-order surrogate models for estimation, which limits the type of models used. It is important to choose a model class and its parameters...

This chapter presents a hybrid deep-learning methodology for seismic structural monitoring, damage detection, and localization of instrumented buildings. The proposed methodology develops mechanics-based structural models to generate sample response datasets by accounting for the uncertainty of model parameters that can highly affect the estimation...

This paper presents a novel probabilistic performance-based monitoring approach for high-resolution seismic damage assessment and resilience quantification in instrumented buildings. The objective is to estimate seismic loss and functionality metrics, which can be integrated into multidisciplinary community resilience models consisting of interdepe...

This paper presents a new concept for performance-based monitoring (PBM) of instrumented buildings subject to earthquakes. This concept is achieved by simultaneously combining and advancing existing knowledge from structural mechanics, signal processing, and performance-based earthquake engineering paradigms. The PBM concept consists of 1) measurem...

This paper presents a multidisciplinary resilience modeling methodology to assess the vulnerability of the built environment and economic systems. This methodology can assist decision-makers with developing effective mitigation policies to improve the seismic resilience of communities. Two complementary modeling strategies are developed to examine...

We integrate a stochastic engineering model and an economic impact model to evaluate earthquake mitigation policies in Salt Lake County, Utah, USA. We demonstrate how earthquakeinduced economic losses can vary across both economic sectors and household groups (distinguished by income), providing a framework for comparing benefits of a variety of ex...

This paper proposes a high-resolution seismic monitoring framework that employs dissipated energy as a feature for damage detection and localization in instrumented building structures. The methodology consists of (1) implementing a nonlinear state observer to reconstruct the dynamic response at all degrees of freedom (DoF) of a structural model, (...

This paper aims to integrate life-cycle analysis into civil infrastructure resilience modeling and decision-making in seismic-prone communities. To achieve this aim, the authors present a methodology for modeling seismic life-cycle resilience of interdependent buildings and lifeline systems and subsequently informing resilience decisions directly r...

This paper presents a hybrid deep-learning methodology for seismic structural monitoring, damage detection, and localization of instrumented buildings. The proposed methodology develops mechanics-based structural models to generate sample response datasets by accounting for the uncertainty of model parameters that can highly affect the estimation o...

Transportation systems, such as railways, are considered critical infrastructure. It is essential to identify potential hazards that can affect the functionality of these systems and quantify metrics that can be used for resilience-informed decision-making. This paper develops an integrated probabilistic model for seismic multi-hazard risk and rest...

This paper presents a hybrid deep learning methodology for seismic structural monitoring, damage detection, and localization of instrumented buildings. The proposed methodology develops mechanics-based structural models to generate sample response datasets by accounting for the uncertainty of model parameters that can highly affect the estimation o...

This paper presents a methodology for seismic functionality modeling of interdependent buildings and lifeline systems, including electric power and water distribution networks. The methodology begins by developing geospatial datasets to characterize the buildings and lifeline systems of the community and the interdependency between infrastructure s...

This study investigates the role of data and information availability in urban-scale seismic modeling for resilience-informed decision-making. This process consists of the following main steps: 1) model development, 2) seismic hazard analysis, 3) physical damage analysis, 4) loss analysis, in which the outcome is the probability of expected damages...

The data and information available at the community-scale are directly linked to the ability to make a resilience-informed decision in natural hazards. This paper develops a systematic approach to quantify the implication of building inventory accuracy on resilience metrics for informed decision-making across engineering, economic and sociological...

This paper develops a decision making framework for post-earthquake assessment of instrumented buildings in a manner consistent with performance-based design criteria. This framework is achieved by simultaneously combining and advancing existing knowledge from seismic structural health monitoring and performance-based earthquake engineering paradig...

The authors propose a seismic monitoring framework for instrumented buildings that employs dissipated energy as a feature for damage detection and localization. The proposed framework employs a nonlinear model-based state observer that combines a nonlinear finite element model of a building and global acceleration measurements to estimate the time...

This paper presents a framework for decision-making regarding post-earthquake assessment of instrumented buildings in a manner consistent with performance-based design criteria. This framework is achieved by simultaneously combining and advancing existing knowledge from seismic structural health monitoring and performance-based earthquake engineeri...

The authors propose a seismic monitoring framework for instrumented buildings that employs dissipated energy as a feature for damage detection and localization. The proposed framework employs a nonlinear model-based state observer, which combines a nonlinear finite element model of a building and global acceleration measurements to estimate the tim...

This document is supplementary to the paper titled “Effectiveness of Seismic Isolation for Long-Period Structures Subject to Far-Field and Near-Field Excitations”. Summary: This document primarily shows that for isolated structures (in general, for long-period structures) subjected to near-fault excitations, the maximum responses of the forward-...

This study evaluates primarily the effectiveness of seismic isolation for structures with intermediate and relatively long non-isolated periods (e.g., bridges with tall piers) subjected to near-field (NF) and far-field (FF) excitations. The inelastic response spectrum approach is used to systematically evaluate the effects of the two fundamental as...

This document primarily shows that for isolated structures (in general, for long-period structures) subjected to near-fault excitations, the maximum responses of the forward-directivity component of the ground motion (the component with the largest pulse) occur at a different time than those of the parallel component (the component with the weakest...

The authors present a methodology to reconstruct nonlinear seismic response and assess seismic performance of instrumented wood-frame buildings subjected to earthquakes. The paper proposes the use of a nonlinear model-based state observer that combines global acceleration measurements and a nonlinear structural model of the building to estimate the...

This dissertation develops a new concept for performance-based monitoring (PBM) of instrumented buildings subjected to earthquakes. This concept is achieved by simultaneously combining and advancing existing knowledge from structural mechanics, signal processing, and performance-based earthquake engineering paradigms. The PBM concept consists of 1)...

The authors propose a methodology to perform seismic damage assessment of instrumented wood-frame buildings using response measurements. The proposed methodology employs a nonlinear model-based state observer that combines sparse acceleration measurements and a nonlinear structural model of a building to estimate the complete seismic response inclu...

This paper presents a methodology to estimate element‐by‐element demand‐to‐capacity ratios in instrumented steel moment‐resisting frames subject to earthquakes. The methodology combines a finite element model and acceleration measurements at various points throughout the building to estimate time history of displacements and internal force demands...

This paper presents a methodology to estimate member-by-member demand-to-capacity ratio for instrumented buildings whose lateral-force resisting system consists in steel moment-resisting frames. The methodology estimates internal forces and displacements in all members by combining a model and acceleration measurements using a model-based observer....

Vibration measurements from building structures during the occurrence of an earthquake can be used to estimate member-by-member demand-to-capacity ratio for instrumented buildings. Demand-to-capacity ratios of members provide useful information for structural engineers in the variety of applications including post-earthquake condition assessment an...