Rita L Sousa

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Verified

Rita verified their affiliation via an institutional email.

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• PhD
• Professor (Associate) at New York University Abu Dhabi

Conventional slope stability evaluation is limited to deterministic analyses, in which only mean values are used in the numerical simulations. However, natural soils are spatial random fields due to highly complex sediment deposition. Deterministic calculation ignoring soil spatial variability can significantly underestimate the safety factor, posi...

Achieving robust generalization in machine learning for tunnel boring machine performance prediction is challenging, particularly when models are developed on data from different projects. This study assesses the generalization abilities of K-nearest neighbors, support vector regression, artificial neural networks, random forest, classification and...

The Azores Archipelago, prone to multiple geohazards such as earthquakes, volcanic eruptions, and extreme weather events, faces significant risks of landslides, particularly due to the complex geological characteristics of its volcanic formations. This study focuses on assessing the seismic stability of a slope near Porto Formoso on São Miguel Isla...

Landslides significantly threaten lives and infrastructure, especially in seismically active regions. This study conducts a probabilistic analysis of seismic landslide runout behavior, leveraging a large-deformation finite-element (LDFE) model that accounts for the three-dimensional (3D) spatial variability and cross-correlation in soil strength-a...

The stability of a wide rectangular tunnel in spatially variable soils is investigated using deep-learning surrogate models combined with a mixed formulation of limit analysis. The mixed formulation is employed to perform stochastic simulations of tunnels in spatially random soils, generating the data to train the surrogate models. Two types of dee...

Soil properties exhibit inherent spatial variability, which can significantly affect the bearing capacity of foundations. This study conducted two-dimensional stochastic simulations of the bearing capacity of shallow foundations on spatially varying soils, utilizing random field theory and smoothed finite-element limit analysis. Despite the use of...

Accurately predicting the Penetration Rate (PR) in tunnelling is crucial for evaluating the performance of Tunnel Boring Machines. However, a significant shortcoming of many existing studies is that the predictive models are developed using data from a single project, which limits their applicability to future tunnelling projects. This research add...

In response to challenges in the design process of concrete arch pre-supporting systems (CAPS) for urban subway stations, we propose a novel approach that integrates robust multi-objective decision-making, ensemble learning, and clustering algorithms. This integrated framework aims to achieve an optimal design by considering both design objectives...

In this work, the massive landslide of Daguangbao was modeled in 3D using the material point method (MPM). The paper focuses on modeling the failure, the run-out, and the final deposition of the failed mass in 3D. The numerical model considers in detail the distribution of materials within the domain. The materials were modeled as elastoplastic wit...

The 2008 Wenchuan earthquake resulted in a large number of fatalities and caused significant economic losses, in China. Thousands of landslides, many of which are very large, were triggered by the earthquake. Most of these catastrophes were distributed along the Longmenshan fault system, on the edge of the Tibetan plate. Some of these landslides bl...

Most existing models about penetration rate (PR) prediction have been developed and validated against data from one single project. This poses the question whether these models can perform well when faced with new data. We use two datasets of two tunnels built with the same construction method and in similar geological conditions. Different machine...

Due to the continuous development of urban areas, excavation has become a crucial part of the building’s construction. From the geotechnical point of view, excavation safety must be considered. Nail walls are an economical solution, widely used to support excavations. In this study, the construction of a nailed wall is simulated using a limit equil...

In this work, the massive landslide of Daguangbao was modeled in 3D using the Material Point Method (MPM). The paper focuses on modeling the failure, the run-out, and the final deposition of the failed mass in 3D. The numerical model considers in detail the distribution of materials within the domain. The materials were modeled as elastoplastic wit...

Sinkholes are a significant underground hazard that threatens infrastructure and lives and sometimes results in fatalities. The annual cost of sinkhole damages exceeds $300 million, although this estimate is likely underestimated due to the need for national tracking. Sinkholes can also alter natural drainage patterns, leading to increased flood ri...

The Azores Archipelago is affected by several geohazards and natural disasters, including earthquakes, volcanic eruptions, and extreme meteorological events. This makes this region quite susceptible to landslides. To ensure the safety of natural slopes, it is vital to systematically assess and manage risk to propose measures to reduce the geotechni...

Investigating hydraulic and petrophysical properties of porous media has been an active area of research. Despite numerous progress in modeling flow and transport over the past decades, we are still far from accurately estimating the scale dependence of soil and rock properties. In this study, we propose applying renormalization group theory (RGT)...

Prediction of tunneling performance is intimately connected to the predictionof Advance Rate (AR), which is crucial to optimize tunnelling operation and steering tunnel-ling processes. However, the forecasting AR is accuracy remains a challenge due to its depend-ency on several factors. Several methods have been introduced to predict the performanc...

The FEM software RS2's efficiency in modelling an MSE wall was verified through numerical simulation of the significant structural components of a field-constructed MSE wall in Seattle, Washington. A 10.7-meter high wall was simulated, and its performance was evaluated by plotting strain and load profiles for different geogrid reinforcement layers...

Advance rate (AR) prediction is crucial for optimal mechanized tunneling performance. However, the type of input features used when developing AR prediction models vary greatly from study to study. In this paper, a hybrid automatic feature selection method is presented and demonstrated through the development of a support vector regression (SVR) mo...

Slope instability is one of the major problems in geotechnical engineering. Slope instability affects both man-made and natural slopes and may cause significant economic damage, and sometimes injuries and loss of lives. During the construction of the Musandam Independent Power Plant (MIPP) in Northern Oman, a rock slope failure occurred on a benche...

Risk assessment involved in storage of CO2 in coal is analyzed, with particular emphasis on cases where the injection is made into unminable coal seams and in abandoned coal mines. The risks associate are studied in detail, different types of hazard scenarios are identified and described. The importance of modelling and monitoring is emphasized in...

This work presents indirect tensile tests and uniaxial and triaxial monotonic and cyclic compression tests of Berea sandstone (BST) under different levels of confining pressure (CP) where the axial and lateral strains are measured in addition to the axial stress. Based on these experiments, the influence of the CP on the mechanical behavior and the...

Slope instabilities present significant geotechnical problems involving a variety of geomaterials in different geological and climatic environments. These phenomena, which can be natural or man-made, are difficult to predict because their initiation depends on many factors. Man-made slopes are expected in a large number of civil and mining engineer...

Underground energy storage plays an important role in electric energy supply systems. Hydroelectric power schemes are important undertakings that can make use of underground space and storage of energy. Reversible hydro power plants are one of several technologies that allow to store energy, by pumping water from a lower reservoir to an upper reser...

This paper characterizes volcanic rocks through the application of an empirical geomechanical system designated as VRS (Volcanic Rock System). For the VRS, geotechnical information was collected from samples from several Atlantic Ocean islands that include Madeira and Canarias archipelagos, taking also into consideration data from other different s...

Landslide disasters, one of the most destructive geo-hazards, often have serious consequences that range from economic losses to fatalities. Earthquakes, particularly those with strong ground motion, can trigger thousands of landslides in mountainous regions. The 2008 Wenchuan earthquake which occurred in China is such an example. The massive Dagua...

The number and complexity of tunnel systems will surely increase with ever increasing population and urbanization. Although most tunnel construction projects have been completed safely, there have been several incidents that have resulted in delays, cost overruns, and sometimes more significant consequences such as injury and loss of life. In this...

Formal methods to handle decision-making under uncertainty that have been created for business management lend themselves to applications in many other areas, in which uncertainties play a major role. Hence, the authors and their co-workers have applied decision analysis to landslides since the 1980′s but many other approaches to landslide assessme...

A key aspect that affect many deep underground mines over the world is the rockburst phenomenon, which can have a strong impact in terms of costs and lives. Accordingly, it is important their understanding in order to support decision makers when such events occur. One way to obtain a deeper and better understanding of the mechanisms of rockburst i...

This paper presents a geometric, mechanics-based, stochastic model—FracProp—that was developed to predict fracture initiation and propagation in rock. FracProp is capable of quantifying uncertainties associated with the point of fracture initiation and direction of fracture propagation. The current version of FracProp uses compounded probability di...

Landslides are one of the most vital natural hazards on Earth. To satisfy the demand for protection against landslides, it is necessary to systematically assess and manage landslide hazards and risk. Landslide mechanisms related to hydrology are analyzed with focus in the major risks, and formal risk assessment methodologies are presented in the pa...

Given the deepening awareness of the limited nature of fossil fuel reserves and the environmental consequences of consuming it, the increasing appetite for better public transportation infrastructure persists worldwide. A huge amount of investments and resources is being injected into the development of transportation infrastructures, including lig...

Landslides are one of the most important natural hazards on Earth. 12 Landslide mechanisms related to hydrology are analyzed with focus in the major 13 risks, and formal risk assessment methodologies are presented. The management 14 of accidents in slopes is discussed, with particular emphasis to Hong Kong and 15 to Rio de Janeiro. Specific aspects...

This paper presents a study on the stability of a mine entry of an innovative approach to non-pillar coal mining—gob-side entry retaining using cantilever beam theory (GERMC). This method is on the rise in China and it has shown to increase the coal seam rate of recycling and mining productivity. The method utilizes the caved-in material resulting...

In recent years, the evaluation of geomechanical parameters in rock masses and particularly in soft rock masses has gone through significant improvements. New instruments and equipment for in situ and laboratory tests allow for a more accurate evaluation of the properties of soft rock masses. Advancements in data mining (DM) techniques allow for be...

The purpose of this chapter is to analyze the behavior of underground works associated to hydroelectric schemes when soft rocks formations are present. The work starts with a brief introduction to the different types of underground hydroelectric schemes with a reference to the specific works related to the hydraulic circuit, to the powerhouse compl...

In this work, a newly designed experimental setup is used to perform in-lab fracking under controlled triaxial loading on cylindrical cores of Berea sandstone. Fracking tests are conducted at 10 MPa confining pressure, with vertical compressive loading, as well as two horizontal stresses that simulate reservoir triaxial stress state. Multiple injec...

A database of three-component acceleration time series recorded at downhole arrays in earthen dam cores was published by the Japan Commission on Large Dams (JCOLD 2014). The present study reviews the acceleration time series in nine earthfill and rockfill dams in Japan. The apparent shear wave velocities between downhole sensors in each dam during...

Subsurface characterisation relies heavily on geological information such as borehole data, which are often sparse and uncertain. Traditionally borehole interpretation is often qualitative and without formal incorporation of uncertainties. In this paper, we propose a methodology based on multivariate Gaussian probability distributions to generate p...

Tunnel maintenance and management is an important issue. A KBS system was developed and applied to old railway tunnels in Portugal. Applications of Bayesian networks were applied to a scenario of water infiltration.

A database of three-component acceleration time series recorded at downhole arrays in earthen dam cores was published by the Japan Commission on Large Dams (JCOLD 2014). The present study reviews the acceleration time series in nine earthfill and rockfill dams in Japan. The apparent shear wave velocities between downhole sensors in each dam during...

Abu Dhabi is expecting a huge growth over the next 20 years and is planning a massive integrated transportation system, including several modes of transportation to ensure that Abu Dhabi becomes a sustainable city on a global scale. Most of these structures are expected to encounter difficult ground conditions, which are a concern for construction...

Hydraulic fracturing is commonly used to enhance the production of hydrocarbon reservoirs, particularly that of unconventional reservoirs. Field data from hydraulic fracturing treatments is scarce and often difficult to interpret. Thus, laboratory experiments and numerical simulations play a key role in understanding hydraulic fracturing mechanisms...

This work presents, uniaxial and triaxial compression tests of Berea sandstone (BST) under different levels of confining pressure (CP) where the axial and lateral strains are measured in addition to the axial stress. Based on these experiments, the influence of the CP on the mechanical behavior and the damage mechanics of BST is investigated. Resul...

The 2008 Wenchuan earthquake resulted in a large number of fatalities and caused significant economic losses. Thousands of landslides, many of which are very large, were triggered by the earthquake. A majority of catastrophic landslides were distributed along the central Longmenshan fault system, at the eastern margin of the Tibetan Plateau. Some o...

to assess and manage the risks associated underground construction [7-10]. Most accidents in underground construction are associated with uncertainties. It is therefore essential to develop risk analysis systems. Historically, risk assessment and risk analysis have not assumed particular relevance when evaluating underground projects and other majo...

Rock fracture characterization is essential for several applications, which include geothermal energy extraction, hydraulic fracturing and radioactive waste disposal. Unfortunately, observing rock fractures is not possible, therefore, methods were developed to use site-specific observable data such as borehole logs and exposed outcrops to predict f...

Hydraulic fracturing is a proven means of enhancing rock mass permeability in tight reservoirs, which ultimately leads to a more efficient and increased productivity. However, the existence of natural discontinuities, may cause propagation of hydraulic fractures to be arrested or offset. In this paper, simulations of hydraulic fracturing within a r...

An innovative approach to the gob-side entry retaining non-pillar mining is being used to increase the coal seam re cycling rate and productivity in China’s coal mining. The retained entry with a sidewall formed by gob caved-in filling rocks is unique in this method and the stability of caved-in material is critical to ensure efficient and safe min...

The dissolution of rocks in underground flow paths is transport-controlled if their dissolution rates are relatively high, while the dissolution is reaction-controlled if their dissolution rates are relatively low. Transport-controlled dissolution is a common process in the formation of gypsum karst and oil reservoir acid stimulations. As an initia...

Subsurface gypsum dissolution hazards imply risks to the construction and operation of new transport infrastructure including subsidence, cavity collapse and cavity flooding. This is a concern in Abu Dhabi, United Arab Emirates, where gypsum geohazards are observed and an extensive transportation network is planned. This paper proposes an artificia...

Rockburst is an important phenomenon that has affected many deep underground mines around the world. An understanding of this phenomenon is relevant to the management of such events, which can lead to saving both costs and lives. Laboratory experiments are one way to obtain a deeper and better understanding of the mechanisms of rockburst. In a prev...

In this paper, we describe approaches to risk determination in underground construction. The center piece of what we describe are the decision aids for tunneling (DAT), which allow one to predict cost-, time- and resource probability distributions reflecting uncertainties in geology and in the construction process but also many others. The DAT have...

Abu Dhabi is predicting a huge growth in population over the next 20 years (Plan Abu Dhabi 2030); further, it seeks to become an international destination for tourists, businesses, and investment while protecting its cultural heritage. A crucial aspect of achieving this goal is the development of large integrated transportation system, underground,...

Storage of CO2 in deep onshore and offshore geological formations uses many of the technologies developed by oil and gas industry and has been proved to be economically feasible under specific conditions in oil and gas fields, and in conjunction with enhanced oil recovery (EOR) and enhanced gas recovery (EGR), and in saline aquifers (IPCC, 2005; EA...

The paper presents methodologies for exploration planning under uncertain conditions based on virtual exploration and Bayesian updating. The process starts with site characterization using existing information to produce geologic profiles. Initial distributions of cost and time are obtained with a Bayesian network model that optimizes the construct...

A coupled elastic-plasticity-damage constitutive model, AK Model, is applied to predict fracture propagation in rocks. The quasi-brittle material model captures anisotropic effects and the distinct behavior of rocks in tension and compression. Calibration of the constitutive model is realized using experimental data for Carrara marble. Through the...

Abu Dhabi is predicting a huge growth in population over the next 20 years (Plan Abu Dhabi 2030); further, it seeks to become an international destination for tourists, businesses, and investment while protecting its cultural heritage. A crucial aspect of achieving this goal is the development of large integrated transportation system, underground...

An extensive network of urban and transportation systems is planned within the Abu Dhabi 2030 master plan. This includes planning, implementing and operating underground infrastructure for which it is extremely important to consider the uncertainties, and the inherent risks, affecting them. The research presented here intends to account for natural...

The stability of ancient cavities in historic areas presents high complex problems due to their nature, existing environment and valuable cultural heritage. There are risk sources which might cause large damages and deterioration and, in some cases, it is necessary to put forward conservation measures in order to prevent damage or destruction of th...

Tunnel construction is increasing worldwide in mining and civil engineering. There have been several accidents that resulted in delays, cost overruns, some with more severe consequences. To help minimize these accidents, it is necessary to assess and manage the risks associated with tunnel construction and exploration. A particular type of accident...

Risk management for landslides involves, in addition to active and passive countermeasures, the collection of information through exploration. With such information, it is possible to reduce uncertainties, make more reliable decisions and therefore reduce risk. This paper addresses two types of exploration, namely (1) exploration (information colle...

This paper presents results from research conducted at MIT during 2010-2012 on modeling of natural rock fracture systems with the GEOFRAC three-dimensional stochastic model. Following a background summary of discrete fracture network models and a brief introduction of GEOFRAC, the paper provides a thorough description of the newly developed mathema...

The former Homestake gold mine in Lead, South Dakota, was selected as the site for DUSEL (Deep Underground Science and Engineering Laboratory) by the National Science Foundation. Several reports were done by a consortium of companies concerning geological and geotechnical studies performed at 4850 level. In this paper a summary of these studies are...

Heat transfer between fluid flow and fractured rocks is governed by a very complex mechanism. The challenge of modeling this heat transfer process results from the complex geometry of rock fracture networks, variation of rock and fluid properties with temperature, and uncertainty of the flow and heat transfer types. As the heat transfer models are...

Heat transfer between fluid flow and fractured rocks is governed by a very complex mechanism. The challenge of modeling this heat transfer process results from the complex geometry of rock fracture networks, variation of rock and fluid properties with temperature, and uncertainty of the flow and heat transfer types. As the heat transfer models are...

Rockburst is characterized by a violent explosion of a certain block causing a sudden rupture in the rock and is quite common in deep tunnels. It is critical to understand the phenomenon of rockburst, focusing on the patterns of occurrence so these events can be avoided and/or managed saving costs and possibly lives. The failure mechanism of rockbu...

This paper presents a methodology to systematically assess and manage the risks associated with tunnel construction. The methodology consists of combining a geologic prediction model that allows one to predict geology ahead of the tunnel construction, with a construction strategy decision model that allows one to choose amongst different constructi...

Data Mining (DM) techniques have been successfully used in many fields and more recently also in geotechnics with good results in different applica-tions. They are adequate as an advanced technique for analysing large and com-plex databases that can be built with geotechnical information within the frame-work of an overall process of Knowledge Disc...

Rockburst is characterized by a violent explosion of a certain block causing a sudden rupture in the rock and is quite common in deep tunnels. It is critical to understand the phenomenon of rockburst, focusing on the patterns of occurrence so these events can be avoid and/or managed saving costs and possibly lives. In order to further understand th...