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Ronaldo I. Borja - US grants
Affiliations: | Stanford University, Palo Alto, CA |
Area:
Applied Mechanics, Civil Engineering, Materials Science EngineeringWebsite:
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The funding information displayed below comes from the NIH Research Portfolio Online Reporting Tools and the NSF Award Database.The grant data on this page is limited to grants awarded in the United States and is thus partial. It can nonetheless be used to understand how funding patterns influence mentorship networks and vice-versa, which has deep implications on how research is done.
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High-probability grants
According to our matching algorithm, Ronaldo I. Borja is the likely recipient of the following grants.Years | Recipients | Code | Title / Keywords | Matching score |
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1989 — 1991 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
@ Stanford University The objective of this project is to investigate the combined effects of hydrodynamic lag and creep on the long-term performance of excavations in saturated soils addressing the issues of stability and deformation behavior. To achieve this objective, a recently developed excavation analysis solution algorithm proposed by Borja, Lee and Seed which provides a theoretically correct and analytically efficient solution to the basic problem of nonlinear elasto-plastic modelling of incremental excavation will be extended to incorporate hydrodynamic log and creep effects. No theoretically correct solution is presently available for modelling important phenomena associated with the problem of incremental excavation below the water table such as hydrodynamic lag, free surface flows, and the viscous behavior of the soil skeleton itself. The Finite Element program thus developed will be used to investigate the influence of the above phenomena on the long-term performance of excavations in saturated, creep susceptible soils. |
0.915 |
1991 — 1994 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
A Study of Creep Instability in Granular Materials as a Localization Problem @ Stanford University The phenomenon of accelerated deformation observed during undrained soil creep as a bifurcation problem will be investigated. A quasi-static linear stability analysis and a fully nonlinear analysis to analyze the problem of localization in rate-dependent materials will be performed. The scope of the proposed research ranges from theoretical formulation, to micro- and macro-mechanical analyses, numerical modeling, and experimentation. |
0.915 |
1992 — 1995 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
A Coupled Fe-Be Model For Nonlinear Soil-Structure Inter- Action Analysis @ Stanford University The objective of this research program is to investigate the effects of nonlinear soil behavior on the response of soil- structure systems to earthquake loading. The project involves: (a) the development of a numerical model to represent the various phenomena to be studied, such as the mechanical response of the soil and nonreflecting boundary conditions; (b) validation of the model by first comparing the predictions of the linear component of the model against closed- form analytical solutions for simplified systems, then by introducing nonlinearities into these simplified systems; and (c) following calibration of the numerical model, use of this model to analyze and interpret the data for a scaled-down nuclear containment vessel in Lotung, Taiwan, where soil nonlinearities and soil-structure interaction effects are dominant. This component is jointly sponsored by the Electric Power Research Institute (EPRI). |
0.915 |
1997 — 2001 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
@ Stanford University This project involves the study of strain localization on the stability and deformation behavior of open and supported excavations. Previous studies have demonstrated the usefulness of the standard finite element (FE) method in modeling the process of sequential excavation and construction particularly when the soil mass is deforming homogeneously. However, when a narrow band of intense shearing forms within the soil, the standard FE interpolation becomes inadequate because it is incapable of representing the effect of shear bands which could form across the finite elements. Therefore, in the regime of intense shearing, the standard FE method would predict a stiffer structural behavior even though a bifurcated response is already in order. In braced and tied-back excavations, this implies that the predicted movements and support loads will be smaller, and so the standard FE solution will err on the unsafe side. This research will address this problem by modeling strain localization as a problem of strong discontinuity, which involves jumps in the displacement field. The idea of slip lines in soil mechanics is consistent with this analysis. Within the context of FE analysis, problems involving strong discontinuities result in solutions that are completely independent of the FE mesh, in particular showing a sharp resolution of the discontinuities even in unstructured meshes. Furthermore, this approach admits the use of traditional rate-independent models of continuum mechanics, even those which do not offer a characteristic length scale, since the discontinuities are now assumed to correspond to sets of measure zero in the mathematical sense. The investigation will cover drained and undrained behavior using a finite deformation theory based on multiplicative plasticity, and will involve the use of J2 plasticity and modified Cam-Clay plasticity models. There are numerous field cases where strain localizations are known to have formed during the process of sequential excavation, and these will be used to test the accuracy of the proposed analytical methodology. |
0.915 |
2002 — 2007 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Static and Dynamic Instability of Liquefiable Soils @ Stanford University Abstract |
0.915 |
2003 — 2009 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
@ Stanford University Strain localization is a ubiquitous feature of granular materials undergoing nonhomogeneous deformation. Localized deformation typically is followed by a reduction in the overall strength, and thus can have a significant impact on material and structural behavior. Because shear bands are quite often observed in soils, it is of considerable interest and importance to the geotechnical community to be able to capture the full effects of strain localization in predictive models for analysis and design. Of key relevance are the ability to predict when a shear band forms, how this narrow zone of discontinuity is oriented within the material, and how the propagation of the shear band influences the post-localization constitutive response. Currently, even the most advanced and well-calibrated numerical models cannot predict the onset of localization, as the mechanisms governing localized deformation still are not properly understood. |
0.915 |
2004 — 2011 | Pollard, David [⬀] Mazzeo, Rafe (co-PI) [⬀] Borja, Ronaldo |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
@ Stanford University In this project, supported by the Collaborations in Mathematical Geosciences Program (CMG), the investigators are: 1) characterizing the geometric shapes of km-scale folded sedimentary strata using Airborne Laser Swath Mapping (ALSM) data and the principles of differential geometry; 2) investigating the dynamics of the folding process using continuum mechanics and Finite Element Methods (FEM); and 3) studying the physical interactions between km-scale folds and m-scale fractures within them using fracture and damage mechanics. Their underlying hypothesis is that the 3D shape of folded strata adequately constrains the internal deformation such that the orientation and spatial density of m-scale fractures can be predicted using these shapes. The study was motivated by the unprecedented opportunity to characterize fold shapes with decimeter precision using ALSM data and high resolution digital photography acquired by the NSF-sponsored National Center for Airborne Laser Mapping (NCALM), operated jointly by the University of Florida and the University of California. The folds selected for this study are Sheep Mountain Anticline, Wyoming, and Raplee Ridge Monocline, Utah. |
0.915 |
2008 — 2012 | Borja, Ronaldo Loague, Keith (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Coupled Solid-Deformation/Fluid-Flow Simulation of Failure Initiation in Variably Saturated Slopes @ Stanford University Landslides occur when earth material moves rapidly downhill after failing along a shear zone. Debris flows are differentiated from landslides by the pervasive, fluid-like deformation of the mobilized material. Landslides and debris flows threaten lives and property worldwide. Despite the fact that good progress has been made within the last two decades relative to understanding hydrologically-driven slope failure, important research has yet to be conducted in 3D physics-based fluid flow and hydrologically-driven slope instability in variably saturated soils. |
0.915 |
2009 — 2014 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Neesr-Cr: Properties of Cohesionless Soil Subsequent to Liquefaction and Resedimentation @ Stanford University This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes Stanford University (lead institution), Arizona State University (subaward), and Bucknell University (subaward). This project will utilize the NEES equipment sites at the University of California at Davis, and at the University at Buffalo. The project will experimentally and numerically investigate the properties of resedimented soil following liquefaction, including void ratio distribution and shear strength. To investigate the properties of cohesionless soil subsequent to liquefaction, a series of coordinated physical model tests, numerical analyses, imaging analyses, and laboratory shear strength tests will be conducted. Physical model testing will include laboratory column testing, small- and large-scale shake table testing, and centrifuge testing. Numerical analyses will include simulations of the impact of non-homogeneities (as revealed by the physical model testing) on shear banding and the undrained shear strength of cohesionless soil, and novel computational fluid dynamics- (CFD-) based analyses of resedimentation of cohesionless soils. Laboratory testing will include shear strength testing on specimens recovered from the physical models, using special techniques to preserve their structure. Imaging will include bright field microscopy (BFM) and computer-aided tomography (CT) scanning of recovered specimens to evaluate their structure prior to and after liquefaction. |
0.915 |
2010 — 2011 | Borja, Ronaldo Kuhl, Ellen (co-PI) [⬀] Dunham, Eric (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
@ Stanford University Stanford University will host the International Workshop on Multiscale and Multiphysics Processes in Geomechanics June 23-25, 2010. The workshop will highlight the diverse and complex processes encountered in geomechanics in terms of scale (from nanometer to kilometer) and scientific scope. Topics of interest include coupled physics phenomena such as thermo-poro-mechanical and electro-poro-mechanical processes, chemical species reactivity and transport, liquefaction and solidification of sediments, strain localization phenomena, double porosity continua, and frictional faulting and fluid flow in porous solids. The workshop will also focus on multiscale numerical techniques, including the lattice Boltzmann, discrete element, finite element and finite volume methods, as well as the laboratory and field investigation methods supporting these numerical techniques. This project provides funds to support younger scientists from U.S. schools (new assistant professors, postdoctoral students, and Ph.D. students in advanced stages of thesis development) so they may be able to travel to Stanford University and participate in the workshop. The Workshop will bring together researchers working on many central challenges facing modern geomechanics. A key strength of the forthcoming workshop is the diversity of research backgrounds, methods, and applications that will be represented. Apart from the area of geomechanics, the broader impact of the workshop spans many other disciplines in science and engineering, including geophysics, geosciences, mechanical engineering, and biomechanics. For example, coupled multiscale and multiphysics phenomena, such as chemo-, poro-, electro-, thermo-, and biomechanics, are characteristic problems in nearly all branches of engineering. |
0.915 |
2015 — 2016 | Borja, Ronaldo Linder, Christian (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
@ Stanford University Over fifty percent of the world's population now lives in urban areas, a proportion that is expected to increase further as more and more names are added to the list of megacities in the world. Projections show that urbanization combined with the overall growth of the world's population could add another 2.5 billion people to urban populations by 2050. This imposes considerable demands on the environment to find resources for its inhabitants. The Engineering Mechanics Institute Conference to be held at Stanford University on June 16-19, 2015 focuses on the role of engineering mechanics to tackle important problems associated with sustainable urban systems. The Conference will be attended by experts in different areas of engineering mechanics from all over the world. The objective of this project is to provide graduate students an opportunity to present their work in front of experts in their field of specialization, as well as promote exchange of scientific knowhow with these experts. Graduate students will be provided financial assistance in the form of travel fellowships to enable them to attend the Conference. |
0.915 |
2015 — 2018 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Creep Deformation in Shale At Submicron Scale @ Stanford University Shale is a fine-grained sedimentary rock consisting of a mixture of clay, quartz, feldspar, pyrite, carbonate, and organic materials forming a highly heterogeneous nanocomposite. As a seal rock, shale has been used to contain toxic, long-lived chemical and radioactive waste products in the ground. In fact, crystalline rocks and thick shale sequences have long been considered as prime storage sites because of the shale's ability to resist fracture. The mechanical properties of shale depend on the properties of its basic constituents, including those of clay particles and organic inclusions, as well as the porosity of the mixture. Due in large part to its clay and organic content, shale exhibits significant creep deformation that can create subsidence issues on a regional scale, as well as alter its effectiveness as a seal for toxic waste products that must be contained for thousands of years. This award supports fundamental research to investigate the creep deformation behavior of shale at the nanometer scale. Investigation into the mechanical properties of this heterogeneous material provides insight into the fundamental processes governing creep at a scale critical for its function as a seal, as well as allows interpretation of the creep phenomena at larger scales. The research involves several disciplines including materials science, biomechanics, and other scientific disciplines concerned with the studies of nanoporous materials. It supports a female doctoral student who will help broaden the participation of underrepresented groups and undergraduate students. |
0.915 |
2019 — 2022 | Borja, Ronaldo | N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Creep in Shale Across Space and Time @ Stanford University Shale is a fine-grained sedimentary rock composed of softer materials such as clay and organics, as well as stiffer minerals such as quartz, feldspar, pyrite, and carbonates. It is the most common sedimentary rock on Earth, estimated to represent between 44 and 56 percent of all sedimentary rocks. Unlike crystalline rocks that tend to fracture under deformation, shales can serve as a seal because they are more pliable in the sense that they can undergo significant deformation without breaking. However, they are also known to exhibit significant time-dependent deformation behavior, or creep, that is observed across spatial and temporal scales. The tendency of shale to creep is well correlated with how the softer and stiffer components of this rock share an imposed load. In addition, the reduction in sample volume during creep suggests that this phenomenon is accommodated by compaction of the pore spaces between the solid grains. The latter process can lead to significant ground subsidence that often compromises the integrity and sustainability of civil infrastructures. Using laboratory and numerical modeling techniques, this project will investigate the multiscale creep behavior in shale across space and time. Laboratory experiments include indentation tests to probe the creep behavior at the nanometer scale, and triaxial tests on cylindrical specimens of rock to investigate creep at the millimeter scale. The combined laboratory experimentation-numerical simulation activities of the project will involve the participation of undergraduate students through summer research. A promotional video of the laboratory tests and numerical simulation results will be produced for recruiting graduate students as well as for outreach. |
0.915 |