Making Sense of Asian Beach Litter on a Remote Costa Rican Beach
Environmental Article - Jan 12, 2023
This is an article I wrote describing an incidence of beach litter which occured in August of 2022 on the Osa Peninsula of Costa Rica and my attempt to discover the origins of the mostly Asian debris. I submitted the article to Mongabay.com in November, however I have not heard back from them. Currently it is only viewable here on my website.
Slope Stability Analysis of the Coricancha Tailings Storage Facility
Technical Memorandum - Global Resource Engineering - May 28, 2021
This slope stability analysis evaluates the current condition of the facility, to assess the safest areas where tailings can be removed, and to determine the future condition of the facility after removal of tailings.
Preliminary Design of MSE Wall Alternative for Modification Alternatives of Anderson Ranch Dam
Technical Memorandum - Bureau of Reclamation - March, 2019
This report presents a preliminary analysis and design for a Mechanically Stabilized Earth (MSE) alternative to accomodate a proposed increase in reservoir elevation for Anderson Ranch Dam.
One Dimensional Site Response Analysis and Dynamic Deformation Analysis of Fresno Dam
Draft - Technical Memorandum - Bureau of Reclamation - August, 2018
The scope of this report is to present the analysis and conclusions of various dynamic analyses performed for Fresno Dam. This report includes the analysis of (1) material properties, (2) liquefaction potential analysis via the equivalent linear method and simplified methods, (3) seismic input screening, and (4) FLAC dynamic deformation modeling.
Slope Stability Analysis for Heart Butte Downstream Conduit Filter Excavation
Technical Memorandum - Bureau of Reclamation - April, 2018
This technical memorandum (TM) documents the slope stability analysis performed in determining the appropriate means of excavation for the downstream conduit filter modifications proposed for Heart Butte Dam.
Evaluation of Boundary Conditions for Dynamic Numerical Modeling of Embankment Dams
Technical Memorandum - Bureau of Reclamation - February, 2018
As part of an ongoing research project to understand how surface waves can be incorporated into Reclamation’s dynamic numerical modeling of embankment dams, an effort was made to research and categorize the effects of absorbing boundary conditions on these numerical models. The following report reviews the currently available absorbing boundary conditions in commercial software currently licensed to Reclamation.
Dynamic Deformation and Limit Equilibrium Analyses of Proposed Modification of B.F. Sisk Dam
Draft - Technical Memorandum - Bureau of Reclamation - January, 2018
This report presents a dynamic deformation analysis using FLAC to evaluate the risk reduction of proposed modifications to B.F. Sisk Dam.
Detection of Anomalies using Geophysical Methods - Center for Geotechnical Practice and Research (CGPR) Geophysics Competition 2017
Technical Memorandum - Bureau of Reclamation - December, 2017
Virginia Tech’s Center for Geotechnical Practice and Research (CGPR) has conducted a research project, inviting competitors from industry and academia to perform a geophysical site investigation using non-invasive (surface-based) geophysical methods to detect anomalies at a roadside site with deliberately placed anomalies between 5 to 30 feet in depth overlaid by fill. The Bureau of Reclamation participated in this (non-prize) competition in order evaluate (1) the performance and abilities of various geophysical methods in finding the anomalies and (2) Reclamation’s relative performance in the competition with respect to other participants from academia and industry. This report summarizes the findings of the team sent by Reclamation.
Material Properties Analysis Technical Memorandum for Issue Evaluation, Unity Dam
Technical Memorandum - Bureau of Reclamation - May, 2016
The purpose of this Technical Memorandum (TM) is to document the estimation of material input parameters to be used for liquefaction potential assessment and numerical modeling planned for an issue evaluation (IE) for Unity Dam.
Evaluating Settlement of Fresno Dam with Numerical Modeling using the Duncan-Chang Hyperbolic Model
Technical Memorandum - Bureau of Reclamation - December, 2016
The purpose of this Technical Memorandum is to document the procedures used analyze the settlement of Fresno Dam using numerical modeling via a two-dimensional finite difference model using Itasca’s FLAC and a two-dimensional finite element model using Geostudio’s Slope/W. This report serves as a memorandum of the details in incorporating the Duncan-Chang Hyperbolic stress-strain behavior in these two numerical models as to represent the stress-strain behavior of the clay layer responsible for the settlement of the dam.
Updated Seismic Deformation Analyses with As-Built Properties, Mormon Island Auxiliary Dam
Technical Memorandum - Bureau of Reclamation - December, 2016
This technical memorandum documents the procedures and results of updated FLAC deformation models of the Mormon Island Auxiliary Dam.
The Use of Surface Wave Methods in Terrain Suceptible to Shallow Land Slides in the City of Campos do Jordão, Brazil
Master's Dissertation - Feb 19, 2016
This study seeks to prove the usefulness of the Multichannel Analysis of Surface Waves (MASW) method as complementary data to conventional geotechnical and geological data in the characterization of areas of landslide risk. The setting is located in a low income housing neighborhood in the city of Campos do Jordão, state of São Paulo, Brazil. The area was devastated by numerous landslides between December 1999 to January 2000 after heavy rainfall in the area. The landslides in this area are known to be shallow. Refraction and MASW surveys were performed in this research and then processed to obtain seismic velocity profiles of the subsurface. In order to better identify the fundamental mode of the Rayleigh wave, separate surveys isolating the vertical and radial components of the Rayleigh wave were performed. By comparing the inverted shear wave and compressional wave profiles with the already known geotechnical and geological data of the site, a better understanding of the geological interfaces that constitute the landslide prone area is obtained.
Study of Near-Surface Seismic Methods on Terrain Susceptible to Landslides in the City of Campos do Jordão, State of São Paulo, Brazil
AGU Fall Meeting 2015 / SAGEEP 2016 - Mar 22, 2016
Poster Presentation at the Fall Meeting of the American Geophysical Union (AGU) 2015 and Symposium on the Application of Geophysics to Engineering & Environmental Problems (SAGEEP) 2016.
Travels in Geology: Trekking the high terrain of Tajikistan
EARTH Magazine - Jul 1, 2014
EARTH is a nonprofit magazine published by the American Geosciences Institute with a mission to inform the public on the science of Earth, energy and environmental topics.