Geotechnical Engineering Commons^™

Investigation Of Casting Methods Of Photoelastic Particles To Study The Geomechanics Of Granular Media, Daniel Schullek

Williams Honors College, Honors Research Projects

The research being conducted within this project is to observe force chains in different samples of soil media with varying shapes. The method for observing the force chains is a process called photoelasticity. Photoelasticity uses two polarizing sheets, with the clear media being tested placed between, and light is directed through the sheets to observe how the light is refracted as force is applied to the tested media. Through our research, we are coming up with a method of casting soil particles through the utilization of resin, silicone, and 3D printing. Once the clear particles have been cast, we will …

Comparative Analysis Of Bridge Abutment Types, David Fell

Williams Honors College, Honors Research Projects

This project was developed to serve as a brief overview of design practices and considerations in the selection of highway bridge abutment types. This involved a review of literature in the form of reviewing national design guides and department of transportation (DOT) requirements from both US DOTs and international DOTs. The abutment types covered in this research included conventional reinforced concrete abutments with bearings, integral abutments, and semi-integral abutments. This research focused solely on highway bridge abutments, particularly on Ohio Department of Transportation design requirements due to their extensive use of semi-integral abutments. Superstructure elements and geometric requirements are primary …

Non-Destructive Characterization Of Bio-Cemented Soils Via Seismic Wave Measurement, Kyle Best

Williams Honors College, Honors Research Projects

The final outcome of this project is to examine the mechanical and resulting physical properties of bio-treated soil through microbial activity via non-destructive testing by seismic waves. The proposed bio-treatment strategy is through supplying specific nutrients for indigenous microbes within a soil specimen which in return produce calcium carbonates. The bio-minerals produced during these biogeochemical activities will improve the mechanical properties of soil by making cementation between soil grains. Additionally, a theoretical laboratory experimentational description will be provided to explain any associative effects on a specimen's water permeability or mechanical strength due to bio-mineralization within the samples. The characterization of …

Investigating The Mechanical Properties Of Frozen Soil Using Non-Destructive Seismic Wave Measurements, Sean Mach

Williams Honors College, Honors Research Projects

This proposed project will be dealing with investigating the mechanical properties of soil under frozen conditions. This will be done by an innovative non-destructive technology measuring the propagation of seismic waves through the frozen soils from multiple piezoelectric sensors. For the duration of this research, a freezing cell must be constructed to carry out the experimental testing. Multiple levels of saturation will be tested under the given freezing conditions. This should highlight the effect that the level of saturation will have on the propagation of seismic waves throughout the soil. Piezo-electric sensors will be placed in each layer of soil …

Development Of A Decision-Making Tool For Prediction Of Rainfall-Induced Landslides, Faisal Shakib Ahmed

Theses and Dissertations--Civil Engineering

Landslides are frequently observed in mountainous places following prolonged periods of rain, frequently resulting in substantial topography changes. They pose a significant risk to human lives and the built environment globally, particularly in areas prone to excessive rainfall. While slope failures can occur because of human-caused factors such as slope loading or toe cutting for construction purposes, many failures occur because of rainfall penetrating an otherwise stable slope. A greater understanding of the characteristics and mechanics of landslides is consequently critical for geotechnical research, particularly in evaluating prospective mitigation strategies. The potential of slope failure is a primary consideration when …

Geophysics-Based Ground Control And Excavation Design Methodology Based On Acceptable Damage, Jorge Romana Giraldo

Theses and Dissertations--Civil Engineering

This dissertation is structured around a novel conceptual framework for designing deep excavation retaining systems and using geophysical data to estimate the mechanical response of soft soil deposits. It begins with presenting an approach to design excavation retaining walls based on limiting damage to adjacent infrastructure. In this approach, the damage is defined based on critical distortions of an idealized laminate beam model used for representing the adjacent building deformations. The wall and support elements of the support system are then designed such that the system yields the limiting ground deformations. The resulting excavation support system limits damage to adjacent …

Image-Data-Driven Deep Learning For Slope Stability Analysis, Behnam Azmoon

Dissertations, Master's Theses and Master's Reports

Landslides cause major infrastructural issues, damage the environment, and cause socio-economic disruptions. Therefore, various slope stability analysis methods have been developed to evaluate the stability of slopes and the probability of their failure. This dissertation attempts to take advantage of the recent advancements in remote sensing and computer technology to implement a deep-learning-based landslide prediction method.

Considering the novelty of this approach, this dissertation leads with proof-of-concept studies to evaluate and establish the suitability of deep learning models for slope stability analysis. To achieve this, a simulated 2D dataset of slope images was created with different geometries and soil properties. …

North 14th Street Corridor Improvements Project, Ashley Nguyen, Samantha Corey, Maricela Paramo Reyes, Pooja Rajeev

Honors Theses, University of Nebraska-Lincoln

The following project report was a study of the North 14^th Street corridor ranging from Adams Street to Virginia Street conducted by University of Nebraska-Lincoln students for a senior design capstone project. Main focuses of the project were the intersection of Adams and 14^th Street and the 14^th Street bridges over Cornhusker Highway and Oak Creek. Study of this area included work in transportation, traffic, structural, geotechnical, water resources, and environmental engineering. However, this report done by students should not take the place of work done by licensed professional engineers.

This project was done in collaboration with …

Lunar Regolith Simulant Behaviours Affected By Shock Metamorphism And Mineralogy, Xiao Chen Zhang

Electronic Thesis and Dissertation Repository

There are still many gaps in improving the fidelity of lunar regolith simulants to simulate more properties. This study compares some fundamental physical and mineralogical properties of three types of lunar highland regolith simulants: LHS-1, a commercial product with high mineralogical fidelity; UWO-1G, an original simulant that is the main component of LHS-1; and UWO-1S, another original product that is attempted to produce shocked grains in lunar simulants from pulverizing and mixing impact rocks sourced from the Mistastin Crater.

Preliminary results indicated that even though all simulants are composed of mostly plagioclase minerals and have similar particle size distribution patterns, …

Seismic Response Of Driven And Helical Piles In Non-Liquefiable And Liquefiable Soils, Ahmed Fouad Hussein

Electronic Thesis and Dissertation Repository

The thesis investigates the nonlinear soil-pile-structure interaction through three-dimensional nonlinear finite element models (FEM) employing the OpenSees platform. The FEMs were validated with the results of large-scale shaking table tests of model pile groups-superstructure systems in dry and saturated sand and large-scale field tests on single piles installed in cohesive soil. The numerical models correctly predicted the different pile deformation modes that were exhibited in the experiments. The results illustrated that the inertial interaction contributed to the bending moments at the pile top, while the kinematic interaction contributed to the bending moment at the layers interface. In addition, the excess …

Static Liquefaction Of Oil Sand Tailings: An Experimental Investigation Into The Effect Of Saturation And Fines Content, Farshad Zehforoosh

Electronic Thesis and Dissertation Repository

The main goals of this research are to explore the influence of partial saturation and fine content on the shear response of oil sand tailings, to identify the liquefaction susceptibility under different initial states. Monotonic triaxial compression tests were carried out to understand the mechanical behavior of the saturated oil sand tailings with varying void ratios. Then the effect of fine content on the yield and critical shear strength, critical state line, and instability line was evaluated by increasing the fine content up to 50%. The experimental results revealed that the shear strength of the oil sand increases with fine …

Towards Modeling Projectile Penetration In Dry And Multiphase Granular Materials, Mohmad Mohsin Thakur

Doctoral Dissertations

The present work aims at developing and validating numerical modeling strategies in granular materials impacted by a projectile. The focus is on two regions: (a) near-field: region near the tip and along the path of a projectile where comminution of grains is significant, (b) intermediate-field: region far from the projectile where grain-scale interactions are important but stresses are not high enough to cause crushing of the grains.

A novel framework has been introduced and validated wherein particle shape captured using X-ray CT imaging was incorporated in FEM simulations using shell elements for simulating triaxial boundary value problems. The results indicate …

Measuring Foundation Course Modulus Using Falling Weight Deflectometer, Light Weight Deflectometer, And Dynamic Cone Penetration, Bruce Barrett, Kellie Troxel, Brady Dresselhaus, David Hansen

Nebraska Department of Transportation Research Reports

The purpose of this investigation was to determine the feasibility of measuring bituminous foundation course modulus under concrete roadways by comparing testing results derived before and after paving using FWD, Light Weight Deflectometer (LWD), and Dynamic Cone Penetrometer (DCP). The foundation course modulus was determined using FWD data and Darwin design software (‘93 AASHTO). Results from Phase I data collection, which occurred prior to pavement placement, provided a baseline for comparison. The maximum modulus was 398,000 PSI and the minimum was 85,000 PSI, yielding a range of 315,000 PSI and an average modulus of 123,000 PSI over the length of …

Additive Manufacturing Of Soil Using Bio-Cementation, Christina Childress

Graduate Theses and Dissertations

Microbially Induced Calcite Precipitation (MICP) is an emerging soil treatment technique that is proven to increase strength, decrease erosion, reduce liquefaction risk, enhance slope stability, decrease compressibility, decrease swelling potential, and overall create a more competent soil. The benefits and applications of MICP are broad, and this research seeks to broaden them further by developing a single-phase additive manufacturing application with no treatment time delay. This is done by analyzing layering behaviors of five USCS soil classifications (100 % Ottawa sand, sand clay mixtures, and 100% lean clay) which provides insight into process variables such as the solution volume and …

Gap Study For The Impact Of Braced Deep Excavation On The Behavior Of Excavation Bed, Abdelrahman E. Aboelela, Ahmed M. Ebid, Ayman L. Fayed

Future Engineering Journal

Two geotechnical topics were investigated in this research; shored deep excavation and modulus of subgrade reaction. Both topics were extensively studied by many earlier researchers. The aim of this study is to answer the following question, "Is deep excavation effects on excavation bed behavior of sufficiently investigated? Or there still un-studied gaps should be fulfilled?”. Litterateurs were collected, reviewed and classified for both topics especially in the interaction zone between the two topics, and it is concluded that deep excavation effect on the modulus of subgrade reaction values and distribution at excavation bed level is not sufficiently addressed especially the …

Investigation Of Sand-Biochar Mixtures As A Potential Roadway Fill Material, Katia J. Lele Lagmago

LSU Master's Theses

Biochar is a sustainable and lightweight carbon-rich material with a high surface area and porosity. Previous studies reported that biochar can reduce soil erosion and cracking, retain contaminants, and enhance soil aggregation. Given these favorable properties, soil-biochar mixtures have the possibility to serve as a multifunctional lightweight fill material for roadway embankment applications. The purpose of this research is to develop sand-biochar mixtures as a sustainable and multifunctional lightweight fill material for roadway embankment applications.

This research investigated the consolidation and hydraulic properties of sand-biochar mixtures by (1) performing 1D consolidation tests, (2) performing permeability tests, and (3) assessing the …

Density State And Shear Behavior Of Granular Soils With Influence Of Particle Size Distribution, Yibing Deng

Doctoral Dissertations

Heterogeneous granular soils are ubiquitous in nature and man-made deposits. Heterogeneity of soil is characterized by its particle size distribution (or fines content for gap-graded soils). The particle size distribution of soil is the main factor that affects its mechanical properties. However, in soil mechanics, the influence of particle size distribution on mechanical properties is only considered in an empirical manner. There are few analytical methods that can explicitly account for the effect of particle size distribution. In this study, there are two purposes: 1) to develop a particle packing theory for modeling the effect of particle size distribution on …

Undrained Cyclic Loading Of Low Plasticity Silty Soils In The Pacific Northwest Using Laboratory And Field Cyclic Shear Testing, Angelica Melissa Preciado Reyes

Dissertations and Theses

The cyclic behavior of a fine-grained low plasticity silty soil (plasticity index of approximately 15) at a site in Portland, Oregon, is characterized using a field and laboratory cyclic shear test program. The field cyclic tests were performed using the NHERI@UTexas large mobile shakers T-Rex and Rattler. The laboratory tests were performed using resonant column torsional shear and cyclic direct simple shear devices. This testing program's results were used to evaluate the soil's potential to develop excess pore water pressure with cyclic shear strains ranging from 0.00001% to 3%. The laboratory cyclic test results are compared against field cyclic test …

Geological Origin As An Input Variable In Reliability-Based Designs: For An Accurate Exploration In Geotechnical Engineering, Juan Camilo Viviescas, Juan Pablo Osorio

Conference papers

Soil is one of the most difficult materials to characterize realistically, which partly explains the uncertainty between the designs and the geostructures real behavior. Different recommendations have arisen with respect to carrying out field investigations in order to reduce the uncertainties inherent to the soil. However, the field exploration and the implementation of sophisticated geotechnical models have proven to be insufficient to mitigate the geotechnical uncertainty. Therefore, Reliability-Based Designs (RBD) emerge as a decision-making tool through the definition of the probability of failure in conjunction with the typical Factors of Safety. RBD requires a previous understanding of the most appropriate …

Development Of A New Electro-Osmotic Consolidation Apparatus, Yenni Mariana Ramírez-Mazo, Juan Pablo Osorio, Sergio Agudelo

Conference papers

Electro-osmotic consolidation is a ground improvement technique in which a DC voltage is applied to the soil via electrodes, in order to drain the water contained in the pores increasing the effective stress, and thus improving the geotechnical properties of the soil. The technique increases the shear strength, reduces the compressibility, and changes the chemical composition of the saturated soft clayey and silty soils to which it can be applied. Electro-osmotic consolidation has been successfully applied in different projects worldwide. This paper presents the development of a new electro-osmotic consolidation apparatus built at Universidad de Antioquia. Tests were carried on …