Engineering Commons^™

Investigation Of Subsurface Stratigraphy And Groundwater Dynamics In The Mississippi River Delta, An Li

LSU Doctoral Dissertations

The Mississippi River Delta (MRD) is socioeconomically important to the state of Louisiana and the United States. Various types of land-water system data have been collected in the MRD. However, very few efforts have been made to utilize these datasets in modeling regional stratigraphy and groundwater dynamics in the MRD, especially for the upper 50 m of the depth. In this interval of depth, the Mississippi River and surrounding interdistributary bays intensively interact with the groundwater system. The lack of knowledge in regional stratigraphy and groundwater dynamics hinder an understanding of how hydrogeological setting affects processes such as surface-groundwater interaction, …

Integrated Full-Scale Physical Experiments And Numerical Modeling Of The Performance And Rehabilitation Of Highway Embankments, Navid Jafari, Anand Puppala, Sayantan Chakraborty, Burak Boluk

Publications

The study aimed to fundamentally understand how soil strength and hydraulic properties are impacted by recurring cycles of wetting and drying induced by climate variability, with the practical implication of forecasting the stability of highway embankment slopes. The review of literature on the effects of long-term cyclic wetting-drying phases on hydro-mechanical properties of clayey soils suggests that only a few cycles of wetting and drying can impact the strength and hydraulic conductivity, where the latter can increase several orders of magnitude. Laboratory model-scale experiments of Louisiana and Texas soils are still ongoing and will relate the laboratory test results to …

Performance Of Drilled Shaft Under Combination Of Complicated Loads Under Hurricane Event, Jie Huang, Sazzad Bin-Shafique

Publications

This project includes experimental and numerical studies to investigate and assess the impact of vertical loads on a laterally loaded drilled shaft under various conditions. The experimental study includes lab testing and lab-scale load test to examine a drilled shaft subjected to vertical and lateral loads at a reduced scale. With the data obtained from the lab-scale testing, a numerical model was calibrated, which was used to perform a parametric study to scrutinize the effect of many possible factors such as soil stiffness, soil friction angle, and drilled shaft geometry. With all the factors considered in this study, the vertical …

Development Of Metals Corrosion Maps Of Arkansas And Maintenance Of Cross-Drains, Zahid Hossain, Ashraf Elsayed, Mdariful Hasan

Publications

Corrosion potential of metallic structures in alluvial soils is governed by chemical and electromagnetic properties of the soils. Geotechnical engineers are generally more concerned about different types of soils and their physical and mechanical properties than the chemical aspects. The main objective of this study is to analyze the geotechnical, electrochemical and electromagnetic properties of soils in Arkansas. Important parameters (e.g., soil resistivity) related to corrosion potential of metal culverts have been predicted through neural network (NN) models. The developed NN models have been trained and verified by using laboratory test results of soil samples collected from Arkansas Department of …

Karst Sinkhole Detecting And Mapping Using Airborne Lidar, Su Zhang, Shirley Baros, Susan Bogus

Publications

The focus of this study is to detect sinkhole hazards using airborne light detection and ranging (LiDAR) data. The premise is sinkholes, particularly those close to transportation infrastructure assets, could cause substantial damages to infrastructure assets, and therefore, being able to accurately and rapidly detect them is essential. However, it is expensive, time-consuming, labor-intensive, and unsafe to survey sinkholes using conventional ground observation methods. This research project was focused on developing accurate and rapid airborne LiDAR-based sinkhole detection and mapping methods, and transfer the technologies to transportation engineers for implementation and workforce development. The project team also identified best practices …

Developing Implementable Climatic Input Data And Moisture Boundary Conditions For Pavement Analysis And Design, Rifat Bulut, Amir Hossein Javid

Publications

The main objective of this study is to develop a practical and implementable numerical model for predicting the moisture (suction) regime within the pavement subgrade system. The research quality and uniformly-dispersed climate data over short distances from Oklahoma Mesonet and the Mitchell based moisture (suction) prediction methods establish the main background of the research study. The study involved numerical modeling and statistical analysis of climatic weather data. The proposed moisture variation model predicts the suction distribution throughout the soil subgrade by solving the diffusion equation and incorporates the measured suction from the Oklahoma Mesonet to estimate the diffusion coefficient. The …

Field Performance And Cost Effectiveness Of Crack Sealing In Flexible And Composite Pavements, Momen Ragab Mousa

LSU Doctoral Dissertations

Surface cracking is one of the major surface distresses in asphalt concrete (AC) pavement, allowing water infiltration through the cracks, causing stripping in asphalt pavement layers, and weakening and deteriorating the base and/or subgrade. Its treatment, therefore, is one of the major activities in pavement preservation for many state DOTs. Among the various treatment methods currently available to preserve AC pavement with existing surface cracking are various forms of crack sealing. Crack sealing is not a common practice to Louisiana highways since the benefit of such treatment appears to be affected by the elevation of the ground water table. Studies …

Analytical And Numerical Modeling Of Cavity Expansion In Anisotropic Poroelastoplastic Soil, Kai Liu

LSU Doctoral Dissertations

Cavity expansion/contraction problems have attracted intensive attentions over the past several decades due to its versatile applications, such as the interpretation of pressuremeter/piezocone penetration testing results and the modelling of pile installation/tunnel excavation in civil engineering, and the prediction of critical mud pressure required to maintain the wellbore stability in petroleum engineering. Despite the fact that various types of constitutive models have been covered in the literature on this subject, the soils and/or rocks were usually treated as isotropic geomaterials.

In recognition of the above fact, this research makes a substantial extension of the fundamental cavity expansion theory by considering …

Modeling Of Fluid Injection For Hydraulic Fracturing Initiation In Porous Rock Formations, Krishna Adhikari

LSU Master's Theses

Hydraulic fracturing has been widely opted in recent times to simulate the unconventional reservoirs and thus, has become key a subject of interest in petroleum engineering. The stress concentration around the borehole affects the breakdown pressure and fracture reopening pressure during the hydraulic fracturing treatments. Thus, the state of stress around borehole wall and its surrounding rocks due to instantaneous drilling and a fluid injection at borehole surface needs to be determined accurately to initiate the hydraulic fractures. This research intends to derive the analytical stress solution of inclined borehole subjected to time-dependent fluid injection and in-situ stress, verify the …

Synthesis Of Fault Traces In Se Louisiana Relative To Infrastructure, David Culpepper, Elizabeth Chinn Mcdade, Nancye Dawers, Mark Kulp, Rui Zhang

Publications

Geological faulting has been implicated as a contributor to subsidence, coastal land-loss and submergence of marshlands in southern Louisiana. This report reviews whether fault motion, either by slow creep or more sudden slip, can cause deformation of engineered structures resulting in increased infrastructure maintenance and repair costs. The impact of surface, or near-surface, geologic faulting on critical infrastructure is insufficiently documented in southeastern Louisiana, but the state has a vast amount of energy-sector subsurface data that to date has been under-utilized for transportation and other near-surface engineering applications. Recent and on-going work by research groups at Tulane University, University of …