Digital Commons Network^™

Numerical Updating On Collapse Simulation Of Multi-Story Buildings Through Hybrid Testing, Miguel Negrete-Padilla

Doctoral Dissertations

The present dissertation introduces an innovative numerical updating approach within fully simulated hybrid testing with substructuring techniques through collapse. The proposed approach is based on utilizing the measured response from the experimental substructure to update during the test the parameters of the components of the numerical substructure. The main research objective is to improve the ability to predict and simulate collapse through hybrid testing with substructuring techniques. The proposed numerical updating approach demonstrates to be capable of reliably reduce the epistemic uncertainty existent on the calibration of initial component parameters of the numerical substructure, especially when the system is near …

Developing Index Parameters For Cracking In Asphalt Pavements Through Black Space And Viscoelastic Continuum Damage Principles, David Jonathan Mensching

Doctoral Dissertations

Cracking is a major distress for asphalt concrete pavements and presents significant challenges to effective design and maintenance. Fatigue and thermal cracking decrease ride quality of the pavement and allow water to penetrate into underlying layers, which can result in major damage if left unchecked. The primary obstacle in predicting field performance for cracking in asphalt pavements is related to the interaction of material, structural, and environmental components. The major objective of this work is to develop index parameters to relate material and structural parameters, identifying whether a mixture is prone to fatigue or thermal cracking.

A Simplified Viscoelastic Continuum …

Investigation Of Resin Regeneration In The Suspended Ion Exchange (Six®) System, Jihyon Im

Master's Theses and Capstones

This research investigated 1) evaluation and optimization of the SIX® anion exchange regeneration efficiency and 2) compatibility of cation exchange for hardness removal and shared-regeneration with the current anion exchange regenerant. The first objective was addressed by comparing the effects of three variables on desorption efficiencies: regenerant volume, salt concentration, and contact time. Sorption studies were performed to quantify resin blinding, and removal kinetics were established and compared. The second part of this research tested a strong acid cation resin for softening performance and regenerability with sodium chloride regenerant.

Inefficient DOC and nitrate desorption were observed as larger regenerant volume …

Suction-Controlled Cyclic Triaxial Test To Measure Strain-Dependent Dynamic Shear Modulus Of Unsaturated Sand, Ganna Suprunenko

Master's Theses and Capstones

Recent advancement in unsaturated soil mechanics revealed the influence of the degree of saturation on dynamic properties of soils due to inter-particle suction forces. However, because of the complexities in states of stress and experimental modeling, most of the recent studies only focused on small-strain shear modulus. Cyclic triaxial system at the University of New Hampshire was renovated and modified for suction control to enable testing the soils with different degrees of saturation at medium to large strain levels. A set of strain- and stress-controlled cyclic triaxial tests were performed on dry, saturated, and partially saturated sand specimens. The measured …

Finite Element Analysis Of Pv Drains For A Test Embankment On Soft Clay, Americo Joseph Santamaria

Master's Theses and Capstones

In 2012 the New Hampshire Department of Transportation constructed a test embankment with prefabricated vertical drains on top of soft marine clay in Dover, NH. The test embankment was built with variable drain spacing and embankment geometry in order to determine effective and efficient treatment for long term ground settlement. Findings from this study are to be implemented in future applications in the New Hampshire seacoast where soft marine clay is present. Using data collected from several in situ and laboratory tests, this thesis investigates the use of finite element analysis to predict total settlement and time rate of consolidation …

Critical Shear Stress Estimates Of Sunken Alberta Bitumen, Charles Bruno Richter Watkins

Master's Theses and Capstones

As observed in several recent spills (e.g., DBL-152, TX; Enbridge-Kalamazoo, MI), under certain circumstances, released oil can sink to the bottom of a water body. Once on the bottom, the oil can move or remobilize into the water column. The National Oceanic and Atmospheric Administration’s (NOAA) Office of Response and Restoration (ORR) uses mathematical models to predict the trajectory of spilled oil. The critical shear stress (CSS) for an oil is used to predict the movement of sunken oil along and off the bottom. The CSS has only been measured for one oil (Hibernian crude). The Coastal Response Research Center …