Civil Engineering Commons^™

Active Rheological And Stiffening Control Of Cementitious Systems For Additive Manufacturing, Abdul Basit Peerzada

All Dissertations

Technological advancements and automation in the last two decades have made additive manufacturing of cementitious systems a reality. Among all the additive manufacturing techniques used for cementitious materials, layer-by-layer extrusion-based printing is the most used technique. For a layer-by-layer printing process, the requirements of cementitious materials vary from those of a conventional construction process. Typically, the cementitious materials are pumped to a print head using a positive-displacement pump. The pumpability of the cementitious material for a specific pumping system depends on its rheological properties. For effective pumping, the yield stress and plastic viscosity of a cementitious system should be low. …

Application Of Experimentally Calibrated Numerical Models For Prediction Of Composite Masonry Prism Strength, James Bristow

UNLV Theses, Dissertations, Professional Papers, and Capstones

The composite masonry prism test is a common laboratory test to determine the compressive strength of a set of masonry prisms (f’mt) to verify that the composite masonry prism assembly, and more importantly, the constituent materials, are providing adequate strength. While constructing masonry structures, the subcontractors, designers, and inspectors rarely provide continuous supervision or inspection of the construction process. Accordingly, verification of grout mix design, mixed proportions, proper installation of blocks, placement of mortar, dimensions of joints, etc. are more traditionally performed on a periodic basis instead. However, through the use and review of the composite masonry prism test results, …

Effects Of Particle Size And Replacement Proportion Of Post-Consumer Glass In Concrete, Negasi Gebremichael

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concrete, next to water, is the most used material (Gagg, 2014), which consumes natural or manufactured aggregates and resource-intensive cement. Concrete is also a more wasteful construction material than timber and steel. Depleting the natural resource due to aggregate extraction and the environmental unfriendliness of cement production have left the construction industry with no choice. Reducing waste, reusing, or recycling can help conserve natural resources. In this regard, the construction industry constantly seeks full or partial replacement of concrete aggregates and cement with recycled material. Glass is a candidate for replacing the three major components: cement, fine aggregate, and coarse …

Development Of An Excel Model To Evaluate The Stability Of Slopes, Bradley Davis

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This objective of this study is to determine a method or tool for taking given slope stability parameters and quickly and effectively determining the factor of safety against sliding of fully softened slopes. This study evaluates the effects of soil and geometric parameters of common slopes, and models these properties in a hypothetical model. The methodology is based on a parametric analysis using the Spencer’s Method of Slices limit equilibrium analysis used in the computer program Slide2. A parametric analysis is performed to determine which soil and/or geometric properties have a high influence on slope stability. The parametric analysis is …

Identification Of Factors Contributing To Traffic Crashes By Analysis Of Text Narratives, Cristian D. Arteaga-Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fatalities, injuries, and property damage that result from traffic crashes impose a significant burden on society. Current research and practice in traffic safety rely on analysis of quantitative data from crash reports to understand crash severity contributors and develop countermeasures. Despite advances from this effort, quantitative crash data suffers from drawbacks, such as the limited ability to capture all the information relevant to the crashes and the potential errors introduced during data collection. Crash narratives can help address these limitations, as they contain detailed descriptions of the context and sequence of events of the crash. However, the unstructured nature …

Automated Approach For The Enhancement Of Scaffolding Structure Monitoring With Strain Sensor Data, Sayan Sakhakarmi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction researchers have made a significant effort to improve the safety of scaffolding structures, as a large proportion of workers are involved in construction activities requiring scaffolds. However, most past studies focused on design and planning aspects of scaffolds. While limited studies investigated scaffolding safety during construction, they are limited to simple cases only with limited failure modes and simple scaffolds. In response to this limitation, this study aims to develop an automated scaffold monitoring approach capable of monitoring large scaffolds. Accordingly, this study developed an automated scaffold safety monitoring framework that leverages sensor data collected from a scaffold, scaffold …

Development And Application Of A Safety Index For Transit Stops: A Case Study From Las Vegas, Nevada, Rithesh Shivuni

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research developed a methodology to evaluate safety proximate to transit stops through a Safety Index, identified key factors associated with fatal crashes proximate to bus transit stops, and illustrated the applications of these using a case study based on the Las Vegas metropolitan area in Nevada, USA. The methodology is based on motor vehicle crashes that involve pedestrians recorded in the proximity of transit stops, and the severity of the crash outcomes. It focused on crashes which involved pedestrians that occurred within walking distances of individual transit stops. The severity of the crash outcomes was classified based on the …

Flexural Bond Strength Of Masonry Assemblies With Lightweight Grout, Benjamin L. Hiner

All Theses

Lightweight grout has many potential benefits in masonry construction, including minimizing mass, improving thermal performance, and potentially reducing shrinkage cracking via internal curing. However, insufficient testing of masonry assemblies with lightweight grout has been conducted to suggest appropriate design modification factors akin to the lambda factor in ACI 318-19. The objective of this paper is to study the tensile bond behavior of masonry assemblies grouted with lightweight grout and to suggest appropriate equations for predicting design capacity. A moment couple test is designed specifically for grouted masonry assemblies and has additional capacity compared to the traditional ASTM 1072 bond wrench …

Investigation Of Geopolymer Based Soil Stabilization Methods For Expedient Airfield Pavement Surfaces, Brett Albertson

All Theses

The United States Air Force (USAF) has the unique capability of being able to interdict superior airpower anywhere, at any time. However, superior airpower is only as effective as the amount of time an aircraft can spend in a particular area. The closer an aircraft can get to the mission need, the more time that can be spent in the air, or the less time that must be spent moving in and out of the operational area. Through the use of skilled and experienced men and women, the USAF is able to apply expedient and unsurfaced airfield paving techniques that …

The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy impacted 443,000 people and caused nearly $19 billion (about $58 per person in the US) worth of damage within New York City. As part of the New York City infrastructure reparation plan, the Living Breakwaters project in Tottenville addressed coastal resilience, allocating $100M of public funds to a series of artificial breakwaters by the southwest coast of Staten Island. Each breakwater is constructed and designed to mitigate water flow in storm events. ECOncrete, a primary element of the breakwater, is a specialty cast cementitious product that is marine organism-friendly that encourages biocalcification and photosynthesis. …

Energy Dissipation Of Highly Convergent Chutes In Stilling Basins Of Concrete Dams, Rafael Morán, Miguel Ángel Toledo, Jaime I. Masides

Protections Conference

This article presents the results of a combination of experimental and numerical research on the performance of stilling basins of spillways with highly convergent chutes (HCC). The comparison between the energy dissipation of the stilling basins with flat slab and baffle blocks shows that the latest are more efficient. Because of that, the cost savings of using such blocks can be significant. The results obtained could be applied in different cases such as increasing the capacity of existing spillways and protecting dams against overtopping. The application of HCC spillways in new dams could lead to a reduction in the cost …

A Novel Computational Method To Compute Rock Scour Due To Dam Overtopping, Erik F. R. Bollaert

Protections Conference

Flood events generating potential risk for dam overtopping may become more frequently in the future, especially because of increasing climate change. Crest overflows at arch dams generally impact the downstream rock mass very close to the dam foundation. As such, any scour of the rock mass generated by this phenomenon may potentially endanger the stability of the dam and its appurtenant structures. Hence, pertinent assessment of this scour formation through space and time is becoming increasingly relevant to dam safety. This paper presents a novel computational method for detachment of prismatic rock blocks from their mass when impacted by high-velocity …

Bedrock Erosion In Swedish Spillways - A Methodology For Assessing Design Pore Pressures Aimed For Design Of Erosion Mitigation Via Reinforcement Of The Rock Mass, Per Eriksson, Jonas Persson, Carol-Oscar Nilsson

Protections Conference

This article presents a collection of literature and data that enables calculations of hydraulic pressures inside a structurally simplified rock mass. The causation between the pressure in the rock mass and the near plane-parallel turbulently flowing waters on natural surfaces of igneous rock is expressed. The article is mainly aimed at rock reinforcement calculations given magmatic rock types with high durability and large block size.

Erodibility Evaluation Of An Unlined Rock Spillway: Comparison Between The Erodibility Index Method And A New Method Based On Block Theory, Michael George, Cole Christiansen, Ariel Rickel, Benjamin Israel, George W. Annandale

Protections Conference

Following the 2017 events at the Oroville Dam spillways that prompted evacuation of nearly 200,000 downstream residents and resulted in over $1B USD repair costs, there is highlighted focus on evaluation of spillways (both lined and unlined) at dams across the USA. In the case of unlined channels, flow conditions are often complex which presents several challenges for erodibility evaluation given methods are often based on idealized circumstances. High-resolution data available for the site (both in terms of 3D point cloud geometry data for the rock mass and 3D CFD model simulations of flow conditions) permitted a more detailed analysis …

Hydro-Geotechnical Rock Scour Assessment At Petit-Saut Dam, Seven E. Pells, Fanar Al-Qassab, Felicia Weir, Anaïs Faivre, Thierry Leturcq, Benoit Blancher

Protections Conference

This paper presents a recommended design procedure for assessment of rock scour which is illustrated for the case study of Petit-Saut Dam in French Guiana. The methodology, referred to as a “hydro-geotechnical scour assessment”, promotes a multi-discipline approach, applying expertise in both rock mechanics and hydraulics, and guides the diagnosis of scour and response to risk by application of currently available scour assessment techniques.

Failure Thresholds For Rcc Crest Caps, Tony L. Wahl, Bryan J. Heiner, Jacob F. Kepler

Protections Conference

Overtopping protection using roller-compacted concrete (RCC) overlays is a common improvement made to address hydrologic deficiencies at existing small- to medium-height embankment dams. Overlays allow floods to pass over the dam while preventing erosion of the original embankment. The United States has many examples of such projects on both private and public dams, including many associated with federal agencies of the Departments of the Interior and Agriculture. For one project modified with an overlay in 1993, deterioration of the RCC and poor bonding between lifts has caused concern for stability of the 0.3-m (1-ft) thick RCC lifts that cap the …

First Application Of Articulated Concrete Block Armoring With A Stabilized Stone Drainage Layer, Jeremy R. Young, Jim Nadeau

Protections Conference

Results from recent hydraulic testing of Articulated Concrete Block (ACB) systems have shown variations in the level of the ACB surface is attributed to the movement of an unconfined stone drainage layer. This movement appears to be exacerbated by thicker drainage layers, higher overtopping depths, and longer test flumes. While the apparent movement did not constitute “threshold of performance” as currently defined by ASTM D7276 and D7277, there was a desire to mitigate movement of the stone drainage layer and maintain conservatism in ACB design and construction. This paper will review the findings of Nadeau and Wedin’s paper from Protections …

Applying The Submerged Jet Erosion Test To Embankment Dam Breach Modeling, Tony L. Wahl, Blake Armstrong

Protections Conference

The submerged jet erosion test (JET) is one of several methods available for quantifying erodibility of cohesive soils, a crucial input for modeling erosion and breach of embankment dams with models such as WinDAM, EMBREA (Morris 2011), and DL BREACH (Wu 2013; 2016a; 2016b). The JET was initially developed in the late 1980s as a relatively large-scale device with a 13-mm diameter nozzle creating an impinging jet that erodes a soil sample submerged in a 61-cm diameter tank. This first device was documented in an ASTM standard (D5852-1995), but the standard was withdrawn in 2016. In the last 15 to …

Overtopping Erodibility Analysis For A Steep-Sloped Rockfill Embankment Dam, Ariel Rickel, Michael F. George, Rob Millar

Protections Conference

Erosion of embankment material during an overtopping event is one of the major mechanisms of failure for earthfill dams. The ability to analyze the progression of overtopping failure can prove useful in assessing the breakthrough risk of the dam, which involves understanding the behavior of the material that the dam is comprised of. While there have been studies on the behavior of smaller-grained materials such as clays and sands (e.g. Hahn et al 2000; Coleman et al. 2002; Hanson et al. 2005; Hanson et al. 2011), few have focused on erosion of larger-grained rockfill embankments.

This paper presents the erosion …

Data-Driven Analysis For Facility Management In Higher Education Institution, Ashish Kumar Pampana, Jungho Jeon, Soojin Yoon, Theodore J. Weidner, Makarand Hastak

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Planned Preventive Maintenance (PPM) and Unplanned Maintenance (UPM) are the most common types of facility maintenance. This paper analyzes current trends and status of Facility Management (FM) practice at higher education institutions by proposing a systematic data-driven methodology using Natural Language Process (NLP) approaches, statistical analysis, risk-profile analysis, and outlier analysis. This study utilizes a descriptive database entitled "Facility Management Unified Classification Database (FMUCD)" to conduct the systematic data-driven analyses. The 5-year data from 2015 to 2019 was collected from eight universities in North America. A preprocessing step included but was not limited to identifying common data attributes, cleaning noisy …