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Articles 31 - 60 of 1334
Full-Text Articles in Civil and Environmental Engineering
The Effect Of The Socioeconomic Variety In Greater Cairo On Transport Mode Choices, Rafik Yanni
The Effect Of The Socioeconomic Variety In Greater Cairo On Transport Mode Choices, Rafik Yanni
Theses and Dissertations
In the last decade, Egypt has experienced a noticeable upgrade in its infrastructure investment, implementing a lot of transport projects, especially in the Greater Cairo region. In a city with over 20 million residents, variations lie in socioeconomic elements like income, age, gender, and neighborhood, which shape people’s choice of mobility modes based on their culture and lifestyle. The questions then become: whom are these new projects targeting? What are the barriers to using these services? And is there any willingness to change commuting habits if conditions changed? This thesis investigates how the socioeconomic variety in Greater Cairo metropolitan region …
A Point-Cloud Data Analysis Framework For Early Deformation Detection, Avinash Pandey
A Point-Cloud Data Analysis Framework For Early Deformation Detection, Avinash Pandey
Theses and Dissertations
Frost heave and thaw-related deformation threaten the performance of roads, runways, embankments, and buried utilities in cold regions, yet traditional inspections remain reactive and often miss early uplift. This study evaluates the capability of LiDAR (Light Detection and Ranging) to detect small-scale ground deformation and introduces a practical point-cloud framework designed for early-stage characterization. Controlled jack-lift experiments quantified handheld LiDAR accuracy at uplift increments of 6.35, 12.7, 19.05, and 25.4 mm, with corresponding detection accuracies of 88%, 86%, 93.33%, and 94%. Registration quality had a significant impact. The targetless scans showed slight misalignment, whereas spherical targets provided precise, repeatable outputs. …
Quantifying Benefits Of Biochar With Variable Absorption Capacity As A Partial Cement Replacement In Concrete, Benjamin Shannon
Quantifying Benefits Of Biochar With Variable Absorption Capacity As A Partial Cement Replacement In Concrete, Benjamin Shannon
Theses and Dissertations
Extensive research has been conducted on biochar-incorporated concrete. However, no concrete mixture design guideline is currently available for implementing biochar incorporation in practice. The objective of this study was to correlate biochar absorption capacity with the compressive strength of biochar-incorporated concrete, to quantify the benefits of biochar and develop mix design guidelines. Biochar with varying absorption capacities was incorporated into concrete at 10%, 20%, and 40%. Strength and moisture loss were recorded over the 90-day curing period of the biochar-incorporated concrete. Results revealed three main findings: (1) in 10%, 20%, and 40% biochar mixes, the normalized strengths ranged from 0.65–0.85, …
Evaluating Three Lightweight Airfield Matting Systems Under F-35b Aircraft Loading, Brett D. Cobb
Evaluating Three Lightweight Airfield Matting Systems Under F-35b Aircraft Loading, Brett D. Cobb
Theses and Dissertations
Aircraft matting has been in service since WWII. It has provided a maneuverable substrate to allow aircraft forward operations to take place in austere environments. AM2 is the main matting system that has been used for generations. In recent years, the need for a lightweight matting system has come to the forefront of the matting community. This is not only to improve the maneuverability, but also the shipping restrictions. This research is on three different light weight matting systems above subgrade with two CBR values (i.e., 6 and 25). A specially designed load cart was adopted to simulate F-35B loading. …
Analysis Of Trends From Mass Concrete Case Studies, Bradford Songer
Analysis Of Trends From Mass Concrete Case Studies, Bradford Songer
Theses and Dissertations
While conventional mass concrete is well understood, high strength and ultra high performance concrete present unique challenges when placed in large volumes. This thesis compiles and analyzes thermal data from mass high strength and ultra high performance concrete placements collected over the past eight years by the U.S. Army Corps of Engineers in support of military construction projects. The datasets span a wide range of material types and volumes. The analysis identifies trends in temperature development, temperature differentials, and the influence of mixture constituents on heat generation. This thesis contributes to the improved understanding of thermal behavior in mass concrete. …
Influence Of Channel Geometry And Inflow Hydrograph On Hydraulics And Air Volume Around Shafts Of A Stormwater Main, Lylie Vindie Wilkie
Influence Of Channel Geometry And Inflow Hydrograph On Hydraulics And Air Volume Around Shafts Of A Stormwater Main, Lylie Vindie Wilkie
Theses and Dissertations
Stormwater management in urban areas is complex, in part because of difficulties related to modeling water flowing in closed conduits, as well as to controlling odor, noise, and pipe corrosion. This thesis summarizes the main findings of a study on how changes in inflow discharge and the geometry of a stormwater main may affect water flow, and how changes in water depth impact air volume and pressure around an air shaft. The study is conducted using CHAN, a one-dimensional model that simulates both flow hydraulics in mains and associated changes in air volume and pressure around air shafts. Main difference …
Erosion Of Bermuda Grass Covered Soils, Oru-Ntui Johnwatters Nkiri
Erosion Of Bermuda Grass Covered Soils, Oru-Ntui Johnwatters Nkiri
Theses and Dissertations
Earthen embankments are the most common type of embankment due to the relatively low cost, simplicity, and material availability. However, they are also the most prone to erosion related failure, typically due to overtopping and piping. Research has been conducted to identify ways to control soil erosion and protect earthen embankments with different approaches such as addition of chemicals and biopolymer to the soil, installation of protective layering (geotextiles, concrete), increased soil compaction, and use of vegetation. This thesis considers the use of Bermuda Grass to increase resistance to erosion and protect embankments from failure during overtopping. Grass coverage and …
Structural Response Of Rc Columns Strengthened Using Bfrp Based Bfegc System – Under Fire And Cooling Regime, Ruba P
Theses and Dissertations
Retrofitting fire-damaged columns is essential for restoring structural integrity. This study evaluates the effectiveness of BFRP based Basalt fiber Engineered Geopolymer Composites (BFEGC). The performance of basalt fiber wrapping and BFEGC was tested for fire protection system and retrofitted system. An optimal BFEGC mix achieved a compressive strength of 55.34 MPa, with split tensile strength, flexural strength, and strain hardening behaviour of 15.5 MPa, 5.13 MPa, and 6% respectively.
Microstructural analysis was accessed for the optimum mix. Durability tests include water absorption, sorptivity, and RCPT which confirmed compliance with standards. Thermo gravimetry analysis (TGA) shows the minimal weight loss of …
Impact Of Ionic Liquids On The Treatment Of Various Derivatives Of Prosopis Juliflora For Removing Toxic Pollutants From Wastewater, Karthikeyan A
Impact Of Ionic Liquids On The Treatment Of Various Derivatives Of Prosopis Juliflora For Removing Toxic Pollutants From Wastewater, Karthikeyan A
Theses and Dissertations
Water resources are increasingly contaminated by toxic pollutants, particularly industrial effluents, posing significant environmental concerns. Addressing the toxicity of these pollutants, especially those released from textile industries, presents challenges due to their harmful effects on living organisms. Various treatment methods are employed to mitigate this issue, including coagulation, flocculation, membrane filtration, photocatalytic degradation, adsorption, anaerobic processes, and chemical oxidation. Among these, adsorption emerges as an effective and economical method due to its minimal secondary contamination, negligible sludge production, and the use of inexpensive agricultural and marine waste materials.
This study examines the ability of Prosopis juliflora treated with imidazolium-based ionic …
Thermo-Mechanical Advancements For Very High Strength And Ultra High Performance Concretes, Lana Grayson Brown Sisung
Thermo-Mechanical Advancements For Very High Strength And Ultra High Performance Concretes, Lana Grayson Brown Sisung
Theses and Dissertations
Interest in the use of high-strength concrete (HSC) has increased in recent years with demand for improved concrete performance. HSCs are widely associated with high heat of hydration and elusive behavior when exposed to high temperatures commonly occurring in mass structures. The optimization of HSC mixture proportioning is difficult due to a wide variety of constituents that influence thermal and mechanical properties. Additionally, determining in-place properties of mass concrete placements is elusive, and there are currently minimal to no test methods available that are both predictive and a direct measurement of mechanical properties. The objective of this dissertation is to …
Fresh And Mechanical Properties Of Self-Compacting Concrete Using Kaolin Limestone Blend And Hybrid Slag Blend, Selesca Devi S
Fresh And Mechanical Properties Of Self-Compacting Concrete Using Kaolin Limestone Blend And Hybrid Slag Blend, Selesca Devi S
Theses and Dissertations
This study examined the consequences of mono and hybrid natural fibers on the mechanical and fresh properties of self-compacting concrete (SCC), in response to the growing demand for environmentally friendly building materials. In mono fiber, Abaca fiber (AF) at 0.25% and 0.5% dosage, basalt fiber (BF) from 0.25% to 2% at 0.25% increments, and sisal fiber (SiF) from 0.25% to 1.5% at 0.25% increments were evaluated through slump flow diameter, T500, compressive and tensile strength. AF at 0.25% ensured good flow with 6.6% and 4.16% higher compressive and tensile strength over 0.5% AF. SiF up to 1% improved strength but …
Integrating Ensemble Hydrologic Forecasts With Policy Optimization Models For Forecast-Informed Reservoir Operations (Firo), Alessandra Estefania Perez Salas
Integrating Ensemble Hydrologic Forecasts With Policy Optimization Models For Forecast-Informed Reservoir Operations (Firo), Alessandra Estefania Perez Salas
Theses and Dissertations
Effective reservoir management in hydrologically variable regions such as California’s Central Valley faces increasing pressure to balance flood control, water supply reliability, hydropower generation, and ecosystem health. Traditional rule-based operations, while operationally simple, often lack the adaptability required to respond to real-time hydrologic conditions and forecast uncertainty. This study presents an integration of a policy tree optimization model with ensemble streamflow forecasts to enhance Forecast-Informed Reservoir Operations (FIRO) at Folsom Reservoir. Building on historical data for inflow, storage, and release, an interpretable, threshold-based decision framework was developed and coupled with 14-day ensemble inflow forecasts from the California-Nevada River Forecast Center’s …
Satellite Radar Imagery Analysis For Ground Hazard Risk Monitoring In Railway Tracks And Slopes, Sumanth Varma Byrraju
Satellite Radar Imagery Analysis For Ground Hazard Risk Monitoring In Railway Tracks And Slopes, Sumanth Varma Byrraju
Theses and Dissertations
Railway transportation is essential to national economies globally, and disruptions from geohazards can result in significant operational delays and considerable economic consequences. Satellite radar technologies, including Interferometric Synthetic Aperture Radar (InSAR), offer an effective means to monitor geohazard risks across extensive railway networks. This thesis employs Multi-Temporal InSAR (MTInSAR) techniques, including Persistent Scatterer InSAR (PSInSAR) and Small Baseline Subset (SBAS), to identify high-risk areas along railway rights of way (ROW) prior to geohazard occurrences. However, the efficiency of these MT-InSAR and, consequently, the caliber of the data generated may be restricted by elements like topographical profile, vegetation, and surface soil …
Monitoring And Mitigation Of Per- And Polyfluoroalkyl Substances (Pfas) In Urban Stormwater Runoff, Mustafizur Rahaman
Monitoring And Mitigation Of Per- And Polyfluoroalkyl Substances (Pfas) In Urban Stormwater Runoff, Mustafizur Rahaman
Theses and Dissertations
Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants known for their persistence with widespread environmental and health concerns. Urban stormwater runoff could be a non-point pollution source that transports PFAS to receiving water bodies. This study analyzed types and concentrations of PFAS in stormwater runoff from Trenton and Glassboro, New Jersey, with samples collected from high- and low-traffic areas during precipitation events in February, June, July, and August 2024. Significantly higher concentrations of PFAS were identified in high-traffic areas than low-traffic areas (p< 0.05) in both cities for most sampling events, confirming the role of traffic in PFAS dispersal. To address PFAS contamination in stormwater runoff, this study evaluated the removal of six U.S. Environmental Protection Agency (USEPA)-regulated PFAS compounds from synthetic stormwater runoff using aluminum-based water treatment residuals (Al-WTRs, by-products of the drinking water treatment process). The findings demonstrated that Al-WTRs exhibited high sorption capacities and low desorption rates for PFAS, particularly for long-chain PFAS compounds such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), supporting their potential as an economical and effective sorbent for stormwater PFAS management. Furthermore, the durability and sustained performance of Al-WTRs indicated their feasibility for future field-scale applications.
Practicality Of Implementing Sub-Clause 8.4 [Advance Warning] Of The Fidic 2017 Red Book In Egypt, Gehad Ibrahim
Practicality Of Implementing Sub-Clause 8.4 [Advance Warning] Of The Fidic 2017 Red Book In Egypt, Gehad Ibrahim
Theses and Dissertations
Disputes in construction projects can cause cost and time overruns that can be detrimental to the parties involved and to the project. Several measures have been advocated by the industry’s practitioners in an attempt to avoid disputes and their adverse impacts. One of these measures is the introduction of advance warning sub-clauses in construction contracts, where the contracting parties play a proactive and collaborative role in warning each other of potential adverse impacts to the project. Such clauses have been in the NEC suite of standard construction contracts for decades and have recently found their way to the 2017 edition …
Multi-Parameter Optimization Of Brine Desalination Using Machine Learning, Elaf Mman Seif
Multi-Parameter Optimization Of Brine Desalination Using Machine Learning, Elaf Mman Seif
Theses and Dissertations
Air Gap Membrane Distillation (AGMD) is a promising desalination technology with significant potential for addressing global water scarcity. However, the interplay of operational parameters significantly impacts its performance, making optimization a challenging task. This research focuses on brine desalination as a means to mitigate the negative environmental impacts of brine disposal which will eventually help in provide a sustainable solution for handling brine while producing freshwater. The study seeks to develop a predictive model and optimize the AGMD process for efficient brine desalination. To achieve this, Response Surface Methodology (RSM) and Artificial Neural Networks (ANNs) were utilized to develop predictive …
An Llm Approach For Automating The Analysis Of Bim (Ifc) Data, Miral Selim
An Llm Approach For Automating The Analysis Of Bim (Ifc) Data, Miral Selim
Theses and Dissertations
This thesis introduces a novel methodology for automating the analysis of Building Information Modeling (BIM) data using LangGraph, an advanced extension of the LangChain framework, and integrating Google’s Gemini Large Language Model (LLM) with IfcOpenShell. BIM, and specifically Industry Foundation Class (IFC) files, are widely used in the construction industry for representing and managing building data. However, analyzing this data effectively remains a significant challenge due to its volume and complexity. Additionally, analyzing BIM data typically requires knowledge of different BIM software depending on the application. This research addresses this challenge by creating a workflow that utilizes LangGraph’s ability to …
Optimization Of Pile Construction Sequence Using Cfa Machines, Omar Wael Ammar
Optimization Of Pile Construction Sequence Using Cfa Machines, Omar Wael Ammar
Theses and Dissertations
In most construction projects with deep foundations, piling activities are critical to the project schedule and often fall on the critical path. The piling construction process requires a diverse range of resources, including equipment, materials, and skilful labour. Without carefully planning the construction process according to installation standards, there is a significant risk of time and cost overruns. These overruns are caused by inefficiencies such as equipment idle or lost time due to required lags between closely spaced piles. Therefore, it is essential to develop an optimized construction sequence to minimize these risks and enhance overall project efficiency. The primary …
Enhancing Gpr Reliability For Concrete Infrastructure: Integrating Signal Processing And Deep Learning For Defect And Corrosion Assessment, Priyam Chowdhury
Enhancing Gpr Reliability For Concrete Infrastructure: Integrating Signal Processing And Deep Learning For Defect And Corrosion Assessment, Priyam Chowdhury
Theses and Dissertations
This research addresses the critical issue of deteriorating civil infrastructure by utilizing GPR integrated with advanced signal processing and machine learning. Employing the Conquest 100 system, four concrete slab configurations were tested: multi-layer rebar with defects, single- and double-layer rebar setups, varied rebar spacing, and pre-corroded rebars (0–30% mass loss). GPR B-scans collected over 3–60 days demonstrated that detection accuracy varied significantly with curing time, structural complexity, and moisture levels. A custom-developed Python script surpassed EKKO_Project software in rebar localization, achieving lower position errors (0.4–0.7 inches compared to 0.5–1.25 inches). Notably, the amplitude of GPR signals unexpectedly increased with corrosion …
Heat Pumps And Sustainable Building Operations: An Analysis Of Energy Efficiency, Emissions, And Life Cycle Costs, Mahdiyeh Zafaranchi
Heat Pumps And Sustainable Building Operations: An Analysis Of Energy Efficiency, Emissions, And Life Cycle Costs, Mahdiyeh Zafaranchi
Theses and Dissertations
Heating, ventilation, and air conditioning (HVAC) systems are a major contributor to energy demand. Heat pump technologies, particularly Ground Source Heat Pumps (GSHPs) and Air Source Heat Pumps (ASHPs), have emerged as key solutions to reduce energy use worldwide. However, their adoption is challenged by economic, operational, and environmental trade-offs. This dissertation develops a comprehensive framework for evaluating the energy efficiency, lifecycle emissions, and cost-effectiveness of GSHP and ASHP systems in sustainable building operations. Through advanced energy modeling, lifecycle assessments (LCA), and lifecycle cost (LCC) analyses, this research provides data-driven insights to optimize heat pump system selection. This study is …
Study Of Capital And Operation Costs For Reverse Osmosis Desalination Plants, Habiba Mahdy Mohamed
Study Of Capital And Operation Costs For Reverse Osmosis Desalination Plants, Habiba Mahdy Mohamed
Theses and Dissertations
Desalination is a progressively common solution to supply freshwater in numerous parts of the globe where this resource falls short. Among all desalination techniques, seawater reverse osmosis (SWRO) is the most globally prevalent technology. Evaluating a desalination technology's cost-effectiveness is essential to ensure a well-designed plant can be implemented successfully and within an acceptable budget. In the Egyptian context, where water scarcity heightens the urgency of effective resource allocation, economic indicators such as capital expenditure (CAPEX) and operational expenditure (OPEX) are pivotal in shaping policy and planning decisions. Adopting this integrated financial perspective ensures that desalination projects are not only …
Uhpc Incorporated With Non-Metallic/ Hybrid Fibers And Industrial Wastes - A Comprehensive Study On The Physical, Mechanical Properties And Performance, Sujitha Magdalene P
Uhpc Incorporated With Non-Metallic/ Hybrid Fibers And Industrial Wastes - A Comprehensive Study On The Physical, Mechanical Properties And Performance, Sujitha Magdalene P
Theses and Dissertations
The demand for sustainable and high-performance construction materials has led to the exploration of alternative fine aggregates and fiber reinforcements for Ultra-High-Performance Concrete (UHPC). This study investigates the feasibility of using iron ore tailings (IOT), manufactured sand (MS), and copper slag (CS) as partial replacements for river sand (RS), along with various fiber reinforcements, to enhance mechanical properties, durability, and microstructural integrity in UHPC.
The results indicate that IOT at a 30% replacement level (IOT1) exhibited the highest 56-day compressive strength, outperforming MS and CS. Copper slag was found unsuitable for UHPC due to its lower long-term strength. While both …
Wildfire Hydrologic Impacts, Kathleen E. Inman
Wildfire Hydrologic Impacts, Kathleen E. Inman
Theses and Dissertations
Wildfires are essential processes for certain ecosystems but are increasing in severity and occurrence. These increases are negatively changing hydrology. Anticipating the hydrologic changes is necessary for management of effected watersheds, infrastructure, and downstream users. This study hypothesized land cover changes post-fire would increase water temperature and discharge in burned watersheds located in the Willamette Basin. This study (1) evaluated the change in estimated curve numbers (CN) from land cover pre-fire and post-fire to assess expected runoff impacts in watersheds, and (2) identified the significance of actual water temperature and discharge changes using non-parametric statistical analysis. An unburned watershed and …
Asphalt Durability Improvements By Way Of Specification Advancements, Jessica V. Lewis
Asphalt Durability Improvements By Way Of Specification Advancements, Jessica V. Lewis
Theses and Dissertations
The objective of this dissertation is to provide content through which industry and agencies can adjust and/or update standards and specifications, as appropriate, to accommodate the present-day needs of the asphalt industry towards producing more durable asphalt. A total of 78 asphalt mixtures and 9 asphalt binders were evaluated for up to 10 years of field aging to provide content that was analyzed to meet this objective. A full-scale aging site in Columbus, Mississippi was the focal point of the aging experiments. A major conclusion from this work was that Cantabro Mass Loss (CML) testing of cores was able to …
Removal Of Harmful Algal Bloom Toxin, Microcystin-Lr Via Graphene Coated Polymers, Justin Douglas Puhnaty
Removal Of Harmful Algal Bloom Toxin, Microcystin-Lr Via Graphene Coated Polymers, Justin Douglas Puhnaty
Theses and Dissertations
This study investigates a novel 3D-printed graphene-coated polymer (GCP) for the removal of Microcystin-LR (MC-LR), a harmful cyanotoxin produced during harmful algal blooms (HABs). While graphene nanoplatelets (GnPs) exhibit high adsorption capacity, their powdered form limits practical application. To address this, GnPs were coated onto 3D-printed poly(lactic acid) (PLA) substrates, enabling enhanced handling for field deployment. Surface characterization using laser confocal microscopy, Raman spectroscopy, and thermogravimetric analysis confirmed GnP distribution and coating uniformity. Batch adsorption experiments revealed pseudo-second-order kinetics, a maximum adsorption capacity (qmax) of 596 μg/g, and adsorption behavior best described by the Langmuir isotherm. Statistical analysis and comparison …
The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin
The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin
Theses and Dissertations
The geotechnical engineering field requires high-quality in-situ testing equipment that ensures consistency in the test execution. This research focuses on developing and testing a prototype of a fully automated pressuremeter control unit to allow the industry to obtain reliable and controlled stress-strain data, thereby improving efficiency and reducing testing time.
The objectives of this work are to design and develop a system with the necessary components to perform the pressuremeter test, integrate the testing procedure into the state machine design, enable automated testing, and validate the results by comparing the stress-strain data with that obtained from the existing hand-operated pressuremeter …
Cross-Frame Effects And Design Optimization For Skewed Steel I-Girder Bridges, Nisha Sthapit
Cross-Frame Effects And Design Optimization For Skewed Steel I-Girder Bridges, Nisha Sthapit
Theses and Dissertations
Cross-frames are critical for load distribution and stability in steel I-girder bridges with complex geometry, especially during construction. However, they are often designed with standardized cross-sections that are uniform throughout the bridge. This thesis presents an optimization approach for cross-frame cross-sections for skewed steel I-girder bridges with integral and stub abutments with skews ranging from 15⁰-60⁰. This optimization, using Method of Moving Asymptotes (MMA), minimizes girder flange lateral bending stress while maintaining or reducing the total volume of the cross-frames from the original design. Validated 3D finite element models in CSI Bridge showed that the optimization achieved around 20% decrease …
Evaluating Structural Response Of Steel I-Girder Bridges Under Different Support Conditions: Construction Loading In Skewed Straight And Thermal Loading In Horizontally Curved Configuration, Bikesh Sedhain
Theses and Dissertations
Skewed and horizontally curved steel I-girder bridges are commonly designed and constructed to connect existing roadways and navigate obstacles in densely populated areas. However, these bridges can introduce significant challenges to bridge design and analysis, including complex lateral movements and torsional effects. Simplified support representation techniques that are commonly adopted in analysis and design may not accurately capture these effects, which lead to potential misestimations of bridge responses. This research aims to evaluate skewed and curved steel I-girder bridges for complicated loading and support conditions – skewed integral abutment bridges were studied during pre-composite deck placement and horizontally curved bridges …
Porous Geopolymer Composite For Geotechnical Applications, Karla Viviana Sierra Flores
Porous Geopolymer Composite For Geotechnical Applications, Karla Viviana Sierra Flores
Theses and Dissertations
This research investigates the development of a porous geopolymer cement grout for soil grouting applications, aiming to reduce carbon emissions associated with Portland cement while maintaining critical performance characteristics such as strength and permeability. Class F fly ash and metakaolin were used as aluminosilicate precursors, activated by sodium silicate and sodium hydroxide solutions. The addition of hydrogen peroxide served as a foaming agent to introduce porosity by creating a thermodynamic reaction that releases oxygen gas during mixing. Compressive strength, porosity, and hydraulic conductivity were evaluated, with results showing that metakaolin significantly increased compressive strength due to its smaller particle size …
Development Of A New Seismic Metamaterial For Passive Vibration Control Of Civil Structures, Shayan Khosravi
Development Of A New Seismic Metamaterial For Passive Vibration Control Of Civil Structures, Shayan Khosravi
Theses and Dissertations
Seismic metamaterials are engineered structures that control mechanical wave propagation through frequency bandgaps, making them useful for structural control and seismic hazard mitigation. This study introduces the Passive Friction Seismic Metamaterial Base Isolation (PFSMBI) system, which combines frequency bandgaps and solid friction energy dissipation to improve the seismic performance of civil structures. The PFSMBI consists of a lattice structure with identical cells connected by springs and dampers, shifting a building’s natural frequency away from earthquake excitations. A dynamic model analyzes the system’s absolute acceleration, drift responses, and base shear force, optimizing parameters such as frequency ratios, mass ratios, and the …