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Articles 4621 - 4650 of 11809

Full-Text Articles in Engineering

Fate And Impacts Of Triclosan, Sulfamethoxazole, And 17Β-Estradiol During Nutrient Recovery Via Ion Exchange And Struvite Precipitation, Yiran Tong, Patrick J. Mcnamara, Brooke K. Mayer Jan 2017

Fate And Impacts Of Triclosan, Sulfamethoxazole, And 17Β-Estradiol During Nutrient Recovery Via Ion Exchange And Struvite Precipitation, Yiran Tong, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Increasing emphasis on resource recovery from wastewater highlights the importance of capturing valuable products, e.g., nutrients such as nitrogen and phosphorus, while removing contaminants, e.g., organic micropollutants. The objective of this research was to evaluate the fate of the micropollutants triclosan (present as a mixture of neutral and anionic species at neutral pH), 17β-estradiol (neutral at neutral pH), and sulfamethoxazole (anionic at neutral pH) during nutrient recovery using ion exchange-precipitation. Adsorption of the three micropollutants to the phosphate-selective ion exchange resins LayneRT and DOW-HFO-Cu ranged from 54% to 88% in Milli-Q water tests and 50% to 71% in …


Virtual Reality Of Earthquake Ground Motions For Emergency Response, Ting Lin Jan 2017

Virtual Reality Of Earthquake Ground Motions For Emergency Response, Ting Lin

Civil and Environmental Engineering Faculty Research and Publications

Ground motions interface earthquake science and engineering to advance understanding of seismic hazards and risk. Virtual reality provides an attractive tool to extend knowledge of the research community to a larger audience. This work visualizes emergency response under extreme motions, in the CAVE of the MARquette Visualization Laboratory. The visualization (a) displays ground motions (from the science community), (b) inputs these motions to structural models (from the engineering community) and illustrates the resulting responses, (c) translates structural responses to damage states of building elements, (d) creates a virtual room subjected to the perception associated with such earthquake shaking, and (e) …


Editorial" Fibre Reinforced Polymer Composites For Structural Applications In Construction, Jun Deng, Marcus M.K. Lee, Baolin Wan, Giuseppina Amato Jan 2017

Editorial" Fibre Reinforced Polymer Composites For Structural Applications In Construction, Jun Deng, Marcus M.K. Lee, Baolin Wan, Giuseppina Amato

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.


Baseline Rolling Resistance For Tires’ On-Road Fuel Efficiency Using Finite Element Modeling, Jaime Hernandez, Imad L. Al-Qadi, Hasan Ozer Jan 2017

Baseline Rolling Resistance For Tires’ On-Road Fuel Efficiency Using Finite Element Modeling, Jaime Hernandez, Imad L. Al-Qadi, Hasan Ozer

Civil and Environmental Engineering Faculty Research and Publications

Calculation of truck tires rolling resistance, using the finite element method and considering variables such as incompressible visco-hyperelastic rubber materials, accurate tire geometry and steady temperature distribution, is presented. The model was validated using experimentally measured contact area and contact stresses. Rolling resistance was calculated for three values of axle load, tire inflation pressure, temperature and speed. In addition, regression analysis was used to propose a mathematical expression for predicting rolling resistance as a function of the considered variables. Finally, the contribution of tire’s rubber components to the internal energy was quantified, and it was found that sidewall and subtread …


Life Cycle Assessment (Lca) Of Ore Transportation Route Alternatives For Eagle Mine, Soumith Kumar Oduru Jan 2017

Life Cycle Assessment (Lca) Of Ore Transportation Route Alternatives For Eagle Mine, Soumith Kumar Oduru

Dissertations, Master's Theses and Master's Reports

Transportation sector at large is a major consumer of fossil fuels and constitutes more than a quarter of the global greenhouse gas emissions. When making infrastructure route and mode choice decisions for new freight-oriented projects, it is important that environmental and emissions considerations are included as an integral part of the selection process. Emissions from freight transportation projects related to mining and natural resource industry are especially critical, as they involve high volumes and tonnages often in pristine environments. The most logical time for emissions analysis is during modal and route analysis that are often conducted in the planning stage …


Social, Economic, And Technical Feasibility Of Ablution Gray Water Reuse In Tong, Ghana, Adrienne Masterton Jan 2017

Social, Economic, And Technical Feasibility Of Ablution Gray Water Reuse In Tong, Ghana, Adrienne Masterton

Dissertations, Master's Theses and Master's Reports

Water insecurity is a constant stressor for millions of people around the globe. The potential of gray water as an alternative water source has gained increasing attention in the literature. In water-scarce Muslim communities, the practice of ablution – the rinsing of the face, hands, and feet before prayer – offers a unique opportunity for gray water reuse.

This report investigates the feasibility of treating and reusing ablution gray water (AGW) with respect to religious acceptability, economic measures, and physical parameters in Tong, a rural community of Muslim subsistence farmers in northern Ghana. Investigatory tools included: household water use surveys, …


Design, Laboratory Testing, And Yield Line Analysis Of A Ferrocement Pit Latrine Slab, Larry Alan Schirmer Jr Jan 2017

Design, Laboratory Testing, And Yield Line Analysis Of A Ferrocement Pit Latrine Slab, Larry Alan Schirmer Jr

Dissertations, Master's Theses and Master's Reports

Access to sanitation for rural and indigenous Panamanians is the vision of global efforts to improve their quality of life. As part of on-site work from the Peace Corps to change public perceptions about open defecation, the author designed and tested a new type of ferrocement latrine slab to reduce the amount of materials involved in building latrines and by extension the manual labor involved. In the course of this investigation, a sanitation based case study establishes the precedent for working with ferrocement in these areas, and the author explores the history and structural properties of ferrocement. In laboratory experiments, …


Polyvinyl Alcohol (Pva) Fiber-Reinforced Rubber Concrete And Rubberized Self-Compacting Concrete, Jiaqing Wang Jan 2017

Polyvinyl Alcohol (Pva) Fiber-Reinforced Rubber Concrete And Rubberized Self-Compacting Concrete, Jiaqing Wang

Dissertations, Master's Theses and Master's Reports

This study experimentally investigates the mechanical performance and durability of Polyvinyl Alcohol (PVA) fiber-reinforced rubber concrete and the rubberized self-compacting concrete. The waste rubber particles were introduced as a partial replacement of fine aggregate in the plain concrete. In addition, the waste tire rubbers were pre-treated with alkali surface treatment method to enhance the performance. The PVA fibers were added to the concrete mixes to enhance the post-failure resistance and thus fracture energy. Rubberized fiber concrete samples were prepared with different fine aggregate replacement ratios and the optimum fiber content. At the same time, the rubber particles had been used …


Travel Time Estimation And Prediction For Urban Arterial Roads, Porntep Puangprakhon Jan 2017

Travel Time Estimation And Prediction For Urban Arterial Roads, Porntep Puangprakhon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Travel time information has been accepted as the core of advanced traveler information systems (ATIS) and advanced traffic management systems (ATMS). Providing the accurate travel time information to traffic operators and travelers allows them to make informed decisions, leading to more advantage for individual road users and the entire transportation system. Most of the traffic information providers normally deliver the current traffic conditions or current travel times to public assuming the state of traffic remains constant in the near future. Aimed at the more effective applications, short-term future traffic conditions have been proposed as a valuable piece of information in …


Uav-Based Bridge Inspection And Computational Simulations, Luis Duque Jan 2017

Uav-Based Bridge Inspection And Computational Simulations, Luis Duque

Electronic Theses and Dissertations

The use of Unmanned Aerial Vehicles (UAV), commonly known as drones, has significantly increased in the field of civil engineering due to the poor condition of the United States’ infrastructure. The American Society of Civil Engineers (ASCE) recently reported that more than 9.1% of the United States’ bridges were structurally deficient and required attention and maintenance to ensure appropriate structural performance. Meanwhile, current practices are expensive and unsafe for bridge inspectors, requiring innovative and safer methods for the study of bridges. The goal of this paper was to identify better techniques to not only inspect, quantify, and determine the effect …


Rubber Additives To Concrete Specimens, Kendall J. Sweitzer, Mary Mccannon Jan 2017

Rubber Additives To Concrete Specimens, Kendall J. Sweitzer, Mary Mccannon

Williams Honors College, Honors Research Projects

Rubber, as an additive to concrete, would hypothetically cause a concrete specimen to take on some mechanical characteristics of the rubber to a certain degree. In particular, the concrete’s durability should increase when exposed to fluctuating temperature conditions due to the rubber additive. This experiment sets out to test crumb rubber as a concrete additive, cured under various atmospheric conditions. The effects shall be measured via a simple concrete compression test.

Unfortunately, several errors took place during experimental process that led to inconclusive results. However, it can be reasonably considered from testing Matrix One that the addition of crumb rubber …


Compressive Strength Relative To Sustainable Materials In Concrete, Brad Harvey Jan 2017

Compressive Strength Relative To Sustainable Materials In Concrete, Brad Harvey

Williams Honors College, Honors Research Projects

The objective of this study is to determine how integrating abundant waste materials into concrete affects its compressive strength. This research will be used to benefit the construction industry by replacing a portion of a conventional concrete mix (cement, stone, sand, and water) with more sustainable materials. In order to create a more sustainable concrete mixture, the following mix design and methodology was followed.

The initial step was to create an updatable MS Excel spreadsheet to aid in the mix development (the spreadsheet is shown in Appendix A). These sheets allowed for easy transitions from one mix to another by …


Chemical Modification Of Crumb Rubber To Increase Its Bonding With Concrete, Mary T. Mccannon, Kendall J. Sweitzer Jan 2017

Chemical Modification Of Crumb Rubber To Increase Its Bonding With Concrete, Mary T. Mccannon, Kendall J. Sweitzer

Williams Honors College, Honors Research Projects

The hydrophilicity of crumb rubber was increased with wet chemical modification and added to concrete to increase its adhesion with concrete, consequently the compressive strength relative to that of concrete with untreated rubber. Other modification methods were tested on crumb rubber and rubber sheets to yield an increase in hydrophilicity. Certain tests were less reliable for powder testing or tedious and time consuming and concrete materials and rubber may not be homogeneous.

For wet chemical modification, several approaches were attempted. First, crumb rubber was soaked in 5% sodium hydroxide, 5% potassium permanganate and saturated sodium bisulfite, tested for hydrophilicity using …


Experiences Of Public Agency Managers When Making Outsourcing Decisions, Shakeel Baig Jan 2017

Experiences Of Public Agency Managers When Making Outsourcing Decisions, Shakeel Baig

Walden Dissertations and Doctoral Studies

Managers in state transportation agencies in the United States must frequently choose between using the talents and abilities of in-house staff or outsourcing for road and bridge design projects. Budgetary crises have strongly affected funding for transportation infrastructure. Facing budgetary pressures to suppress costs, managers must frequently make the choice of outsourcing a project or performing it in-house. Yet, decision-making models for these decisions are inadequate. The purpose of this phenomenological study was to explore and describe the lived experiences of public agency managers when making decisions to outsource the core government functions such as road and bridge design projects. …


Bs News January/February Jan 2017

Bs News January/February

Building Services Engineering

No abstract provided.


Development Of A Test Level 3 Transition Between Guardrail And Portable Concrete Barriers, Robert W. Bielenberg, David Gutierrez, Ronald K. Faller, John D. Reid, Phil Tenhulzen Jan 2017

Development Of A Test Level 3 Transition Between Guardrail And Portable Concrete Barriers, Robert W. Bielenberg, David Gutierrez, Ronald K. Faller, John D. Reid, Phil Tenhulzen

Department of Civil and Environmental Engineering: Faculty Publications

Road construction often requires that work zones be created and shielded by portable concrete barriers (PCBs) to protect workers and equipment from errant vehicles as well as to prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed so a PCB system can be placed. A study was done to develop a crashworthy transition between W-beam guardrail and PCB systems. Design concepts were developed and refined through computer simulation with LS-DYNA. Additionally, a study of critical impact points was conducted to determine impact …


Study Of Liquefaction Mechanism In Chiang Rai Province, Lindung Zalbuin Mase Jan 2017

Study Of Liquefaction Mechanism In Chiang Rai Province, Lindung Zalbuin Mase

Chulalongkorn University Theses and Dissertations (Chula ETD)

ทางภาคเหนือของประเทศไทยได้เผชิญภัยแผ่นดินไหวครั้งใหญ่ถึง 2 ครั้งคือ แผ่นดินไหวที่ศูนย์กลางอยู่ ที่เมืองทาร์เลย์ในประเทศเมียนมาปี ค.ศ. 2011 และแผ่นดินไหว ที่อ.แม่ลาว จ.เชียงรายในปี ค.ศ. 2014 งานวิจัยนี้จึงดำเนินการศึกษาการเกิดทรายเหลวระหว่างการเกิดแผ่นดินไหวโดยเฉพาะในจังหวัดเชียงราย งานวิจัยนี้เริ่มจากการวิเคราะห์ด้วยสูตรเชิงประสบการณ์โดยใช้ข้อมูลในหลายพื้นที่ในภาคเหนือ การศึกษาผลตอบสนองแผ่นดินไหวสามารถนำไปใช้ประเมินผลของการแผ่ขยายของคลื่นแผ่นดินไหวในชั้นดินได้ นอกเหนือจากนี้ มีการสำรวจพื้นที่ด้วยการทดสอบไมโครทริมเมอร์และการวิเคราะห์สเปกตรัมคลื่นผิวดินบริเวณพื้นที่ที่เคยเกิดทรายเหลวในระหว่างแผ่นดินไหวทั้งสองครั้ง การวิเคราะห์ผลตอบสนองต่อการเกิดทรายเหลวแบบหนึ่งมิติเพื่อสังเกตพฤติกรรมพลศาสตร์ของชั้นดินพบว่า ชั้นทรายชั้นแรกและชั้นที่สองของบริเวณที่ทำการศึกษามีโอกาสการเกิดทรายเหลวค่อนข้างสูง นอกเหนือจากนี้ ผลวิเคราะห์การแผ่ขยายของคลื่นพบว่า ที่บริเวณอ.แม่สาย ชายแดนไทย-เมียนมา อาจเกิดความเสียหายต่ออาคารความสูงปานกลางจากการขยายตัวของคลื่นแผ่นดินไหวได้ เนื่องจากการสั่นพ้องระหว่างดินและโครงสร้าง ส่วนผลการสำรวจพื้นที่ยังพบว่าสภาพทางธรณีวิทยาประกอบไปด้วยชั้นดินตะกอนของแม่น้ำที่มีความต้านทานต่อแรงเฉือนค่อนข้างต่ำ พฤติกรรมของดินพวกนี้ระหว่างการแผ่ขยายคลื่นน่าจะโอกาสเกิดทรายเหลวได้ง่าย การศึกษานี้น่าใช้แนะนำวิศวกรท้องถิ่นเพื่อให้ตระหนักถึงความไม่ปลอดภัยต่อแผ่นดินไหวและการเกิดทรายเหลวในพื้นที่ภาคเหนือโดยเฉพาะในจังหวัดเชียงรายได้


Optimum Patch Design For Repairing Cracked Steel Plates Using Genetic Algorithm, Bach Kim Do Jan 2017

Optimum Patch Design For Repairing Cracked Steel Plates Using Genetic Algorithm, Bach Kim Do

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents a design optimization process that combines the finite element (FE) method, genetic programming (GP), and optimization solvers, i.e., genetic algorithm (GA) and nonlinear programming, for double-sided fiber-reinforced polymer (FRP) patches used to repair center-cracked steel plates under tension fatigue. An optimization statement is to minimize the patch volume and reduce the stress intensity factor (SIF) range at crack tips below the fatigue threshold range. A detailed three-dimensional (3D) FE model of patch-repaired cracked plates is developed to compute SIF. A total of 864 FE models of patch-repaired cracked plates with different combinations of design parameters are then …


Autocatalytic Pyrolysis Of Wastewater Biosolids For Product Upgrading, Zhongzhe Liu, Patrick J. Mcnamara, Daniel Zitomer Jan 2017

Autocatalytic Pyrolysis Of Wastewater Biosolids For Product Upgrading, Zhongzhe Liu, Patrick J. Mcnamara, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

The main goals for sustainable water resource recovery include maximizing energy generation, minimizing adverse environmental impacts, and recovering beneficial resources. Wastewater biosolids pyrolysis is a promising technology that could help facilities reach these goals because it produces biochar that is a valuable soil amendment as well as bio-oil and pyrolysis gas (py-gas) that can be used for energy. The raw bio-oil, however, is corrosive; therefore, employing it as fuel is challenging using standard equipment. A novel pyrolysis process using wastewater biosolids-derived biochar (WB-biochar) as a catalyst was investigated to decrease bio-oil and increase py-gas yield for easier energy recovery. WB-biochar …


Tire-Pavement Interaction Modeling: Hyperelastic Tire And Elastic Pavement, Jaime Hernandez, Imad L. Al-Qadi Jan 2017

Tire-Pavement Interaction Modeling: Hyperelastic Tire And Elastic Pavement, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The interaction between deformable tire and pavement was studied using the validated finite element model; the full understanding of tire–pavement contact has implications for pavement damage prediction and pavement life-cycle assessment (fuel consumption estimation). The tire’s rubber and reinforcement were considered hyperelastic and linear elastic, respectively, with material constants obtained from the tire manufacturer (rubber) and laboratory testing (reinforcement). On the other hand, the pavement was assumed linear elastic supported by linear elastic springs. This assumption was made as a first step to examine the impact of using a deformable-on-deformable tire–pavement system to predict energy in the tire and contact …


Hydroshare Gis: Visualizing Spatial Data In The Cloud, Shawn Crawley, Daniel P. Ames, Zhiyu Li, David G. Tarboton Jan 2017

Hydroshare Gis: Visualizing Spatial Data In The Cloud, Shawn Crawley, Daniel P. Ames, Zhiyu Li, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

Cloud-based data management systems are more conducive to collaborative efforts when they are integrated with cloud-computing tools that interact with their stored data. HydroShare, a web based data management system for climate and water data, has implemented an Application Programming Interface and a web application platform deployed using Tethys Platform to encourage the development of apps that interact with its data. HydroShare GIS is the result of one such development effort to provide cloud-based visualization of spatial data stored in HydroShare. It functions by accessing the spatial metadata contained within the HydroShare resource data model and overlaying datasets as layers …


Cive 463: Traffic Engineering—A Peer Review Of Teaching Project Benchmark Portfolio, John Sangster Jan 2017

Cive 463: Traffic Engineering—A Peer Review Of Teaching Project Benchmark Portfolio, John Sangster

UNL Faculty Course Portfolios

This course portfolio documents the backward design of a senior-level design elective course in traffic engineering within the Department of Civil Engineering at the University of Nebraska. An extensive discussion of stakeholder needs for the course is followed by an analysis of formative and summative feedback assessments that are designed to meet the needs of a heterogeneous group of students in the course. As a senior-level design elective, there is a wide variety of interest levels among participants in the course, varying from those who have experience with internships in the topic and offer letters to conduct work in this …


Characterization Of Subgrade Resilient Modulus For Mepdg And The Effects On Pavement Rutting, Md Mostaqur Rahman Jan 2017

Characterization Of Subgrade Resilient Modulus For Mepdg And The Effects On Pavement Rutting, Md Mostaqur Rahman

Theses and Dissertations

In 2008, the American Association of State Highway and Transportation Officials (AASHTO) released a modified pavement design method (i.e., the Mechanistic Empirical Pavement Design Guide (MEPDG)) based on Long Term Pavement Performance (LTPP) data from all over the United States. The MEPDG default design parameters developed from the LTPP database are expected to be significantly different than those for South Carolina material, traffic and weather conditions, thus the default design parameters may not be accurate for South Carolina. Therefore, the new pavement design method should be calibrated for South Carolina conditions by performing MEPDG local calibration.

Different input variables should …


Performance Assessment Of Hsrm Concrete Ties Through Finite Element Model Simulations, Adam I. Zeitouni Jan 2017

Performance Assessment Of Hsrm Concrete Ties Through Finite Element Model Simulations, Adam I. Zeitouni

Theses and Dissertations

Concrete ties have become a promising alternative to timber ties for freight lines with increased curvature, high annual traffic, and large axle loads. They are also widely adopted in passenger lines. High strength (HS) concrete is the material of choice in the fabrication of prestressed concrete railroad ties. The higher strength of the concrete is directly related to higher values of the Elastic Modulus, thus increasing the rigidity of the material. The combination of increased strength, rigidity, and the material brittleness may lead to the development of high amplitude stresses with high gradients, which appears to be a common underlying …


Intermodal Network Design And Expansion For Freight Transportation, Fateme Fotuhiardakani Jan 2017

Intermodal Network Design And Expansion For Freight Transportation, Fateme Fotuhiardakani

Theses and Dissertations

Over the last 50 years, international trade has grown considerably, and this growth has strained the global supply chains and their underlying support infrastructures. Consequently, shippers and receivers have to look for more efficient ways to transport their goods. In recent years, intermodal transport is becoming an increasingly attractive alternative to shippers, and this trend is likely to continue as governmental agencies are considering policies to induce a freight modal shift from road to intermodal to alleviate highway congestion and emissions. Intermodal freight transport involves using more than one mode, and thus, it is a more complex transport process. The …


Influence Of Crumbed Para Rubber Modifier In Aggregate Blend On Deformation Resistance Properties Of Hot Mix Asphalt, Hatthaphone Silimanotham Jan 2017

Influence Of Crumbed Para Rubber Modifier In Aggregate Blend On Deformation Resistance Properties Of Hot Mix Asphalt, Hatthaphone Silimanotham

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the influence of crumbed para rubber which is added into a portion of aggregate in hot mix asphalt (HMA) during the batch mixing process or called "Dry Process". The dry process has an advantage on its simplicity of quality inspection and less modification in the hot mix plant production process. This study has investigated the effects of adding crumbed para rubber particles on the engineering properties related to permanent deformation resistance of asphalt concrete. In this study, the asphalt mixture is prepared via Marshall Mix design, which contained with limestone and asphalt cement of Pen 60/70 at …


Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira Jan 2017

Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multi-layered nano-scale structures have been found in a wide range of applications these days. Since the surface energy effect is presented at the nano-scale level, a novel calculation scheme is required to accurately capture the mechanical behaviors of such structures. In this study, a solution scheme for analysis of a multi-layered elastic medium with influence of surface energy effects subjected to axisymmetric loading by adopting Gurtin-Murdoch surface elasticity theory is presented. The standard Love's representation and Hankel integral transform are employed to derive the general solutions, and the obtained solutions are employed in the determination of the stiffness matrix for …


Factors Affecting Building Damage And People's Preparedness For Earthquake In Chiang Rai, Narongdej Intaratchaiyakit Jan 2017

Factors Affecting Building Damage And People's Preparedness For Earthquake In Chiang Rai, Narongdej Intaratchaiyakit

Chulalongkorn University Theses and Dissertations (Chula ETD)

On May 5, 2014, an earthquake with a magnitude of 6.3 on the Richter scale occurred in Chiang Rai, Thailand. This earthquake was the strongest earthquake in Thailand at the Mae Lao District region. It also caused building damage and casualties. In this research, 277 participants living in village no.2 and village no.7 of Dong Mada, a sub-district at Mae Lao district in Chiang Rai, were selected. A questionnaire was used to interview these participants, and the data were analyzed by Chi-square, Fisher's exact test, a Mann-Whitney U test, and a Kruskal-Wallis test. The objective of this study was to …


Weakly Singular Boundary Integral Equation Method For Analysis Of Generalized T-Stresses Of Cracks In 3d Coupled-Field Media, Naruethep Sukulthanasorn Jan 2017

Weakly Singular Boundary Integral Equation Method For Analysis Of Generalized T-Stresses Of Cracks In 3d Coupled-Field Media, Naruethep Sukulthanasorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents the development of a weakly singular boundary integral equation method for the analysis of the generalized T-stress of isolated cracks embedded in a coupled-field whole space. A pair of weak-form integral equations, one for crack-face generalized traction and the other for the gradient of the crack-face generalized displacement, is established in a general framework allowing various types of materials including elastic, piezoelectric, piezomagnetic and piezoelectromagnetic solids, general crack geometry and loading conditions to be handled in a unified fashion. In addition, the final governing integral equations contain only weakly singular kernels and this, as a result, renders …


An Application Of Geosynthetic Cementitious Composite Mat For Slope Stabilization, Phong Tan Ngo Jan 2017

An Application Of Geosynthetic Cementitious Composite Mat For Slope Stabilization, Phong Tan Ngo

Chulalongkorn University Theses and Dissertations (Chula ETD)

In recent years, soil erosion and slope instability caused by seepage and rainfall are major problems, especially in the mountain area. Many research studies have focused on finding a new technology or material to stabilize the soil slope. In this study, a novel material called geosynthetic cementitious composite mat (GCCM) is selected to study its performance on soil slope stabilization. A series of 1-g physical model tests and numerical simulation (Plaxis 2D) on sandy soil slopes stabilized with and without GCCM are performed under seepage condition. In addition, centrifuge modeling of soil slopes is performed under 25-g in seepage and …