Civil Engineering Commons^™

Modelling Tree Contribution In Susceptibility Analysis Of Shallow Llandslides, Roberto José Marín Sánchez, Juan Pablo Osorio

Articles

In this paper an assessment of shallow landslides susceptibility in a tropical and mountainous terrain is made. A method that allows to model slope stability over large areas is used. Tree contribution is quantified by means of three parameters: rainfall interception, root reinforcement and tree surcharge. A rainfall interception model is used to determine the rain available for infiltration and its temporal distribution during the simulation. The hydrological models included in TRIGRS are described, which allows to determine the pore water pressure depending on the initial conditions. This pore water pressure is used in the revised infinite slope stability model, …

An Evaluation Of The Efficiency Of Compartmented Alginate Fibres Encapsulating Rejuvenator As Asphalt Pavement Healing System, Amir Tabakovic, Luke Schuyffel, Aleksandar Karac, Erik Schlangen

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This paper explores the potential methods for evaluating a healing system for asphalt pavements. The healing system under investigation involves compartmented calcium-alginate fibres encapsulating an asphalt binder healing agent (rejuvenator). This system presents a novel method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are used to distribute the rejuvenator throughout the pavement mixture, thereby overcoming some of the problems associated with alternate asphalt pavement healing methods, i.e., spherical capsules and hollow fibres. The asphalt healing efficiency methods to be evaluated in this paper include: (i) standard test methods for asphalt pavements, such as the Indirect Tensile Strength …

Effects Of Vegetation On Slope Stability: A Review, Roberto José Marín Sánchez, Juan Pablo Osorio

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Slope stability is usually affected by factors that reduce soil strength and increase driving forces acting on the slope material, sometimes generating mass movements. Among these factors, vegetation has an important role related to hydrological (e.g. evapotranspiration and infiltration) and mechanical (e.g. tree surcharge and root reinforcement provided by trees) mechanisms. In this review, vegetation influences associated to slope stability are identified, describing the mechanisms involved in the occurrence of mass movements. Finally, the way these factors affect slope stability is explained according to soil properties, climatic conditions and environmental characteristics.

Irish Bim Study 2017, Barry Mcauley, Alan Hore, Roger West

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The Construction IT Alliance (CitA) recently published its Global BIM Study as part of its BIM Innovation Capability Programme (BICP). The study sought to identify how BIM was being currently addressed in 27 countries across the globe. The study sought to identify the presence of three key ingredients in these countries:

1. Regulatory requirement for BIM

2. Champions driving BIM

3. Noteworthy publications

The report identified a number of recurring themes that would help to shape Ireland’s BIM programme. The report concluded that Ireland should adopt a programme of partnership between industry and the Irish Government in order to affect …

Compact Facility For Testing Steady And Transient Thermal Performance Of Building Walls, Aimee Byrne, Gerard Byrne, Anthony Robinson

Articles

Energy efficiency retrofit of buildings represents a key effort in reducing EU energy demand by 20% by 2020. However, predictions tend to overestimate savings by large percentages. The shortfall in savings can be attributed to incorrect predictive techniques, comfort takeback along with other behavioural and workmanship variables. Common predictive techniques related to heat loss tend to be based on the U-value of the building envelope. This paper presents the design of a more straightforward and compact version of the traditional Hot-Box apparatus (measures U-value) which instead determines the thermal resistance of samples of building envelope. U-value includes the need to …

Optimising The Performance Of Cement-Based Batteries, Aimee Byrne, Shane Barry, Niall Holmes Dr., Brian Norton

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The development of a battery using different cement-based electrolytes to provide a low but potentially sustainable source of electricity is described. The current, voltage, and lifespan of batteries produced using different electrolyte additives, copper plate cathodes, and (usually) aluminium plate anodes were compared to identify the optimum design, components, and proportions to increase power output and longevity. Parameters examined include water/cement ratio, anode to cathode surface area ratio, electrode material, electrode spacing, and the effect of sand, aggregate, salts, carbon black, silica fume, and sodium silicate on the electrolyte. The results indicate that the greatest and longest lasting power can …

Bim Innovation Capability Programme: An Irish Bim Study, Barry Mcauley, Alan Hore, Roger West

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In 2011 the Royal Institute of Architects Ireland (RIAI) conducted a survey which found that BIM adoption within Ireland was quite low at 16%. Over the last five years these figures have risen significantly, with the 2016 Irish Digital Transition Survey reporting that 76% of respondents possess confidence in their organisation’s BIM skills and knowledge. This represents a significant shift of BIM adoption in Ireland over the last five years.

The BIM Innovation Capability Programme (BICP) Irish BIM study, builds on the findings from the BICP Global BIM Study by providing an in depth review of BIM in Ireland with …

Evaluating A Microbial Water Quality Prediction Model For Beach Management Under The Revised Eu Bathing Water Directive, Zeinab Bedri, Aisling Corkery, John O'Sullivan, Louise Deering, Katalin Demeter, Wim Meijer, Gregory O'Hare, Bartholomew Masterson

Articles

The revised Bathing Water Directive (2006/7/EC) requires EU member states to minimise the risk to public health from faecal pollution at bathing waters through improved monitoring and management approaches. While increasingly sophisticated measurement methods (such as microbial source tracking) assist in the management of bathing water resources, the use of deterministic predictive models for this purpose, while having the potential to provide decision making support, remains less common.

This study explores an integrated, deterministic catchment-coastal hydro-environmental model as a decision-making tool for beach management which, based on advance predictions of bathing water quality, can inform beach managers on appropriate management …

Case Studies Of Cavity And External Wall Insulation Retrofitted Under The Irish Home Energy Saving Scheme: Technical Analysis And Occupant Perspectives, Aimee Byrne, Gerard Byrne, Garrett O'Donnell, Anthony Robinson

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The residential sector represents 27% of primary energy consumption in Ireland. This paper examines the case study of the Irish government’s national grant scheme to encourage energy efficiency retrofit in private housing. That is the Home Energy Saving (HES) Scheme, later rebranded the Better Energy: Homes (BEH) Scheme. The methodology involved monitoring several homes immediately before and after retrofit alongside discussions with occupants. The examination focused on specific measures commonly introduced through the HES/BEH programme − cavity and external wall insulation. It has been found that a significant decrease in heat loss through the walls was measured in all cases. …

Structural Control Of Wind Turbines With Soil Structure Interaction Included, Breiffni Fitzgerald, Biswajit Basu

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The importance of considering soil structure interaction in structural control of wind turbines is investigated in this paper. An Euler–Lagrangian wind turbine mathematical model based on an energy formulation was developed for this purpose which considers the structural dynamics of the system and the interaction between in-plane and out-of-plane blade vibrations. Also, the interaction between the blades and the tower including a tuned mass damper (TMD) is considered. The turbine is subject to turbulent aerodynamic loading simulated using a modification to the classic Blade Element Momentum (BEM) theory with turbulence generated from rotationally sampled spectra. The turbine is also subject …

Thermal Energy Storage In Building Integrated Thermal Systems: A Review. Part 2. Integration As Passive System, Dervilla Niall, Sarah Mccormack, Philip Griffiths, Luisa Cabeza, Lidia Navarro, Albert Castell, Alvaro De Grazia, Maria Brown

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Energy consumption trends in residential and commercial buildings show a significant increase in recent decades. One of the key points for reducing energy consumption in buildings is to decrease the energy demand. Buildings envelopes are not just a structure they also provide protection from outdoor weather conditions always taking into account the local climate. Thermal energy storage has been used and applied to the building structure by taking advantage of sensible heat storage of materials with high thermal mass. But in recent years, researchers have focused their studies on the implementation of latent heat storage materials that if well incorporated …

Lightening Strikes Twice For Dit Geomatics, Audrey Martin

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The Technological University Dublin (DIT) is rapidly becoming known as an international centre for excellence for all things geospatial. In September 2014, Kevin O'Mahony, a final-year BSc Geomatics student, won the international Trimble Geospatial Student Competition. Kevin is the second consecutive DIT student to win this prestigious award, following on from the success of David Hyland (BSc Geomatics) in 2012. Both students submitted their papers under the supervision of Dr Audrey Martin FSCSI FRICS, Chair of the recently accredited (by SCSI) DIT MSc in Geospatial Engineering. The worldwide student competition is held every two years and is open to all …

Assessing The Water Quality Response To An Alternative Sewage Disposal Strategy At Bathing Sites On The East Coast Of Ireland, Zeinab Bedri, John O'Sullivan, Louise Deering, Katalin Demeter, Bartholomew Masterson, Wim Meijer, Gregory O'Hare

Articles

A three-dimensional model is used to assess the bathing water quality of Bray and Killiney bathing sites in Ireland following changes to the sewage management system. The model, firstly calibrated to hydrodynamic and water quality data from the period prior to the upgrade of the Wastewater Treatment Works (WwTW), was then used to simulate Escherichia coli (E. coli) distributions for discharge scenarios of the periods prior to and following the upgrade of the WwTW under dry and wet weather conditions. E. coli distributions under dry weather conditions demonstrate that the upgrade in the WwTW has remarkably improved the bathing water …

A Review Of Probabilistic Methods Of Assessment Of Load Effects In Bridges, Eugene J. Obrien, F Schmidt, Donya Hajializadeh, X-Y Zhou, Bernard Enright, Colin C. Caprani, Simon Wilson, Emma Sheils

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This paper reviews a range of statistical approaches to illustrate the influence of data quality and quantity on the probabilistic modelling of traffic load effects. It also aims to demonstrate the importance of long-run simulations in calculating characteristic traffic load effects. The popular methods of Peaks Over Threshold and Generalized Extreme Value are considered but also other methods including the Box-Cox approach, fitting to a Normal distribution and the Rice formula. For these five methods, curves are fitted to the tails of the daily maximum data. Bayesian Updating and Predictive Likelihood are also assessed, which require the entire data for …

Lighting Design In Europe: Aligning The Demands For Lower Energy Usage With Better Quality., Kevin Kelly, James Duff

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Lighting design is one of the fastest changing areas in building engineering. It has evolved significantly in recent years due to changing technology and demands for improved quality, better control, reduced energy and sustainability. This paper is an overview of what is happening in Europe and elsewhere and examines the literature to find that latest recommendations in the Code for Lighting issued by the SLL (Society of Light and Lighting) in the UK change previous demands for equal illuminance across a working plane to more specific and demanding criteria. There are recommendations for qualitative metrics and better distribution of light …

First Steps In Developing Cement-Based Batteries To Power Cathodic Protection Of Embedded Steel In Concrete, Niall Holmes, Aimee Byrne, Brian Norton

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This paper presents the first steps in developing innovative cement-based batteries to power cathodic protection in reinforced concrete structures. Initial electrical outputs of 1.55V and 23mA have been found to be sufficient to polarise prescribed corrosion currents of 20mA per m2 of embedded steel. Cathodic protection is a well-developed and powerful technique to limit the effects of steel reinforcement corrosion. However, as it requires an electrical supply day and night, it is often powered by non-environmentally friendly diesel generators or connected to the electrical grid. This paper focuses on increasing the ionic conductivity of the solution in the cement pores, …

Structural Properties Of Concrete Materials Containing Roadcem, Niall Holmes

Articles

This paper presents findings from a preliminary study to assess the structural and material properties of a nonstandard, concrete type mix containing RoadCem, a traditional soil stabilising additive. Two different mixes determined the effect of adding RoadCem in terms of compressive and flexural strengths, breaking strain, thermal expansion and contraction behaviour, permeability using a falling head, and Young’s modulus. RoadCem is a fine powder containing alkali metals and synthetic zeolites which are complemented with a complex activator. RoadCem modifies the dynamics and chemistry of cement hydration by enhancing the crystallisation process and forming longer needle crystalline structures. It reduces the …

Nonlinear Analysis Of Isotropic Slab Bridges Under Extreme Traffic Loading, Donya Hajializadeh, A. Salam Al-Sabah, Eugene J. Obrien, Debra F. Laefer, Bernard Enright

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Probabilistic analysis of traffic loading on a bridge traditionally involves an extrapolation from measured or simulated load effects to a characteristic maximum value. In recent years, Long Run Simulation, whereby thousands of years of traffic are simulated, has allowed researchers to gain new insights into the nature of the traffic scenarios that govern at the limit state. For example, mobile cranes and low-loaders, sometimes accompanied by a common articulated truck, have been shown to govern in most cases. In this paper, the extreme loading scenarios identified in the Long Run Simulation are applied to a non-linear, two-dimensional (2D) plate finite …

Spatial Time-Dependent Reliability Analysis Of Reinforced Concrete Slab Bridges Subject To Realistic Traffic Loading, Donya Hajializadeh, Mark Stewart, Bernard Enright, Eugene J. Obrien

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Resistance and loads are often correlated in time and space. The paper assesses the influence of these correlations on structural reliability/probability of failure for a typical two-lane RC slab bridge under realistic traffic loading. Spatial variables for structural resistance are cover and concrete compressive strength, which in turn affect the strength and chloride-induced corrosion of RC elements. Random variables include pit depth and model error. Correlation of weights between trucks in adjacent lanes and inter-vehicle gaps are also included and are calibrated against Weigh-In-Motion (WIM) data. Reliability analysis of deteriorating bridges needs to incorporate uncertainties associated with parameters governing the …

Identifying And Modelling Permit Trucks For Bridge Loading, Bernard Enright, Eugene J. Obrien, Cathal Leahy

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Accurate estimates of characteristic traffic load effects are essential in order to optimize bridge safety assessment. Permit trucks dominate the extreme upper tail of the truck loading distribution and as a result need careful examination. This paper proposes rules for filtering these trucks from Weigh-In-Motion data for both the US and Europe. The importance of these trucks in critical bridge loading events is then examined for both regions. A Monte Carlo traffic simulation model is developed which focuses on the accurate simulation of permit trucks.

Effects Of Posttensioning Slippage On 2-Way Spanning Concrete Slabs, Niall Holmes, Eoin Byrne

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This paper investigates the effect of improper posttensioning of a 2-way spanning concrete slab subject to a central point load. Due to plate slippage alone, the support conditions only offered a 1-way spanning action which could have led to premature failure with dangerous consequences. Posttensioning can strengthen a flat slab against punching shear by controlling deflections and cracking under service loads compared with traditional punching shear reinforcing methods leading to more slender structures and economic solutions for longer spans. However, if the method is not properly applied, these thinner floor plates can fail in a brittle and sudden manner by …

Geographic Information System-Based Tools In Environmental Management, Zeinab Bedri, Michael Bruen

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The authors reviewed existing modelling platforms as part of a large study of water and pollution pathways through catchments in Ireland (Irish EPA Pathways project). Worldwide, work on producing catchment management tools (CMTs) has been underway for some time and some of the tools identified here date from as early as 1989. Some of the management problems and model conceptualisations have not changed very much but now there is a stronger emphasis on water quality and more concern about a wider range of contaminants. What has changed substantially is the use of Geographical Information System and Graphical Windows interfaces as …

Experimental Design Of Photo-Fenton Reactions For The Treatment Of Car Wash Wastewater Effluents By Response Surface Methodological Analysis, Maha Tony, Zeinab Bedri

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Establishing a treatment process for practical and economic disposal of car wash wastewater has become an urgent environmental concern. Photo-Fenton’s process as one of the advanced oxidation processes is a potentially useful oxidation process in treating such wastewater. Lab-scale experiments with UV source, coupled with Fenton’s reagent, showed that hydrocarbon oil is degradable through such a process. The feasibility of photo-Fenton’s process to treat wastewater from a car wash is investigated in the present study. A factorial design based on the response surface methodology was applied to optimize the photo-Fenton oxidation process conditions using chemical oxygen demand (COD) reduction as …

Longitudinal Shear Resistance Of Composite Slabs Containing Crumb Rubber In Concrete Toppings, Niall Holmes, Kevin Dunne, John O'Donnell

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This paper investigates the behaviour and longitudinal shear capacity of metal deck composite slabs with the inclusion of crumb rubber in the concrete toppings. The ability of the slabs to act compositely is governed by the shear interaction between the concrete topping and the profiled steel deck. Results here show that crumb rubber concrete (CRC) improve the overall shear bond capacity between the steel deck and topping following an experimental study on full scale loading tests in accordance with Eurocode 4. The results confirm that composite slabs incorporating crumb rubber had no effect on the longitudinal shear resistance with similar …

Acoustic Properties Of Concrete Panels With Crumb Rubber As A Fine Aggregate Replacement, Niall Holmes, Alex Browne, Christopher Montague

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This paper presents the acoustic performance of small scale crumb rubber concrete (CRC) panels in terms of the sound absorbance and insulation at low (63, 125, 250 & 500 Hz) and high (1000, 2000, 4000 and 5000 Hz) frequencies. Acoustic tests were conducted with differing levels of fine aggregate replacement with crumb rubber (7.5 and 15%) with four different grades following freezing and heating. Analysis of the workability, compressive strength and density are also presented. The results found that CRC performed well in terms of sound absorbance particularly with higher proportions (15% here) and grades of crumb rubber. As an …

Active Confinement Of Weakened Concrete Columns, Niall Holmes, Dervilla Niall, C. O’Shea

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This paper investigates the advantages of using of external active confinement to improve the compression load capacity of concrete cylinders using mild steel band clamps. For this, passive and actively pre-stressed steel bands have been attached to concrete cylinders to mimic real structural columns which may otherwise have to be removed and replaced due to poor strength performance. The experimental programme included compression load testing a number of unreinforced concrete cylindrical specimens to establish the effect the confinement had on the compressive load-carrying capacity and the stress-strain behaviour. A number of parameters were investigated in the study including the effect …

A Review Of The Hl-93 Bridge Traffic Load Model Using An Extensive Wim Database, Cathal Leahy, Eugene J. Obrien, Bernard Enright, Donya Hajializadeh

Articles

HL-93, the current bridge traffic load model used in the United States, is examined here. Weigh-in-motion from 17 sites in 16 states, and containing 74 million truck records, is used to assess the level of consistency in the characteristic load effects implied by the HL-93 model. The load effects of bending moment and shear force are considered on single-lane and two-lane same-direction slab and girder bridges with a range of spans. It is found that the ratio of WIM-implied to HL-93 load effect varies considerably from one load effect to another. An alternative model is proposed which achieves improvements in …

Environmental Consequences Of A Power Plant Shut-Down: A Three-Dimensional Water Quality Model Of Dublin Bay, Zeinab Bedri, Michael Bruen, Aodh Dowley, Barthelomew Masterson

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A hydro-environmental model is used to investigate the effect of cessation of thermal discharges from a power plant on the bathing water quality of Dublin Bay. Before closing down, cooling water from the plant was mixed with sewage effluent prior to its discharge, creating a warmer, less-saline buoyant pollutant plume that adversely affects the water quality of Dublin Bay. The model, calibrated to data from the period prior to the power-plant shut-down (Scenario 1), assessed the water quality following its shut-down under two scenarios; (i) Scenario 2: continued abstraction of water to dilute sewage effluents before discharge, and (ii) Scenario …

Using Weigh-In-Motion Data To Determine Aggressiveness Of Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright

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This paper presents results based on the analysis of an extensive database of weigh-in-motion (WIM) data collected at five European highway sites in recent years. The data are used as the basis for a Monte Carlo simulation of bridge loading by two lane traffic, both bidirectional and same-direction. Long runs of the simulation model are used to calculate characteristic bridge load effects (bending moments and shear forces), and these characteristic values are compared with design values for bridges of different length as specified by the Eurocode for bridge traffic loading. Various indicators are tested as possible bases for a “Bridge …

Microsimulation Evaluation Of Eurocode Load Model For American Long-Span Bridges, Bernard Enright, Colm Carey, Colin Caprani

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The ability to accurately predict traffic loading is essential for cost-effective bridge maintenance and repair programs. The traffic load model currently used in the United States for the design of long-span bridges was developed over three decades ago. In the meantime vehicle characteristics and traffic patterns have changed. The Eurocode for traffic loading is more recent, but was calibrated only for bridges up to 200 m long. In this work, Weigh-In-Motion traffic records from 11 different sites across Alabama are used to establish congested traffic loading. Traffic microsimulation is used to generate the congestion, based on the real traffic data. …