Civil Engineering (Conference Papers)

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Civil Engineering Research in Ireland 2024 (CERI2024) conference
(Civil Engineering Research Association of Ireland, 2024-08-29) Finnegan; Finnegan, William; Hajdukiewicz, Magdalena
No abstract available
Staged construction of surcharged embankments over peat for a national road in Co. Donegal, Ireland
(ECSMGE24, 2024-08-26) Kissane, Paul; Ward, F. J.; McCabe, Bryan A.; Fattahi Masrour, Farimah; Towey, F.
The paper describes innovative geotechnical methods to implement staged construction of surcharged embankments up to 5.5 m high on very soft blanket peat soils in north west Ireland. Shear wave velocities, CPT ball tests and direct simple shear tests were used to assess the undrained strength of the peat. Intermediate hold periods and consolidation benefits were exploited to optimise the filling schedule. Changes to instrumentation, basal reinforcement, anchorage detailing and filling rates were implemented to assure stability. Detailed interpretation of settlement and pore pressure responses during loading and unloading at instrument clusters is presented, including back-calculated field coefficients of consolidation and observed deformation ratios.
Surcharged embankments over peat in north-west Ireland: Primary consolidation behaviour
(University of Galway, 2024-09-18) Fattahi Masrour, Farimah; McCabe, Bryan A; Buggy, Fintan J.; Kissane, Paul; Long, Mike; Science Foundation Ireland
This paper presents selected data relating to the primary consolidation of blanket peat under surcharged embankments on a road improvement scheme in Co. Donegal, Ireland, completed in 2022. The back-calculated compression index was found to be compatible with values for Scandinavian peats and in keeping with a well-known empirical prediction at equivalent moisture contents. Coefficients of consolidation, derived using Asaoka final primary consolidation settlements as the starting point, exceeded those inferred from piezometer data, but both values significantly exceeded oedometer-derived values at equivalent effective stress levels. Carlsten’s (1988) method produced a reasonable estimate of time to 90% consolidation once used within the intended loading range. A particular focus of the paper is on the corrections/assumptions necessary to interpret primary consolidation parameters in large strain scenarios.
Embankments over blanket peat in Co. Donegal: Interpretation of piezometer data
(International Association of Hydrologists (IAH) Irish Group, 2024-04-16) McCabe, Bryan A; Buggy, Fintan J; Fattahi Masrour, Farimah
A recent road improvement scheme on the N56 near Glenties, Co. Donegal, involved the staged construction of a surcharged embankment over blanket peat, enabling the peat to be left in place. This paper focusses on the interpretation of the pore pressure regime in the underlying peat during and after construction. The substantial peat strains induced by the embankment rendered buoyant the portion of the embankment that settled beneath the groundwater table and required assumptions to be made about piezometer positions. Additional assumptions necessary to arrive at coefficients of consolidation and permeabilities are presented. A hypothesis is proposed to explain the elevated long-term pore pressures noted at two of the instrument cluster locations.
Pipe-jacking stoppages modelled using direct shear interface tests
(University of Galway, 2022-09-19) McCabe, Bryan A.; O’Dwyer, Kevin G.; Sheil, Brian B; Burke, Padraig F.; Irish Research Council
In long pipe-jacking drives used for installing utility pipelines, maximum jacking load requirements are usually governed by skin friction at the pipe-soil interface. In addition, field experience has shown that transient peaks in skin friction arise upon recommencement of jacking after stoppages; these stoppage durations can be short (due to the addition of a pipe to the string) or long (due to weekend stoppages or breakdowns) and constitute a risk for pipe-jacking contractors. In this paper, the problem is replicated in the laboratory using direct shear interface tests using a concrete specimen in one half of the apparatus and sand/bentonite mixtures in the other. Once critical state conditions were reached in these tests, stoppages of various durations (from 30 mins up to 2 weeks) were incorporated and the increase in shear stress upon recommencement of shearing was noted. From the experiments, there appears to be a threshold stoppage duration beyond which the skin friction increase appears to plateau, suggestive of a time-limited process within the bentonite. These skin friction data are shown to provide an upper bound to corresponding stoppage data from pipe-jacking drives in sandy ground conditions.
Correlation between uniaxial compression strength and point load index for Irish Caledonian granites
(Civil Engineering Reesearch Association of Ireland, 2022-08-25) McCabe, Bryan A.; Flynn, Kevin N.; Baxter, Sadhbh
While the Uniaxial Compression Strength (UCS) test is the gold standard for determining the UCS of rock for geotechnical and mining applications, empirical correlations between UCS and other test measurements are useful in situations where intact cores are difficult to retrieve and/or the scope of UCS testing is constrained by budget. UCS is most commonly correlated with the cheaper and more accessible Point Load Index (PLI) measurement. In ASTM D5731-16 (2016), it is recommended that site-specific correlations are developed between UCS and Is(50), the point load index adjusted to a specimen diameter of 50 mm, as a means of estimating UCS indirectly. However, in the absence of site-specific data, a UCS/Is(50) ratio in the range 18 to 24.5 (dependent on core diameter) may be used. In this paper, the relationship between UCS and Is(50) is explored for Caledonian granites from three regions in Ireland. The effects of variables such as the direction of point load application (diametral versus axial), UCS core diameter and aspect ratio and Rock Quality Designation are also considered. These data supplement the very limited information on UCS-PLI relationships published for granite internationally, while complementing a similar study recently conducted for Calp Limestone in the greater Dublin area.
Building effectiveness communication ratios for improved building life cycle management
(International Building Performance Simulation Association (IBPSA), 2005-08-15) Morrissey, Elmer; Keane, Marcus M.; O’Donnell, James; McCarthy, John; IBPSA.org
Many existing building energy performance assessment frameworks, quantifying and categorising buildings post occupancy, offer limited feedback on design decisions. An environment providing decision makers with pertinent information to assess the consequences of each design decision in a timely, cost effective and practical manner is required to promote viable low-energy solutions from the outset. This paper outlines a performance-based strategy utilising building effectiveness communication ratios stored in Building Information Models (BIM). Decision makers will be capable of rating the building¿s energy performance throughout its natural life cycle without imposing adverse penalties on facilities located in dissimilar climatic zones subjected to stringent building codes and regulations. With this advancement in building energy assessment in place, a progressive improvement in energy efficiency for the building stock is a feasible and realistic target.
Combining engineering and qualitative models to fault diagnosis in air handling units
(IOS Press, 2014-08-18) Struss, Peter; Sterling, Raymond; Febres, Jesus; Sabir, Umbreen; Keane, Marcus M.
This paper presents a methodology for model-based fault localization and identification that exploits both numerical (Modelica) models and a qualitative model-based approach to diagnosis. It has been applied to diagnosis of an air handling unit based on data recorded by a building management system. The main steps from model development to diagnosis based on the recorded data are discussed.
Reduced order modelling of the thermal behaviour of an office space
(Infoscience EPFL Scientific Publications, 2013-09-04) Geron, M.; Monaghan, R. F. D.; Keane, Marcus M.
Reduced Order Models (ROMs) have proven to be a valid and efficient approach to model the thermal behaviour of building zones. The main issues associated with the use of zonal/lumped models are how to (1) divide the domain (lumps) and (2) evaluate the parameters which characterise the lump-to-lump exchange of energy and momentum. The object of this research is to develop a methodology for the generation of ROMs from CFD models. The lumps of the ROM and their average property values are automatically extracted from the CFD models through user defined constraints. This methodology has been applied to validated CFD models of a zone of the Environmental Research Institute (ERI) Building in University College Cork (UCC). The ROM predicts temperature distribution in the domain with an average error lower than 2%. It is computationally efficient with an execution time of 3.45 seconds. Future steps in this research will be the development of the procedure to automatically extract the parameters which define lump-to-lump energy and momentum exchange. At the moment these parameters are evaluated through the minimisation of a cost function. The ROMs will also be utilised to predict the transient thermal behaviour of the building zone.
Community engaged learning: A building engineering case study
(Civil Engineering Research Association of Ireland (CERAI), 2020-08-28) Goggins, Jamie; Hajdukiewicz, Magdalena; Science Foundation Ireland; Horizon 2020
ABSTRACT: Community engaged learning is a form of experiential education with a civic underpinning. Community engaged learning is embedded with the civil engineering curriculum at NUI Galway and is framed by a research orientation, commitments to civic engagement and building university-community partnerships, city-university partnerships and partnerships with other official agencies, so that community users can provide real learning problems and contexts for students and researchers and benefit from the results. This paper presents the positive experience of the authors in facilitating over 300 community engaged learning projects undertaken by undergraduate students in civil engineering at NUI Galway. The paper highlights how well the outlined approach fits with the ideas of engaged scholarship and civic professionalism. Students recognise the long-term value of engaging with community partners, understanding their future role in the community as engineers, reinforcing the idea that their work can respond directly to real needs in the community.
Test machine effect in the determination of modulus of elasticity for strength graded timber
(World Conference on Timber Engineering (WCTE2021), 2021-08-09) Gil-Moreno, David; Ridley-Ellis, Dan; Harte, Annette M.; Department of Agriculture, Food and the Marine, Ireland
This paper investigates if the relationship between the global and local moduli of elasticity (MoE), measured in bending tests, is affected by the test machines employed, and how that may influence strength grading. The ultimate aim is to study the potential influence of those factors on the yields of graded timber in Europe, and improve the standards used. More than 2000 structural timber pieces of Douglas fir (Pseudotsuga menziesii), larch (Larix spp.) and spruce (Picea sitchensis & P. abies) grown in Ireland and the United Kingdom, were tested using two different test machines. The results are examined, and compared to the dynamic MoE measured using longitudinal vibration resonance. Results found that there can be a sufficiently large systematic effect of the test machine on the measurement of MoE, to potentially be transferred to the grading process with important consequences in the yields of structural grade timber. Furthermore, adjustment factors for MoE, as used in the standards, may not be transferable between laboratories, even when the species and timber source are the same. Caution is therefore recommended when deriving or using these MoE adjustment equations, with due care to ensuring the timber is of similar characteristics and tested under as similar as possible setups. The extrapolation of models derived from other sources is best avoided, unless confirmed by cross-checking measurements.
The structural behaviour of compressed wood manufactured using fast-grown sitka spruce
(National University of Ireland Galway, 2021-08-09) O’Ceallaigh, Conan; McGetrick, Patrick; Harte, Annette M.
An investigation was carried out to examine the potential to manufacture a compressed wood product from fast-grown Sitka spruce, using a process of thermo-mechanical compression to increase its strength and stiffness. The process involves subjecting timber to a thermal load followed by a compressive load to reduce its cross-section, increasing its density and improving its structural performance. In this study, the influence of the manufacturing parameters, specifically, the pressing time and compression ratio, are examined. These parameters have been evaluated based on the microscopic structure and bending strength from three-point bending tests. The results have demonstrated that there is significant potential to manufacture a compressed wood product with improved structural behaviour from fast grown timber.
Modified wood as compression reinforcement of timber perpendicular to the grain
(National University of Ireland Galway, 2021-08-09) O’Ceallaigh, Conan; Conway, Michael; Mehra, Sameer; Harte, Annette M.
An investigation was carried out to examine the potential to utilise modified wood as a reinforcement for timber subjected to compression loading perpendicular to the grain. In recent years there has been a significant number of studies examining the use of steel screws and bonded in rods for this purpose. This is becoming more and more important with the increased use of timber in medium-to high rise structures. In this study, thermally densified or modified timber in the form of dowels are utilised as compression reinforcement perpendicular to the grain and tested to failure. Thermally densified dowel reinforcement arrangements of 2, 4, and 6 dowels are examined experimentally under a compressive load and compared to timber samples similarly reinforced but with steel screws specifically designed to resist stresses perpendicular to the grain. The results have demonstrated the potential to utilised modified wood to create an all-wood solution to reinforce against compressive stresses perpendicular to the grain.
Numerical investigation of the structural behaviour of adhesive free connections utilising modified wood
(National University of Ireland Galway, 2021-08-09) O’Ceallaigh, Conan; Mosheni, Iman; Mehra, Sameer; Harte, Annette M.; European Regional Development Fund
An investigation was carried out to examine the potential to use modified wood as a replacement for metallic connections in timber structures. In recent years, there have been several studies examining the potential to utilise modified wood to improve the performance of engineered wood products. This study describes the development of finite element models validated against a series of experimental tests on spliced beam-beam timber connections. The spliced beams are formed using compressed wood (CW) dowels and slotted-in CW plates providing an all-timber solution. A parametric study is utilised to optimise the design of spliced beam-beam timber connections utilising CW plates and dowels. The parameters studied were dowel arrangement, plate length, plate thickness, beam width and depth. The results indicate that connections using CW dowels and plates can be successfully modelled using finite element (FE) software. An optimised design has been developed to improve stiffness and moment rotation capacity of the connection system.
Perception and use of timber in construction: A case study of Ireland and the UK
(National University of Ireland Galway, 2021-08-09) O’Ceallaigh, Conan; Gil-Moreno, David; Ridley-Ellis, Daniel; Harte, Annette M.; Department of Agriculture, Food and the Marine, Ireland
A survey was carried out to examine the perception of timber in construction among industry stakeholders within northwest Europe. The survey received responses from 17 countries in total. The total results of all respondents are presented along with results specifically from Ireland and the United Kingdom to examine differences in these regions in relation to the perception of timber as a construction material, the barriers impeding its use, and the educational needs and requirements of industry stakeholders. The use of timber in construction in these regions has arguably lagged behind the rest of Europe. A large proportion of participants (97.3%) expressed an interest in learning more about the benefits of timber in construction and highlighted topics of interest to them in their respective professions. The key findings from the survey have identified the educational needs and requirements of the industry and will inform future training courses/ material to support the increased use of timber in construction.
Key considerations in the design of a one-stop-shop retrofit model
(Civil Engineering Research Assiciation of Ireland (CERAI) and Cork Institute of Technology, 2020-08-27) McGinley, Orlaith; Moran, Paul; Goggins, Jamie; Horizon 2020; Science Foundation Ireland; MaREI Centre
The Irish Government’s Climate Action Plan emphasizes the need for increased retrofit activity within the built environment. As such, the plan has set targets for the completion of 500,000 energy efficient retrofits by 2030 at a rate of 50,000 per annum. Ireland’s current retrofit uptake rate is considered relatively low, at approximately 23,000 primarily shallow retrofits per annum. Thus, a significant step change is required to drive retrofit investment at a national scale, however, there are various barriers existing to such. Considering these targets, the establishment of a One-Stop-Shop (OSS) retrofit model has been identified in the Climate Action Plan as a key action. Such OSS models are emerging across Europe, with some OSS style models already introduced in Ireland. However, significant upscaling is required to deliver on the targets set. This paper provides a definition of a OSS model, highlights its benefits and how it responds to some of the barriers limiting retrofit uptake in Ireland. Secondly, this paper reviews existing literature and business models of existing European OSS models, with focus on the customer segment in these models. A brief discussion on the potential reach of such customer segments in the Irish context are presented, based on available statistics. The main finding of the paper is that there is limited published research on the characteristics and motivations of households engaging with existing OSS models and retrofitting in general in Ireland. A deeper understanding of such will be crucial to the success of the establishment of a OSS model in Ireland as a policy measure toward the achievement of the Climate Action Plan targets set.
Can DEAP help us to predict the energy demand and indoor temperature of homes before and after renovation ? A case study from Dublin
(Civil Engineering Research Association of Ireland (CERAI) and Cork Institute of Technology, 2020-08-27) Moran, Paul; Goggins, Jamie; Science Foundation Ireland; Horizon 2020
Improving the energy efficiency of buildings via retrofitting is seen as one of the key mitigation measures to reducing the energy demand and carbon emissions of the built environment in Ireland. However, while energy efficiency retrofits for buildings are effective in theory, the energy savings estimated by statistical or engineering models can often be inaccurate. The Domestic Energy Assessment Procedure (DEAP) is the standard assessment procedure used for assessing the energy performance standard of residential buildings in Ireland. This paper examines the gas energy demand for space and water heating and the internal temperature profiles in contrast to DEAP estimates for a group of social housing units which were retrofitted to improve their energy performance standard. For the 16 households examined, theoretical energy demand was overestimated and theoretical average temperatures were underestimated on average. Based on the sample of houses in this study, the DEAP assumption of a 3°C temperature differential between the living area and the rest of the dwelling during heating hours is not representative of temperatures in actual buildings.
Temperature profiles of private rental housing occupied by third level students in Ireland
(Civil Engineering Research Assiciation of Ireland (CERAI) and Cork Institute of Technology, 2020-08-27) Ryan, Ailbhe; Walsh, Eimear; Moran, Paul; Goggins, Jamie
The Irish Government published a National Student Accommodation Strategy to tackle issues surrounding the availability of accommodation for students in higher education. 23,634 students could not be accommodated with a bed space supplied by a Higher Education Institution in 2017. Therefore, many students live in private rental accommodation during the academic year. This paper examines the indoor temperature profiles of private rental housing occupied by third level students in Ireland. From the results, the temperature levels across the majority of the 16 cases were found to have temperatures below the recommended 18°C. At least 90% of the recorded temperature data during February for all but three of the cases was less than 18°C, highlighting the poor indoor temperature levels that the students were living in. While the sample size of this study is small and more research needs to be carried out on this topic in the future, the data suggests more accommodation needs to be provided for people in higher education that allows them to achieve indoor temperature levels within recommended guidelines.
CASCADE methodology and tool: appliedICT for energy efficient airports
(World SB14 Barcelona, 2014-10-28) Costa, Andrea; Blanes, Luis M.; Réhault, Nicolas; Keane, Marcus M.
This paper gives an overview on the CASCADE project, methodology and on a stakeholdercentered solution called the CASCADE Tool that integrates Fault Detection and Diagnosis (FDD)into a comprehensive energy management system. Two major European airports are used as the test bench of the CASCADE solution. The solution delivers a common integrated platform including several innovative commercial and under development technologies including an ISO-50001 energy management software, advanced data visualization and FDD which has become a robust scientific field offering proven methods for the optimization and more effective operation of HVAC systems.
A SWOT framework to investigate the integration between building management systems and fault detection and diagnosis tools
(National University of Ireland Galway, 2013-07-01) Costa, Andrea; Sterling, Raymond; Blanes, Luis M.; Howley, Martin; Keane, Marcus M.; Seventh Framework Programme
This paper presents a research work carried out under the umbrella of the CASCADE project, which is a European FP7 research project which is developing facility-specific measurement-based energy action plans for the airport energy managers that are underpinned by Fault Detection Diagnosis (FDD). The paper first describes the context of the project then it focuses on Building Management Systems describing the current status of the technology and presenting an outlook on their future development. Then a Strengths Weakness Opportunity and Treads (SWOT) framework is defined with the aim of verifying the suitability of an installed BMS system to incorporate Fault Detection and Diagnosis (FDD) tools

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