Tripping the Flight Fantastic: Slipstream,Terminal 2, Heathrow Airport

Ralph Parker and Tim Lucas of Price & Myers Geometrics explain the complex architectural and engineering challenges of turning a simple idea – solidifying the motion of a joyfully cartwheeling aircraft – into a vast kit-of-parts jigsaw puzzle for Richard Wilson's new sculpture at Heathrow.     

Effects of different tunnel face advance excavation on the settlement by FEM

The excavation process for a tunnel changes in terms of its service requirements, ground conditions and the stability of surface buildings in urban areas. When a tunnel is excavated, there will be settlement, which may cause damage to surface structures. To control and limit the settlement caused by tunnelling operations, there have been many tunnelling techniques proposed. Thus, in this paper, a number of Finite Element Method analyses were conducted to investigate the effects of different patterns for advancing the tunnel face on the settlement. The Heathrow Express Trial tunnel was constructed in accordance with the principles of the New Austrian Tunnelling Method (NATM). The settlement measurements taken during its construction were used to validate the results from the analyses undertaken. Three different face advance techniques were used during the construction of the Heathrow Express Trial tunnel viz. Twin sidewall excavation (TS1), single sidewall excavation (TS2), and Crown, Bench and Invert excavation (TS3). As the trial work proved that TS2 produced the minimum settlement above tunnel centreline, only TS2 was subjected to the FEM analysis in this research. In order to simulate TS2 correctly three types of excavation models were devised and the results compared to field measurements of TS2. For the FEM analysis the Hypothetical Modulus of Elasticity (HME) soft lining approach was used and a practical method to estimate HME is proposed for when it is used for different face advance sequences. Results proved that when the excavation pattern was changed, the HME value was also changed and settlement over the tunnel centreline changed in terms of the face advance pattern adopted.     

From hero to hubris – Reconsidering the project management of Heathrow’s Terminal 5

Heralded as the first stage in the regeneration of Heathrow Airport leading up to the 2012 Olympics, the construction of Terminal 5 had bucked the trend. In a world where most mega infrastructure projects fail, the T5 project was not only on schedule, it was on budget. At its official opening by the Queen it was being trumpeted as the 21st century gateway to Britain. But multiple problems emerged on the opening day culminating in the cancellation of numerous flights and thousands of lost bags requiring manual sorting before being returned to their owners. What should have been an occasion for celebration turned into a national disaster. Using accounts drawn from the media, from a House of Commons Transport Committee report and material from research into the construction phase of the project, this paper examines the episode via two theoretical lenses – normal accident theory and high reliability theory.     

Interchange Now

Not for them was the Modernism of neat, smooth, regular solids, notes Banham. ‘The younger megastructuralists clearly saw technology as a visually wild rich mess of piping and wiring and struts and catwalks and bristling radar antennae and supplementary fuel tanks and landing-pads all carried in exposed lattice frames, NASA-style. Much of this intellectual underpinning for this picturesque view of advanced technology came, directly or otherwise, from the writings and projects of the Futurist architect Antonio Sant'Elia, in spite of the fact that he had been dead since 1916.’ Appreciating Futurism, Robert Stewart of YRM looks at prospects for the modularisation of megastructural transport projects, having been engaged in the vast and largely subterranean development of Terminal 5 at Heathrow Airport, London. He argues for a flexible architecture in the service of mobility.     

A survey of air pollution in the vicinity of Heathrow airpot (London)

An investigation of atmospheric quality in the vicinity of Heathrow airport (London) has been undertaken. Ambient concentrations of total hydrocarbons, methane, carbon monoxide, non-methane hydrocarbons and airbone particulate lead were monitored. Eight sites were visited in each of the years the survey was undertaken, approximately half of the sites were close to the airport perimenter and the remainder in the surrounding urban residential areas. This was achieved by the use of a mobile laboratory containing the necessary continuous monitors. Although the objective of the study was to assess the impact of the airport upon air quality, no distinction could be made between the relative contributions to air pollution of the airport sources and those arising from motor vehicle and industrial activity in the area.     

The organisational architecture of megaprojects

This research explores the formation and evolution of the organisational architecture in megaprojects. We introduce the Project System Organisation (PSO) conceptual framework, which charts the architecture of megaproject organising, from intra- to inter-organisational design, and ultimately to system-level design. The PSO identifies the multiple and evolving actors across the multi-level and multi-layer megaproject system and defines four roles often used to label the client in megaprojects: owner, sponsor, client, and partner. Six megaprojects that currently represent a combined investment of more than £100 Bn have been analysed through 171 interviews in the United Kingdom: High Speed One, Heathrow Airport Terminal 5, London 2012 Olympics, Crossrail, Thames Tideway Tunnel, and High Speed Two. The PSO provides a structure to design megaproject delivery models and prototype the configuration of inter-organisational relationships. We suggest designing megaprojects as dynamic production systems, decomposing and integrating the organisational boundaries of the system in the evolving architecture.     

Innovation in construction: a sociology of technology approach

An alternative approach to understanding innovation is made using two intersecting ideas. The first is that successful innovation requires consideration of the social and organizational contexts in which it is located. The complex context of construction work is characterized by inter-organizational collaboration, a project-based approach and power distributed amongst collaborating organizations. The second is that innovations can be divided into two modes: 'bounded', where the implications of innovation are restricted within a single, coherent sphere of influence, and 'unbounded', where the effects of implementation spill over beyond this. Bounded innovations are adequately explained within the construction literature. However, less discussed are unbounded innovations, where many firms' collaboration is required for successful implementation, even though many innovations can be considered unbounded within construction's inter-organizational context. It is argued that unbounded innovations require an approach to understand and facilitate the interactions both within a range of actors and between the actors and technological artefacts. The insights from a sociology of technology approach can be applied to the multiplicity of negotiations and alignments that constitute the implementation of unbounded innovation. The utility of concepts from the sociology of technology, including 'system building' and 'heterogeneous engineering', is demonstrated by applying them to an empirical study of an unbounded innovation on a major construction project (the new terminal at Heathrow Airport, London, UK). This study suggests that 'system building' contains outcomes that are not only transformations of practices, processes and systems, but also the potential transformation of technologies themselves.     

Back analysis for tunnelling induced ground movements and stress redistribution

Analysing tunnelling process in 2D plane strain conditions is widely used method to calculate tunnelling induced settlement profiles as well as soil structure interactions. Possibility of damage to the surface and/or underground structures can be estimated using powerful finite difference method (FDM) and finite element method (FEM) of analysis. However, setting up a realistic model that would be able to achieve this goal is rather difficult. In this paper, 2D FDM analysis has been conducted to assess tunnelling induced settlement, stress redistribution phenomena along with movements around shallow soft ground tunnels excavated in accordance with the New Austrian Tunnelling Method. Measurements recorded during construction of the Heathrow Express Trial Tunnel in London Clay were compared with the predicted values to validate numerical estimations. As a soil model, the Mohr–Coulomb plasticity model has been used in the FDM analysis. Results obtained from 2D FEM are also included in this paper for comparison purposes to evaluate performance of both numerical analysis procedures. Predictions from both FDM and FEM analyses proved to be procedures used within this work can be a tool in practical engineering applications to simulate tunnelling operations.     

An assessment of waste management efficiency at BAA airports

The issue of waste management within airports is becoming increasingly important with enormous increases in passenger numbers and is a key responsibility of the facilities manager. Airports are notoriously poor environmental performers and this growth in the industry is leading to increasing levels of waste production. The purpose of this paper is to assess the efficiency of waste management operations at BAA airports, with reference to best practices within airports in continental Europe. The paper presents the findings of a survey of waste management methods in a sample of UK airports. The analysis of numerical data is based on those airports in the BAA group. Many of these are among the busiest airports in Britain, and Heathrow and Gatwick are two of the world's busiest. Data constraints prevented a more detailed analysis of other airports outside BAA. The paper highlights some difficulties in measuring BAA's waste management efficiency based on the waste hierarchy and concludes that some European airports have achieved greater efficiency in waste management. The situation is now changing though and BAA is taking environmental management seriously. However, a more co-ordinated approach to environmental strategy is needed across the industry and this is best produced at government level.     

Project capabilities for operational outcomes in inter-organisational settings: The case of London Heathrow Terminal 2

Project and strategic management scholarship recognises the importance of project capabilities that allow firms to deliver projects. Although work on project capabilities is a fast-growing line of inquiry, little is still known about how clients assemble project capabilities to achieve operational outcomes in inter-organisational settings. This study seeks to apply theoretical work on project capabilities to the domain of infrastructure project delivery in order to understand how the assembly of project capabilities in temporary inter-organisational settings contributes to the delivery of operational outcomes. The empirical enquiry takes place in the context of the delivery of London Heathrow Terminal 2. Through an inductive theory building approach drawing upon semi-structured interviews with client-side project leadership, internal documents, publicly available data and ongoing engagement with the field, we identified three key capability-enabling mechanisms that help explain the genesis of project capabilities in inter-organisational settings: (1) reconfiguring project capabilities, (2) adapting project capabilities and (3) maintaining project capabilities. We discuss and expand these findings by engaging with theoretical ideas from project studies, and mainstream strategy, organisation, and management research to induce a dynamic model that can be helpful to guide future research, policy and management practices relating to the client side management of project capabilities.     

Rate constants of reactions of ozone with organic and inorganic compounds in water—III. Inorganic compounds and radicals

Second-order rate constants for reactions of ozone with 40 inorganic aqueous solutes are reported. Included are compounds of sulfur (e.g. H₂S, H₂SO₃, HOCH₂SO₃H), chlorine (e.g. Cl⁻, HOCl, NH₂Cl, HClO₂, ClO₂), bromine (e.g. Br⁻, HOBr), nitrogen (e.g. NH₃, NH₂OH, N₂O, HNO₂) and oxygen (e.g. H₂O₂), as well as free radicals (e.g. O₂⁻, OH^•). Most of these compounds exhibit an increase in rate constant with increasing pH corresponding to their degree of dissociation. Rate constants are based on ozone consumption rates measured by conventional batch-type or continuous-flow methods (10⁻³-10⁺⁶ M⁻¹ s⁻¹ range) and determinations of stoichiometric factors. Also listed are data determined by pulse-irradiation techniques using kinetic spectroscopy (10¹⁰ M⁻¹ s⁻¹ range). Additional literature data are reviewed for completeness. Results are discussed with respect to water treatment and environmental processes.     

TOXICITY TESTING OF GROUNDWATER QUALITY

Groundwater is an important resource in the UK, with 45% of public water supplies in the Thames Water region derived from subterranean sources. In urban areas, groundwater has been affected by anthropogenic activities over a long period of time and from a multitude of sources. At present, groundwater quality is assessed using a range of chemical species to determine the extent of contamination. However, analysing a complex mixture of chemicals is time-consuming and expensive, whereas the use of an ecotoxicity test provides information on (a) the degree of pollution present in the groundwater and (b) the potential effect of that pollution. Microtox^TM, Eclox^TM and Daphnia magna microtests were used in conjunction with standard chemical protocols to assess the contamination of groundwaters from sites throughout the London Borough of Hounslow and nearby Heathrow Airport. Because of their precision, range of responses and ease of use, Daphnia magna and Microtox^TM tests are the bioassays that appear to be most effective for assessing groundwater toxicity. However, neither test is ideal because it is also essential to monitor water hardness. Eclox^TM does not appear to be suitable for use in groundwater-quality assessment in this area, because it is adversely affected by high total dissolved solids and electrical conductivity.     

Synthesis and characterisation of multi-walled carbon nanotubes (MWCNTs)

ABSTRACT

Carbon nanotubes are one of the major research areas in the field of nanotechnology, due to its mechanical and electro-conductive properties in the field of engineering and medical sciences. This paper focuses on preparation of multi-walled carbon nanotubes (MWCNTs) for the mass production using thermal catalytic chemical vapour deposition method. The synthesis of MWCNTs was made by breakdown of acetylene (C₂H₂) gas and Fe/MgO acting as catalyst. The surface morphology and structure of MWCNTs were characterised by scanning electron microscopy (SEM). Also phase identification and crystalline size of the nanopowder were determined by XRD. The particle size of MWCNTs was verified by SEM analysis and it was in the range of 20–30?nm and elemental analysis was carried out through energy dispersive analysis X-ray. Furthermore, thermal decomposition of the material property was studied by thermogravimetric analysis.     

Data-driven estimation of joint roughness coefficient

Joint roughness is one of the most important issues in the hydromechanical behavior of rock mass. Therefore, the joint roughness coefficient (JRC) estimation is of paramount importance in geomechanics engineering applications. Studies show that the application of statistical parameters alone may not produce a sufficiently reliable estimation of the JRC values. Therefore, alternative data-driven methods are proposed to assess the JRC values. In this study, Gaussian process (GP), K-star, random forest (RF), and extreme gradient boosting (XGBoost) models are employed, and their performance and accuracy are compared with those of benchmark regression formula (i.e. Z₂, R_p, and SD_i) for the JRC estimation. To analyze the models’ performance, 112 rock joint profile datasets having eight common statistical parameters (R_ave, R_max, SD_h, i_ave, SD_i, Z₂, R_p, and SF) and one output variable (JRC) are utilized, of which 89 and 23 datasets are used for training and validation of models, respectively. The interpretability of the developed XGBoost model is presented in terms of feature importance ranking, partial dependence plots (PDPs), feature interaction, and local interpretable model-agnostic explanations (LIME) techniques. Analyses of results show that machine learning models demonstrate higher accuracy and precision for estimating JRC values compared with the benchmark empirical equations, indicating the generalization ability of the data-driven models in better estimation accuracy.     

A modification of the Trent Index for use in Denmark

A new pollution index based on macroinvertebrates has been devised which can be used as a surveillance system in Danish streams. The index is inspired by the Trent Index although it was necessary to incorporate two new principles. First, the pollution indicators Asellus aquaticus and Chironomus sp. are used as negative taxa, with a negative influence on the index value, thereby strongly enhancing the utility of the keygroups. Secondly, the taxonomic groups used in the Trent Index have been replaced by establishing positive and negative index groups, where the number of negative index groups is subtracted from the number of positive. Thus, the utility of the basic principle, increasing pollution effecting decreasing numbers of taxonomic groups, is enhanced.     

Behavior of alkylphenol polyethoxylate metabolites during soil aquifer treatment

The attenuation of alkylphenol polyethoxylates (APEOs) metabolites was studied at a soil aquifer treatment (SAT) site located in Arizona, USA. Two parcels of water were monitored during infiltration; one parcel was predominantly oxic while the other was predominantly anoxic. In this study, only alkylphenol ethoxycarboxylates (APECs) and carboxyalkylphenol ethoxycarboxylates (CAPECs) were detected, no short-chained APEOs were observed-even under anoxic conditions. APEO metabolites were rapidly (<7 days) removed under both aerobic and anoxic conditions. In general, the length of the ethoxycarboxylate chain decreases with depth--at depths greater than 3m, only alkylphenoxy acetic acids (AP1ECs), carboxyalkylphenoxy acetic acids (CAP1ECs), and alkylphenols (APs) remain. Under aerobic conditions, octylphenol and nonylphenol concentrations decreased by approximately 80% (w/w) within 3m of the ground surface. Under anoxic conditions however, alkylphenol concentrations increased by approximately 200% during the first 1.5m and then decreased during the next 1.5m; overall, under anoxic conditions, alkylphenol concentrations increased by approximately 38% within 3m. During infiltration, APEC and CAPEC concentrations decrease by more than 95% within 3m of SAT. Alternate flooding and drying cycles appear to enhance overall APEO metabolite removal efficiencies.     

Prediction of flyrock distance induced by mine blasting using a novel Harris Hawks optimization-based multi-layer perceptron neural network

In mining or construction projects, for exploitation of hard rock with high strength properties, blasting is frequently applied to breaking or moving them using high explosive energy. However, use of explosives may lead to the flyrock phenomenon. Flyrock can damage structures or nearby equipment in the surrounding areas and inflict harm to humans, especially workers in the working sites. Thus, prediction of flyrock is of high importance. In this investigation, examination and estimation/forecast of flyrock distance induced by blasting through the application of five artificial intelligent algorithms were carried out. One hundred and fifty-two blasting events in three open-pit granite mines in Johor, Malaysia, were monitored to collect field data. The collected data include blasting parameters and rock mass properties. Site-specific weathering index (WI), geological strength index (GSI) and rock quality designation (RQD) are rock mass properties. Multi-layer perceptron (MLP), random forest (RF), support vector machine (SVM), and hybrid models including Harris Hawks optimization-based MLP (known as HHO-MLP) and whale optimization algorithm-based MLP (known as WOA-MLP) were developed. The performance of various models was assessed through various performance indices, including a10-index, coefficient of determination (R²), root mean squared error (RMSE), mean absolute percentage error (MAPE), variance accounted for (VAF), and root squared error (RSE). The a10-index values for MLP, RF, SVM, HHO-MLP and WOA-MLP are 0.953, 0.933, 0.937, 0.991 and 0.972, respectively. R² of HHO-MLP is 0.998, which achieved the best performance among all five machine learning (ML) models.     

Novel electrokinetic approach reduces membrane fouling

An innovative submerged membrane electro-bioreactor (SMEBR) was built to reduce membrane fouling through a combination of various electrokinetic processes. The objective of this research was to assess the capability of SMEBR to reduce fouling under different process conditions. At the bench scale level, using synthetic wastewater, membrane fouling of the SMEBR was compared to the fouling of a membrane bioreactor (MBR) in five runs. Different protein concentrations in the influent synthetic wastewater were selected to develop different membrane fouling potentials: high (240 mg/l), low (80 mg/l) and zero protein addition. The MBR and SMEBR were operated at a flux equal to the membrane critical flux in order to create high fouling rate conditions. Membrane fouling rate, expressed as the change in the trans-membrane pressure per day (kPa/d), decreased in the SMEBR 5.8 times (standard deviation (SD) = 2.4) for high protein wastewater, 5.1 times (SD = 2.4) for low protein content, and 1.3 times (SD = 0.7) for zero protein, when compared to the MBR. The supernatant concentrations of the soluble microbial products (SMP) were 195–210, 65–135 and less than 65 mg/l in respective experimental series. Following the bench scale study, membrane fouling was assessed in a pilot scale SMEBR, fed with raw un-clarified municipal wastewater, and operated under real-sewage variable quality conditions. The pilot SMEBR exhibited three times smaller membrane fouling rate than the MBR. It was concluded that electrokinetic processes generated by SMEBR led to a reduction of membrane fouling through: i) removal of soluble microbial products (mainly protein and polysaccharides) and colloidal organic materials; ii) change of the structure and morphology of the suspended solids due their conditioning by DC field.     

Comparison of drinking water treatment process streams for optimal bacteriological water quality

Four pilot-scale treatment process streams (Stream 1 - Conventional treatment (coagulation/flocculation/dual media filtration); Stream 2 - Magnetic ion exchange (MIEX)/Conventional treatment; Stream 3 - MIEX/Conventional treatment/granular activated carbon (GAC) filtration; Stream 4 - Microfiltration/nanofiltration) were commissioned to compare their effectiveness in producing high quality potable water prior to disinfection. Despite receiving highly variable source water quality throughout the investigation, each stream consistently reduced colour and turbidity to below Australian Drinking Water Guideline levels, with the exception of Stream 1 which was difficult to manage due to the reactive nature of coagulation control. Of particular interest was the bacteriological quality of the treated waters where flow cytometry was shown to be the superior monitoring tool in comparison to the traditional heterotrophic plate count method. Based on removal of total and active bacteria, the treatment process streams were ranked in the order: Stream 4 (average log removal of 2.7) > Stream 2 (average log removal of 2.3) > Stream 3 (average log removal of 1.5) > Stream 1 (average log removal of 1.0). The lower removals in Stream 3 were attributed to bacteria detaching from the GAC filter. Bacterial community analysis revealed that the treatments affected the bacteria present, with the communities in streams incorporating conventional treatment clustering with each other, while the community composition of Stream 4 was very different to those of Streams 1, 2 and 3. MIEX treatment was shown to enhance removal of bacteria due to more efficient flocculation which was validated through the novel application of the photometric dispersion analyser.     

Facilitated transport of Cu with hydroxyapatite nanoparticles in saturated sand: effects of solution ionic strength and composition

Column experiments were conducted to investigate the facilitated transport of Cu in association with hydroxyapatite nanoparticles (nHAP) in water-saturated quartz sand at different solution concentrations of NaCl (0-100 mM) or CaCl₂ (0.1-1.0 mM). The experimental breakthrough curves and retention profiles of nHAP were well described using a mathematical model that accounted for two kinetic retention sites. The retention coefficients for both sites increased with the ionic strength (IS) of a particular salt. However, the amount of nHAP retention was more sensitive to increases in the concentration of divalent Ca²⁺ than monovalent Na⁺. The effluent concentration of Cu that was associated with nHAP decreased significantly from 2.62 to 0.17 mg L⁻¹ when NaCl increased from 0 to 100 mM, and from 1.58 to 0.16 mg L⁻¹ when CaCl₂ increased from 0.1 to 1.0 mM. These trends were due to enhanced retention of nHAP with changes in IS and ionic composition (IC) due to compression of the double layer thickness and reduction of the magnitude of the zeta potentials. Results indicate that the IS and IC had a strong influence on the co-transport behavior of contaminants with nHAP nanoparticles.