ABSTRACT. Assessing pavement condition is essential in any efforts to reduce future economic losses and improve the pavement performance. The resulting data are used as a record to evaluate pavement performance and assess their functionality and reliability. Traditional pavement condition assessment approaches rely on expert visual inspection and observational information along with testing using specialized equipment. However, these approaches are challenging because of the cost associated with assessment, safety issues, and the accessibility restrictions, especially after natural hazard events. This paper aims to develop an automated classification model to rapidly assess pavement condition by classifying pavement distresses using image classification that is based on Convolutional Neural Network (CNN) model. High-resolution aerial images representing alligator and longitudinal cracks for flexible pavements are collected using Unmanned Aerial Vehicle (UAV) images. The results of the developed model indicate an accuracy of 96.7% in classifying the two categories of pavement distress, while the use of UAV provides flexibility and manoeuvrability to capture the necessary data without risking personal safety and provides operational benefits in relatively lesser time. The methodology behind the developed model will help to reduce the need for on-site presence, increase safety, and assist emergency response managers in deciding the safest route to take after hurricane events. Additionally, application of the model will enable pavement engineers in rapidly assessing the pavement damage, aid in making quick decisions for road rehabilitation and recovery and devise a restoration or repair plan..

ABSTRACT. Musaimeer outfall tunnel is the longest outfall tunnel in the Middle East. The tunnel was excavated by Earth Pressure balance (EPB)Tunnel Boring Machine (TBM) and encountered three distinct rock masses namely Rus formation, Midra-Shale, and Simsima Limestone along with water inflows at high pressure, complex mixed ground, and weaker ground strata prone to cavities with the presence of vertical and lateral fractures connected to the seabed. These conditions resulted in the TBM operating in very dry conditions where the addition of soil conditioners and water sprayed in the excavations chamber and cutterhead were required to avoid clogging situations and create a pasty excavation material which impacted TBM operation. The opposite scenario occurred when the TBM encountered very wet conditions while passing through weathered Simsima Limestone fully connected hydrostatically with the seabed. Such situations directly impacted on the productions rates, quantities of consumables, extra cost on the tunnel enabling activities and finally, the need of both atmospheric and hyperbaric interventions into the cutterhead up to 3.5 bar to replace cutting tools. Long tunnels with only one access shaft pose many programme problems for logistics, combine these with the requirement to drive directly out under the seabed for 10.2 km, and the programme issues become even more challenging. To meet and eventually improve on the planned completion date required a complex and extensive management of all tunnel logistics activities required to support consistent tunnelling for a two-year period. This technical paper will discuss the management issues and solutions implemented to meet the challenges of the outfall tunnel construction.

ABSTRACT. The city of Doha has grown and expanded rapidly in the last 20 years, but this growth has strained the city’s infrastructure, including its aging sewerage system and treatment facilities. The Public Works Authority (Ashghal) has therefore launched several strategic schemes which involve shallow and deep sewer tunnels and a new sewage treatment works (STW) to serve Doha’s growing population in the years to come. One of such schemes is the C853/1 Wakrah-Wukair Drainage Network Branches (WWDNB) which includes more than 15km of bored pipes between 400mm and 2.4m inner pipline diameter, with more than 60 shafts ranging in depths from 10m to 47m. The geology in the Wukair area is made up of several distinct strata typically ranging in material strength between 10 and 48MPa, and it is the range of strengths which decides the method of shaft excavation. This paper will provide a production comparison between two types of excavation methods adopted for the same depth shafts and geological conditions. In the first method, the Contractor adopted the more traditional method using an excavator with appropriate attachments to break the ground, where this progressed in a cyclical manner until the shaft base was reached. The second method incorporated a piling rig to drill a specific pattern of holes within the shaft envelope, which enabled a faster excavation cycle and allowed for time and cost savings as well as improved safety. This paper will assess both methods, why both were utilised, and the lessons learned.

ABSTRACT. Micro-tunnelling Shaft Excavation (MTSE) is a major part in the development of infrastructure networks in Public Works Authority (ASHGHAL) projects in the State of Qatar. Despite the importance of this activity there has been minimal improvement to the existing methodology. Traditional methods are producing large amount of operational waste such as extra manhours, over-excavation and excess of backfilling materials used. Using collaborative pull planning, a system involving key stakeholders and last planners have been developed to streamline the micro-tunnelling activity. Using a panoply of lean tools, data collection and analysis, MTSE was monitored and evaluated through the Plan, DO, Check and Act (PDCA) cycle that led to around 60% of time saving. The paper summarises the process improvement using collaborative pull planning and applying PDCA with project stakeholders’ engagement.

ABSTRACT. This paper addresses the potential for design standardization of bridge construction moulds as a means to minimize waste and cost. Specifically, the paper looks at the potential for standardizing the design of bridge Glass Reinforced Polymer (GRP) shutter moulds that typically vary in size and design based on project-specific requirements. Environmental and economic sustainability aspects are addressed using a two-tiered approach. Views of construction experts were solicited, and production-to-demolition and disposing costs of a sample of completed projects estimated. There appears to be a consensus that there are significant benefits from standardizing the design of the modes including material waste reduction, cost savings, shorter procurement processes and possibly the reuse of shutter moulds. Given the size of the construction sector and its contribution to material and energy consumption and harmful emissions, and non-hazardous waste, the potential savings are significant.

ABSTRACT. In contrast to traditional piecemeal onsite construction, offsite construction comprises the planning, designing, production, transporting, and assembly of building elements for speedy site assembly to a higher degree of completion. Offsite building utilises a wide range of materials, scales, and systems, as well as modern manufacturing and fabrication techniques and computer software. Offsite construction is utilised to create componentised, panelised, and modular elements that support structural, enclosure, service, and interior partition systems. Integrating these systems with the supply chain through research, design, testing, and prototyping is an off-site optimisation technique. Due of economic, health and safety, and environmental factors, major UK contractors have adopted offsite construction over the past decade. Large projects are requiring major contractors like Mace, Laing O' Rourke, and Balfour Beatty to invest in off-site manufacturing. Offsite construction is defined in detail in this paper, along with how it can help construction projects succeed economically and environmentally. The impact of offsite construction was examined in this research using a narrative review of the existing literature, and the findings demonstrate that there are numerous advantages both economically and environmentally. Offsite construction is more environmentally friendly because it requires less energy and large machinery uses on site. Since it is simpler to anticipate the amount of material required and buy in bulk, the organisation may reduce waste and the number of vehicles required to transport the finished product to the site. Cost savings always result from transferring site processes to a production workshop setting. The cost of labour in mechanical and electrical installation is one of the highest costs in construction industry, therefore, as prefabricated solutions have been fully or partially completed before they arrive on-site, labour can be reduced with offsite construction.

ABSTRACT. The world is becoming increasingly interconnected, and the exchange of information, knowledge, and services assists in developing and managing many aspects of the built environment. Sustainable, resilient, and interdependent development of infrastructure emphasizes relationships among systems with benefits of creating one system of systems that includes enhancing the delivery of primary services, increasing systems efficiency in performing more than one function, exchanging benefits between systems, sharing information among systems, reducing carbon emission, eliminating waste, enhancing the operation of all systems, and reducing the cost of developing, managing, operating, and maintaining them. Infrastructure development in the Gulf region presents many challenges, such as excessive use of scarce natural resources, limited areas of development, and high cost of development, operation, and maintenance in each system. This study addresses the importance of developing a sustainable, resilient, and interdependent infrastructure system that can work with the natural processes and flows and respond to challenges specific to the Gulf Region. Its findings will guide decision-makers in the appropriate choices and the economic, environmental, and social opportunities in developing an integrated and efficient one-system network. The relationship between the infrastructure systems, such as simple, colocation, or geographical relationship, and an integrated relationship in the Gulf region will be compared with other relevant international projects. Data from project-specific literature and case studies were used to carry out the study.

ABSTRACT. The current practice of Architecture, Engineering, and Construction (AEC) management systems is relying on manual and time-consuming methods for data collection, analysing, and decision-making. That affects the productivity of the industry in all phases, design, construction, operation, and maintenance of their assets. The adoption of technologies is the key solution for the AEC industry to overcome the challenges that facing and follow other reinvented industries. Although recent advancements have been proposed for more productive data acquisition and decision support by leveraging digital tools, Building Information Modelling (BIM), Internet of Things (IoT) and Artificial intelligence (AI), the fragmented approach of adoption and the lack of a connected workflow is a barrier towards gain it benefits in buildings and infrastructures. Digital Twin (DT) is a digital presentation of a physical entity that replicates the status and behaviour of its physical counterpart. It can help to improve overall systems effectiveness and reliable data-informed decisions. However, the concept of DT and its key features is still not well-understood in the AEC industry. Therefore, this paper aimed to review and investigate the twining requirements and characteristics of DT and discuss its structure and potential solutions in terms of AEC infrastructure and buildings assets operations and maintenance systems. The DT concept, main characteristics, and critical considerations for the AEC sector were highlighted and classification for DT levels was introduced and discussed.

ABSTRACT. Mathematical optimization refers to the process of finding the values of variables that maximize or minimize a function. Structural optimization is the process of designing a structure in such a way as to minimize its weight or cost, while meeting a set of performance requirements, ensuring that it is robust, lightweight, and efficient. Two large categories of optimization algorithms are mathematical and metaheuristic algorithms. The ones of the first rely on mathematical principles, are deterministic and exact but may fail if the problem is too large or complex. The latter category, metaheuristics, represents algorithms that are used to find approximate solutions. They are high-level strategies that guide the search toward a good solution, rather than being a specific, deterministic algorithm. They are often used for problems where it is difficult or impractical to find the optimal solution using exact methods. Metaheuristics typically involve iteratively improving a solution through some type of search or exploration process. They make use of techniques from probability and statistics, such as randomization and stochastic optimization, to explore the search space and guide the search toward good solutions. Some examples include genetic algorithms, simulated annealing, differential evolution (DE), particle swarm optimization (PSO), and ant colony optimization. In this study, a mathematical optimizer and two metaheuristics (DE, PSO), are employed for the optimum structural design of plane truss structures aiming to minimize the weight of the structure under constraints on allowable displacements and stresses. A 10-bar plane truss is considered as the numerical example of the study. The constraints are checked by performing an analysis with matrix methods. All calculations are done on a spreadsheet. The results of the algorithms are compared to each other as well as to results from the literature in terms of convergence speed, number of function evaluations, and accuracy of the solution.

ABSTRACT. The city of Doha has grown and expanded rapidly in the last 20 years, but this growth has strained the country’s infrastructure, including its aging sewerage system and treatment facilities. ASHGHAL has therefore launched several schemes which involve shallow and deep sewer tunnels and new treatment works to serve Doha’s growing population in the years to come. Wakrah and Wukair Drainage Tunnel (WWDT) project scope includes 13.3 km long of bored and lined tunnel using 2 no’s 5.85m Diameter EPB TBMs, 8 Shafts, adits with provisions for future connections, ancillary hydraulic structures and Odour Control Facility. Based on WWDT project restrictions the Contractor were required to launch a 148m long Tunnel Boring Machine (TBM) inside a 15m Diameter shaft at a depth of 59.4m. This paper describes how the WWDT project contractor overcame these constraints and successfully launched both TBM’s. The TBM launch and commissioning were a contract milestone. The methodology used, involved partially mining a stub adit/logistics tunnels using a sequential excavated mining method (SEM) to accommodate several TBM sections at the bottom of the shaft at the same time several of the TBM gantries were operational on the surface umbilically connected to the cutterhead. This paper will also provide a brief overview of 2 types of TBM launches used recently in Qatar for comparison.

ABSTRACT. Given the inherent nature of how deep cast in situ concrete foundations (piles and diaphragm walls) are constructed, evaluating their integrity is difficult. Several well-established methods for testing integrity have been established, but each has its own advantages and disadvantages. In recent years, a new integrity test method called thermal integrity profiling (TIP) has been put into use in deep foundation construction. The primary characteristic utilised in this test is the early-age concrete release of heat during curing; abnormalities such as voids, necking, bulging, and/or soil intrusion inside the concrete body lead to local temperature fluctuations. During concrete curing, temperature sensors installed on the reinforcing cage collect precise temperature data along the entire pile, allowing empirical identification of these temperature variations. This paper proposes a staged data interpretation framework for pile integrity assessment, with the thermal integrity test serving as the initial step. The framework, which is adaptable to different concrete mixtures and pile designs, utilises the heat of hydration and the theory of heat transmission, as well as numerical modelling with the Finite Element (FE) method. It also adopts a staged procedure to assess the as-built quality; for a particular pile, more details are revealed about any anomalies being investigated (including location, size and shape) at each subsequent stage. The primary advantage of this staged process is that it enables practitioners to follow a risk-based approach and decide whether or not to pursue sub-sequent stages of construction depending on the results they get at the end of each stage. This provides practicing engineers with vital information about the quality of the pile immediately after pile building, so permitting immediate and less expensive repair and remedial work if required.

ABSTRACT. The outfall tunnel, which forms part of the Musaimer Pump Station and Outfall project (MPSO), is a 10.2 km long subsea tunnel that extends from the south coast of Doha, starting onshore, and continues under the Arabian Gulf to end in a connection with a diffuser field via riser shaft. The excavation of the outfall tunnel using a Tunnel Boring Machine (TBM) with a 4.42 m diameter and 180 m long backup, starts from a 40 m deep shaft and has an inclination of 0.05% upward to the riser shaft. The tunnel is constructed by precast concrete elements of 3.7 m internal diameter passing through different geological formations typical in the State of Qatar. Although planning a TBM tunnel involves a significant amount of engineering knowledge and experience, what is equally challenging is the enabling works which are required to be designed and constructed before the TBM even arrives at the site. On this project, these works which were substantial within themselves commenced 16 months before the TBM arrived on site. This paper will discuss the planning and execution of these outstanding underground enabling works, the logistic shaft required to facilitate the assembly and launch of the TBM at the initial stage of tunnelling and also how to arrange the sequence and space in terms of TBM logistics supply requirements to allow simultaneous construction of key permanent structures, namely the drop shaft structure which resulted in 6 months saving on the overall completion on this section of the works.

ABSTRACT. The objective of this work is to use some machine learning algorithms and test its efficiency in developing models to predict Locked Wheel Skid Trailer (LWST) values from Dynamic Friction Tester (DFT) and Circular Texture Meter (CTM) measurements conducted on asphalt pavement surfaces. For this prediction, Three models was developed using DFT measurements at different speeds starting from 20km/h (12.5 mph) up to 64 km/h (40 mph) and then same DFT measurements as combination with Mean Profile Depth (MPD) and the last model used the International Friction Index (IFI) parameters (F60 and SP). The Machine learning techniques includes two supervised learning algorithm; the Multi-Layer Perceptron (MLP) type of Artificial Neural Networks (ANN) and M5P tree model. In addition to one lazy algorithm called the K nearest neighbor (KNN) or Instance based learner (IBL). The result showed that MLP models are the best in term of correlation coefficient that resulted in 81% prediction power using DFT parameters. Additionally, it was shown that the result of tree models was close to ANN but with much simpler regression. However, KNN models were recommended for LWST prediction of similar data characteristics and it is expected that this algorithm will be more efficient as the training data set become larger.

ABSTRACT. Rock and soil erosion materials are transported under the effect of wind, tides, or human actions (development works), and deposited as sediments in ports, estuaries, and rivers. The sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. As a result, dredging is necessary to reduce sediment deposits and restore the natural environment for proper port functioning. At the national level, the maintenance of the 6500-kilometer French coastline would require the extraction of about fifty million m3 of marine sediment every year. These sediments have been used in civil engineering applications for about ten years, in order to reduce their economic and environmental impact. The proposed study addresses the potential use of sediments to produce accropode blocks for maritime public works applications. It consists in developing concrete mixtures using dredged marine sediments treated to protect against erosion. A study of material characterization, optimization of the composition of the concrete formulation, as well as a determination of the mechanical, physical and durability properties of the concrete were necessary to validate the technical feasibility of this new solution. Around 700 small accropode blocks were then prepared to better analyze the structure stability against swell effects. The obtained results show that the sediments could not produce Self Compacting Concrete (SCC). However, sediment treatment with 6% by weight of cement has enabled the production of SCC. It is worth noting that the use of superplasticizer was essential to ensure concrete workability. Increasing the cement percentage has also improved the composite workability. Finally, a concrete compressive strength larger than 40 MPa has been achieved when using 300 kg/m3 of treated sediments.

ABSTRACT. This paper describes the outcomes of a preliminary study focused on the evaluation of four full-scale pavement sections in which reclaimed asphalt (RAP) was used in partial substitution of virgin aggregates during the production of asphalt mixes. Considered mixes were produced with different RAP percentages and were thereafter laid on site for the formation of asphalt base course layers of pavements in local roads of the State of Qatar. For comparative purposes, two trials included asphalt mixes containing no RAP, and in one case use was made of a rejuvenating agent. Activities carried out for the monitoring of field trials included analysis of component materials, critical observation of production and laying operations, assessment of the most relevant characteristics of produced asphalt mixes, and evaluation of the degree of compaction achieved during construction. Experimental results were of crucial importance for the introduction of RAP-related paving technologies in the State of Qatar, providing a meaningful background to the preparation of the “Ashghal Recycling Manual” issued by Ashghal and of the draft updated version of Qatar Construction Specifications.

ABSTRACT. The main objective of this paper is to develop predictive models using Beta regression for laboratory-prepared hot mix asphalt (HMA) specimens’ thermal properties, including thermal conductivity (TC), thermal diffusivity (TD) and specific heat (SH). Thirty such specimens were prepared while varying the mixture’s nominal maximum aggregate sizes (NMAS) and gradation coarseness. The widely used Transient Plane Source (TPS) method was employed to determine the thermal properties of the asphalt concrete. Only one type of asphalt binder was used for preparing all specimens. The air void volume (Va) and the effective binder volume (Vbe) were calculated for each mixture. To this end, the multiple linear regression and the nonlinear Beta regression were employed. Laboratory work resulted in hundred and fifty (150) data points. Three nominal maximum aggregate sizes, two gradation coarseness levels, five replicates and five different locations of measurements to ensure accuracy and repeatability in the obtained results. In conclusion, using Va and Vbe as predictors provided reliable predictive models for the thermal properties of different asphalt mixtures. The distribution of Va and Vbe was identified, and synthetic data were created to evaluate the accuracy of the models. Apart from R2 values, Beta regression was more reliable to predict thermal properties of asphalt mixtures than multiple linear regression.

ABSTRACT. Sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. In France, the maintenance of the 6500-kilometer coastline would require the extraction of about 50 million m3 of marine sediments every year. For several years, these sediments were considered waste. However, they are increasingly being acknowledged as a resource in need of management. Several research studies were conducted to find valorisation ways that satisfy technical and regulatory requirements. These sediments present interesting heterogeneous physicochemical, mineralogical, and geotechnical characteristics. However, they may contain contamination, which could limit their uses. The paper deals with the possibility of producing self-compacting backfills using dredged marine sediments, fly-ash, and hydraulic binders for public work applications. The impact of dredged sediments on the composition of self-compacting backfills was studied. Moreover, the impact of fly ash and binder type and percentage on the backfill behaviour and mechanical properties was discussed.

ABSTRACT. This paper briefly illustrates the structure and contents of an ongoing research program aimed at developing a set of procedures and tools to be used for the design of pavements in renewable energy projects and mainly in wind and solar farms. Challenges related to this topic derive from the non-standard nature of several factors that affect the structural and functional performance of such pavements, with the consequent need of employing purposely defined prediction methods, design criteria and specifications. Further crucial aspects to be taken in account in the research program are related to the life cycle cost analysis of pavements, to be carried out in a multinational context by considering alternative scenarios according to an OPEX (operating expense) versus CAPEX (capital expenditure) philosophy. It is envisioned that results and deliverables of the project will contribute to the enhancement of the effectiveness of operations in wind and solar farms, optimizing investments and leading to the selection of more sustainable pavement solutions.

ABSTRACT. Water recharge wells can provide a solution for 3.5 billion people, living in regions suffering from water scarcity. Due to fines migration, freshwater wells that are used to recharge aquifers, often experience expedited deterioration. Colloidal clay fine particles can be mobilized from within aquifers due to hydrodynamic forces or the sweeping of gas-water interface (GWI). The released colloids concentration increases then starts to retain and clog at the pores within the aquifer formation. Although fines migration is responsible for decommissioning many recharge wells, yet there is a lack of pore scale observations that uncover clogging mechanisms within porous media. Thus, this study utilizes wide-field optical macroscopy and microfluidic models with pore morphology of sandstone, to investigate the clogging mechanisms of hydrophobic colloids. The aim is to discover how interfacial surfaces within porous media retain colloids. Hence imbibition and drainage of colloidal suspension were carried to vary water saturation. Flow experiments were imaged at a resolution of 1µm/pixel, while colloids diameter was 5 µm. Images were segmented into solid, water, gas and colloids. Then the amount of colloids retained on each interface was quantified. Findings revealed that hydrophobic colloids retained mainly on the GWI. For colloids suspension in deionized water, affinity of colloids to GWI was high enough to cause bubble stabilization. In both hydrophobic and hydrophilic porous media, colloids disconnected the gas phase to create larger GWI surface. More than 90% of hydrophobic colloids were cleaned from the media after drainage, uncovering an efficient remediation technique for water aquifer.

ABSTRACT. The purpose of the Musaimeer Pump Station and Outfall (MPSO) project is to receive storm water runoff and groundwater flows from the Abu Hamour Tunnel and to provide a pumping station, a 10 km marine outfall tunnel and a diffuser field to dispose of the flows into the sea. The project site is located immediately south of the land that was reclaimed for the newly constructed Hamad International Airport (HIA) at the eastern terminus of the Abu Hamour Tunnel which forms a link to allow discharge of storm flows collected in the southern and western parts of the Doha over a total catchment area of approximately 190 km2. Hydraulic Design for MPSO (Musaimeer pumping station and outfall) was implemented for dry weather flow of 1.9m3/sec and wet weather flow of 19.7m3/sec. The system was designed with increased operational redundancy including 2 screen channels, bar screens and grab rakes, each channel being able to handle the maximum design flow, 2 wet wells with grit removal and oil and grease removal system, 10 submersible pumps (9 duty+1 standby), outfall chamber, drop shaft, 10 km marine outfall tunnel and diffuser field comprising of 6 HDPE pipe branches and 84 non return diffuser ports-duckbill valves. Hydraulic Design calculations were cross verified by CFD modelling, physical modelling in 1:9 scale and surge analysis results concluding on final hydraulic design conclusions and recommendations. Hydraulic Design parameters presented in this paper were verified during operation and maintenance period of the project and will be demonstrated herewith.

ABSTRACT. The purpose of the Musaimeer Pump Station and Outfall (MPSO) project is to receive storm water runoff and groundwater flows from the Abu Hamour Tunnel and to provide a pumping station, a marine outfall tunnel and a diffuser field to dispose of the flows into the sea. Musaimeer outfall tunnel is one of the longest storm water tunnels in the world with a total length of 10.2 km. The tunnel is connected via a drop shaft to the main pump station. This system will accommodate surface and storm water received from the drainage networks of 190 km2 of urban areas in southern Doha. The outfall tunnel comprised precast segmental lining with internal diameter of 3700 mm sloped at 0.05% upward to the riser shaft. The riser shaft, which is located at the end of the outfall tunnel, is connected to a diffuser field positioned on the Arabian Gulf seabed. This paper will focus on the design considerations and recommendations related Marine outfall riser shaft, distribution manifolds and diffuser field. to The MPSO marine outfall was designed in two phases, first comprising installation of riser shaft, primary and secondary manifolds, 3 lines of HDPE piping with variable internal diameter, 84 diffuser duckbill valves, 84 diffuser protection boxes and scour protection. The diffuser is laid in an area of 280mX40m 15m beneath the sea water level. Second phase of marine outfall design included the meticulous connection works between GRP riser shaft and 10.2km TBM tunnel 15m beneath the seabed. Design considerations and final conclusions of such marine design works will be presented.

ABSTRACT. Tremendous amounts of oily wastewater are produced daily from industrial processes, including petrochemical, textile, leather, and steel processing. This wastewater is a huge challenge to the environment and industry uses multiple approaches to separate the water from oil including oil-absorbing materials, gravity separation, flocculation, and coagulation. However, these concepts are ineffective in separating oily water emulsions where the oil droplets are smaller than 20 µm in size and do not perform well upon incorporating chemicals or using an electric field. Membrane filtration is one of the best strategies to handle such emulsions, especially the surfactant-stabilized ones, as they yield highly pure water permeate via simple filtration process and they can be cleaned re-used for multiple times at large-industrial scales. This presentation will give an overview of novel polystyrene-based copolymer membranes developed and tested at Qatar University in collaboration with the University of Southern Mississippi. The newly developed membranes display substantial enhancement in separating oil from water in tight emulsions while demonstrating remarkably high resistance to fouling over five runs in comparison to the commercial membranes that get fouled within only two emulsion runs. The presentation will outline the membranes’ oil rejection efficiency, chemical, morphological, and mechanical stability after cycles of cleaning and reuse. Finally, the membranes were tested using synthetic oily water and real-field samples and testing protocols from the oil & gas companies in Qatar.

ABSTRACT. Musaimeer Pump Station and Outfall project (MPSO) is a strategically important drainage asset initiated, developed, and completed by Ashghal in 2022. This project accommodates ground and storm water received from the drainage networks of 270 km2 of urban areas in southern Doha, along with storm protection for four soccer stadiums used during the FIFA 2022 world cup. The key elements of this project were a pump station with a capacity of 19.7 m³ / s, one of the longest ground and storm water tunnels in the world with a total length of 10.2 km and the diffuser bed structure measuring 194 m x 40 m. The diffuser bed structure is connected to the outfall tunnel by a riser shaft and is the structure used to disperse the ground and storm water in a controlled manner and in accordance with environmental standards. This technical paper will detail the entire process from dredging and material stockpiling, riser shaft drilling and construction, diffuser bed fabrication onshore, transportation to final location, installation on the sea floor, backfilling and protection works and finally commissioning of the entire project.

ABSTRACT. The evaluation of hydrogeological conditions and groundwater inflows, as part of the geotechnical risk assessment, poses one of the key challenges during the design and construction of major infrastructure projects and underground works. This paper presents an example of a recently developed geotechnical and hydrogeological investigation program for the Pre-Tender design of the South of Wakrah Pumping Station and Outfall project in Qatar, where a comprehensive hydrogeological study was carried out to characterize heterogeneous hydrogeological conditions along the project area and to determine potential impacts on the groundwater levels drawdown and groundwater inflows during excavation and dewatering activities. The results of the hydrogeological evaluation concluded that a proper groundwater management approach and mitigation measures are required at an early stage of the project to minimize the impact on dewatering, groundwater inflows and groundwater levels drawdown for construction works. A similar approach can be adopted for future infrastructure projects to support the geotechnical risk assessment and to minimize the impact of construction activities on the environment.

ABSTRACT. Green Buildings (GBs) are becoming increasingly popular as an alternative way of building development. Like any other construction project, GB projects are subject to project management-related criteria, including cost, quality, and schedule performance. In addition to these criteria, GBs also include sustainability performance criteria. As a GB is being developed, some criteria are prioritized over others. To understand GB project development, it is necessary to understand the priorities given to different performance criteria and the factors which result in such priorities. Using an online survey of 46 GB professionals across Australia and some Asian countries, it is found that project management criteria are typically ranked higher in GB projects compared to sustainability performance criteria. The survey has also revealed that these priorities of performance criteria are driven by the choice of owner/developer, obligations from state development authorities, developer’s market position, investor requirements, etc. The survey has also informed that performance criteria priorities in GBs are also associated with regional factors such as climate, availability of natural resources, regulations, and culture. The findings of this study will support the theoretical development in the field of GB project management.

ABSTRACT. One of Ashghal values, the occupational health and safety of our customers, employees and contractors is our top priority. Ashghal prioritizes and is concerned about developing worker welfare on the site and in the camp. Ashghal develops welfare specifications for the projects to protect workers and be sure the specifications align with international and national requirements. The specification covers the facilities within the site, such as: number of toilets, handwashing basins, rest area/mess hall, shelter, drinking water, first aid room, transportation, clinic, etc. Ashghal develops an implementation and monitoring system to be sure welfare specifications are provided to all workers, referring to welfare specifications as contractual requirements, then linking worker welfare as one of the monthly KPIs for the project, implementing it by the contractor, and monitoring it by the consultant. Ashghal is also working on developing specifications and requirements for worker welfare, for example, developing and updating the specifications and requirements for worker welfare on Ashghal construction sites, which will be issued soon as the "ACS."

ABSTRACT. Existing research reveals that by adopting leading technologies in the construction industry, worker's safety could be maximized. Presently, the application of technologies to promote safety in the construction sector is limited. The data for accident cases on the construction sites are very limited. Many tools and techniques have been created to increase worker safety on construction sites by designing and implementing good safety plans. A bibliometric and scientometric approach was used to identify the most prominent technologies in construction safety management. The data was retrieved from WoS database, and the analysis of the study is based on using VOS viewer to visualize the domain-specific knowledge. This study helps in the identification of emerging digital technologies such as Building Information Modelling (BIM), IT applications, Augmented Reality (AR) and Virtual Reality (VR), its application, and barriers in adoption during safety management. This study also highlights critical factors that promote technology adoption in construction safety management. This research also traces the current trends, future directions and supports crucial knowledge on safety technology to construction researchers and practitioners.

ABSTRACT. The elements of the storm water network are made to safely drain most water during a heavy rainstorm. Flood risk modelling (mathematical modelling) with hydraulic software is a good way to check the network's level of service, especially now that technology has changed. Flood risk modelling is an essential method for checking the network sufficiency and adequacy for different kinds of rain. Modelling flood risk should be done for the whole network to ensure that flows are connected and get accurate results. In this study, one-dimensional flood risk modelling is needed for a sub-network that is part of Qatar's full stormwater network. The flood risk modelling is conducted using InfoWorks ICM software. Running the whole model takes a lot of computational data processing. Splitting the entire stormwater network to the concerned sub-network without considering the hydraulic effects of upstream and downstream flows at the boundary conditions of the sub-network will lead to erroneous conclusions. In this research, a new method for hydraulically dividing the network into sub-networks is presented, taking into account the characteristics of the boundaries. This method increases the efficiency and viability of hydraulic modelling for sub-networks in big networks. For purposes of validation, the results of the reduced model in terms of flood depths and volumes are compared with those of the full model. The results of the split model are in good agreement with the entire model

ABSTRACT. Multiple official documents from various departments have contributed to rising the number of printed pages in construction projects. The dominant explanation for this trend is that printed pages have a direct relationship with the progression of the project as the number of quality assurance, quality control documents, health and safety documents, technical documents, lean and enhancement documents, and store documents get increased with the project timeline. The research data was obtained from one of the infrastructure projects in the north of Qatar between 2020 and 2023 and in line with multiple academic references as listed in the last section of the paper. (Ågren, 2014). Contrary to what has often been assumed, the rise in printed pages due to mentioned documents contributes to impacting the earth’s environment badly, affecting global warming, cutting additional trees from green lands, reducing project KPIs, increasing overall project budget cost, and generating material waste. Lean enhancement engineers proposed replacing all the above-mentioned documents to be used in the digital format

ABSTRACT. This paper aimed to survey participants of the construction industry at Khartoum State, Sudan, to gauge their perceptions towards the main challenges that face the proper administration of construction contracts. Results are expected to provide reasonable understanding for the root causes, the risk factors involved and may help anticipate the types of problems that are likely to occur so that the project participants can develop plans to avoid these problems or minimize their potential negative consequences. Based on observations and communications with peers and after reviewing a number of contractual problems highlighted in the literature, a list of issues that can occur and threaten the contract administration and ultimately the success of the project was compiled. A questionnaire was then designed in two main sections. To determine which problems were reported to be most common across all participants, the frequencies of occurrence of each of the practices and challenges listed problems were compiled from the respondents’ feedback. RII were computed for each problem in each of the three categories of participants. Then the overall RII for each problem was determined. The Spearman’s Coefficient was also calculated to check the variability in the participants’ views regarding problems that affect their contracts administration activities. The results confirmed that the participants have different considerations for what concern them regarding issues hindering proper contract administration. Contractors consider “choice of unsuitable contractor” as the main challenge while consultants believe that “drafting a contract using ambiguous language and ill-defined terms” is a real threat and consequently rated the “imprecise definition of parties’ contractual obligations” as a challenge. With knowledge of the potential problems, any of the project participants can use this information to develop a risk mitigation plan by selecting the best option for the procurement process to achieve the overall goal of successful project completion.