Moatassem Abdallah

Modeling Microtunneling Projects using Computer Simulation

Tunnels projects are constructed to facilitate the execution of underground works with minor disturbance on surface structures and traffic. This is deemed important especially in downtown cities where disturbances should be minimized to assure flowability on surface and underground infrastructures. Microtunneling involves the use of a remotely controlled, guided pipe-jacking process in order to support excavation face. Microtunneling aids in avoiding the need of open trench for pipe laying, which causes extreme disruption to the surrounding. This paper presents a tool for planning microtunnels projects using computer simulation. The proposed tool aids contractors in planning microtunneling by estimating their associated time and cost of construction. There are six models that are coded in the proposed tool in order to capture the construction of microtunnels and shafts. The tool breaks down microtunnels projects into microtunnels segments and shafts which constitute several construction zones. An application example is presented to demonstrate the features of the proposed tool.

Operational Performance of Sustainable Measures in Public Buildings

AbstractBuildings in the United States account for 40% of the national annual energy consumption, 39% of carbon footprint, and 13% of water consumption. To minimize these negative environmental impacts and improve life-cycle cost performance, an increasing number of public and private owners are requiring that their existing and new buildings incorporate more sustainable building measures. Despite the recent increase in the use of these sustainable building measures, there is a pressing need to explore their actual operational performance. This paper presents the findings of a recent study that evaluated the performance of sustainable measures in public buildings, such as rest areas, including energy efficient fluorescent and LED lights, solar photovoltaic systems and water heaters, daylight tubes, geothermal heat pumps, wind power technology, motion-activated lighting, double-pane glass, energy-efficient hand dryers, water-conserving fixtures, rain gardens, and graywater systems. The study conducted a co...

Multiobjective optimization model for maximizing sustainability of existing buildings

AbstractAging buildings in the United States represent 70% of existing buildings, and they are often in urgent need of upgrades to improve their operational, economic, and environmental performance. Recent studies reported the need for and significance of improving the sustainability of existing buildings to stabilize and reduce their greenhouse gas emissions and minimize their negative environmental impacts. This can be accomplished by integrating sustainable upgrade measures in existing buildings to improve their energy efficiency, water consumption, material recycling, waste reduction, lifecycle, and indoor environment. These upgrade measures include energy-efficient lighting and HVAC systems, renewable energy systems, water-saving plumbing fixtures, and sustainable management of building solid waste. Decision makers often need to identify an optimal set of these upgrade measures capable of maximizing the sustainability of their buildings while complying with limited upgrade budgets and building functi...

Automated Decision Support System for Optimizing the Selection of Green Building Measures

Buildings in the United States account for 72% of electricity consumption, 40% of energy consumption, 13% of water consumption, 39% of carbon footprint, and 30% of waste output. In order to minimize these negative environmental impacts, many public and private owners are requesting that their buildings be more sustainable and certified under the widely known programs such as leadership in energy and environmental design for existing buildings (LEED-EB). To accomplish this, buildings are increasingly integrating green building measures including energy efficient lighting, motion sensors, thermal pane glass, geothermal heat pumps, EnergyStar rated HVAC systems, photovoltaic systems, and wind turbines. This research paper presents the development of an automated decision support system (DSS) that is designed to optimize the selection of green building measures which can be used to upgrade existing buildings. The developed DSS incorporates two optimization models that are capable of (i) minimizing the total upgrade costs required to accomplish a specified LEED-EB certification level such as silver or gold; and (ii) maximizing the number of accredited LEED-EB points within a specified budget of upgrade costs. The DSS is designed to identify a set of optimal upgrade decisions that accomplishes these two optimization objectives. An application example is used to illustrate the capabilities of the DSS and to validate its result.

Minimizing upgrade cost to achieve LEED certification for existing buildings

AbstractAging buildings represent a significant percentage of existing buildings and are often in urgent need of upgrading to improve their operational, economic, and environmental performance. The owners of these buildings often seek to identify and implement building upgrade measures that are capable of improving building sustainability as well as achieving certification under various green building rating systems such as the Leadership in Energy and Environmental Design (LEED). In order to support decision-makers in promoting building sustainability and achieving LEED certification for existing building, this paper presents the development of a novel optimization model that is capable of minimizing the required upgrade cost of achieving a desired LEED certification level such as Silver or Gold. The model is designed to identify cost-effective building measures, plans, and/or performance to achieve a specified LEED certification for existing buildings while keeping required upgrade cost to a minimum. Th...

Sensing Occupant Comfort Using Wearable Technologies

Thermal comfort of building occupants is a major criterion in evaluating the performance of building systems. It is also a dominant factor in designing and optimizing building’s operation. However, existing thermal comfort models, such as Finger’s model currently adopted by ASHRAE Standard 55, rely on factors that require bulky and expensive equipment to measure. This paper attempts to take a radically different approach towards measuring the thermal comfort of building occupants by leveraging the ever-increasing capacity and capability of mobile and wearable devices. Today’s commercially-off-the-shelf (COST) wearable devices can unobtrusively capture a number of important parameters that may be used to measure thermal comfort of building occupants, including ambient air temperature, relative humidity, skin temperature, perspiration rate, and heart rate. This research evaluates such opportunities by fusing traditional environmental sensing data streams with newly available wearable sensing information. Furthermore, it identifies challenges for using existing wearable devices and to developing new models to predict human thermal comfort. Findings from this exploratory study identify the inaccuracy of sensors in cellphones and wearable as a challenge, yet one which can be improved using customized wearables. The study also suggests there exists a high potential for developing new models to predict human thermal sensation using artificial neural networks and additional factors that can be individually, unobtrusively and dynamically measured using wearables.

ANALYZING TAX CREDITS FOR RESIDENTIAL ENERGY EFFICIENCY USING ENERGY MODELING

ABSTRACT From roughly 2013 to 2016, ten building product categories related to residential energy efficiency were eligible for United States ENERGY STAR Federal Tax Credits. In general, the objecti...

Initial Assessment of a Newly Launched Interdisciplinary Construction Engineering Management Graduate Program

AbstractIn the fall of 2014, the University of Colorado Denver (CU Denver) launched a new interdisciplinary graduate program in the Department of Civil Engineering. The mission of the Construction ...

Implementing a Collaboration Activity in Construction Engineering Education

Collaboration skills are increasingly necessary in today’s construction workforce. However, classroom activities that incorporate collaboration skills, ones involving interactive work among individuals towards a common goal, are underrepresented in many construction classes. This research documents and illuminates implementation of a team activity where groups of interdisciplinary students were asked to build a structure using the provided (paper and tape) resources with the objectives to create a structure that stands at least 4″ tall and supports as much weight (under textbook loading) as possible. Two rounds of activities were performed with differing levels of role definition provided to the students. Team interactions and performance were recorded, along with student self-assessments, and reporter observation. The implementation of this collaboration activity continues to provide valuable lessons, which informs the integration and assessment of collaboration activities in construction education.

Economic and GHG Emission Analysis of Implementing Sustainable Measures in Existing Public Buildings

AbstractBuildings in the United States are responsible for 72% of the nation’s electricity consumption, 39% of energy consumption, 39% of carbon dioxide emissions, and 13% of potable water consumption. These significant energy and water consumptions and their carbon emissions contribute to global warming, ozone depletion, and air pollution. To reduce these negative impacts of buildings and improve their economic performance, there is an increasing demand for integrating sustainable measures in public buildings such as energy-efficient lighting; motion sensors for interior lighting; motion sensors for lighting of vending machines; motion sensors for exhaust fans; solar daylight tubes; energy-efficient HVAC systems; thermal-pane glass; vestibule entrances; energy-efficient hand dryers; solar photovoltaic systems; and water-saving toilets and urinals. Despite the recent increase in the availability of these sustainable building measures and technologies, there is a pressing need to analyze the economic and g...