Gabriel B. Dadi

Cognitive Workload Demands Using 2D and 3D Spatial Engineering Information Formats

AbstractConstruction project performance is significantly reliant on the effective communication of the project’s design to the end construction worker. Spatial design is frequently represented in two-dimensional (2D) drawings of various views. These views must be combined and decoded by the end user to effectively understand all orientations of a building element and can lead to errors. Advances in three-dimensional computer-aided design (3D CAD) and 3D printing have provided promising advancements in the presentation of spatial engineering information. This research investigates cognitive-workload demands of each information format. Cognitive workload is the amount of mental resources required to complete a task from the total available mental resources. Asking subjects to complete a reconstructing task of a simple structure using 2D drawings, a 3D CAD interface, and a 3D printed model introduces the individuals to alternative forms of information presentation. After completing the task, the subjects we...

Establishing the Influence of Owner Practices on Construction Safety in an Operational Excellence Model

AbstractOften, construction contractors usually consider safety as the sole responsibility of the contractor. Under this prevailing assumption, owners are often excluded and exempted from construct...

A Case Study of 3D Imaging Productivity Needs to Support Infrastructure Construction

The national infrastructure system is at a crossroads with a need for renewal and expansion in the most efficient manner possible. Light railway construction requires the installation of embedments in reinforced concrete pavement along the length of elevated sections of the railway system. Conventionally, wooden dowels are manually placed into the reinforcing steel mat before concrete placement to form the slot for the embedments; however this is labor intensive and can yield inconsistent spacing. An alternative method is digitally mapping the locations of the reinforcing steel-free space prior to concrete placement to identify where holes could be drilled without hitting the steel reinforcement. The challenge is avoiding impacting production. Using field-based data, this study identifies the number of hours to create the map without impacting production for a typical railway section. Discrete event simulation (DES) modeling is utilized to conduct the analysis. To substitute the alternative method, scanning a typical railway section falls within the capabilities of most laser scanning technologies; however, the processing of images to create a useable model controls. This research demonstrates a case study of applying DES to analyze productivity impacts on a repetitive process and investigates the capabilities of 3D imaging technologies for effective field use. PROJECT BACKGROUND Traditionally, the resources required to support a construction crew included manual labor, equipment, and materials. Over time as information systems and sensing agents have advanced in their capabilities and durability, advantages are becoming more apparent in providing greater information and automation to crews as well. If the realm of construction resources is to be expanded to include information, then the pertinent restraints to providing the necessary information when required has to be planned as is the case with labor, equipment, and materials. The following case

Improving Concrete Trade Labor Productivity through the Use of Innovations

Concrete activities are typically critical to a project’s schedule, therefore examining how to improve their labor productivity can have a direct impact on a project’s overall performance. As part of a research program to improve construction productivity sponsored by the Construction Industry Institute (CII), the authors investigated innovations in the concrete trades and their impact on labor productivity. The innovations studied were 100ksi steel reinforcement, self-consolidating concrete (SCC), and modular formwork. The 100ksi reinforcing steel study analyzed a typical beam cross-section and compared its total weight to that of a typical 60ksi reinforcing design. Often, high strength reinforcing steel is a lower cost alternative to a standard design due to lower amounts of steel. The SCC study collected quantities and unit rates of SCC and a comparable conventional mix at several projects. The projects using SCC had faster placement unit rates compared to conventional concrete mixes. Modular formwork was found to have significant advantages in productivity over stick-built formwork systems. From the analysis of a sample project, modular formwork gains a cost advantage at varying floors based on local labor rates. The findings should help management understand performance of these concrete innovations when considering their use.

Towards an Automated Asphalt Paving Construction Inspection Operation

Collecting load tickets is an example of an antiquated practice that puts inspectors in harm’s way either adjacent to traffic, in close proximity to moving or backing equipment, or at times requires climbing onto trucks to reach tickets. Technology exists to collect this information electronically allowing for safer, efficient inspection methods. Departments of Transportation are charged with inspecting an increasing work load with a diminishing number of inspection staff. Recently, doing more with less has led to the prioritization of inspection activities and resulted in less collection of data and visual inspection on projects. Technology advancements are available to improve data collection and provide for more efficient inspection. Using GPS and GIS technology tied into electronic scale report-out systems, a fleet tracking system traces haul routes, reports travel time and tonnage, and even assists contractors with equipment matching and balancing. Data from this system coupled with other technologies remote monitoring of temperature, intelligent compaction, and network enabled cameras provide an opportunity to enhance inspection and increase construction inspection productivity all the while enriching detail of project records. Challenges to the system include connectivity, interoperability, and usability. The contribution of this paper is to provide a framework in which to combine these commercially available technologies into a multi-faceted, enhanced inspection approach.

Developing a Pre-Task Safety Briefing Tool for Kentucky Maintenance Personnel

The dangerous work environment in the construction industry and the inherent high risks associated with its work make it the focus of safety training and regulations. Highway construction and maintenance has unique hazards but seemingly less directly applicable safety standards, regulations, and programs. Department of Transportation (DOT) employees working in highway maintenance are exposed to a variety of unique hazards specifically associated with their work and not relating to the adjacent traffic. Highway site safety does not receive sufficient attention in terms of safety research and programs. As part of the efforts of the Kentucky Transportation Cabinet (KYTC) to improve safety for their employees, this paper describes the data-driven design of a pre-task safety briefing tool. By analyzing previous incident data of KYTC maintenance workers and identifying frequent hazards present within their typical work operations and the reasons behind such hazards, the final product of this study is a tool that is relatable and relevant to KYTC maintenance workers. The tool presents these hazards along with the associated reasons and the appropriate safety practices to avoid or mitigate the associated risk. The data analysis of this study highlighted that human factors and ergonomics play a significant role in the injuries related to the subject population, yet there is little guidance or standards for addressing these factors. The goal of this safety tool is to improve the safety performance of KYTC maintenance crews by increasing workers’ safety awareness.

Estimating Earthwork Volumes Through Use of Unmanned Aerial Systems

Unmanned aerial systems (UASs) and unmanned aerial vehicles (UAVs) have become increasingly attractive for numerous surveying applications in civil engineering, agriculture, and many other fields. The unmanned systems and vehicles are capable of performing photogrammetric data acquisition with equipped digital cameras that allows for converting images to highly precise, georeferenced three-dimensional models. However, more studies are needed to demonstrate practical applications of UAS systems and UAVs on construction sites. In this project, UAS systems and UAVs and digital photogrammetry technology are introduced to estimate the earthwork volume of a highway extension project. The georeferenced images were processed by the photogrammetry software, Pix4Dmapper, which is a tool for converting images into an accurate and applicable three-dimensional point cloud model. Progress models were created over the course of several weeks. The volume of earth was computed by comparing the point cloud of the progress models after model processing. To ensure reliability, the accuracy of the UAS and UAV photogrammetry was verified by comparison with conventional ground survey methods and the results from different flights. The project presents the feasibility and effectiveness of using UAS systems and UAVs in estimating earthwork volumes on the basis of the results of an accuracy test and the efficiency of the survey.

Modeling Long-Term Highway Staffing Requirements for State Transportation Agencies

State transportation agencies (STAs) across the country face many challenges in repairing and enhancing highway infrastructure to meet rapidly increasing transportation needs. One of these challenges is maintaining an adequate and efficient agency staff. To effectively plan for future staffing levels, STAs need a method for forecasting long-term staffing requirements. However, the methods currently in use cannot function without well-defined projects; therefore, making long-term forecasts is difficult. This paper seeks to develop a dynamic model that captures the feedback mechanisms within the system that determines highway staffing requirements. The system dynamics modeling method was used to build the forecasting model. The formal model was based on dynamic hypotheses derived from a literature review and interviews with transportation experts. Qualitative and quantitative data from literature and federal and state databases were used to support the values and equations in the model. The model integrates STAs’ strategic plans, funding situations, and staffing strategies and determines future staffing levels and will hopefully fill the absence of long-term forecasting tools at STAs. Standard system dynamics validation procedures were used to test the model, after which input data specific to the Kentucky Transportation Cabinet were used to calibrate the model and to simulate an expected retirement wave and search for solutions to address temporary staffing shortages.

Uses of Mobile Information Technology Devices in the Field for Design, Construction, and Asset Management

This report documents the state-of-the-practice and state-of-the-art applications of state transportation agencies related to their use of mobile information technology (IT) devices in the field for the areas of design, construction, and asset management. Mobile IT devices such as laptop computers, mini-laptop computers, handheld multifunctional data collectors, tablets, and smartphones play a critical role in bringing the transportation industry into digital platforms. The synthesis was developed through a literature review and surveys to gather information from end users and IT professionals at state transportation agencies. The findings highlight processes for identifying, selecting, and evaluating mobile IT uses; potential field uses; procedures for application development, integration, and optimization; potential benefits; challenges and issues; strategies for successful implementation; strategies for managing the data collected; and advances and emerging technologies.

Analyzing the Use and Policies for Mobile Information Technology Devices within State Departments of Transportation

The use of mobile Information technology devices on construction projects is becoming more powerful and increasingly accessible and efficient. The traditional methods for field data collection and communication, such as written record and photograph, carry a higher possibility of making mistakes and longer task completion times. Recently conducted surveys and interviews of staff at state transportation agencies (STAs) in the areas of design, construction, and asset management reflect the current and potential use of hand-held mobile IT devices is on the rise. Based on the investigation results, around 90% of STAs benefit from the application of mobile IT devices in daily contact, accessing standards and manuals, and record entry. STAs believed overall return on investment of mobile IT devices could be around 50%, although about 50% believe they are low implementers of the technologies. While, for most, implementation is in early stages and requires more investment, mobile IT devices are being adapted to overcome shortcomings of traditional on-site communication methods. This means that applications have broad prospects and potential in construction management. The primary contribution to the body of knowledge is to gain an understanding of current practices and present opportunities for STAs to advance methods and improve efficiencies in their use of mobile IT devices nationwide.