The importance of integrating construction knowledge into the design process has long been recognized by the construction industry. This paper studies early contractor involvement in design and its impact on construction schedule performance through a combined empirical case study and theoretical simulation analysis. Pipe and steel fabricators’ inputs at different design stages of industrial construction projects are identified. The case study shows that these inputs lead to improved drawing quality, material supply, information flow, and consequently improved construction schedule performance. This impact on construction schedule is illustrated using actual project data and simulation techniques. Simulation models were developed to demonstrate intuitively the impact at the construction operation level and they allow people to gain management insights through simulation experiments. Better understanding of the early contractor involvement process and its benefit can improve buy-in and help industry practitioners to reach the full potential of this concept.

Labor productivity is a fundamental piece of information for estimating and scheduling a construction project. The current practice of labor productivity estimation relies primarily on either published productivity data or an individual’s experience. There is a lack of a systematic approach to measuring and estimating labor productivity. Although historical project data hold important predictive productivity information, the lack of a consistent productivity measurement system and the low quality of historical data may prevent a meaningful analysis of labor productivity. In response to these problems, this paper presents an approach to measuring productivity, collecting historical data, and developing productivity models using historical data. This methodology is applied to model steel drafting and fabrication productivities. First, a consistent labor productivity measurement system was defined for steel drafting and shop fabrication activities. Second, a data acquisition system was developed to collect l...

Compaction quality is critical to the stability and durability of earth-rock dams. The traditional quality inspection method relies primarily on testing randomly sampled spots of a job site, which may cause unreliable representation of the compaction quality of the entire work and lead to delays not only in performing the construction work but also in identifying and rectifying quality issues. In this paper, a quality-inspection process is developed that monitors compaction operations of earth-rock dam construction in real time and establishes a multiple regression model to predict compaction quality by using independent variable data obtained from the real-time quality-monitoring system. These independent variables include compaction operation parameters (i.e., compaction passes, roller velocity, vibration status, and pavement thickness) and earth-rock aggregate’s moisture content and gradation. Furthermore, by using the kriging interpolation procedure, the compactness at any point of a work area...

Traditionally, project planning in industrial shops, such as in a steel fabrication shop, has employed the experience of production engineers as its primary source in decision making. A scientific technique for analyzing a variety of short-term planning problems encountered during daily operations would therefore be of great benefit. This paper proposes the use of experimental methods to support engineers in analyzing daily production performance and making informed decisions through the implementation of a virtual production environment. In this study, a virtual shop model using a number of modeling techniques captures the intricacies of a dynamic shop environment. Specifically, the research presents solutions in modeling product uniqueness and labor productivity that are unique issues in modeling the steel fabrication process. A prototype model developed for an Edmonton-based steel fabricator is used to illustrate the development of the system and its application in project planning.

The velocity pulse contained in near-fault ground motions have a tremendous impact on dam safety. Previous studies have mainly focused on the response of dams under near-fault seismic records without considering the obliquely incident seismic waves. In this study, the structure–soil interaction (SSI) is taken into consideration, and the nonlinear behavior of a conventional concrete roller-compacted concrete (CC-RCC) gravity dam under near-fault pulse records and non-pulse records is investigated with consideration of the obliquely incident P waves. On the basis of the dam site conditions, three groups of near-fault pulse records are chosen, and three corresponding non-pulse records are fitted by their acceleration response spectra. Combining with the viscous-spring artificial boundary, the wave input method is proposed to transform the near-fault seismic records into the equivalent nodal forces at the boundary of the foundation. The concrete damaged plasticity model is used for the nonlinear analysis. The results show that the pulse ground motions are more destructive than the non-pulse motions. The nonlinear behavior of the dam varies with the incidence angle of P waves and generally reaches a maximum at 60° and 75°, the worst damage occurs at the interface between different materials of the dam, and the spatial variation of its damage is very obvious under near-fault seismic records with various incidence angles. Therefore, the effect of the angle of obliquely incident seismic waves and near-fault pulse effect should be considered comprehensively in the seismic analysis of dams.

In industrial construction, each fabricated material item such as a steel piece or a pipe spool is a unique building element. They are typically staged in a large laydown yard before final on-site installation. Manually tracking and locating each particular item in a large laydown yard can be very time consuming, and excessive man hours spent in this process can negatively impact on field installation activity and overall project performance. This study developed a robust and accurate yet cost effective material tracking and locating solution based on mature tracking technologies. The proposed solution features a handheld computer equipped with barcoding and GPS technologies for laydown yard material tracking and fast retrieval in a cost effective manner. The device scans item barcodes when the item is unloaded in the yard and, meanwhile, captures the GPS coordinates along with the item image, and stores these data in a central database. For material retrieval, material lookup through the database provides geographical location and images of an item, and navigation function gets the crew to the item in a shorter duration. To validate the accuracy of GPS and practicality of this solution, various handheld computing devices with built-in GPS functions were tested by comparing their GPS recordings against the true coordinates of selected geological survey benchmarks. The accuracy is measured by the distance between the true coordinates to the device-recorded coordinates using Vincenty's formula. A prototype system consisting of a mobile device and a software module was developed, and the achieved GPS accuracy is within 3 meters. While the proposed solution has the potential to significantly improve material tracking efficiency, its low initial and operating costs and robust performance make it practical to use in a wide range of projects.