Journal of Construction Engineering and Management

Federally mandated backup alarms and safety management have been unable to eliminate fatalities and injuries due to maneuvering trucks and mobile equipment on construction sites. Workers appear to ignore the alarms as part of the general noise level. When reversing, drivers and equipment operators tend to depend on the alarm's effectiveness to clear areas in which drivers have limited visibility. Using human factors analysis, the problem was recognized as one of decremented vigilance, a person's natural inability to sustain attention without positive feedback. This paper presents experimental data on the use of a simulated, discriminating, personal alarm activated by a short range, directional transmitter to encourage safe behavior. During the experiment there was a significant increase in response time, as expected, for the conventional backup alarm and a decrease in response time for the discriminating personal alarm. The proposed backup alarm system has the potential to eliminate on-site vehicle/equipment accidents.

The knowledge-based expert system for construction planning is part of an automated building realization process. The system uses an object-oriented representation of the building and production rules, routines, and functions to manipulate objects and to generate the construction plan. The building is represented by its zones, functional systems, and works. The procedural knowledge employs rules for the generation of activities and their dependences. The algorithms are employed to allocate resources and to generate the construction schedule. The algorithms reflect the different objectives of managerial decision making, such as least cost, managerial efficiency, or fastest completion. This paper presents the principles of the system, explains the structure of its knowledge base, and discusses various implementation aspects. It also includes an example of the application.

The build-operate-transfer (BOT) concept is being used increasingly by governments across a number of infrastructural sectors in their drive to privatize major public projects. Governments see BOT schemes as a method of financing the construction of urgently needed infrastructure projects without direct sovereign guarantee of the loans and with all the technical and financial risks being borne by the private promoter. This paper is concerned with the issues of risks to be retained by the promoter and the guarantees to be offered to the government in the selection process of a BOT tender. It is critical for the promoter to understand that the ability to retain risks and offer guarantees does provide the competitive advantage in being awarded the concession.

This paper provides information on radio-frequency identification (RFID) and its potential applications in the construction industry. RFID involves the use of miniature read/write transponders that are capable of storing data in harsh environments. These transponders can be used in situations where optical scanning is not practical because vision is blocked or because labels fall off or become unreadable due to dust, dirt, or other contaminants. The technology is currently used in several applications outside the construction industry (e.g., reading meters, preventing theft of store merchandise, tracking railroad cars and intermodal freight containers, collecting tolls, and performing agricultural and animal research), and is seen as having potential in the construction industry. Potential construction applications for RFID technology discussed here include concrete processing and handling, cost coding for labor and equipment, and materials control. Conceptual design systems for these applications are also considered and developed. Discussion of limitations of RFID technology for construction applications include proximity of equipment, nearby metallic objects, costs, and workforce attitudes. Conclusions are drawn regarding possible future impacts on construction industry.

Midcareer reflections based on work combining computers and construction leave an appreciation for the rapid progress that has taken place in both fields in recent decades. Computers have brought many benefits in helping the industry to meet increasingly complex challenges, but as automation becomes pervasive, greater attention must be focused on the social and economic impacts on construction people. Construction education and research have also become much more computer-oriented, but it may be time to take stock of evolving curriculums and more systematically consider what should be done to meet future industry needs. In general, construction has a strong cadre of young researchers who have become well-grounded in advanced computer technologies and are in a position to continue bringing its benefits to construction practice in the future, but they must stay attuned to the needs of industry.

This paper focuses on how arbitrators perceive the effects of poor project documentation on the arbitration process, and what advice arbitrators would give construction professionals to help them properly record project information before a dispute arises. The study is based on a survey questionnaire collected from seven different U.S. cities. The arbitrators were asked to compare the veracity of written documentation with oral presentation to highlight how a document, prepared in the ordinary course of building a project, would weigh in the arbitrator's consideration. The arbitrators were asked to give examples of problems they most often encountered with respect to documentation, and whether they had ever been involved in a dispute in which one party failed to provide documentary evidence that in their opinion could have altered the outcome of the case. The overall results of this study support the notion that the party keeping the most comprehensive and detailed records will have the decided advantage in any dispute-resolution proceeding.

The Occupational Safety and Health Administration (OSHA) has had the long-standing mandate to promulgate standards and to enforce them. Another mandate is for OSHA to collect injury and illness information. While vast amounts of information have been collected over the past two decades, only isolated studies have been conducted to evaluate that information. An independent study was conducted on selected injury data pertinent to the construction industry. This analysis focused on those areas in which the greatest numbers of violations have been recorded and those in which the greatest number of fatalities have occurred. This examination of the data revealed some interesting trends. Some of the findings confirmed the work of other research efforts and others appear to be unique to this study. The injury data can be useful to identify key areas that warrant special attention. Falls continue to be the major cause of fatalities. Safety efforts must be focused on fall protection if dramatic improvements in safety performance are to be made. Through the examination of the existing data it was concluded that the injury data is not consistently coded and this leads to less meaningful information.

This paper presents a design optimization method for all-wood concrete-slab forms. This procedure was formulated to provide for a safe slab-form design with minimum cost. It considers in its design process the cost of each slab-form component (sheathing, joist, stringer, and wood shore) and all available combinations of slab-form components. The performance of the optimum design method is compared to that of the traditional design method, which uses design charts/tables. The optimum design method was found to have a potential cost savings over the traditional design method. A study was conducted to confirm these cost savings. The results of the study show that cost savings as high as 9.9% were achieved by using the design optimization method.

Construction operations involve complex resource interactions and are typically performed in the field with exogenous factors such as inclement weather conditions and equipment breakdowns. The complexity of resource interactions combined with external factors creates a transient environment for construction operations. This research uses computer simulation techniques and a graphical method, DISCO (Dynamic Interface for Simulation of Construction Operations), for the evaluation of the transient effects of construction operations. DISCO uses the CYCLONE schematic model diagram of a process as the modeling framework and allows breaks or interruptions in the simulation run and stopping of the simulation time clock to investigate the transient states of resources and tasks in a process. The scope of the study focuses mainly on the transient effects caused by the process mobilization of construction operations every day. Two construction operations are used as case studies for the investigation. Results of the study and observations are discussed.

A method is proposed to evaluate the risk of cost growth in competitively procured construction projects. It uses computer records of past bid data and an inferential statistical technique to simultaneously assign projects into two risk categories. One category is based on the observed disagreement between the winning bid and the other submitted bids. The other is based upon the observed bias in the bidding pattern of the winning bidder. Results verify differences in cost growth for both risk categories. Projects awarded to the most extreme bids are seven times more likely to experience excessive cost growth than a project awarded to a more reasonable bid. Similarly, projects awarded to extreme bidders have average cost growths 3.5–4 times higher than if awarded to more reasonable bidders. This risk-assessment method would prove useful in the bid-evaluation procedures of public agencies. It appears from these results that agencies that make bargains based upon competitive procurement, often do not receive the bargain that had been anticipated.

The evaluation of competitive bids is a difficult process with little objective guidance provided to those who make the decisions to accept or reject bids. A quantitative evaluation method is proposed to utilize a collective assessment of project value, a measure of disagreement, and an expected recurrence relationship in order to identify unreasonably low bids. The unreasonable bids could then be subject to verification, investigation, or rejection based upon the agency's preference. In doing this careful evaluation of bids, public agencies may accomplish most, if not all, of the objectives currently sought by the alternative procurement procedures while remaining consistent with the low-bid philosophy.

An acceptance-sampling method plays an important role in designing quality-assurance (QA) specifications. It applies statistics to specify the requirements of (1) how many measurements are needed; and (2) how to make an acceptance or rejection decision based on measured data. The key function of the acceptance-sampling method is to guide the decision between accepting or rejecting the quality of the products. The purpose of this paper is to present four acceptance-sampling methods, including (1) variable–single-sampling method; (2) quality-index–sampling method; (3) attribute–double-sampling method; and (4) attribute–proportion-sampling method. In this paper, the theories will be derived and the applications of the four developed quality-acceptance–sampling methods will be described. The advantages and disadvantages of using different sampling methods are compared. The application of the developed quality-acceptance-sampling methods is illustrated using bridge-painting examples.