Journal of Construction Engineering and Management

This paper describes the development of a prototype system for planning access routes for large vehicles within an industrial construction site. Access planning is an important consideration in the development of an effective project-execution plan. But conventional planning tools do not facilitate effective planning. The primary objectives of this work are to define a structured process for planning access and to automate the tedious and difficult tasks within the process. Concepts from the areas of information representation, geometric reasoning, and artificial intelligence are found to be applicable for automating route-planning tasks. The implementation of these concepts to develop the route-planning system is achieved by using the expert system Nexpert Object and the geographic information system Arc/Info in conjunction with the computer-aided design (CAD) package Microstation, the spreadsheet Excel, and custom programs.

The Ameria Tunnel Pumping Station (ATPS) is the main pumping station of the Greater Cairo Wastewater Project. The objective of ATPS is to lift the wastewater for a vertical distance of 32.0 m (from the collection tunnel at approximate mean sea level (MSL) of −14.0 m, to box culverts at ground level, +18.0 m MSL) to continue the flow under gravity to the final treatment plant. The ATPS contains eight huge centrifugal pumps, each with a lifting capacity of 3,600 L/s. It is considered one of the highly technological civil engineering works in Egypt, probably the largest installation of its kind in the world. This paper outlines the construction method used to carry out various work elements of such a large civil engineering project. The problems encountered during construction (mainly due to the soil structure and characteristics), and the solutions innovated for these problems are also presented. A call is made for extensive soil investigation to minimize uncertainty and problems during future underground constructions.

Factors that can be fairly easily identified and modified and can lead to significant improvements in production rates for activities in construction are considered in this paper. These factors are divided into four work categories. Two of the four work categories in which each construction activity was subdivided were idle and waiting times. Productivity measurements generally do not distinguish between the idle and waiting times. Conclusions can therefore be misleading, and more importantly, the attention of management is only vaguely and imprecisely directed to the cause of the inefficiencies. The breakdown of nonproductive time into two factors is therefore very important in directing the attention of management to the root causes of inefficient time. The variation in production rates used by contractors' estimators are given and compared with actual on-site production rates. The frequency of different sources of information used by contractors when estimating production rates, and the percentage use of production monitoring methods, are also given. A prototype expert system, using the Personal Consultant Plus shell program of 1987, was developed to assist in the acquisition and management of knowledge and data for the estimation of production rates.

This paper offers an economic comparison between two construction methods, lightweight and conventional. The first aspects to be compared are the initial and life-cycle ( LC ) costs. Due to the infrequency of lightweight construction in Israel before the beginning of this decade, and the consequent uncertainty regarding its cost-related data, the lightweight method was examined in three different ways. It is shown that costs are relatively similar for the two methods. The influence of the duration of construction is investigated next. The shorter time requirement of the lightweight method enables the construction industry to provide more housing solutions at a faster rate; this paper presents a simplified, yet sufficiently accurate, assessment of this quantitative advantage, which comprises three elements: the benefit accruing from early exploitation of the facility, saving in time-dependent site overhead expenses, and the capital cost of a faster cash outflow. It is shown that, subject to various assumptions, the net benefit of the shorter construction period is 3%–9% of its initial cost, or 2%–6% of the LC cost. The influence of the lower man-hour input is also investigated against the background of the 30,000–40,000 labor shortage forecast for this decade in Israel. It is shown that the advantage of the lightweight method versus the conventional one increases with wage escalation. The influence of the lower man-hour input on the industry's output potential, and the ability to compensate for labor shortage are also discussed.

The Construction Industry Institute in Australia, modeled on the U.S. group of the same title, published a “Constructability Principles File” in November 1992. These principles include precepts used in conducting a postconstruction analysis by a project team drawn from the staff of Prince-Bisley Pty. Ltd., Toowoomba, Queensland, Australia, and the University of Southern Queensland. There may be a danger in conducting such an evaluation if participants wrongly believe that managers will seek to apportion blame for disappointing outcomes. A protocol was therefore established and is presented in this paper; the protocol clearly sets out guidelines and states that the aim is not to seek scapegoats but to improve company performance. Case-study material is presented for a feed mill project, that was designed and fabricated in Australia for erection in China, which ran over budget and was late in shipment. Feedback from participants in the review is summarized, together with recommendations for action by management to improve the organization's performance on similar future projects. Experience has shown that postconstruction evaluation is a valuable exercise.

One of the reasons for the development of nonunion construction was to allow management the flexibility of designing jobs without the constraints of jurisdictional and collective-bargaining agreements. The job-characteristics model was developed to identify differences in jobs and the motivational potential of a job. This paper reports the results of studies of a large sample of unionized construction workers and of a large sample of nonunion construction workers. Six hypotheses were formulated based on expected differences between union and nonunion environments and tested. In terms of the job-characteristics model, there is no difference in the perceptions of union and nonunion construction workers for task variety, task significance, and feedback. Union workers perceive greater task identity, while nonunion workers perceive greater autonomy. The implications of these findings are discussed and recommendations made for improving the motivational potential of jobs. The results of the study indicate that there is considerable opportunity for redesigning jobs in the construction industry.

This paper outlines the key elements of defective specification disputes. The framework for resolving defective specification disputes is based on an in-depth examination of more than 100 appellate court decisions. The decision process is based on the following questions: What caused the failure? Which party had control over the feature that led to the failure? These two questions define whether the specifications are of the method or performance type. Thereafter, the following questions apply: Did the contractor follow the specifications? Could the work have been successfully performed by any method? Did the contractor warrant the outcome? A flowchart detailing the important questions is provided to guide a step-by-step procedure for determining issues of entitlement. The questions and hierarchial order of the flowchart generally reflect the manner in which courts resolve similar disputes. The paper concludes with an example that illustrates how an administrator can resolve a dispute using the flowchart.

Most employers regard workers' compensation insurance (WCI) as an outrageously expensive, but necessary cost of doing business. One of the objectives of WCI, to provide incentives for employers to improve safety performance, has been lost in the complex method used to calculate WCI premiums. Few employers and few insurance agents understand the process. This paper explains how WCI Standard Premiums are calculated using manual rates, payroll, and an experience modification rating. Manual rates help predict loss rates for different work classifications, payroll gives an indication of risk exposure, and an experience modification rating compares an individual employer's actual loss experience to its expected record. This paper shows that employers with WCI are really self-insuring for most losses and ultimately pay for their own injuries. The paper shows how several small losses cost far more than one severe loss, how employers who try to save money by reporting incorrect work classifications may end up paying more, and why using the experience modification rating to compare the safety performance of different employers is not valid. Employers who understand how their WCI premiums are calculated will have far more incentive to improve safety, and will be better prepared to negotiate savings when purchasing WCI.

For many years the construction industry in China has been controlled by the government and used to support China's centrally planned economy. Most construction projects have been financed by the government, designed by state-owned design institutes, and built by state-owned construction companies. This bureaucratic system, combined with the poor project-management skills of the enterprises, has resulted in low-quality work, cost overruns, and the late completion of projects. Since 1979, China has been reforming the country's economy. Construction industry reforms were announced at the Chinese Party Congress Convention in October 1992. These reforms are designed to improve efficiency in the state-owned construction enterprise, to establish a construction market, and to make the Chinese construction firms more competitive with international firms. This paper presents a discussion of the Chinese reform agenda for the overall Chinese economy, and for the Chinese construction industry specifically. It also describes the reform agenda of the Chinese construction industry for the rest of the 1990s, and questions if the Chinese government will be able to meet those goals.

Due to many uncontrollable and often unpredictable factors such as ground-water inflow rate, equipment availability and cost, weather, and various geological details, drilled shaft construction can become highly complex. At present, decisions on how best to install drilled shafts are made by foundation subcontractors, who have most often become experts in construction in local conditions. Unfortunately, the assistance of these field experts is not always easily obtained. Thus, a decision support system called “DS^2” has been developed to assist in the construction of drilled shafts. If used correctly, DS^2 can reduce construction costs by providing a large quantity of expert advice that would otherwise be both difficult and very expensive to obtain. DS^2 is composed of three prototype expert systems that interface with spreadsheet, database, and graphics packages. DS^2 uses a heuristic, rule-based, backward-chaining system to analyze geological information, suggest a construction method, prepare a preliminary cost estimate, and suggest key specification items.

Many construction safety issues are closely connected to environmental problems. The consolidation of safety and environmental regulation at federal and state levels, either partially or totally, would provide the construction industry with a single agency that would provide uniform and accurate guidance, avoid unnecessary duplication of guidance and information, and virtually eliminate conflicts that are currently caused by multiagency oversight. In addition to benefits to the industry, there are also significant cost savings that could be attained by the various levels of government involved in monitoring the construction industry by combining their various safety and environmental regulatory functions. Combining certain Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) functions would increase efficiency and provide a good model for the contemporary movement to reinvent government. The resulting consistency of regulation would decrease conflicting guidance from agencies that are regulating similar issues and, at the same time, increase the quality of worker safety and environmental protection. In addition to the regulation of hazardous materials by both agencies, there are significant additional opportunities for consolidating operations and regulation of the construction industry.

The concept of a global economy is changing the traditional perceptions of national borders. As national borders become more flexible, competition for construction projects will continue in increase. In addition, dwindling resources have caused governments to evaluate many nontraditional approaches to generate the needed revenue and expertise to undertake public construction projects. The construction industry, faced with the continuing move toward a global marketplace, must examine the possible competitive advantages offered by forming international alliances. Alliances will play an important role in determining the future growth of many companies. It is imperative to begin planning now for something we consider inevitable. The writers were the primary participants in a Construction Industry Institute sponsored research project to study the impact of forming alliances as a way to enhance the competitiveness of U.S. construction firms. Using data collected from interviews with 30 international construction industry executives during that study, this paper discusses why alliances are formed and the benefits that can be gained from them.

Contract incentives have traditionally been used as a means of aligning the goals of the contracting agency with those of the contractor. One area in which contract incentives are used is highway construction and refurbishing. The use of incentives and disincentives (I/Ds) for project completion time has helped highway agencies in various states to reduce construction time significantly. However, I/D provisions increase costs to the contracting agency, and should therefore be used sparingly. For these types of contracts to succeed, it is necessary for the contracting agency to be extremely careful in the development, documentation, and execution of I/D clauses. In this research, the current use of I/D contracts in many states and the experience of several contractors were examined. Then, a general set of guidelines was developed for the use of I/D provisions in highway construction or refurbishing contracts. The guidelines aid in determining which projects should contain the I/D provisions and how to structure the I/D provisions to achieve maximum success.

This paper reviews the important issues related to determining if substantial completion of a construction project has been reached. This milestone is important because it means that the contractor is entitled to the release of retainage, less deductions for uncompleted work. Because the owner has the right to occupy and use the facility, there can be no breach of contract beyond this point in time because of late completion. Liquidated damages cannot be assessed beyond substantial completion. Equipment warranties also take effect. Four questions are addressed: Was the purpose of the project defeated? Did the owner benefit from using the project? How extensive are the defects? And, how easy are the defects to correct? Of these questions, the principle one is whether the purpose of the project was defeated. If no, or if the owner benefitted from the work, substantial completion has likely been achieved. Several examples are given.

A neural network (NN) based approach is proposed for predicting the adoption potential or acceptability of a new construction technology. The acceptability of a technology for a target operation is defined as the proportion of users that choose to use the technology in comparison to a conventional (base) technology. All existing alternative technologies for the considered operation are collected as samples for study. The performance characteristics of each sample technology are stored in a vector comprising eigenvalues determined by using the analytical hierarchy process (AHP) method, and its acceptability is determined using a poll. The obtained performance-acceptability pairs are used to train a neural network using the back-propagation algorithm. The trained network can then be used to predict the acceptability of a new technology in question, given its performance attributes. Possible information sources for training set construction and possible applications of the approach are discussed. An example estimate of the adoption prospect of a new concrete distribution system for concrete placement on a mid-rise building project is provided. Tests of the presented NN approach with simulated data show a promising result, especially when the poll size used is sufficiently large.

Research in construction automation and robotics has increased in popularity over the past few years. Although interest is high in the research and education communities, sustaining robust programs is difficult due to the diverse interests of constituents associated with the research and development process. The premise of this paper is that there is a need to develop and maintain strong construction automation and robotics programs in the United States. One way to assist in this goal is to address the concerns of the constituencies of research and development by focusing on a process leading to implementation. The interests of the constituents of the research and development process are examined, a process leading to implementation is presented, and results from a recently completed research project are presented as an example of the process. It is concluded that a systematic approach such as the one presented will enhance the success of construction automation and robotics programs as well as lead to faster adoption of advanced technologies for field applications.