Journal of Construction Engineering and Management

Network‐based techniques as planning tools are widely used in the construction industry. They have proven effective for certain types of projects. However, these techniques have many limitations. They are usually carried out in an unstructured form with considerable reliance on the planner's judgment, imagination, and intuition. They require abstract visualization of the perceived configurations, characteristics, and spatial relationships among various components of the project. Because of limitations in the current planning techniques, there is a need for the development of new techniques. These techniques rely on advanced visual tools in addition to construction knowledge rules defined by planning experts to enhance and automate the planning process of complex projects. The availability of advanced computer technology (both hardware and software) allows both researchers and practitioners in the construction industry to develop such techniques. This paper presents KNOW‐PLAN, a knowledge‐based planning system proposed by research being done at Virginia Tech. The system integrates artificial intelligence (AI) technology with computer‐aided design (CAD) technology to generate and simulate construction plans. The system can be classified as a new direction in approaching a planning problem that integrates AI and CAD.

The damage of prestressed concrete pile (PCP) during the installation process has resulted in injuries, time delay, and cost overruns. Diagnosis of the damage is one of the most important problems in foundation engineering. This paper describes a diagnosis expert system PCPILE (prestress concrete pile) for diagnosing the damage of PCP during the construction process. Because there is no way to avoid subjective judgment, imprecise data, and experience‐based knowledge in this problem, fuzzy logic is employed to solve it efficiently. In PCPILE, the inference is mainly implemented by the deductive inference mechanism with depth‐first backward chaining. But, when the deductive inference mechanism cannot satisfy a diagnosis goal directly, a specific case base is opened for the analogical influence mechanism. The expert system is novel in at least two respects: (1) Case base is employed for knowledge representation; (2) analogical inference technique is applied when there is a lack of sufficient experience in getting reliable rules.

The volume of international work undertaken by U.S. contractors has declined considerably in the last few years. The share of the international market held by U.S. companies also declined in the same period. The paper reports the findings of a study conducted to explain the performance of U.S. contractors in international markets. Performance indexes were developed that can be calculated by making use of publicly available company information. A questionnaire survey was administered to U.S. contractors that have been active in overseas markets in the last five years. Statistical analyses were performed to explain international performance in terms of commitment, presence, and growth. Findings indicate that the type of construction, the type of contract, financing sources, the geographical location of projects, sources of information, and research and development activity tend to affect U.S. contractors' international performance.

The goal of an owner is to have a project that incorporates the latest technology with timely completion. This goal has resulted in fast‐track construction. The trade‐offs for this are design‐related problems that are often not found until the construction phase of the project. The results of these problems are work stoppages or rework and increased costs. This paper uses an industrial‐project case study to identify the number, type, and time of occurrence of design‐related problems. This information is used to develop a model to forecast potential design‐related problems. Results of this study show that design‐related problems can be traced back to the design phase of a project and that design complexity is the main cause of these problems. Profile curves are presented for specific disciplines that predict the pattern of problems throughout that discipline's progress. Forecasting models using design or construction man‐hours are developed to predict the potential number of design‐related problems that can be expected during the construction of an industrial project.

Experienced construction personnel have provided input into construction projects for many years. However, only recently, under the impetus of the Business Roundtable's Construction Industry Cost Effectiveness Study, have the benefits of a constructability program received widespread recognition for their savings of time and cost, and their quality improvements. To receive maximum benefits, the construction input, or constructability, has to be started at the earliest stages during the conceptual planning stages. This paper covers the background, some of the considerations that have to be factored into a constructability program, the rationale for a constructability program, and how to implement a constructability program. This paper emphasizes that the integration of experienced construction personnel into the earliest stages of project planning as full‐fledged members of the project team will greatly improve the chances of achieving a better quality project, completed in a safe manner, on schedule, for the least cost.

The function of the crew foreman has not received the degree of attention in research the crucial role in construction deserves. In this study, we investigate aspects of the foreman's role that have strong implications on the productivity of the crew. By enquiring into how the foreman divides workaday time between various functions and activities, how these are affected by the size of the crew, what factors determine the span of control, and what effect the size of the crew has on its performance, the study has come to the conclusion that: (1) The size of the crew and the managerial assistance, if given, affect the mode of daily activities; (2) the size of the crew can vary considerably, depending on circumstances; (3) the size of the crew can affect its performance; and, finally, (4) the size of the crew has to be adapted to prevailing conditions.

Contract provisions of more than 100 owner agencies are examined to determine the extent to which cultural resources are addressed in construction contracts. Results show that owner agencies are becoming increasingly aware of the need to preserve artifacts of cultural and historical importance as evidenced by the increased use of provisions concerning cultural resources, research reveals that there is a considerable discrepancy between the clarity and completeness of the various provisions. Before any construction activities take place on a site and before construction contracts are awarded, owners should conduct thorough investigations of their properties to determine the likelihood that artifacts of value might be present. In addition, owners should include contract provisions that require construction contractors to suspend work activities when suspected items of value are discovered during construction. To assure compliance with these provisions, it is also important to include provisions that compensate contractors for such suspensions of work activities. Guidelines for other related construction contract provisions are provided.

This paper describes and formalizes knowledge utilized by skilled schedulers for sequencing construction activities. Although it is recognized that construction scheduling involves many tasks (activity identification, duration estimation, etc.), the focus here is limited to an understanding of a number of key activity sequencing principles. This paper provides a grammar or language that represents governing factors for construction activity sequencing. Four basic factors are identified and described in detail. The physical relationships that exist among the different building components is one of the factors. Another is the interaction of construction trades. Sequencing is also affected by the requirement of an interference‐free path for all the objects to be displaced around the job site at construction time. Code regulations are also relevant for determining the order of execution of certain activities. A discussion of the flexibility of these four different sequencing constraints and of their relation to time is also presented. Finally, a brief overview of a knowledge‐based prototype system that incorporates a few of the identified sequencing governing factors is provided.

Fabric‐reinforced mortar faces on expanded polystyrene (EPS) core structural sandwich construction is used for low‐cost quonset buildings. The construction, especially suitable for warehousing and agricultural buildings, consists of: (1) Laying polystyrene insulation boards on a flat surface; (2) stretching reinforcing fabric over the boards to keep them tightly abutted; (3) screeding a cement‐fly ash slurry containing styrene‐butadiene latex admixture through the fabric; (4) inflating a polyethylene film under the EPS boards thus joined to form them into an arch after the mortar hardens; and (5) tilting precut sandwich panel end walls up under the arch to support it. A cement mortar reinforced with polypropylene chopped fiber is then gunned inside the arch to complete the structural sandwich construction. Required cylindrical sandwich core and face thicknesses to resist buckling at minimum material cost are calculated. Material costs are tabulated. Flexural modulus is determined from panel‐bending tests. The flexural stiffness/dead weight ratios are compared with those ratios for precast prestressed concrete decks.

This paper describes the legal aspects of oral change orders or directives. It provides basic criteria for an owner, contract administrator, or contractor to determine if an oral directive is valid, entitling the contractor to additional compensation. The criteria are based on common law rules extracted from a review of more than 70 appellate court cases. The rules provide that for an oral directive to be valid, there must be no statutes requiring a written change, the owner must have knowledge of the work, and he must know that the contractor is expecting compensation for the additional work. A promise to pay cannot be rescinded. Other aspects discussed include proper or apparent authority and waiver. The case law review revealed substantial consistency in the application of these rules, and no discernible differences were found between the public and private sectors. The rules are arranged in an easy‐to‐follow flowchart, and numerous case citations are included. Recommended practices are also included.

This paper critiques the common practice in managing and tracking the engineering/design phase of major projects and presents an alternative integrated approach. It addresses in detail the development of control budget, project schedule, progress measurement procedure, and project data base to accomplish full cost and scheduling integration. Cost/schedule integration is achieved by: (1) Developing control budget based on the project work breakdown structure (WBS); (2) identifying all project documents on the project WBS; (3) grouping the project documents in work packages; (4) making reference to the work packages on the project schedule; (5) determining distinguishable events (control points) for each package; and (6) using the earned value concept as the means for progress measurement. The procedure is capable of objectively determining the progress of the scheduling activities, performance indices, and budget forecasts. A numerical example and a case study are provided to illustrate the implementation and computational procedure of the presented approach.

The Disadvantaged Business Enterprise (DBE) program is a federally funded program designed to provide opportunities for minority contractors to perform highway construction projects. The DBE program is six years old. A survey of DBE and prime contractors was conducted to determine the status of the program. The results of the survey are used to identify several serious fundamental problems with the current DBE program. The primary problem is in the nature of set‐aside programs, which does not contribute toward the development of independent minority contractors. Set‐aside programs feed money into a system without really considering if the desired product will be achieved. Financial and bonding assistance are required to augment the DBE system, and DBEs need to perform mainstream highway work. These problems provide a framework from which a model DBE program is developed. The model DBE program is based on an input of education and assistance, as opposed to set‐asides, to provide for the development of inexperienced minority contractors into independent qualified firms. The objective of the model DBE program is to provide a look at an alternative to the current way of providing DBE assistance.