Journal of Construction Engineering and Management

Barrettes are huge concrete piers, basically rectangular. The cross‐sectional areas of barrettes have often been more than 75 sq ft $\left(7m^2\right)$ and they have been used for depths exceeding 260 ft (80 m) facilitating heavy vertical loads of the order of 3,000 tons/barrette to be transmitted to the bearing layer. Barrettes are used also as Moscovite wall for deep basements of high‐rise buildings to resist both vertical and lateral loads. The fact that a single barrette can replace a group of conventional piles results in a more compact, economical, and reliable foundation system. The installation technique of barrettes follows closely the method of constructing diaphragm wall using bentonite slurry, reinforcing cage, and tremie concreting with careful quality control. Although there are certain reservations for using barrettes instead of conventional piles and diaphragm walls, the inherent advantages and the confidence gained by experience have been responsible for their increased usage, especially as heavy load‐bearing elements for high‐rise foundations and basements.

Project constructability improvement data collection techniques including voluntary survey, questionnaires, interviews, preconstruction meeting notes, and final project reports are discussed and analyzed in detail. Constructability data collected on a large refinery expansion project solicited with various collection techniques from various project personnel are presented. Considering six major types of constructability improvements, from both quantitative and qualitative points of view, two primary questions are addressed: (1) Which data collection methods are best in soliciting certain types of data; and (2) which source types are the most effective contributors in soliciting certain types of data? Numerous recommendations for effectively collecting constructability improvement data are presented.

Many projects, such as the construction of roadways, pipelines, and high‐rise buildings, involve repetitive activities. A method for scheduling such work, the Linear Scheduling Method (LSM) is presented. In an LSM schedule, the repetitive activities are plotted as lines of constant or varying slopes on two axes, distance versus time. Discrete activities may be shown at their appropriate times and locations and then referenced to a network schedule for additional detail. The Linear Scheduling Method is illustrated by applying it to an actual roadway construction project. The simplicity of the system and advantages for certain types of projects are revealed. A sample schedule is used to derive information that is comparable to what may be obtained from an equivalent CPM network.

The feasibility of applying inferential statistics to the parameter estimate of manhours lost in the construction field in the Craftsman Questionnaire Survey is discussed. Currently, the Craftsman Questionnaire Survey only employs descriptive statistics to deal with masses of collected data. Inferential statistics have not yet been applied. Based on the theory of inferential statistics, the research can reliably infer the population properties from the data collected from a sample. To examine the feasibility of using inferential statistics to the Craftsman Questionnaire Survey, random and repeated sampling from past data was simulated. The results of the simulated samples are compared with the true results of the population, which were obtained from the past data. The comparisons empirically support that the inferential statistics can be applied to the Craftsman Questionnaire regarding the parameter estimate of lost manhours.

In this study, we examined the enabling and triggering events that caused failures in temporary structures. Using event tree analysis, we then analyzed the propagation of component failures. The concept of fuzzy sets is used to manipulate human‐based subjective judgments, which are abundant during the construction of temporary structures, and to minimize the complexities of conditional events in the trees. Ranking of critical paths, based on the highest probability of failure, is also presented for quality control purposes.

A model is presented to highlight actions that both owners and contractors, who do construction overseas, need to take in order to obtain costeffective construction projects. The model delineates a clear relationship between inflation, price escalation, time‐lag, prepayment, and the effects of price escalation on the value of the project. To simplify that relationship, the model concentrates inflation, price escalation, time‐lag, and profits into one term, the project's net present value. The analysis reveals three major points. First, the prepayment can be viewed and quantified as an additional markup whose benefits should be shared with the owner. Second, there is, indeed, an equilibrium point that defines the extent to which the prepayment accounts for inflation coverage, and thus no price escalation is needed. Finally, price escalation clauses in countries having high levels of inflation do not encourage prudence in spending. On the contrary, price escalation clauses encourage price escalation.

Various methods for the measurement and classification of safety performance at construction sites, e.g., timing relative to the moment of accident, data collection method, safety effectiveness criterion, performance measure, and frequency and severity of the measured event, are analyzed. The effectiveness of the various methods and the extent of their use at construction sites are examined. Attributes that are investigated include efficiency, reliability, and validity and diagnostic capacity of the measure in order to identify the cause for success or failure, respectively, of the safety program at a site. The data for the study were collected through questionnaires which were addressed to the largest construction companies in the United States. The most effective and the most widely employed measurement methods were lost‐day cases, doctor's cases, and cost of accidents. The least effective and most limited in use were the no‐injury cases.

Craftsman Questionnaire Sampling (CQS) was recently developed for performance measurement and productivity improvement at construction sites. CQS uses a questionnaire to collect data. It has the virtues of the Craftsman Questionnaire Survey, which provides information regarding the sources of delays, the amount of rework performed, as well as creating a participating atmosphere on site. Meanwhile, CQS imitates the sampling procedure from the Work Sampling method by randomly selecting craftsmen in the field and asking them to determine the activities involved in the immediate past. This procedure empowers the CQS to apply the theory of binominal distribution to estimate ratio delays and to maintain the advantages of relative simplicity and statistical reliability as the Work Sampling method does. CQS was tested at a large nuclear power plant site. The results indicated the feasibility and efficiency of CQS in helping construction management identify delays that could provide a base for productivity improvement.

The increasing interest in computer‐aided design (CAD) has prompted research that is aimed at identifying the opportunities for construction managers and building contractors. It has been found that the use of CAD systems in the U.K. is mainly confined to the production of detailed drawings. Indeed, most of the systems used are 2‐D drafting tools and incapable of supporting the integration of even modest amounts of nongraphical (construction) data. On the other hand, many 3‐D modeling systems have the potential to integrate construction data, although they appear to be almost ignored. The use of 3‐D modeling systems is considered to be the most suitable vehicle for successfully integrating these data. However, this is likely to necessitate the introduction of separate databases, preferably of the relational type. The use of 3‐D modeling systems in assessing the construction implications of outline designs also presents interesting possibilities and is discussed.

A study of a selected group of building and engineering construction contractors in the Australian construction industry was performed in order to determine the actual site cost control procedures and techniques being practiced. The study was conducted through a detailed questionnaire completed by the researcher during the course of interview sessions with the site managers of the 18 construction projects in the sample. The main trends disclosed from the questionnaire allowed a model of actual site cost control procedures to be flowcharted. This system was then subjected to a comparative analysis with an idealized site cost control system developed in a previous study. Cost control functions that are discussed in this paper include, among others, the method of work breakdown for site use in cost control, performance data feedback techniques and uses, yardsticks for cost control, and management action at the site. The study concludes with a set of general recommendations aimed to bring current site cost control practices more in line with the available body of knowledge.

Staged construction of a long, post‐tensioned, concrete highway bridge faces a falsework designer with the alternatives of a costly overdesign of falsework bents for all but a one‐time, short‐term load or the provision for expensive lowering devices. The problem is solved by using crushable foamed plastic support blocks. The support blocks can be designed to safely support the dead load of the superstructure and to crush when post‐tensioning increases the reaction, thus limiting the reaction. While crushing, the blocks continue to provide the necessary support for the superstructure. Stress and strain graphs for foamed isocyanurate are provided, which demonstrate its suitability for this application and provide the basis for design.