Journal of Construction Engineering and Management

The cumulative sum procedure is an effective statistical process control tool that can be used to monitor the quality of ready mixed concrete during its production process. In this paper, an attempt has been made to design and apply a new cumulative sum procedure for the ready mixed concrete industry, which takes care of the risks involved in and associated with the production of concrete. This new procedure can be termed as risk adjusted cumulative sum. The 28-day characteristic cube compressive strengths of the various grades of concrete and detailed information regarding the production process and the risks associated with production were collected from the operational ready mixed concrete plants in and around Ahmedabad and Delhi, two important cities in India. The risks were quantified using a likelihood-based scoring method. Finally, a risk adjusted cumulative sum model was developed by imposing the weighted score of the estimated risks on the conventional cumulative sum plot. This model is a more effective and realistic tool for monitoring the strength of ready mixed concrete.

A more rapid and widespread use and implementation of technology in construction often fails since its benefits and limitations remain somewhat unclear. Project control is one of the most variable and time consuming task of construction project managers and superintendents and yet continues to be mostly a manual task. Controlling tasks such as tracking and updating project schedules can be assisted through remotely operating technology such as high-resolution cameras that can provide construction management and other users with imaging feeds of job site activities. Although construction cameras have been around for many years, the costs, benefits, and barriers of their use have not been investigated nor quantified in detail. Subsequently, definitions and understanding vary widely, making it difficult for decision makers at the organizational level to decide on the investment in camera technology. This paper reviews the status of high-resolution cameras and their present use in construction. Results of a multiphased survey to industry professionals were collected in order to identify benefits and barriers and develop a cost-benefit model that can be used for implementation technology in construction.

This paper further develops the models proposed by prior research in the field of workspace conflict using four-dimensional computer-aided design. The approach developed here analyzes spatial demand and supply from the perspective of construction operators, and a modeling methodology based on spatiotemporal utilization is proposed. The utilization factor model is developed to show that the criticality of the operator’s spatiotemporal demand leads to worksite congestion and that congestion is a form of worksite conflict. The interference of other space entities increases the space demand, and this increment is quantified with a “dynamic space interference” index This indicator is developed to identify activity spaces which suffer congestion. A decision making tool, the “congestion penalty indicator,” is developed which obtains a schedule-level value for analysis, evaluation, and comparison. Finally, a case study on the refurbishment of an oil refinery column is used to demonstrate the application of the above concepts in successfully identifying a better schedule with respect to on-site congestion.

Construction professionals are subjected to a plethora of occupational demands that can have a negative effect on their psychological wellbeing. Such demands can have an adverse influence on individual and organizational performance. To investigate the nature of self and social supports and mental health among construction professionals, an exploratory study was undertaken using the Stress and Mental Health Survey. The survey was distributed to construction professionals throughout Australia and 449 responses were received. Analysis revealed that those working for a contracting organization on-site reported higher levels of poor mental health and greater work stress than consultants. Those working on-site also experienced greater levels of self-stress, whereas consultants reported higher levels of self and work support. Work support was a significant predictor of poor mental health for consultants. Good health, however, was predicted by self, situational, and work support, whereas those working for a contractor only self-support predicated good mental health. It is concluded that while supports are essential in the fostering of good mental health, the absence of these supports can have a significant impact on poor mental health.

Changes are the main causes of delays and cost overruns in construction projects. Various change management systems have been developed to minimize the impacts of changes and to facilitate good project management. This paper presents a change prediction system using activity-based dependency structure matrix (DSM) to facilitate change management. DSM is used to model the process that may occur as a result of changes. Consequently changes can be predicted by setting the change criteria for each activity in the form of rework scope. Furthermore, Monte Carlo simulation is introduced to analyze the change probability of activities involved in construction projects. The effectiveness of the prediction system is verified by applying this system to an office building project. This study provides a useful tool for project management teams to manage changes proactively and efficiently.

Tunnels projects are constructed to facilitate the execution of underground works with minor disturbance on surface structures and traffic. This is deemed important especially in downtown cities where disturbances should be minimized to assure flowability on surface and underground infrastructures. Microtunneling involves the use of a remotely controlled, guided pipe-jacking process in order to support excavation face. Microtunneling aids in avoiding the need of open trench for pipe laying, which causes extreme disruption to the surrounding. This paper presents a tool for planning microtunnels projects using computer simulation. The proposed tool aids contractors in planning microtunneling by estimating their associated time and cost of construction. There are six models that are coded in the proposed tool in order to capture the construction of microtunnels and shafts. The tool breaks down microtunnels projects into microtunnels segments and shafts which constitute several construction zones. An application example is presented to demonstrate the features of the proposed tool.

The pipe jacking method pushes a tunneling machine through concrete pipes ahead of the jacks. The main factors influencing the thrust force are friction around the pipe and face resistance. Both of these forces can be estimated by the analytical or empirical calculation models established by various researchers. So far, most of the models do not consider the overcutting distance; thus, the pipe behavior is still not clarified. Therefore, this paper introduces a developed stack pipe model with the overcutting effect to describe pipe behavior and evaluate the thrust force using the surrounding ground spring model and pipe positioning model with phase analysis in the finite-element method. A simulation of the pipe behavior was carried out to examine the model’s validity and performance. As a result, it was found that the developed model can simulate the soil-pipe interaction behavior and the thrust force reasonably well. Furthermore, it can be pointed out that the thrust force is greatly influenced by the developed friction around the pipe and the moment distribution at the cushion.

Although the Korean government reported a housing supply ratio of more than 100% in the early 2000s, regional and class disparities in the Korean housing sector have not been correspondingly alleviated. Unfortunately, many Korean households are still enduring the economic burden caused by cyclical price variation, while many housing construction companies are on the verge of bankruptcy. To resolve the ever-expanding socioeconomic problems in the housing and real estate sector, the current Korean government proposed 831 Countermeasures, which has since met with much controversy. In an effort to address these issues, this paper utilizes a qualitative system dynamics model to elucidate and interrogate complex Korean housing mechanisms. By mapping bibliographical and experimental knowledge with causal loop diagrams, the positive and adverse effects of the 831 Countermeasures are also analyzed. Finally, based on the research findings, alternative policy guidelines are proposed that can be used to strengthen positive housing structures and obviate negative ones.

Analysis of historical projects, with the dual benefits of hindsight and modern concepts of construction systems, can help fill the gaps in our theoretical understanding of production in construction, which have increasingly been identified as a barrier to progress in improving construction project management. The richness of the historical record describing construction of the Empire State Building provides a unique opportunity to analyze and compare it with the paradigms of craft, industrialized, and lean construction. Its size and its record rate of construction, which has not been broken since for tall buildings, make it of prime interest. The project progress was reconstructed using line-of-balance software and its different flows were assessed. The results lead to the conclusion that it is an archetypal example of what we propose be called “mass construction.” This enables a richer understanding of the taxonomy of production systems in construction, and should aid theoreticians and practitioners alike to devise better production systems for construction projects.

Completing a project with minimal time as well as minimal cost is a critical factor for scheduling a project. However, because completion speed tends to be correlated with cost (e.g., usually, time can be saved if more workers are hired), the relationship between time and cost is a trade-off. This study employed a phenomenon-mimicking algorithm, harmony search to perform this biobjective trade-off. The harmony search algorithm was applied to two test examples, and good Pareto solutions were obtained when compared with other algorithms, such as the genetic algorithm and the ant colony optimization algorithm. The harmony search algorithm explored only a small amount of total solution space in order to solve this combinatorial optimization problem. The model in this study has obtained good results with a network of up to 18 nodes, however it is anticipated that the model could be useful to solve bigger networks in practice without any difficult problem.