Construction Management & Economics

Benjaoran, Vacharapoom; Peansupap, Vachara

doi: 10.1080/01446193.2019.1600708pmid: N/A

AbstractMany temporary facilities are required during on-site construction operations of most projects. They must be situated in convenient locations as ease of access can have a significant impact on the efficiency and safety of the construction project. The feasible locations and layouts that satisfy all specified conditions and constraints can still be very large in number; thus, optimal layout planning can be very challenging, even for experienced engineers. A model for solving the construction site layout problem (CSLP) is proposed. A grid system is implemented to simulate sites and facilities more realistically. This model incorporates an algorithm that imitates and calculates the distances of typical travel paths of workers between a pair of facilities during construction operations. In addition, Particle Swarm Optimisation is adopted to solve the problem model. The prototype program was developed and tested on a real construction project case. The results show that the model was able to lay out the site efficiently and optimally. The resulting layouts were better than those from engineers and conventional distance calculation methods.

Matar, Mohamed; Osman, Hesham; Georgy, Maged; Abou-Zeid, Azza; Elsaid, Moheeb

doi: 10.1080/01446193.2019.1605185pmid: N/A

AbstractEnvironmental performance criteria currently represent major decision factors in civil engineering projects, including pipeline construction. This paper presents a framework based on systems modelling and multicriteria decision analysis (MCDA) that captures different setups of pipeline installation techniques and the environmental impacts expected from different execution scenarios. A model is developed via SysML using the principles of systems modelling and engineering to capture the interactions of the pipeline as a product, the installation technique utilized, together with the environment. A TOPSIS-based MCDA module permits selecting the optimum alternative among construction alternatives. Open cut trenching and microtunneling are exemplified and a case study is provided where both techniques are evaluated in terms of environmental impacts. The contribution of this work is providing a structured and versatile framework that properly captures the interactions of different pipeline installation techniques and the environment, enabling the quantification of environmental impacts to a high degree of precision. The capacity to model different scenarios allows comparison and selection of the most suitable alternative.

Ammar, Mohammad A.

doi: 10.1080/01446193.2019.1606924pmid: N/A

AbstractThe Critical Path Method (CPM) has failed practically for scheduling repetitive projects and Line Of Balance (LOB) has emerged as an alternative for scheduling such projects. Because of the size of most repetitive projects, efficient resource management plays a vital role in their successful implementation. However, resource levelling and allocation have not been formally investigated in repetitive projects. Heuristic methods and optimization techniques have been traditionally used to solve resource scheduling problems like the latter. Although heuristic methods can handle large-size projects, they do not guarantee optimal solutions. In this paper, resource levelling and allocation problems under LOB scheme are modelled as an optimization problem that guarantees optimal solutions. Resource continuity and logical dependency between activities are maintained where constant activity progress rate is assumed. An example project is used to demonstrate the details of model formulation. A complete solution for the range of feasible project durations is obtained as a Time-Resource Trade-Off curve. A pipeline project is used to validate the developed model revealing that the developed model is superior. The proposed model provides contractors with a complete picture for resource usage along with the range of feasible project durations from which the optimal alternative can be selected.

Hessami, Amir R.; Faghihi, Vahid; Kim, Amy; Ford, David N.

doi: 10.1080/01446193.2019.1608369pmid: N/A

AbstractPrograms to improve the sustainability of building infrastructures often consist of project portfolios that need to be prioritized in an appropriate chronological fashion to maximize the program’s benefits. This is particularly important when a revolving-fund approach is used to leverage savings from the initial projects to pay for later improvements. The success of the revolving-fund approach is dependent on the appropriate prioritization of projects. Competing performance measures and scarce resources make this task of project prioritization during the planning stage a complex and challenging endeavour. The current study examined the impact of different project prioritization strategies for revolving-fund sustainability program performance. A novel modeling approach for sustainability decision-analysis was developed using the system dynamics method, and the model was calibrated using a campus sustainability improvement program at a major university. The model was applied to evaluate the effects of five common project-prioritization strategies on three program-performance measures, across a wide range of initial investment levels. For the university case study, we found that the strategy of prioritizing projects according to decreasing benefit/cost ratio performed best. The research demonstrated that using a system dynamics model can allow sustainability program managers to make better-informed sequencing decisions, leading to a financially and environmentally successful program implementations.

Zhang, Jing; Chen, Fangjian; Yuan, X.-X.

doi: 10.1080/01446193.2019.1645344pmid: N/A

AbstractCost overrun and schedule delay are pervasive in large public infrastructure projects in Canada and there is an ongoing debate over the root causes of these delivery risks and how best to mitigate them. Since public-private partnerships (P3s) have been long touted as an effective mitigating measure, this study aimed to provide comparative empirical evidence to explore this claim. By collecting cost and schedule data at three key milestones (decision to build, contract awarding and substantial completion) from 39 traditional projects and 27 P3 projects across Canada between 2004 and 2016, the study develops an innovative longitudinal profiling approach to inform the debate about the causes of cost overruns in large public projects. Statistical analyses of the collected data unambiguously demonstrate that P3s outperform non-P3 traditional delivery models during the construction stage in both cost overrun and schedule delay. However, substantial budget underestimation is found in the strategic decision-making process of both models of project delivery. Results from the study also provide solid objective grounds for the development of advanced value-for-money assessment methodology.

Hammad, Ahmed W. A.

doi: 10.1080/01446193.2019.1659510pmid: N/A

AbstractEffective construction site layout planning is imperative for ensuring the productivity and safety of construction operations during the various phases of a project. Contrary to previous studies where the focus has been merely on the location decisions of operating facilities, this study examines the site layout planning problem from the perspective of incorporating planning considerations for on-land traffic assignment on site. The site layout planning problem is thus solved by accounting for location decisions, on-land material handling equipment choices, and traffic assignment on the site’s ground during construction. A sustainable site layout is ensured through minimizing noise pollution measured at noise-sensitive receivers located around the construction site, minimizing the cost of the layout adopted, as well as minimizing the total travel time of on-land equipment traversing between the positioned temporary facilities. The problem is initially formulated as a bi-level model and then later reformulated into a single-level model based on a justified relaxation. To handle the multi-objective nature of the resulting problem, the augmented -constraint approach is utilized to generate the non-dominated Pareto front. Applied to a realistic case, the results of the proposed bi-level model demonstrate that errors of up to 55% in total system travel time can be avoided when traffic assignment on-site is considered.