Effective risk management is critical to the success of infrastructure projects. Although several studies in the literature have focused on various aspects of infrastructure project risk management, limited efforts have investigated the overall dynamics of infrastructure project risks and how dynamic risk interactions can affect a project schedule. This study, therefore, takes a holistic view to investigate the effects of dynamic risk interactions on a schedule delay in infrastructure projects. First, major risks that can cause a schedule delay in infrastructure projects are identified through a review of related literature and questionnaire survey. Second, the interactions among main variables related to infrastructure schedule risks are analyzed using causal loop diagrams. Afterward, a system dynamics (SD) model for the investigation of risk effects on a project schedule is developed based on the causal loop diagrams and the underlying relations among the variables. Finally, the model is applied and simulations are carried out. The findings show clearly that dynamic interactions among diverse infrastructure project risks are critical in evaluating risk effects on a schedule delay. Because of the complex and dynamic behavior of the studied system, compared with previous studies in which risk impacts are investigated separately, risk effects on an infrastructure project schedule delay would be larger when major risks are collectively considered. The SD model can be used as a basis for simulating various risk effects on a project schedule to explore the optimum measures to prevent such risks in advance.

The Belt and Road Initiative (BRI) is a Chinese development strategy developed in order to establish connectivity and deepen cooperation between China and other countries, increase trade, and support the socio-economic development of vast regions. A significant number of railway projects are planned to be constructed under BRI since railways are the most efficient means of transportation. This paper investigates the critical risks in railway projects implemented under BRI. In total, 24 potential risks in BRI railway projects are identified and categorized into 6 groups. A questionnaire survey is conducted in order to collect data about the probability of risk occurrence and their impact. To identify the critical risks in railway projects, a novel method based on fuzzy and sensitivity analysis is developed and applied for risk assessment. This method uses a fuzzy synthetic evaluation approach to assess risks and sensitivity analysis as criteria for critical risk identification. The results show that the most critical risks in railway projects are changes in design, design errors, cooperation between China and BRI country, loan risk, complex geological conditions of terrain, and geopolitical risk. The theoretical contribution of this paper is a novel method which combines fuzzy and sensitivity analysis into a single approach.

Building information modeling (BIM) can theoretically facilitate collaboration among diverse design participants in construction projects, but in practice, its implementation tends to prolong the design period. Existing literature has examined some technical and managerial causes of this problem but still lacks an overall coverage of related factors. This study aims to identify the comprehensive factors affecting the teamwork efficiency in China’s BIM-based collaborative design, and to investigate the critical factors and their interactions. Based on the input-process-output theory, this study initially established a hypothetical model. Potential factors were further identified through the literature review and semi-structured interviews. Questionnaire survey was conducted, and structural equation modeling was used for analysis. The results indicated that the team cooperation atmosphere is the most significant factor, followed by the collaborators’ learning ability, comfort of the working environment, BIM software function, and the characteristics and arrangement of the design task (CADT). Besides, the CADT negatively affects the teamwork efficiency through the human interaction process, while other factors exert positive impacts by affecting both the personal work process and the human interaction process. The findings can help design units to determine the management focus of BIM-based collaborative design and prioritize the allocation of limited resources accordingly to maximize teamwork efficiency.