Due to multiple factors influencing the construction safety of TBM hydraulic tunnels, risk assessment is a critical point of a construction management plan to avoid possible risks. In this paper, a safety-risk evaluation index system of TBM construction for hydraulic tunnels is built based on the identification and analysis of possible sources of risk in techniques, geologic, equipment, management, and accidents. Considering the influence of factors such as the experience level and the expertise of decision makers, a combination assignment method of index weights is proposed based on binary semantics. On the basis of a fuzzy normal distribution used as the subordinate function distribution of fuzzy evaluation levels, the subordinate function distribution of fuzzy evaluation levels under multi-level intersection situations is introduced, and a comprehensive evaluation model of safety risks for TBM tunnel construction is built. The validity and practicality of the evaluation model is examined with the combination of a long-distance water conveyance tunnel project. Results show that the construction safety-risk of the TBM hydraulic tunnel project belongs to the middle-high level, and the safety accident risk belongs to the low level. The study provides guidance of evaluation and control of risks for this tunneling construction being successfully completed.

By changing the alignment angle of spur dike, this study focused on the evolution of scour hole morphology in three alignments under clear-water scour conditions, including the 3-D structure of the scour hole, 2-D profile morphological evolution process and the evolution characteristics of the local bed shear stress. The results show that the plane area and volume of the scour hole both are power functions over time, which is similar to the evolution characteristics of scour depth. Local scour includes three stages: The initial stage, development stage and balance stage. The local bed shear stress presents successively: τ_b > τ_c, τ_b = τ_c and τ_b < τ_c. Based on this characteristic, the evolution mechanism between scour hole morphology and the local bed shear stress is further clarified. Furthermore, although the alignment of the spur dike significantly affects the longitudinal and vertical dimension erosion rates of the scour hole, the scour hole morphology is not only relatively constant but also has a specific proportion, and the evolution process is orderly in the whole process of evolution. To the scouring equilibrium state, the length of the scour hole on the upstream and downstream of the spur dike is approximately in line with the golden section feature. The related results provide technical support for scour parameter design and scour hole protection of spur dike in flood period.

Nie, X.T.; Liu, C., and Wang, B., 2020. Inverted normal quality gain-loss function and its application in water project construction. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 415–420. Coconut Creek (Florida), ISSN 0749-0208.As the existing quality gain-loss function is not able to solve the boundless problem in engineering practice, an inverted normal quality gain-loss function is proposed. This function is based on the characteristics of inverted normal function. Considering the variable situation of the quality compensation, the hyperbolic tangent compensation quality gain-loss function is established, and in which a quality gain-loss function with larger-the-better characteristic and smaller-the-better characteristic is designed. In view of the interaction between the characteristics of product quality, a multivariate quality gain-loss function model is also established. Through empirical analysis, the gain-loss function model is proved to be feasible.

Nie, X.T.; Wang, Y.H., and Wang, B., 2020. Quality control of water conservancy construction projects considering contractor's credibility. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 410–414. Coconut Creek (Florida), ISSN 0749-0208.This paper studies the decision-making on quality supervision and the issue of retaining quality margin of the owner in different situations of available information within a construction supply chain composed of both the owner and the contractor of water conservancy projects. Based on the influence of the credibility level of the contractor in varying situations of information availability and by drawing from the principle of maximum value as well as the game theory, we have analyzed the relationship among the level of quality supervision, the amount of retained quality margin, and the quality credibility level with different information. Through our analysis, we aim to help owners avoid moral hazards by contractors as well as the latent risks and potential losses. The study helps to improve the quality supervision by owners and achieve the win-win outcomes for both owners and contractors.

In engineering projects, project duration and a cost increase occur in every phase and will propagate their impacts downstream. Associated with the compensation of project duration, the duration and cost impacts are transferred among phases. In this paper, after illustrating the transmission of project duration and cost impacts, we will use the risk transmission theory and GERT (Graphic Evaluation and Review Technique) network technique to build a transmission model. We have designed equivalent parameters of project duration and cost impacts in the GERT model for serial, parallel, and hybrid structures. The algorithm of the GERT network for project cost and duration transmission is analyzed. The effectiveness of this model and algorithm is proved by numerical examples. This paper provides a new analytical method for cost and duration control of engineering projects.

As clean renewable energy with strong advantages, hydropower plays an extremely important role in promoting green development and energy allocation patterns. Hydropower project construction is characterized by long duration, large scale, high cost, many participants, and complex construction conditions, and is closely related to the economy, society, and ecological environment, and its construction management mode and construction risk management have become the focus of extensive attention from all walks of life. In this paper, the risk evaluation index system of hydropower engineering EPC project is constructed, and the linear weighted combination method is introduced to determine the comprehensive weights based on the calculation of weights by sequential relationship method and entropy weight method, and the improved fuzzy normal distribution is introduced as the subordinate function distribution of fuzzy evaluation level based on DS evidence theory and fuzzy theory. The risk evaluation model of a hydropower engineering EPC project is also established. Meanwhile, the model was analyzed with hydropower project examples to verify the accuracy and practicality of the model, which can guide hydropower project stakeholders to manage hydropower project risks comprehensively, collaboratively, and efficiently, and provide decision support for hydropower project construction risk management.