In recent years, in Vietnam, economy has been developing rapidly. To ensure rapid and sustainable economic growth, strong support from the energy sector is required. Governments in Vietnam have invested in numerous hydropower projects, many of which employ the EPC (Engineering, Procurement and Construction) contract. However, the EPC general contractors are facing many difficulties, resulting in schedule delays and considerable losses. This research is conducted to highlight the main risk factors in the delays of hydropower construction projects in Vietnam. The research employs the method of statistical calculations and risk analysis to obtain feedback from experts participating in similar projects. The research outcomes are as follows: identifying the risks that can cause delays in EPC hydroelectric construction projects in Vietnam; calculating and classifying the degree of impact of each risk to the progress of the construction. The practical significance of this study is to ensure the timely completion of projects, benefits for the investors, and the EPC general contractors.

In concrete gravity dams, reinforced concrete, and its components, depending on the working conditions of the concrete in separate parts of the dam during the operation period, should be divided into concrete zones with different intensities. However, many projects choose to construct the spillway’s overhang to save concrete, still assuring working conditions while creating the most cost-effective cross-section of the spillway. Although this will result in a proper partition of the concrete, anchoring the connection between the blocks must be secured;otherwise, the block may separate and even become eccentric and spill over. This may result in objects falling,works being destroyed, and a significant safety danger. This study approaches to ensure the safety of spillwayswith overhanging blocks by calculating and analyzing the risk of block separation and overturning, therebygiving a suitable solution for pouring volume and creating the best anchor connection to keep the whole damsafe and stable during construction and operation.