Engineering survey Survey should cover the environment, loading conditions,engineering efficiency, and so on. Specific survey items include water quality(chemical composition, microbiological, etc.), water flow, freeze–thaw conditions,temperature and humidity, static loads, dynamic loads, maintenance costs and project income. Due to the different sensitivity factors of service life for various hydraulic
structures types, the survey should also have different focus. Take concrete dams for an example, shear strength of dam foundation is an important control factor, so the investigation should focus on the foundation.