Carbonaceous mudstone belongs to a special type of soft rock,which is widely distributed and has poor engineering properties,and has a significant impact on canal projects.Therefore,it is urgent to study the engineering characteristics and prevention mechanisms of carbonaceous mudstone.The Madao Hub of the Pinglu Canal is located on a carbonaceous mudstone foundation.During the investigation phase,methods such as drilling sampling,mineral analysis,in-situ shear tests,and laboratory compression tests are employed.During the construction phase,techniques including on-site observation,geological mapping,geological sketching,and safety monitoring are utilized to systematically reveal the engineering characteristics and prevention mechanisms of carbonaceous mudstone.The main research conclusion:the composition of carbonaceous mudstone is primarily clay minerals,with a carbonaceous content of 6% to 40%.The strength of carbonaceous mudstone is influenced by its burial depth,structural features and groundwater environment,leading to significant variability.Reliable data must be obtained through investigation methods such as sampling,in-situ testing,and laboratory experiments.Carbonaceous mudstone is prone to weathering and softening after excavation exposure,with softening resulting from a combination of internal and external factors.Internal factors include its clay mineral composition and hydrogeological properties,while external factors involve excavation unloading and wet-dry cycling.For carbonaceous mudstone foundations,a protective layer must be reserved,and strict foundation cleaning and acceptance procedures should be followed.If necessary,bearing capacity testing and foundation treatment should be conducted.For carbonaceous mudstone slopes,timely sealing should be performed after excavation and slope cutting,and appropriate reinforcement and drainage measures should be implemented based on their distribution and impact extent.