HDD Machine common case and solutions 09

Publication Date: 2021-01-04

Sand mud system design principles

Based on the characteristics of the sand layer, in the horizontal directional cross-construction process, the main difficulties faced are: 1 sand layer particles between the glue “loose structure, once the formation balance is broken, the construction process is very easy to drill hole collapse; In the drilling process, facing the risk of groundwater infiltration leading to mud dilution, once the mud is diluted, will not be able to form dense mud cake ring near the hole wall, the pressure inside the hole and the layer pressure interoperability, mud can not play a role in maintaining the stability of the hole wall, the risk of collapse is great!