Introduction to trenchless horizontal directional drilling (HDD) technology and its working principle
I. Brief introduction to HDD technology Trenchless technology refers to a construction technique for laying, repairing, replacing or detecting underground utilities and pipelines with less excavation or non-excavation. The principle of directional drilling technology is applied in trenchless construction, which greatly reduces the impact of underground pipeline construction on traffic, environment, infrastructure, residential life and work, and becomes an important part of construction and management of modern urban infrastructures. The trenchless construction began in the United States in 1896, and rose in the developed countries in the 1980s and formed an industry. In China, the trenchless technology was used in Beijing in 1953, started in the 1990s, and develops rapidly this year. At pr