HDD is called horizontal directional drilling. This is a technology do not dig the surface of earth, and lay pipes. This usually used in oil and gas transport pipes.
Features of horizontal directional drilling:
1.1 directional drill crossing construction will not obstruct traffic, destroy green space and vegetation, and will not affect the normal life and work order of shops, hospitals, schools and residents. It solves the interference of traditional excavation construction on residents' life, and damages and adverse effects on traffic, environment and surrounding building foundation.
1.2 modern crossing equipment has high crossing accuracy, easy to adjust laying direction and burial depth, and long pipeline arc laying distance, which can completely meet the design requirements for burial depth, and enable the pipeline to bypass underground obstacles.
1.3 the buried depth of urban pipe network is generally less than three meters. When crossing the river, the buried depth is generally 9-18 meters below the riverbed. Therefore, horizontal directional drilling rig is adopted to cross the river, which has no impact on the surrounding environment and does not damage the landform and environment, so as to meet the requirements of environmental protection.
1.4 when horizontal directional drilling machine is used for crossing construction, there is no overwater or underwater operation, it does not affect navigation of rivers, and it does not damage levees and riverbed structures on both sides of rivers. The construction is not subject to seasonal restrictions, and has the characteristics of short construction period, less personnel, high success rate, safe and reliable construction.
1.5 compared with other construction methods, the speed of entering and exiting the site is fast, and the construction site can be adjusted flexibly. Especially in urban construction, it can fully show its superiority, and the construction area is small, the project cost is low, and the construction speed is fast.
1.6 when a large river passes through, since the pipeline is buried 9-18 meters below the stratum, there is little oxygen and other corrosive substances in the stratum, so it plays the function of natural anticorrosion and heat preservation, which can ensure the operation time of the pipeline is longer.
