Construction characteristics of horizontal directional drilling
1. Directional drilling crossing construction will not hinder traffic, damage green space, vegetation and buildings, and affect the normal life and work order of residents.
2. Modern crossing equipment has high crossing accuracy and is easy to adjust the laying direction and burial depth.
3. The buried depth of urban pipe network is generally less than 3m. When crossing rivers, the buried depth is generally 9-18m below the riverbed.
4. There is no operation above or under water, which will not affect the navigation of the river and will not damage the embankment and riverbed structures on both sides of the river.
5. The speed of entering and leaving the site is fast, and the construction site can be flexibly adjusted.
6. Pre reaming is to expand the hole back to the expected diameter by 1.3~1.5 times of the pipe diameter step by step under the condition of clear geological conditions and underground pipeline detection or survey.
What should be paid attention to during directional drilling?
1. Before the construction of directional drilling, the self stability of the crossing stratum must be analyzed to effectively prevent the ground collapse caused by the hole forming diversion.
2. It is necessary to analyze the compactness of stratum soil and select appropriate mud pressure to prevent mud leakage.
3. Mud production, utilization, recovery and waste mud treatment shall avoid environmental pollution. The discharged waste water and waste environment must meet the national pollutant discharge standards. world
4. During directional drilling construction, if it is necessary to cross an important river dam, attention must be paid to prevent the adverse impact of mud on the dam.
5. If the construction is carried out in the area where the rock stratum changes greatly, it is necessary to adopt different drilling speeds for different soft and hard rock strata to prevent the rise and fall of the drilling hole and form staggered platform holes.
Application fields and advantages:
Trenchless construction technology is widely used in urban underground water supply and drainage pipelines, natural gas and oil pipelines, communication cables and other pipelines in economically developed coastal areas of China. It can cross roads, railways, bridges, mountains, rivers, straits and any buildings on the ground. This technology can save a large amount of land acquisition and demolition costs, reduce environmental pollution and road congestion, and has significant economic and social benefits.
The trenchless construction technology has solved the problems such as the damage to urban buildings and road traffic congestion in the pipeline laying construction, and highlighted its advantages in stabilizing soil layers and environmental protection. It is especially suitable for trenchless laying of large and medium pipe diameters.
The advantages of this technology are: no ground excavation, no demolition, no damage to the ground buildings of pipe jacking construction, no impact on traffic, no damage to the environment, and the construction is not affected by the climate and environment; Time saving, high efficiency and low comprehensive cost.
