Horizontal directional drilling rig is a construction machine that lays a variety of underground utilities (pipes, cables, etc.) without excavating the ground surface. It is widely used in flexible pipelines such as water supply, electricity, telecommunications, natural gas, gas, and oil. During paving construction, it is suitable for sand, clay, and other ground conditions, but not suitable for high groundwater levels and pebble formations. It can be constructed in most non-hard rock areas in my country. The working environment temperature is -15℃~+45℃. Horizontal directional drilling technology is a new construction technology that combines the directional drilling technology of the petroleum industry with the traditional pipeline construction method. It has the advantages of fast construction speed, high construction accuracy, and low cost. It is widely used in water supply, Gas, electricity, telecommunications, natural gas, oil and other pipelines are under construction. Horizontal directional drilling equipment has also achieved rapid development in more than ten years and has become an emerging industry in developed countries. Its development trend is moving towards large-scale and miniaturization, adaptation to hard rock operations, self-contained anchoring systems, automatic drill pipe stacking and extraction, automatic drill pipe connection lubrication, anti-shock system and other automatic operation functions, ultra-depth guided monitoring, application The development of characteristics such as a wide range. This kind of equipment is generally suitable for steel pipes and PE pipes with a pipe diameter of φ300~φ1200mm, and the maximum pipe laying length can reach 1500m. It is suitable for various soil conditions from soft soil to hard rock, and has broad application prospects.
1.1 Directional drilling crossing construction will not hinder traffic, will not damage green space, vegetation, will not affect the normal life and work order of shops, hospitals, schools and residents, and solve the interference of traditional excavation construction to residents’ lives and traffic. Environment, damage and adverse effects of surrounding building foundations.
1.2 The modern traversing equipment has high traversing accuracy, easy to adjust the laying direction and buried depth, and the arc-shaped laying distance of the pipeline is long, which can fully meet the design requirements and the buried depth, and can make the pipeline bypass underground obstacles.
1.3 The buried depth of the urban pipeline network is generally less than three meters. When crossing the river, the buried depth is generally 9-18 meters under the riverbed. Therefore, the horizontal directional drilling machine is used to cross the surrounding environment. It does not damage the landform and environment. It is suitable for environmental protection. Item requirements.
1.4 When the horizontal directional drilling rig is used for crossing construction, there is no water or underwater operation, which does not affect the navigation of the river, and does not damage the dams and riverbed structures on both sides of the river. The construction is not restricted by the seasons. The construction period is short and the success rate is high. The construction is safe and reliable. Features.
1.5 Compared with other construction methods, the entry and exit speed is fast, the construction site can be adjusted flexibly, especially in urban construction, it can fully demonstrate 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 crosses, because the pipeline is buried 9-18 meters below the stratum, there is little oxygen and other corrosive substances inside the stratum, so it has the function of natural anti-corrosion and heat preservation, which can ensure the pipeline running time longer.
Defects in the construction of horizontal directional drilling:
2.1 Since the horizontal directional drilling construction is a new production technology, my country does not have a unified technical standard and construction acceptance specification, resulting in no official basis for the control of engineering design and construction quality. Once a quality accident occurs, the identification of the responsible party will also cause certain difficulties.
2.2 Due to the use of directional reaming and dragging, when the construction is completed, the gap between the pipe and the re-expansion hole cannot be backfilled and compacted like the slotting facility worker. Therefore, there are certain risks in actual use of projects that require relatively high pipe settlement.
Brief introduction of horizontal directional drilling rig system:
Horizontal directional drilling rigs of various specifications are composed of drilling rig system, power system, direction control system, mud system, drilling tools and auxiliary equipment. Their structure and functions are introduced as follows:
3.1 Drilling rig system: It is the main body of the drilling operation and towing operation of the traversing equipment. It is composed of the main drilling rig and the turntable. The main drilling rig is placed on the drilling frame to complete the drilling operation and the retracting operation. The turntable is installed at the front end of the main machine of the drilling rig, connected to the drill rod, and by changing the rotation of the turntable and the output speed and torque, the requirements of different operating conditions can be met.
3.2 Power system: composed of hydraulic power source and generator. The power source is to provide high-pressure hydraulic oil for the drilling rig system as the power of the drilling rig, and the generator provides electricity for supporting electrical equipment and construction site lighting.
3.3 Direction control system: The direction control system is a directional tool to guide the drill bit to drill correctly through the computer to monitor and control the specific position and other parameters of the drill bit in the ground. Due to the control of the system, the drill bit can drill according to the design curve. There are two forms of hand-held wireless and wired direction control systems that are often used.
3.4 Mud system: The mud system is composed of a mud mixing tank, a mud pump and a mud pipeline to provide the drilling rig system with mud suitable for drilling conditions.
3.5 Drilling tools and auxiliary tools: various tools used for drilling and reaming during drilling. Drilling tools mainly include drill pipes, drill bits, mud motors, reamers, cutters and other tools suitable for various geological conditions. Auxiliary tools include snap rings, swivel joints and drag heads of various pipe diameters.