Rotary drilling machine is a type of drilling machine that uses a rotating bit to drill through rock or other materials. The rotary drilling rig is a piling machinery suitable for drilling operations in construction foundation projects. Rotary drilling rigs are generally powered by diesel engines, fully hydraulically driven, crawler walking, 360-degree rotation, and self-propelled landing gear. They have low noise, low vibration, large torque, multi-function, fast hole forming speed, maneuverability, high construction efficiency, and multiple functions.
The chassis of the rotary drilling machine adopts the chassis of a crawler excavator, which can walk on its own and accurately position drilling holes. In addition, the rotary drilling rig can operate independently, has strong maneuverability, and can adapt to complex terrain. The installation and disassembly of the drilling rig can be completed without auxiliary facilities. It takes up little space and can be operated against the wall.
2. The construction site is environmentally friendly and clean.
The rotary drilling equipment uses a drill bit to rotate to extract soil, and the drill pipe lifts the drill bit out of the hole and then unloads the soil. The amount of mud used by rotary drilling machine is very small and is only used to protect the wall, not to discharge slag. The mud used to form the hole is basically equal to the volume of the hole, and the mud can be reused many times after sedimentation and sand removal. Therefore, the rotary drilling machine construction site is tidy, causing little pollution to the environment and reducing construction costs.
3. The hole forming speed is fast.
It turns out that most of the foundation pile construction of roads, railways, bridges and large buildings in my country uses traditional circulating drilling rigs or impact drilling rigs, and the production efficiency is very low. When using a rotary drilling rig, the drill bit extracts rock and soil directly from the hole, so the hole formation speed is fast. Since there is less sediment at the bottom of the hole and it is easy to clean the hole, the quality of the project is fully guaranteed.
4. The hole formation has high verticality.
The chassis of the drilling rig is retractable and can be leveled automatically. The verticality of the drilling tower and the drilling depth are both displayed by instruments. Therefore, it is very stable during drilling, which can effectively ensure the verticality of the drilling and improve the drilling quality.
5. Strong geological adaptability.
The connection between the drill bit and the drill pipe is fixed with a shaft pin. The drill bit is easy to disassemble and the drill bit can be quickly replaced for different formations. There are three main types of rotary drilling rig drill bits, namely short spiral drill bits, dredging drill bits, and sand dredging drill bits.
6. The equipment has advanced performance, high degree of automation and low labor intensity.
Rotary drilling machine is a crawler-type fully hydraulic self-propelled drilling rig that use a full set of hydraulic systems, and some are equipped with advanced computer operating systems. In order to ensure the excellent performance of rotary drilling rigs, most rotary drilling rig manufacturers purchase parts from around the world, such as chassis from American Caterpillar (CAT), hydraulic systems from Germany, electrical appliances from Japan, etc. The overall life of the drilling rig will not be affected by damage to any one component. The rotary drilling rig’s machine, electricity and hydraulics are highly integrated, compact in structure, flexible and convenient to operate, with a high degree of mechanization and automation. It can move on its own within the construction site and has a self-standing mast, making movement and positioning of holes convenient and fast. The use of telescopic drill pipes saves manpower and time for adding drill pipes, with less auxiliary time and high time utilization.
7. Easy to use and simple to maintain.
The main components of rotary drilling machine are provided by relatively common origin component manufacturers (such as pumps, engines, motors, reducers, etc.), and can directly receive after-sales service support from the origin manufacturers. At the same time, the rotary drilling machine has a simple structure and an extremely low failure rate.
8. Mud falls out of the orifice and less sediment is produced.
Rotary drilling machine uses underwater conduits to pour concrete. This is a very mature pile filling technology that can avoid the adverse effects of mud falling from the orifice and sediment generated during the filling process.
9. Suitable for various pile foundation projects.
In addition to being used for rotary drilling, rotary drilling rigs can also be used for the construction of long spirals and underground diaphragm walls after simple modifications. The scope of application is extremely wide.
10. The hole backfill has little impact on bored piles.
Rotary drilling machine is generally equipped with a hole casing of about 2m (can be lengthened if the hole backfill is thick), and the drill itself can bury the casing to avoid the impact of the hole backfill on the bored piles.
How to choose a drill bit according to the formation conditions?
Check below:
Clay: Use a rotary drilling bucket with a single bottom. If the diameter is too small, you can use a two-petal bucket or a drilling bucket with a soil unloading board.
Silt, weakly cohesive soil layers, sandy soil, and pebble layers with poor cementation and small particle size can be equipped with a double-bottom drilling bucket.
Hard cement: Use a rotary drilling bucket with a single soil inlet (single or double bottom is acceptable), or a straight screw with bucket teeth.
Frozen soil layer: For those with low ice content, straight auger buckets and rotary drill buckets with bucket teeth can be used. For those with large ice content, conical spiral drill bits can be used. It should be noted that spiral drill bits are used for soil layers (except for (Except for silt), it is effective, but it must be used when there is no groundwater to avoid suction and jamming.
Cemented pebbles and strongly weathered rocks: need to be equipped with a conical spiral drill bit and a double-bottom rotary drilling bucket (single port for larger particle sizes, double ports for smaller particle sizes)
Stroke bedrock: Equipped with a pick-type coring bit – a conical spiral drill bit – a double-bottom rotary drilling bucket, or a pick-shaped straight spiral drill bit – a double-bottom rotary drilling bucket.
Slightly weathered bedrock: Equipped with a cone-type core drill bit – a conical spiral drill bit – and a double-bottom rotary drilling bucket, if the diameter is too large, a graded drilling process must be adopted.
