With the development of industrialization and urbanization in China, pile construction will continue to develop at a high speed, and infrastructure construction will flourish, with more and more tall, large and heavy construction projects. In the pile foundation industry, it is based on the bearing capacity requirements of high-rise, super-high-rise buildings and large Bridges as well as environmental protection (smoke pollution, noise), vibration, construction quality and work efficiency.
Drill pipes and bits are widely used in rotary drills (figure 1)
Rotary drilling machine is a kind of filling engineering machinery. Rotary drilling machine is widely used in the construction of construction foundation engineering, because of its characteristics of fast construction speed, high pore-forming quality, small environmental pollution, flexible and convenient operation, high safety performance, strong applicability and so on. Construction equipment for bored piles.
There are currently about 38,000 rotating RIGS in China, and the market will grow by more than 4,000 RIGS in 2018.
1. Application field of rotary excavator drill pipe
With the improvement of concrete quality, the improvement of pile foundation construction technology, the improvement of cast-in-place pile bearing capacity and the strict implementation of urban environmental regulations, the bored cast-in-place pile has almost replaced other foundations. Become the most widely used foundation. Rotating RIGS account for more than 70% of the construction of large diameter concrete cast-in-place piles abroad, while reverse-circulation RIGS are almost no longer used in the European market. In domestic piling machinery products, gyroscope production accounts for nearly 50% (70% in yunnan).
General rotary drilling is applicable to clay, silt, sand, silt, artificial backfill, which contains some pebbles, gravel stratum, with high torque power head rotary drilling, can adapt to the construction of breeze rock, is the largest rotary drilling truck in China in 600 hours, the maximum diameter of hole is 4.5 meters, the maximum depth of hole is 158 meters. Through adaptive research, development, design and construction techniques, rotary drilling RIGS have a reliable and mature construction method in complex strata such as soft soil, hard rock, dense gravel and isolated rock. Due to the huge demand for roads, Bridges, railways, water conservancy, urban construction and other projects, RIGS have a huge market and development space.
Drill pipes and bits are widely used in rotary drills (figure 2)
2. Rotary drilling pipe construction case
The above is the case of water construction or bridge pile construction of rotary drilling rig, which has won the unanimous recognition of the project department for its safe and efficient performance. Rotary excavation is a safe, efficient and green construction technology. Compared with rotary drilling, impact drilling, manual excavation and other successful methods, it has the characteristics of high pile speed, high quality, safety, convenience, energy saving and environmental protection. And many other advantages.
3. Scope of construction
Rotary excavation can be performed in almost any formation, including silty sand, silty sand, clay, sand, pebbles, gravel, mudstone, sandstone, limestone, and hard volcanic rock. It can effectively drill into rocks with strength less than 180MPa or bearing capacity less than 3000KPa.
4. How it works
Working device of rotary drilling rig: diesel engine provides power for hydraulic device. The work unit includes the drill pipe and drill bit, transmitting downward pressure as well as positive and negative torque. The power of the working device is provided by the power head motor and the pressurized coil motor. For example, the CRRC TR360F rig can provide 36 tons of torque and 43 tons of downward pressure, effectively breaking rock and drill bits.
When working, the main coil lifts and releases the drill pipe, and the power head presses down or rotates to transfer pressure and torque to the bit through the drill pipe. Drills cut through the formation to drill holes. RIGS rotary drills are 15 to 20 times more efficient than gyroscopes and percussion drills.
Drill pipes and bits are widely used in rotary drills (figure 3)
5. Comparative advantage
Efficiency advantage: due to the essential difference between rock penetration and drilling mechanism between rotary drill and percussion drill, it has a great advantage in rock penetration and speed. On many sites, impact drilling requires months of pile drilling and only a few days of rotary excavation.
Environmental advantages: impact drilling USES recycled mud, which consumes a large amount of mud and has a high mud treatment cost. Rotary drilling is static mud retaining wall, consumption of mud volume is small. In environmental protection, rotary excavation has great advantages.
Management advantages: rotary impact drilling machine is used, the number of machines and operators is large, mud pool distribution and auxiliary equipment arrangement is chaotic, field management is difficult, but rotary excavation construction efficiency is high, the number of equipment is small, easy to manage and arrange.
To sum up, spin dig drill is a kind of new construction technology, has been widely recognized in the national major projects, from the construction quality, construction efficiency and construction cost and the geological adaptability, etc., it has the drill bit methods unparalleled advantages, and huan industry machinery to provide special drill bit and drill pipe, high strength, high wear resistance, the coal safety certification.