Small rotary drilling rigs are the main force in the development of rural construction today. They solve the problems of piling in rural house construction, such as large backfill soil and foundation stability. Although large rotary drilling rigs are highly efficient, they are large in size, have high investment costs, and are extremely troublesome to disassemble and transport. Moreover, they are only suitable for large construction sites, and many places can be said to be "impossible to enter, exit, go up, or go down."#borehole drilling machines#
Small rotary drilling rigs offer three major advantages that large rotary drilling rigs lack:
1. Low investment cost.
A typical small rotary drilling rig is one with a capacity of less than 30 meters, and the investment cost ranges from several hundred thousand to one million yuan. Large rotary drilling rigs, on the other hand, have a higher barrier to entry, typically costing between two and ten million yuan, making it difficult for the average person to enter the rotary drilling industry.
2. Easy transportation and relocation with the mast.
The transport height of a small rotary drilling rig is generally between 2.6 and 3.5 meters, and the total weight is under 35 tons. This allows for transport with the mast, naturally resulting in lower transportation costs. Large rotary drilling rigs, on the other hand, typically weigh between 55 and over 100 tons and have a transport height of more than four meters. They typically need to be disassembled for transportation, requiring two or more trailers and resulting in higher transportation costs.
3. Fast return on investment and quick payment. Small rotary drilling rigs are basically used for ordinary people to build their own houses, and pile foundation is the first step in building a house. Moreover, ordinary people pay for their self-built houses after driving the piles. In addition, the unit price of piling in rural areas is high, 100-200 yuan/meter, with high profits, quick payback, and quick payment. Large rotary drilling rigs are generally used by developers for real estate, high-speed rail, and bridge projects. The payment progress is slow, and there are many cases of self-advancement. In addition, the investment cost of large rotary drilling rigs is large, and the payback is slow. Therefore, for people entering and leaving the rotary drilling industry, small rotary drilling rigs have a quick payback.#borehole drilling machines#
Small rotary drilling rigs offer five key advantages not found in large rotary drilling rigs:
1. High pile quality.
Drilling creates minimal ground disturbance, resulting in a thin, thick, and rough L23 hole wall. This increases pile side friction and ensures the designed bearing capacity of the pile foundation. Low bottom sedimentation makes hole cleaning easier, improving the pile end bearing capacity.
2. Low environmental pollution.
Drilling rigs use dry or non-circulating mud drilling, using only 1/10 to 1/20 tons of mud compared to reverse circulation drilling. This keeps the construction site clean and minimizes environmental pollution. Drilling rigs also exhibit minimal vibration and low noise.
3. High drilling efficiency. Rotary drilling rigs can be configured with different drill bits depending on the stratum conditions. Long drill barrels can be used in clayey soils to increase drilling speed. For formations with high sand and gravel content, short drill barrels can be used, along with mud wall support, to control drilling speed. For formations containing boulders, boulders, and hard rock, long and short spiral drill bits can be used to loosen the rock. Once loosened, the drill barrel can be replaced and drilling can continue. Compared to conventional drilling rigs, rotary drilling rigs have greater rotary torque and can automatically adjust according to stratum conditions. They also offer high weight on bit and are easy to control. Furthermore, because rotary drilling bits extract rock and soil directly from the hole, their drilling speeds are very high. Typically, drilling speeds can reach 10 m/h in soil and sand layers, and 4-6 m/h in clay layers, which is 3-5 times faster than conventional rotary drilling, or even higher.
4. Advanced equipment performance, high automation, and low labor intensity.
Rotary drilling rigs are crawler-mounted, fully hydraulic, self-propelled rigs that utilize a comprehensive hydraulic system. Some also feature advanced computer operating systems. To ensure the superior performance of rotary drilling rigs, most manufacturers source components from around the world, such as chassis from Caterpillar (CAT) in the United States, hydraulic systems from Germany, and electrical components from Japan. This extends the overall life of the rig and prevents component failure from impacting its performance. Rotary drilling rigs feature highly integrated mechanical, electrical, and hydraulic systems, resulting in a compact structure and convenient operation. They are highly mechanized and automated, allowing for autonomous movement within the construction site and a self-erecting mast, making movement and alignment of drilling holes quick and easy. The use of a telescopic drill rod saves manpower and the time required to connect drill rods, minimizing auxiliary work and maximizing time efficiency.
5. Multi-purpose drilling rigs, enabling a variety of drilling methods.
Internationally, large-scale pile and foundation drilling rigs utilize hydraulic transmission technology and a modular design approach. While maintaining the same main engine, these rigs can be used for multiple purposes, adapting to diverse construction methods. In my country, the equipment that uses short spiral drill bits or drill buckets for dry drilling or non-circulating mud drilling technology to form holes and piles is called a rotary drilling rig. In fact, it is a large-scale engineering drilling rig that can adapt to different construction methods. In addition to rotary drilling, it can also perform casing or full casing drilling, and be equipped with an underground continuous wall grab to construct underground continuous walls, a dual power head to cut pile walls for construction, and long spiral drilling (CFA method), etc., truly achieving multi-purpose use of one machine.#borehole drilling machines#
Therefore, small rotary drilling rigs are more suitable for purchase and use in building construction in small and medium-sized cities and towns.#borehole drilling machines#
