How long can the rotary drill stay hot?

In recent years, with the continuous acceleration of China's capital construction, rotary drilling rigs, as a new product of construction machinery industry, have been sought after by many enterprises because of their strong market demand and strong profitability.
Rotary drilling rig has the characteristics of large installed power, large output torque, large axial pressure, flexibility, high construction efficiency, environmental protection, etc. With different drilling tools, it adapts to the geological conditions in most areas of China, and becomes the most ideal construction machinery suitable for drilling operations in construction infrastructure projects. In recent years, in the construction of Qinghai-Tibet Railway, Beijing Metro, Olympic Stadium, Capital Airport New Terminal Building and other large-scale projects, the advantages of high efficiency, environmental protection and high efficiency of rotary drilling rigs have been recognized, and "rotary drilling heat" has been set off in China. As can be seen from Table 1, rotary drilling rig is the fastest-growing pile machinery product during the Tenth Five-Year Plan period.
"Rotary drilling hotspot" not only drives the market, but also makes the number of domestic rotary drilling machine manufacturers grow rapidly. At present, there are more than 20 enterprises engaged in the manufacture of rotary drilling rigs in China. The sales of rotary drilling rigs in Sany Heavy Machinery, Xugong, Shanhe Intelligence, Yutong Heavy Industry, Futian Heavy Industry, Northern Heavy Machinery, Zhonglian Heavy Industry and other enterprises account for 70%-80% of the total market sales. In the first eight months of this year, the market sales have exceeded 200 units, far exceeding the sales of the whole year in 2005, which is evident in the popularity of rotary drilling rigs. At the annual meeting of piling machinery industry in 2006, experts in the industry had a heated discussion and exchange on the development status and trend of rotary drilling rigs in China.
Great demand during the Eleventh Five-Year Plan period
Guo Chuanxin, Beijing Research Institute of Construction Mechanization, believes that after recent years of development, the main performance of domestic rotary drilling rigs has approached or reached the international advanced level. Since 2004, domestic rotary drilling rigs have occupied more than 80% of the domestic market. According to the statistics of the Pile Machinery Association, by the end of August 2006, the sales of rotary drilling rigs had exceeded 200 units, which should be around 300 units in the whole year. The output value of rotary drilling rigs exceeded 1 billion yuan, and the output value of rotary drilling rigs has exceeded 50% in the whole pile machinery industry. In addition, the development of rotary drilling rigs has also promoted the technical progress of China's pile machinery industry and the level of pile foundation construction.
During the Eleventh Five-Year Plan period, China will invest a lot of money in the construction of railways, highways, electric power, urban public facilities and so on. Pile foundation construction machinery will certainly have a great development. In railway construction alone, several high-speed passenger dedicated lines, such as Wuguang, Zhengxi, Shitai, Beijing-Tianjin and Beijing-Shanghai, have been started one after another. More than 60% of high-speed passenger dedicated lines are bridges. The diameter of bridge piles is mostly less than 1.5m and the depth is less than 40m, which is suitable for rotary drilling rig construction. For example, at the beginning of 2006, more than 100 rotary drilling rigs were concentrated in the construction of pile foundation on Beijing-Tianjin Railway. At present, nearly 200 rotary drilling rigs are concentrated in the construction of pile foundation on Zhengxi Railway, which far exceeds the use of rotary drilling rigs on Qinghai-Tibet Railway.
Shi Yinfan, Secretary-General of Pile Machinery Branch, analyzed that during the Eleventh Five-Year Plan period, China will invest 100 billion yuan in the construction of high-speed railway. Only Beijing-Shanghai passenger dedicated line will invest more than 200 billion yuan, which is equivalent to a Three Gorges Project. The total length of the line is 1320 km. There are 846 bridges, about 709.3 km, accounting for 53.7% of the total length of the line. More than 20,000 beams will be erected and a large number of rotary drilling rigs will be required. This year, due to the start of some high-speed railway construction projects, the sales of rotary drilling rigs will doubled. The sales of rotary drilling rigs are expected to reach the total volume of the industry in 2005. Therefore, a good macroeconomic environment provides a strong development stamina and a larger market space for the development of the pile machinery industry.
In addition to the Beijing-Shanghai high-speed railway project, during the Eleventh Five-Year Plan period, China will build 17,000 km of new railway lines, including 7,000 km of passenger dedicated line, 8,000 km of additional second line of existing line and 15,000 km of electrification transformation of existing line. In 2010, China's railway business mileage reached 90,000 km, with more than 200 renewal and new construction projects, including 28 passenger dedicated line projects, with a total investment of 1250 billion yuan. In these projects, rotary drilling rigs and other equipment will become the focus of railway construction procurement. Experts predict that the domestic market demand of rotary drilling rigs will reach 600-800 units per year in the next 2-3 years.
Existing problems should not be ignored
Rotary drilling rigs have been widely used only in recent years. At present, there is still a lack of corresponding product standards in our country, construction specifications for rotary drilling rigs have not been compiled, systematic research on construction methods and technical training are lacking, and the study of basic theory needs to be deepened. The engineers and technicians who develop rotary drilling rigs should be familiar with pile foundation construction, and the engineers and technicians who use rotary drilling rigs should know their working principle and performance.
Because most of the domestic rotary drilling rig production enterprises have not worked for a long time, most of the enterprises have not formed a scale of production, products have not been serialized, the product types of more than 20 enterprises in the industry are less than 30, the product homogeneity is serious, the variety is relatively single, most of the products have a torque of 180-220 kNm, the user has a small choice, which directly leads to domestic rotary drilling. There is a fierce price war between machinery manufacturers. According to statistics, 80%-85% of pile foundations in China have diameters less than 1200 mm and depths less than 40 m. In the future, we can give full play to the multi-function of rotary drilling rig, not unilaterally emphasizing the conditions of large torque, and develop domestic rotary drilling rigs which are suitable for our national conditions and meet the construction requirements and lower prices. Most rotary drilling rigs in Japan are below 100 kNm, which is an example. Many second-hand rotary drilling rigs imported from Japan have good effect for users.
Guo Chuanxin believes that, after all, rotary drilling rigs have decades of development history abroad, and we have just started. The main problems of domestic rotary drilling rigs are as follows.
1. Varieties are relatively single, most of them are single.