The most developed countries in the world of pile-driving machinery are mainly Germany, Italy and Japan. The most advanced equipment and construction methods are generally first developed in these three countries, followed by the United States, the United Kingdom, France, the Netherlands, and Finland. In the global pile machinery market, sales of Baodi, Tuoli, and Casagrand should rank among the top three.

Driven by the development of China's transportation, energy, and construction industries in the past two years, especially the construction of high-speed railways, China's piling machinery industry has ushered in a period of rapid development.

1 The development of China's piling machinery industry China's construction machinery industry has benefited from the favorable factors such as the sustained development of the national economy, the pull of fixed asset investment, the implementation of the national strategy to revitalize the equipment manufacturing industry, and the entire industry has continued to develop. According to statistics from the China Construction Machinery Industry Association Pile Machinery Branch, in 2010 China's piling machinery sales reached 8 billion yuan and the sales volume of products was 5,000 units. Although China is still behind Germany, Italy, and other countries in terms of output value, it is already the world's number one in terms of quantity.

1.1 Rotary drilling rigs Rotary drilling rigs are widely used in the construction of bored piles at home and abroad, especially in Europe and Japan and other developed countries have long been the main equipment for the construction of large diameter bored piles.

Domestic rotary drilling rigs started in the 1980s. In 1988, Beijing Chengjian Engineering Machinery Factory developed a crawler crane attached rotary drilling rig. In the mid 1990s, Zhengzhou Exploration Machinery Co., Ltd. introduced the production of adhesive rotary drilling rigs from British company BSP. Technology, but because this technology is relatively backward, coordination of supporting cranes is difficult and there is no mass production. In 1998, Xugong Group successfully developed the first real rotary drilling rig in China, but it was limited by the domestic engine, hydraulic parts, drill rods, power heads and other supporting parts and use, and there was no mass production. Before 2003, China's rotary drilling rigs were mainly imported and expensive, and only a few powerful basic construction companies purchased them. The construction of the Qinghai-Tibet Railway has demonstrated the superiority of the rotary drilling rig on the one hand, and on the other hand, it also reminds domestic manufacturers that the basic construction machinery also has a lot of room for development. Some companies subsequently developed rotary drilling rigs such as Beijing Sany Heavy Machinery, Beijing CSR, Hunan Shanhe Intelligence, and Foton Heavy Industry. The successful development of domestic rotary drilling rigs drastically reduced the price of rotary drilling rigs and broke the import of rotary drilling rigs. The situation in which drilling rigs dominated the world made more users able to afford rotary-drilling rigs, and also achieved better economic benefits through the purchase of rotary drilling rigs. This complementary relationship has greatly promoted the application of rotary-drilling methods in China.

During the “Eleventh Five-Year Plan” and “Twelfth Five-Year Plan” period, China has invested huge sums of money to build railways, highways, electric power, urban public facilities, etc. In particular, the construction of high-speed railways has brought unprecedented opportunities for the development of rotary drilling rigs in China. More than 80% of the high-speed rail passenger dedicated lines are bridges. The diameter of the bridge piles is mostly less than 1.5m and the depth is less than 60m, which is suitable for the construction of rotary drilling rigs.

After the development in recent years, the main performance of the whole domestic rotary drilling rig has approached or reached the international advanced level. At present, China has been able to produce large-, medium- and small-sized rotary drilling rigs ranging from 6tm to 40tm. According to the market demand, the small rotary drilling rigs developed by Shandong Xinguo Heavy Machinery, Zhengzhou Kawashima, and Zhejiang Zhenzhong have achieved very good results in the field of construction of civil- and public-staked piles, with accurate positioning for small rotary excavations, low operating costs, and maintenance. Convenient, fast return, very suitable for small construction units. The large-scale rotary drilling rigs developed by CSR, Xugong, Sany and other companies are applied to the construction of large-scale bridge pile foundations of the Yangtze River and the Yellow River, which greatly increase the construction efficiency and shorten the construction period. Since 2006, domestic rotary drilling rigs have occupied the domestic market. According to statistics of the piling machinery branch, in 2006, the sales of rotary drilling rigs in China were about 350 units, about 450 units in 2007, about 900 units in 2008, 1,200 units in 2009, and 1,700 in 2010. At present, China is the world's largest producer and user of rotary drilling rigs.

Although the broad market prospects provide a market opportunity for China's rotary drilling rigs, compared with the development of foreign rotary drilling rigs for several decades, the domestic rotary drilling rig industry started relatively late, and a large number of applications in the market are not long. Therefore, the need for improvement of domestic equipment can not be ignored. First of all, there is a single type of rotary drilling rig in China. Most manufacturers only produce one or two types of products and should produce a wide variety of products. Second, there are fewer products for domestic innovation. Third, the selection of imported accessory parts is single and should be further diversified. The level of after-sales service should also be gradually strengthened. Fourth, the quality of domestic-made fittings such as drill rods and drilling tools should be further improved. Fifth, there is not enough research on the construction technology of rotary drilling rigs. China has a vast territory and complex geological conditions. For different types of geology, different construction schemes and suitable construction equipment should be selected. For example, the southeast coastal strata are relatively soft, and the strata are complicated in most parts of the southwest and northwest. The Lanxin line is basically a pebble stratum. How to form pores in these areas and how to improve the construction efficiency require companies to make great efforts to study. After the host is finished, it cannot solve the problem.

1.2 Long spiral drilling rig Long spiral drilling rig has the advantages of high efficiency and low cost in the construction of concrete bored piles with small diameter (below 800mm) and small depth (below 30m), especially CFG piles and post-reinforcement cage technology in recent years. The successful development has greatly improved the scope of application of long spiral bored cast-in-place piles, and has been applied to Hubei, Hunan, and Guangdong from the vast northern regions of China. The use of CFG piles for subgrade reinforcement in some sections of the high-speed railway passenger dedicated line has also led to the production of long spiral drilling rigs. The production of long spiral drilling rigs has steadily increased in recent years. Statistics of several major manufacturers, in 2009 produced 363 hydraulic walking long spiral drilling rigs, production of electric, hydraulic crawler long auger 178, the above statistics are not comprehensive, according to the production of long spiral drill power head, 2009 long The output of spiral rigs should be close to 1,000 units, about 1,500 units in 2010. Now China has formed several large long spiral rig production bases in Zhengzhou, Xinhe, Jiaodong, Ruian and Changsha.

The production and production of long spiral drilling rigs are numerous, but the product performance of each factory is not very different. The rig power heads and drilling tools of all manufacturers are almost the same. The long-auger drilling rig construction method used in our country is relatively single, and there are many construction methods for the deformation of the long-auger drilling rig in Japan. The Chinese manufacturer is disjointed from the construction, and the improvement of the equipment has not progressed for many years. In fact, long spiral drilling rigs still have a lot of room for development.

1) Develop a casing-type long-auger drilling rig that is suitable for complex and easily collapsed formations such as soft soil layers and pebble layers, that is, high-speed, low-torque positive rotation of the built-in drill pipe, and low-speed high-torque reverse rotation of the outer casing.

2) The rig's power head is developed from single speed to multi-speed to meet the requirements of different pile diameters and depths, and to increase construction efficiency.

3) The drilling tool directly affects the construction efficiency of the long spiral drilling rig, and the manufacturer should combine it with the construction unit to develop drilling tools suitable for different geological conditions. Foreign manufacturers, such as Japan's Sanhe Machinery, have only dozens of long spiral drill bits.

4) The product lacks necessary safety devices, such as pull-out force limiters and anti-over-roll devices, which have poor stability and frequent accidents.

1.3 Forward and Reverse Cycle Engineering Drilling Rig Although rotary drilling rigs have developed rapidly, the construction of concrete cast-in-place piles in southeastern coastal areas and other small and medium-sized cities in China is still dominated by positive and negative cycle drilling rigs. Positive and negative circulation drilling rig construction requires mud wall protection. A lot of mud is produced, and many construction companies cause serious environmental pollution without any disposal of the mud. With the improvement of China's economic level, the improvement of environmental protection laws and the application of new equipment, the use of such rigs will become less and less. Of course, in the large-diameter (above 2m) large depth (above 60m) pile foundation construction, positive and negative cycle engineering rigs still have advantages. In recent years, the output of forward and reverse cycle drilling rigs has changed little, and is around 1,000 units each year.

In the construction of cross-river bridge foundation piles, there are still gaps between domestic large-diameter positive and negative circulation engineering rigs and imported drilling rigs, such as many failures, low rock-entry efficiency, and easily damaged drill bits. In recent years, there are many projects on the rivers in China. Domestic manufacturers should tackle this issue.

In some areas of our country, such as Wenzhou and Ningbo, the soil is particularly soft, mainly silt, and the friction on the side of the pile is very small. It is required that the pile must enter the rock. The rock-entering equipment in our country is very backward. Nowadays, small and medium-diameter rock-socketed piles are basically constructed with impact drills, but the efficiency is very low. Foreign countries usually use DTH hammers to build rock formations with high efficiency, but domestic large-diameter DTH hammers are still blank, while small-diameter DTH hammers have poor reliability and need further study.

1.4 Hydraulic static pile driver The current construction equipment for pipe piles is mainly hydraulic static pile driver. Its advantages are no vibration, no noise, no pollution, and good quality. Therefore, concrete prefabricated pipe piles are popular in China in recent years. A quick construction method. At present, from the south to the north, there are applications from the coast to most provinces and cities in the interior, especially in the soft soil area, which has become the preferred type of construction for workers and civilians. The main reasons are as follows:

1) The pipe piles are processed in the factory, and the quality is easy to guarantee. Unlike on-site piles, it is prone to quality accidents.

2) The size of pipe pile manufacturing enterprises is increasing, and the cost of pipe piles is greatly reduced;

3) The performance of the hydraulic static pile driver has been significantly improved, and the types of products have become more and more abundant;

4) Vigorously promote the production of pipe piles and pressurizing piles.

In 2009, China produced more than 400 hydraulic static pile drivers. The hydraulic static pile driver manufacturing enterprises are mainly concentrated in Hunan, Zhejiang, Shanghai, and Jiangsu. The market share of Hunan Sunhe Intelligent has exceeded 50%. In view of the difficulty in the construction of the hard stratum static pile driver, Shanhe Intelligence and the Guangdong Academy of Science and Technology are jointly developing a static pile driver with a rig, that is, using an auger set inside the pile pipe to drill and press the pile to reach a predetermined location. Depth, rig reversal, reaming bit retracted, pull the drill pipe from the pile. The biggest drawback of the hydraulic static pile driver is heavy, high transportation costs and troublesome transfer sites.

1.5 Pile hammers Pile hammers include barrel type diesel hammers, guide rod type diesel hammers, hydraulic hammers, and vibratory hammers.

The main diesel cylinder manufacturer is Shanghai Engineering Machinery Factory, Guangdong Liyuan Hydraulic Machinery Co., Ltd., etc. The main manufacturers of lead type diesel hammers include Jiangsu Dongda, Juli, Juwei, and Fushun 6409. Among them, the Shanghai Construction Machinery Plant's technology imported from Germany's Delmark has the best quality and the largest volume. To complement the construction of the Yangshan Port and the Hangzhou Bay Bridge and the Donghai Bridge, the plant has developed D160, D220 diesel hammers, and D220 diesel. Hammer is currently the world's largest diesel hammer. Diesel hammers cannot be solved due to noise, fume pollution, etc., and use will be less and less.

The major manufacturers of vibratory hammers are Zhejiang Zhenzhong Construction Machinery Co., Ltd., Zhejiang Ruian Bada Construction Machinery Factory, etc. The development of electric vibratory hammers in China is very mature. It can be designed and manufactured from several kilowatts to several hundred kilowatts. In the past two years, Zhejiang Zhenzhong Company's adjustable eccentric torque vibratory hammer has been applied to Shanghai Yangshan Port Sand Pile Project and exported to Japan, South Korea and other developed countries. China's hydraulic vibratory hammer has just started. Shanghai Zhenzhong has developed a hydraulic vibratory hammer with an exciting force of 100t and 200t. Hydraulic vibratory hammers should be developed in the direction of high frequency and frequency modulation.

In the next few years, China will invest trillions of dollars in the construction of offshore wind power. In the past, most of the foundations of offshore wind power were group piles, and the construction period of group piles was long and the cost was high. Offshore wind power under construction in Europe, Japan and other countries has been changed to a single pile foundation, that is, direct injection of large steel pipes with a diameter of 5 to 6 m, a wall thickness of about 100 mm, and a length of tens of meters into a hydraulic steel hammer or submerged into the seabed with a vibratory hammer . Such large-scale hydraulic hammers or vibratory hammers are still blank in China and must be imported from abroad. The prices of imported products are very expensive. Combined with engineering needs, domestic companies with strong capabilities should start research.

1.6 Hydraulic Grab Bucket The technology of underground continuous wall has been developing rapidly in the past ten years. Shanghai, Guangzhou, Beijing and other places have applied underground continuous wall support technology in hundreds of projects such as high-rise buildings and subway stations. It is understood that the State Council has approved more than 20 cities for the construction of subways and light rails, and has invested nearly RMB 1 trillion. China's underground continuous wall construction equipment will surely have a big development. The equipment used in the construction of underground diaphragm walls in China is hydraulic grabs and multi-axis drilling machines.

The construction of large-depth large-thickness underground continuous walls usually uses grab bucket-type slot machines, which mainly include steel wire rope grabs, hydraulic guide plate grabs, guide bar grabs, and hybrid grab buckets. The hydraulic guide plate grab has lift of the grab bucket. With the features of high speed, large closing force, strong trenching capacity, high construction efficiency, large construction depth, large wall thickness, and high wall-forming accuracy (automatic corrective device), it is the most used. In recent years, domestic hydraulic grabs have developed rapidly. In 2009, the sales of hydraulic grabs in China were around 80 units. The production companies include Shanghai Jintai, Xugong, CSR, Sanyi, and Shanghai Engineering. At present, Shanghai Jintai's hydraulic grab market share exceeds 50%.

1.7 multi-axis drilling machine SMW construction method is to use a special multi-axis drilling machine (usually 3 axes) drilling cutting soil, while the end of the drill bit will be injected into the soil cement slurry, after mixing and mixing, and then H Shaped steel or other profiles are inserted into the mixing pile body to form a continuous underground wall, and the wall is directly used as a retaining and water stop structure. The construction method replaces the existing method of enclosing the cast-in-situ pile and the water-stop curtain, and has the advantages of rapid construction speed, good water stoppage effect, low construction cost, no pollution, and the like, and is a construction process with popularization prospects. SMW engineering method has been promoted in Shanghai, Tianjin, Nanjing, Hangzhou and other places.

The multi-axis drilling machine used for construction of SMW construction method in China was all imported from Japan in the early days, such as Japan Sanhe Machinery and Sanhe Machinery. It was mainly based on two mobile phones. The price was high and the shortage of equipment severely restricted the promotion of SMW construction method in China. application. In recent years, domestic multi-axis drilling machines for SMW construction methods have been able to meet the needs of domestic construction. The main production companies are Shanghai Engineering, Shanghai Jintai, and Zhenzhong, Zhejiang. In 2009, sales of SMW engineering multi-axis drilling machines were 110 units. about. This year, Shanghai Construction Machinery Plant has developed an ultra-deep multi-axis drilling rig with a construction depth of more than 50m according to the engineering needs, which is very good for the foundation pit construction of Zhengzhou HSR station.

The pile rack is a customary name. According to its use and construction principle, it is actually a lifting and guiding device for piling. The diesel hammer, hydraulic hammer, vibratory hammer, drilling machine, vibrator, deep mixer and other working devices must be used together with the pile frame during construction. The function of the pile frame is mainly to lift various pile hammers and other working devices, pile hoppers. , Reinforcing cages, etc., to guide and vary the working devices such as pile hammers (sloped piles) to determine the pile position.

The pile frame is divided into roller tube type, track type, step type and crawler type according to structural features. The pile racks that are widely used in China are roller tube type and walking type. This kind of pile rack has rarely been used internationally. The hydraulic walking pile frame is a pile frame with Chinese characteristics. It moves piles and turns in a stepped manner. The construction cost is low and it is welcomed by small and medium-sized construction companies. Its biggest drawback is inconvenient transfer. The hydraulic crawler type three-point pile rack is one of the most advanced pile racks widely used abroad. The Shanghai Construction Machinery Plant introduced the Japanese vehicle DH558, DH658 pile rack production technology, and its products have reached the international advanced level.

In the late 1990s, some manufacturers in China developed the electric crawler-type pile carrier by combining the advantages of the foot pile carrier and the track pile carrier. The cost was significantly lower than that of the hydraulic track pile carrier, and the movement was easier than walking. The product is welcomed by the construction company and is the development direction of the pile carrier in the short term, but its external power supply has potential safety hazards.

2 Pile Machinery Products to be Researched in China 2.1 Underground Diaphragm Construction Equipment The underground continuous wall includes a load-bearing continuous wall, a seepage retaining wall and a simple impervious wall. The construction of underground continuous wall in general strata often uses hydraulic grabs, but it is difficult to meet the construction of hydraulic grabs in hard strata. For this reason, Baoji and Casagrand have developed horizontal multi-axis excavators, China's Three Gorges Project and South-to-North Water Transfer Project. The Yellow Crossing Project, the Shenzhen Metro, and the Shanghai Metro introduced the above-mentioned equipment, and the use effect is very good.

In the construction of anti-seepage retaining walls (cemented concrete walls), vertical single-axis or multi-axis drilling rigs have been used in the past, and SMW construction methods are widely used in coastal areas in Japan and China. However, current multi-axis drilling rigs encounter difficulties in the construction of hard and complex strata. For example, the construction of three-axis drilling rigs in Beijing is difficult. To solve this problem, Germany Breguet has developed a BCM series horizontal multi-shaft deep mixer, and Japanese Kobelco has developed a TRD cutting machine. Baodi BCM series horizontal multi-shaft deep mixing machine has two horizontally arranged cutting heads in the lower part. The cutting head is provided with cutting teeth and the upper part is a square guide rod, which is connected to the three-pile pile driver column through the slide. The machine has a wide adaptability and can be constructed in rock and gravel layers. The construction depth can reach 35m, the construction accuracy is high, and the waterproof effect of the wall is good and there is no pollution. The unique structure of Kobelco's TRD cutting machine is that a sprocket chain type cutting mechanism is arranged laterally on the crawler chassis, and a cutter head is mounted on the surrounding chain. Different from the previous longitudinal construction method, the TRD cutting machine begins to drill to a predetermined depth and then cuts horizontally at full depth. At the same time, cutting is performed by injecting cement slurry to form a cement concrete wall. The construction efficiency of TRD cutting machine is very high, the actual depth of construction has reached 60m, and the wall has good quality and no pollution.

2.2 Demolition equipment for underground obstacles With the increasing number of projects for the transformation of old cities, it is a difficult problem to dismantle the underground foundations of old buildings. The stadiums of the 2010 Shanghai World Expo are all built on the original factories on both banks of the Huangpu River. There are similar problems. Now China has adopted vibration and high pressure flushing. The old cities in Japan and other developed countries have undergone a large number of projects and have also developed a variety of construction methods and equipment to remove underground obstacles. Generally, full-sleeve, full-rotary drilling machines are used for cutting. There are three types of obstacles that can be removed from the casing: (1) Crushing with a grapple or a cross-hammer; (2) Electric or hydraulically driven short-screw bits Remove; 3 multi-claw hydraulic crusher clips removed.

2.3 Long spiral drilling rig into rock equipment Many pile foundations now require piles to enter the rock in order to ensure bearing capacity. The rock-entering equipment currently used in our country is very backward, which is basically a percussive drill with low efficiency and serious mud pollution. In countries such as South Korea and Japan, there is an engineering method that is very effective in rock construction. That is, the twin power head long spiral drilling rig and the pneumatic DTH hammer are jointly constructed. The specific method is: the internal power head drives a long spiral drill pipe, and the drill pipe is equipped with a downhole hammer at the lower end. When the drill pipe drives the DTH hammer to rotate, the high pressure air moves the head of the DTH hammer through the internal hole of the drill rod to move up and down. In this way, it is impacted while turning, breaking the rock into small pieces. Due to the reverse rotation of the outer casing driven by the outer head, the rock broken into small pieces is returned to the ground along the spiral blade under the action of high-pressure air. After reaching the predetermined depth, the inner drill rod and the hammer of the submerged hole are pulled out, and the outer casing is pulled out after the concrete is inserted into the reinforcement cage to fill the concrete. This construction method has high efficiency, good hole formation quality and no mud pollution.

3 Main issues and recommendations 1) Combine construction methods and continuously develop new products. The characteristics of piling machinery are: to meet different pile types, different geological conditions and different engineering requirements, and with the continuous emergence of construction methods, it is necessary to develop new varieties. Therefore, every equipment in the piling machinery industry is With their respective scope of adaptation, they are currently in a period of rapid development. Enterprises must seize the opportunities, lay a good foundation, and set a good position.

2) Strengthen independent innovation, enhance the performance of traditional products, and use high technology to transform and upgrade traditional products is an important measure for the industry to improve its competitiveness.

3) Improve core competencies and move to the world with independent innovation. In recent years, the export situation of China's piling machinery industry is gratifying, but there is still a certain gap between the products and the world's advanced level. To build a stable market share and brand, the company must bring products, accessories and services to a certain height. This is The basic guarantee for achieving international development.

4) Avoid disorderly competition, promote harmony and win together. The company’s development strategy should be for the common development of stakeholders. Enterprises must constantly innovate independently in light of the national conditions and the characteristics of project construction, earnestly study the market, so that each company has its own characteristics and brand, forming a differentiated competitive landscape. , out of a steady development path for their own.