Discussion on the Development of Pile Foundation Technology
In recent twenty years, pile foundation construction technology has developed rapidly at home and abroad, at least the following trends worthy of attention.
First, the size of the pile to the long, big direction
Second, the size of the pile to the short, small direction
Third, to the direction of low pollution method pile development
Fourth, to a variety of pile material direction
1. First, the size of the pile to the long, big direction
Based on high-rise buildings and large-scale bridge tower pile foundation and other bearing needs, pile diameter is growing, more and more long pile length. Europe and the United States and Japan, the length of the steel pipe pile has reached more than 100m, the pile diameter of more than 2500mm; Shanghai Jinmao Tower steel pile into the ground 80m below the sand layer, pile diameter of 914.4mm; Wenzhou Prefabricated reinforced concrete piles Length has reached more than 70m, pile section 600mmX600mm.
In 2013, HHP35 (525KJ) hydraulic piling hammer manufactured by Guangdong Liyuan successfully applied a length of 67 meters steel piles to the design depth requirements to fill the technical gap of China's hydraulic hammer energy level. Hong Kong-Zhuhai-Macao Bridge, one of the three main bridge "sail" shape of Jiuzhou waterway bridge foundation construction, piling type of steel pipe pile, pipe diameter φ2500mm, pile length of 67 meters, the depth of 62 meters The depth of strong weathered bedrock), because it is offshore construction, and the construction area for the Chinese white dolphin living water, construction equipment must meet the low noise, low vibration, and zero pollution of environmental protection requirements, and our hydraulic piling hammer come through these big test of these.
HHP35 in Hong Kong-Zhuhai-Macao Bridge Construction (diameter of 2.5 meters, the pile length of 67 meters)
2.Second, the size of the pile to the short, small directionBased on the old urban reconstruction, the old foundation underpinning reinforcement, building corrective reinforcement, building layers and the need to fill the pile, small pile and anchor static pile technology has matured, widely used.
Small pile, also known as micro-pile or IM pile or root pile, is the French Soller Tang She (SOLETANCHE) developed a bored pile technology. Small pile is essentially small diameter pressure grouting pile; pile diameter of 70-250mm (domestic multi-purpose 250mm), long diameter greater than 30 (domestic pile length with 8-12m, aspect ratio is usually 50 or so), the use of drilling (Multi-purpose auger drilling hole), strong reinforcement (reinforcement ratio of more than 1%) and pressure grouting (grouting pressure of 1-2.5mpa) process construction.
Small pile is mainly used for the transformation of old buildings, housing increased layer, the ancient building reinforcement rectification, embankment reinforcement, seismic reinforcement of structures (structures), pit excavation slope and pile foundation anti-floating foundation works.
Speak anchor pile anchor pile anchor pile
China's self-developed anchor static pressure pile is a combination of anchor and static pressure pile technology and a clever combination of the formation of a new pile construction technology, is a new foundation treatment technology. The reinforcement mechanism is similar to that of driving piles and large static piles. The force is direct and clear, but the construction technology is different from that of driving piles and large static piles. Anchor pile static pile construction process is the first in the new (structure) built on the basis of the pile holes reserved, and embedded in the anchor or built (structure) built on the basis of excavation (Pile) hole and anchor hole with a good anchor bolt buried, and then install the pile frame, anchor with the media, the piling frame and building (structure) foundation for the building as a whole, and the use of construction (structure) The weight of the building to do counter-force (if necessary, can increase the weight), with the jack section of the prefabricated pile pressure into the soil, when the pressure and the pressure into the design requirements, the pile and foundation pouring together, the pile can be From the reach to improve the bearing capacity of the foundation and control the purpose of settlement.
The length of pile section depends on construction clearance height and machine conditions, 1-3m, pile into the soil depth of 3 - 30m. (3).
Anchor static pressure pile for the transformation of the old city, the old foundation underpinning reinforcement, narrow space site construction, the new construction can be used reverse construction.
3. Third, to the direction of low pollution method pile development
Although the prefabricated pile of cylinder type diesel hammer has the advantages of reliable pile quality, high construction speed and high bearing capacity, it has many disadvantages such as high noise, large vibration and oil splash during construction. In residential groups and public buildings Group and other sites in the construction of very limited, for this static pressure and hydraulic pile hammer into the reinforced concrete prefabricated pile construction technology in the country by the owners of all ages.
In recent 20 years, the static pressure pile inChina's soft soil areas (Wenzhou,Wuhanand the Pearl River Delta and other regions) are widely used, static pile foundation not only for multi-storey and small high-rise buildings, but also for 20-35 layer High-rise building, pile driver production and use into a new era.China's series of static pile driver is a new type of environment-friendly building foundation construction equipment, with no pollution, no noise, no vibration, fast pile, high quality piles and other significant features, the international advanced level of technology. The static pressure method has the pressure type and the top pressure two kinds of forms, the pressure pile force is 800-12000KN. The static length of the pile construction has reached more than 70m. The practice shows that it is the optimal combination of the pile driver and the pile type and the construction with the Chinese characteristics by the construction of the prestressed concrete pipe piles (PC piles) and the prestressed high strength pipe piles (PHC piles) with the step hydraulic hydraulic pile driver Construction method.
Hydraulic piling hammer
Hydraulic piling hammer to operate flexible, low noise, pollution and other environmental advantages and adjustable hammer rate, hammering frequency and wide range of travel characteristics. Even in complex geological conditions, hydraulic piling hammer can also meet a variety of specifications and types of construction. HHP series hydraulic piling hammer produced by Guangdong Liyuan has been developed and used in the field for more than 10 years. It has been improved and improved to a world-class level. It has become the largest manufacturer of hydraulic piling hammers in the domestic market. The HHP series piling hammer has been widely used in land and sea pile foundation engineering, in theHongKong-Zhuhai-MacaoBridge, offshore wind power and other world-class large-scale infrastructure projects are undertaking an important part of the construction.
HHP30 inShanghaioffshore wind power project construction (1.7 meters in diameter, pile length of 82 meters)
Hydraulic vibration hammer
Hydraulic vibratory hammer is a widely used in a variety of foundation construction of the pile construction machinery. Is the use of its periodic excitation force to pile around the soil liquefaction, in order to reduce soil friction on the pile. The use of pile body weight and pile hammer weight, if necessary, additional downward pressure on the pile body into the soil; the contrary, the application of upward tension, the pile can be pulled out of the soil. With low noise, good effect of pile driving, can be underwater operations and so on. Different from the electric vibration hammer, Guangdong force of the hydraulic vibration hammer has a nose long life, small size, the advantages of high frequency vibration, in the same effect of pile driving, to maximize the protection of the surrounding environment, eliminating resonance caused by low-frequency resonance Pollution; such advantages in large vibration hammer, such as SV80, SV150 species is particularly evident. At the same time a small hydraulic vibration hammer can be assembled on the excavator used by the excavator hydraulic system to provide power, the pile construction process more efficient and efficient.
SV150 in Guangzhou Wanda Guangzhou construction (diameter of 2.7 meters, 10 meters long pile)
4. Fourth, to a variety of pile material direction
In the case of cast-in-place piles, the types of pile materials are also diversified. Ordinary concrete, super-fluid concrete, sandless concrete, fiber concrete, self-leveling concrete and micro-expansive concrete. Driven pile is also a composite pile, such as the steel pipe shell and the concrete wall of the composite pile.
The pile foundation has the characteristics of diversity, competition, variability, applicability, development and complexity. As the pile construction or pile construction machinery manufacturing unit should do the following:
① a shrewd core (the core of science and technology as the guide, grasp the pile construction direction, an agile business philosophy; a core of success, in addition to their technical capabilities, must have the leadership ability, communication skills, management ability As well as visionary ability).
② wisdom of the team (the team to gather scientific research, construction, testing and management talents in all aspects of the team's responsibility to the community - law-abiding dedication, respect for nature; professional responsibility - dedication, innovation and enterprising; , The responsibility of employers - in good faith, mutual trust and mutual benefit; responsibility for colleagues - division of labor, the pioneering).
③ integrity of the operation (in the introduction of the new pile type must seek truth from facts, down to earth for scientific research and development work).
④ strict management (the implementation of total quality management, the implementation of prevention and improvement-based management, so that "three-wide, a diverse", that is, full, the whole process of enterprise-wide quality management and information technology).
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Guangdong Liyuan Hydraulic Machinery Co., Ltd