What Are the Different Methods for Getting Rid of Piles?

Pile foundation construction refers to the process of building foundation construction. The pile foundation consists of piles and pile caps. The pile foundation construction method is divided into two categories: precast piles and cast-in-situ piles. In addition to the selection of pile driving methods, in addition to the engineering geological conditions, the pile type, section, length, site environment, and design requirements must also be considered.

Pile foundation construction

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Pile foundation construction refers to the process of building foundation construction. The pile foundation consists of piles and pile caps. The pile foundation construction method is divided into two categories: precast piles and cast-in-situ piles. In addition to the selection of pile driving methods, in addition to the engineering geological conditions, the pile type, section, length, site environment, and design requirements must also be considered.

Chinese name

Pile foundation construction

English name

pile foundation construction

definition

After the column pile is made of reinforced concrete, steel, wood, etc., it is driven or pressed into the ground with a sinking pile machine until the soil is solid, or a hole is formed before being poured into a concrete column pile, thereby strengthening the bearing capacity of the pile cap. Force craft.

Applied discipline

Electric power (first-level discipline), thermal power generation (second-level discipline)

The above content is

The pile foundation consists of a pile and a pile cap (see pile foundation). Pile construction methods are divided into two categories: precast piles and cast-in-situ piles. In addition to the selection of pile driving methods, in addition to the engineering geological conditions, the pile type, section, length, site environment, and design requirements must also be considered. In ancient China, stone piles were used for tamping. Later, the pile length and diameter increased, and the ballast was gradually replaced by a drop hammer pulling the cast iron. The steam hammer came out in the 1780s. By the 1830s, a diesel diesel hammer had been used. With the development of the construction industry, in order to meet the needs of large-scale pile foundation engineering, pile foundation construction technology must not only increase the hammer weight and improve the lifting and hoisting operation technology, but also reduce vibration noise and environmental pollution. The construction of some prefabricated piles uses a combination of drilling and drilling (or weight-on-drilling) techniques for sinking piles after drilling and taking soil, instead of simply hammering or squeezing. At the same time, high-energy, pollution-free hydraulic hammers weighing more than 60 tons, 125 tons of steam hammers and 15 tons of diesel hammers have been applied. Construction of cast-in-situ piles

The construction methods of precast piles are: hammer method, vibration method, press-in method and water jet method. Hammering. One of the most widely used pile sinking methods in pile foundation construction. The impact energy of the hammer overcomes the resistance of the soil to the pile, so that the pile sinks to a predetermined depth. Generally suitable for hard plastic and soft plastic

1 Reinforcement ratio: When the diameter of the pile body is 300 2000mm, the reinforcement ratio of the normal cross section can be taken as 0.65% 0.2% (the high value for small diameter piles); for piles with special loads, uplift piles and rock socketed end bearings The reinforcement ratio of the pile should be calculated according to the calculation and should not be less than the above-mentioned specified value;

2 Reinforcement length:

1) End-bearing piles and foundation piles on the bank of slopes shall be reinforced along the same length or variable section of the pile body;

2) The reinforcement length of friction-type piles with a pile diameter greater than 600mm should not be less than 2/3 of the pile length; when subjected to horizontal loads, the reinforcement length should not be less than 4.0 /? (? Is the horizontal deformation coefficient of the pile);

3) For foundation piles subjected to earthquakes, the reinforcement length of the pile body shall pass through the liquefiable soil layer and the weak soil layer, and the depth into the stable soil layer shall not be less than the depth specified in Article 3.4.6 of this code;

4) The piles with negative friction resistance, the piles that rebound with the foundation soil due to pile formation and excavation of the foundation pit, the reinforcement length should pass through the weak soil layer and enter the stable soil layer, and the depth of entry should not be less than 2 ~ 3 times the diameter of the pile body;

5) Special anti-pull piles and piles subjected to pull force due to earthquake, frost heave or expansion force should be reinforced with equal sections or variable sections.

3 For piles subjected to horizontal load, the main reinforcement shall not be less than 812; for compression piles and uplift piles, the main reinforcement shall not be less than 610; the longitudinal main reinforcement shall be uniformly arranged along the periphery of the pile body, and the net distance shall not be less than 60mm;

4 The stirrups should be spiral, the diameter should not be less than 6mm, and the spacing should be 200 ~ 300mm; when the pile foundation is subjected to horizontal loads, the pile foundation is subjected to horizontal earthquakes, and the pile's compressive bearing capacity is calculated in consideration of the main reinforcement, The stirrups in the range of 5d below the top should be densified, and the spacing should not be greater than 100mm; the stirrups should be densified when the pile body is within the range of the liquefied soil layer; when considering the forces of the stirrups, the stirrup configuration should meet the current national standard Relevant provisions of the "Specifications for the Design of Concrete Structures" GB 50010; when the length of the reinforcement cage exceeds 4m, a welding stiffener with a diameter of not less than 12mm should be provided every 2m.

4.1.2 The thickness of pile concrete and concrete protective layer shall meet the following requirements:

1 The strength grade of pile concrete shall not be less than C25, and the strength grade of concrete precast pile tip shall not be less than C30;

2 The thickness of the concrete protection layer of the main reinforcement of the cast-in-place pile shall not be less than 35mm, and the thickness of the concrete protection layer of the main reinforcement of the cast-in-place pile shall not be less than 50mm;

3 The thickness of the pile concrete protection layer in the fourth and fifth environments should comply with the relevant provisions of the current national standards "Code for Design of Port Engineering Concrete Structures" JTJ 267 and "Code for Design of Anticorrosive Design of Industrial Buildings" GB 50046.

4.1.3 The size of the enlarged bottom of the enlarged bottom cast-in-place pile shall meet the following requirements (Figure 4.1.3):

1 When the bearing capacity of the bearing layer is high, the overlying soil layer is poor, and the long diameter of the pile is relatively small, the enlarged bottom pile can be used; the ratio D / d of the diameter of the enlarged bottom end to the diameter of the pile body should be based on the requirements of the bearing capacity and the expansion. The soil characteristics of the bearing layer at the bottom side and the pile end and the method of expanding the bottom are determined; the D / d of the excavated pile should not be greater than 3, and the D / d of the bored pile should not be greater than 2.5;

2 The slope of the side of the bottom of the enlarged bottom should be determined according to the actual pore formation and soil self-supporting conditions. A / hc can be 1/4 1/2, sandy soil can be 1/4, silt soil and clay soil can be 1/3 1. /2;

3 The bottom surface of the enlarged bottom should be in the shape of a pot bottom, and the sagittal height hb is preferably (0.15 to 0.20) D. ^[1]