EA007753B1 - Method for erecting piles foundation assembly - Google Patents

Abstract

The invention relates to the building industry, and particular to methods of pile foundation erection, and more definite to the pile foundation assembling. The inventive task is to reduce materials consumption and the cost of the pile foundation assembling. The inventive method comprises driving a pile (1) into ground and subsequent splicing pile by a next pile section (2) until driving it to the depth according to the soil carrying capacity and subsequent cutting-off the upper protruding pile section and moving that pile part (3) into the place of the next pile and use it as the first section of the next pile. The novelty is characterized in that one sized piles are driven into the ground, predetermining the effective load being withstood by said pile based on the material strength to the axial compression and each pile is driven to the depth (6) at which the pile carrying capacity for said ground does not exceed the effective load.

Description

The invention relates to the field of construction, and in particular to methods of erection of pile foundations, in particular on the basis of prefabricated piles.

Prior art

There is a method of erection of a pile foundation, selected as a prototype, including driving a pile into the ground to a predetermined depth in accordance with the bearing capacity of the soil, with a pile-up, if necessary, of the pile with the next successive section, with subsequent cutting of the protruding part of the pile, moving it to the place of immersion the next pile and use it as the first section of this pile (as.with. 8I 1200601). The method allows to reduce the consumption of materials erected foundations, however, requires the definition of approaches and the definition of the specified depth of the pile driving, which would further reduce the consumption of materials.

Summary of Invention

Solved technical problem - the reduction of material consumption and the cost of construction of pile foundations.

A method of erecting a pile foundation is proposed, which includes immersion of a pile into the ground with a pile built up with the next successive section before diving to a depth in accordance with the bearing capacity of the soil, followed by cutting the protruding part of the upper pile section, moving the next piece to the place of immersing the next pile and using it as the first section of the next pile. A new one is that piles of one size are immersed in the ground, the effective load perceived by one pile of this size is pre-determined, based on the strength of the pile material on axial compression, and the immersion of each pile is carried out to a depth at which the bearing capacity of this pile does not exceed effective load. Thus, due to the observance of equal strength over the soil and material, a reduction in the material consumption of foundation construction is achieved, and the use of piles of the same size not only reduces the time required for design and construction, but also reduces construction costs.

Dip each pile can be carried out to a depth at which the bearing capacity of this pile on the ground is 0.5-1.0 of the effective load.

Pile diving can be carried out in a dynamic way, for example, by vibrodiving or driving, while in determining the effective load, the latter is reduced by 5-25%, i.e. considering the dynamic load. In this case, when the pile is submerged by driving, the effective load is reduced by 15-25%.

Also, when a pile is driven into a pile, the driving is carried out until the actual failure rate is reached, which corresponds to the bearing capacity of the pile on the ground, which can be monitored with the use of failure gauges or level markers on the driven pile.

List of figures, drawings and other materials

The invention is illustrated using a single drawing, presented in the attached figure, which schematically shows a general view of a series of piles of pile foundations, built in accordance with the present invention.

Information confirming the possibility of using the invention

The invention is illustrated by example.

Reinforced concrete pile modules with a length of 6 m of continuous square cross-section 300x300 mm of full factory readiness with butt elements at the ends were used as piles of the pile foundation. As the butt elements, you can use any known, for example, in accordance with a.s. 8I 1393878 (published 07/07/1988). B25 concrete was used for the manufacture of piles, and A111 fittings with a diameter of 13 mm were used as reinforcement.

The calculated maximum load on the pile was determined by the material _CLEAR , based on the following data: the design resistance of concrete B25 is 14.5 MPa (taking into account the reduction in compressibility factor for concrete 1.3), the cross-sectional area of concrete is 0.09 m ² ; calculated resistance reinforcement DB - 365 MPa (in terms of reduction in the reliability coefficient for steel compressive 1.07), the cross-sectional area of reinforcement - 5,3-10 ^-4 m ^2. Based on these data, the calculated ultimate load S _CALC was 1,497 MN or 152 tf.

Determined the effective load on the pile according to the formula proposed in accordance with the invention:

^Р ЭФ = кД ^- МРАСЧ where kD is the coefficient of endurance of the pile material, depending on the method of its immersion in the ground, which is taken equal to 0.8 when immersed by the impact method (driving), and when immersed by other methods it is recommended to take this coefficient equal to 0.9 vibration and 1.0 when indented.

Thus, the effective load P _EF for driving amounted to 121.6 ton-force per pile.

In accordance with SNIP, the bearing capacity of the pile on the ground at the place of foundation of the pile foundation was determined - Р _ГР = 90 tf. This amounted to 0.74 of the effective load Р _ЭФ = 121.6 tf, which is the tolerance

- 1 007753 Timo under conditions of equal strength.

For pile driving at the site of foundation construction, a pile driving installation ΣΡΌ-20Τи3 was used on the basis of a KrAZ truck with a C-996 diesel hammer with a mass of 1.8 tf. Previously, taking into account the characteristics of the used diesel hammer, the magnitude of the actual failure was determined at the above-determined bearing capacity for soil E _GD = 90 tf. The calculated actual failure was 8 _a = 0.46 cm / stroke.

Pile driving was performed as follows (see Fig. 1).

The first pile module 1 of the first pile was driven to a depth of 5 m, with a failure of 1.85 cm / stroke, the remaining part above the surface was 1 m. Next, the docking with the next pile module 2 was completed, after which the first pile was driven at 1.95 m to achieve an estimated actual failure of 8 _a = 0.46 cm / stroke. After such a driving of the first pile to a total depth of 6.95 m, the pile module 2 was cut at a height of 0.5 m from the surface of the site by an electric pile sawdust around the perimeter and corners, followed by tilting the headframe in opposite directions before separating the upper part 3 at the propyl places .

The upper part 3 was crammed as the lower section of the second pile at a calculated distance from the first pile to a depth of 4 m, with a failure of 2.0 cm / blow, after which the docking with the next pile module 4 was made and the second pile was driven , 20 m, i.e. to a total depth of 7.20 m to achieve an estimated actual failure of 8 _a = 0.46 cm / hit. Next, the pile module 4 was cut as described above, after which its upper part 5 was used as the lower section of the third pile. The following piles were driven in the same way.

Due to the unevenness of the soil level 6, on which the calculated actual failure was achieved, the depth of the pile driving was different. However, it should be noted that in this case the bearing capacity of piles along the ground is equal.

Comparison of the above-described technology with the well-known technology (without using composite piles of pile modules) in the construction of pile foundations for residential houses based on the 83 series showed that savings in pile material are 15-30% while reducing the time and cost of building the foundation.

The given example is used only for the purpose of illustrating a particular case of the invention, it does not limit the scope of legal protection presented in the claims, and the person skilled in the art is relatively simply able to implement other embodiments of the invention.

Claims (5)

CLAIM 1. The method of erection of a pile foundation, including immersion of a pile into the ground with a pile of the next successive section before diving to a depth in accordance with the bearing capacity of the soil, followed by cutting the protruding part of the upper section of the pile, moving the cut part to the place of immersion of the next pile and using it in as the first section of the next pile, characterized in that piles of the same size are immersed in the ground, the effective load is perceived, which is perceived by one pile of this type size, based on the strength of the pile material in axial compression, each pile and immersion is carried out to the depth at which the load bearing capacity of the pile on the ground does not exceed the effective load. 2. The method according to claim 1, characterized in that the immersion of each pile is carried out to a depth at which the bearing capacity of this pile on the ground is 0.5-1.0 of the effective load. 3. The method according to claim 1, characterized in that the immersion of the pile is carried out in a dynamic way, while at determining the effective load, the latter is reduced by 5-25%. 4. The method according to claim 3, characterized in that the immersion of the pile is carried out by driving, at the same time, when determining the effective load, the latter is reduced by 15-25%. 5. The method according to claim 4, characterized in that the immersion of the pile is carried out until the value of the actual failure corresponding to the bearing capacity of the pile on the ground is reached.