EA001693B1 - Assembly structure of screw-type metal pile - Google Patents

Abstract

An assembly structure of screw-type metal pile, characterized in that to increase the carrying capacity of said pile plates are rigidly fixed on the pile body serving as thrust supports for blade which put on the pile body and fixed with a stopper bolt passing through the pile body.

Description

The invention relates to construction and can be used in the construction and strengthening of buildings and structures, as well as for anchoring retaining walls.

Due to the huge variety of engineering and geological conditions of construction sites on which buildings and structures are being built or have been erected, such ground conditions are often encountered that require the use of pile tools. In the conditions of close urban development, in the presence of a large number of historical buildings and monuments in Russian cities, the traditional way of immersing driven, bored and crushed piles becomes impossible due to significant effects on nearby buildings, causing undesirable deformations in them.

In this regard, in many cities, in particular in Moscow, St. Petersburg and others, this type of work is prohibited.

At the same time, many historic buildings require major repairs, including the strengthening of foundations with piles.

Currently, for these purposes, injection piles are widely used, which have a number of disadvantages, which include

- receipt of a large amount of sludge, which complicates the performance of work in urban conditions, rather bulky equipment that does not allow work in low basements;

- low bearing capacity of injection piles working on friction along the lateral surface;

- low productivity of existing equipment.

All these disadvantages are deprived of screw metal piles.

It is known that the bearing capacity of a screw pile is determined by the physico-mechanical characteristics of the soils on which the blade of the screw pile rests. The larger the diameter of the blade, the larger the cross-sectional area that perceives the load.

In existing screw piles, the diameter of the blade is specified and, as a rule, is rigidly connected to the tip of the pile. In real conditions of construction, the base soils in most cases have variegated strata, significantly different from each other in their physical and mechanical characteristics. Under such conditions, it is preferable to place the blades of a screw pile in those layers of soil that have the best physicomechanical characteristics. To achieve this, you need to make the blades of a screw pile removable. In this case, the diameter of the blade can be selected based on the physicomechanical characteristics of the soils, while the greatest effect of the used pile material is achieved. In addition, in order to be able to perform work on screwing piles in any conditions constrained by height, the screw piles must be composite, and the height of the element of the composite screw piles must vary widely.

Known construction of piles (Japanese patent No. 3-50045 MKI E 02Ό 5/56, 1991).

This pile differs in that at its columnar section discontinuous or continuous blades are made, which are welded to the columnar part. The pile trunk has a circular shape in cross section. The pile has the following disadvantages. Continuous blades are a screw, which, as you know, helps to screw the pile, but does not increase the bearing capacity of the pile. Intermittent blades perceive the load individually. The bearing capacity of each blade is determined not only by the physical and mechanical characteristics of the soil, but also by the quality of the welding connecting the blade to the pile shaft. Even with excellent welding quality, the bearing capacity of the blade will be limited by the length of the weld, which is limited in this design. If the blade is screwed into the soil with high physical and mechanical characteristics, then the soil properties will not be realized. In addition, the pile under consideration in this patent is not composite, therefore, has limited use, i.e. in an open area for the construction of foundations for newly built buildings.

A known design of a screw pile (USSR author's certificate No. 1009001, MKI E 02Ό 5/56, 1983); characterized in that the pile consists of a barrel and a screw tip, consisting of a helical blade with a pointed part. The tip and trunk of the pile are joined point blank.

The design of this pile has only one prefabricated element - the tip, therefore it can be used for immersion in only one bearing layer of soil, which limits its bearing capacity. In addition, the pile blade is welded to the tip, and this drawback was examined in detail when parsing the previous patent. The pile shaft has a circular cross section.

A close technical solution to the claimed one is the design of a screw anchor (USSR author's certificate No. 1315541, MKI E 02Ό 5/56, 1987), characterized in that the hubs with a screw blade are connected to the hollow shaft by screw thread.

The disadvantages of this solution are that the connection of the blade to the hub is carried out by welding. Therefore, the bearing capacity of piles will be determined not only by the bearing capacity of soils, but also by the bearing capacity of welding. With blade thicknesses up to 1.0 cm, a powerful welding seam cannot be formed.

In addition, the connection of the hub with the blades is carried out using a threaded connection. Such a connection does not allow unscrewing the piles, since the unscrewing process occurs in the opposite direction from the screwing. This limits the scope of application of a screw pile, since when eliminating this drawback, it can be repeatedly used as an anchor or an experimental pile for static tests.

The closest technical solution to the claimed one is the design of a screw pile, described in the USSR author's certificate No. 1321535 MKI E 021) 5/56 "Method of installation in the soil of a screw pile."

This design allows you to fully utilize the bearing capacity of soils.

The disadvantages of the design include the impossibility of unscrewing the piles from the ground, since it does not provide for the necessary structural elements for these cases. In addition, the blades are welded to the hub and, therefore, the structural strength of the pile will be determined by the quality of welding and the parameters of the weld.

The aim of the invention is to increase the structural bearing capacity of a metal screw pile.

This goal is achieved by the fact that the barrel of a screw metal pile is a square onto which the stops are welded, which are plates with a thickness of at least 1.0 cm. The blade is a sheet of circular shape cut along the radius. In the center of the blade is a hole in the form of a square, the side of which is 0.5 mm larger than the side of the square of the pile shaft. The ends of the cut radius are separated in relation to each other in a vertical plane. The blade is put on the trunk from the bottom up to the stop of the upper plane of the blade in the thrust plates, and the lower plane of the blade is fixed with a special bolt. The structural bearing capacity of the blade will be determined by the tensile strength of the material

N = K x E where K is the strength characteristic of the material; E is the cross-sectional area of the calculated design.

This design of a screw pile allows you to use the most fully bearing capacity of soils into which the pile blades will be screwed, since it will be possible to determine in advance the area of the blade and select its corresponding diameter.

The cost of the pile itself will decrease, since in the factory it will be necessary to produce only blades, and the assembly of the pile itself can be carried out in any conditions, including the construction site.

Claims (1)

CLAIM Screw metal team pile, characterized in that, in order to increase the bearing capacity of the pile, plates are fixed on its trunk, which are stops for the blade of the pile, which is put on the pile shaft and fixed with a locking bolt passing through the pile shaft.