Buroinjectional piles. Description

Buroinjectional piles are used, as a rule, to strengthen the foundations of buildings undergoing reconstruction. Their wide use is due to several factors. First of all, the drilling pile piles have small dimensions, together with special technical capabilities for use. These designs allow you to work in rooms whose height is up to two meters, punch holes through brickwork, reinforced concrete, concrete up to three hundred millimeters in diameter and up to fifty meters in depth. A small installation can drill in a room with an externally mounted power unit.

Buroinjectional piles have varieties. One of the types are structures used in new buildings to strengthen walls in the ground and fences for vertical slopes. They are called "injection anchors". Special anchor installations are used.

Depending on ground conditions, a choice is made of one or another tool for drilling. The borehole piles have a length and a diameter in accordance with a given load-bearing capacity of the piles or the force perceived by the anchor.

Drilling in unstable and waterlogged soils is carried out with the washing of the well with the aid of clay mortar or using casing pipes.

The construction of bored piles is carried out using reinforcement. In this case, in accordance with the nature of the acting load, the reinforcement is carried out over the entire length or in the upper part. The length of the reinforcement section is determined in accordance with the height of the room. Armomarkas set after, before, or during the testing of the well.

The structure of pile foundations assumes the presence of fixing components, centering piles in the wells and providing the necessary thickness of the protective layer in the concrete. With the help of welded joints it is ensured the connection of reinforcement frames along the length and, accordingly, the strength of the reinforcement. On the contour of the pile at a distance not less than the diameter of the rod itself are located rods. Usually the sectional area of the longitudinal reinforcement is not less than 0.5% of the cross-sectional area of the pile itself.

To strengthen the load-bearing characteristics of the pile, due to compaction of the soil, the well walls and fresh concrete are crimped.

Crimping can be done in various ways.

Thus, it is possible to pump an additional portion of the solution with a pump through a tampon that is unclamped at the wellhead, in a wellhead or an existing base. In this case, pressurization is carried out at a pressure of 0.2-0.3 MPa for two minutes. If the pressure is not maintained during this time, it is not possible to work again, after an hour or two, until the desired result is obtained.

Crimping can also be performed at a certain section of the pile or in the wellbore face through the auger augers.

The work is carried out using electric discharge technology. In this case, an electrohydrodynamic crimping of a well bottom or walls is performed.

Another method is "re-injection." In this case, a particular section is pressed on the pile's trunk by injecting a break in the primary infusion of concrete.

Buroinjectional piles are arranged in accordance with a certain technological cycle, consisting of several operations:

1. Drilling.
2. Organization of a reinforced frame.
3. Filling the well with a concrete (fine-grained) mixture.
4. Pressing fresh mix.

It should be noted that the reinforced frame is allowed to be installed both after and before filling the well with a mixture.

Recently there has been a constant improvement of the equipment used, technological operations and techniques, which, undoubtedly, is aimed at improving the quality and bearing capacity of piles.