The field of use of the invention is construction and technology of cast-in-situ pile basement in soil.
The linear casing tube (1) contains a conical valve (2), located at the lower end and suspended by a shaft (3) at the rotation bearing (4), fixed inside of the casing tube (1). The lower end of the casing tube (1) has conical narrowing having asymmetric gripping gaps (5) for fixing the conical valve (2). On the upper surface of the conical valve (2) asymmetric gripping fangs (6) are fixed. Between the conical valve (2) and the shaft (3) a conical drainer (6) for the concrete mix flow resistance reduction is fixed.
In the technological process, the conical valve (2) is joined at the lower end of the casing tube (1) and it is screwed in the soil by the method of the soil radial compaction. In the casing tube (1) the concrete mix is filled. Then the casing tube (1) is turned in the opposite direction and lifted out of the borehole. Under the pressure of the liquid concrete mix, the conical valve (2) is opened and the concrete mix (9) is poured into the borehole. The conical valve (2) hangs at the rotation bearing (4) and also is lifted out through the liquid concrete mix together with the casing tube (1).
So, the costly metallic valve (2) does not remain in the soil of the boring hole, and the casing tube (1) with the conical valve (2) together are ready for next pile technological processes.