SU1730351A1 - Device for determination of soil strength - Google Patents

Abstract

The invention relates to devices for determining the physicomechanical properties of soils during engineering surveys in construction. The purpose of the invention is to increase the information content, performance and accuracy of measurement. The device comprises an annular ring with grouser on the supporting surface, a tubular element fixed to it, with a rotation handle, a rod with a rotation handle and a screw-and-paste plate, passed through the cavity of the tubular element and an annular plate, as well as a load and measuring device. The grousers on the supporting surface of the annular plate are made in the form of a spiral-twisted flat tape with a sharp internal sharpening of the outer end edge and a sharp external sharpening of the upper end edge. 4 il.

Description

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The invention relates to devices for determining the physicomechanical properties of soils during engineering surveys in construction.

The purpose of the invention is to increase the information content, performance and accuracy of measurement.

FIG. 1 shows the device, a general view; in fig. 2 is a view A of FIG. one; in fig. 3 shows a section BB in FIG. one; in fig. 4 shows a section B-B in FIG. 2

The device for determining the strength of the soil contains a screw-in tip 1 connected to the spraying handle 2 by means of a rod 3 with an upper threaded section 4 passed through the cavity of the tubular element 5 rigidly connected with the lower end by means of racks 6 with an annular plate 7, on the support surface of which is rigidly Grousers are fastened in the form of a flat tape 8 spirally wrapped in a spiral with sharp internal sharpening at an angle and an external end edge and sharp external sharpening at an angle {3 upper end edges.

The upper end of the tubular element 5 communicates by means of a load dynamometer device made in the form of a compression spring 9 with a deformometer 10, and a support bearing 11c with a threaded nut 12 of the rotation handle 13 mounted on the threaded portion 4 of the rod 3.

The tubular element 5 is equipped with a torque wrench 14, mounted on bearings 15, on which is fixed a bracket 16 with plastic 17 installed on its supports, as well as a bracket 18 interacting with its stop 19 through the center of the elastic plate 17 with a deformometer 20 frozen by its deflection

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The device works as follows.

By screwing the rotation handle 2, the screw-tip nozzle 1 is immersed in the soil mass to a depth of 1.5-2 m below the test mark. As they dive, the bars 3 are built up. Then a tubular element 5 with an annular plate 7 and a rotation handle 14 is worn onto the rod 3, they are drilled to a predetermined mark by a constant cut of the soil under the supporting surface of the annular plate 7 with a spiral twisted flat tape 8 grouser and removal of cut soil into the annular cavity of the plate 7.

At the test mark, a load-carrying dynamometric device is installed on the tubular element 5 with a compression spring 9 and a deformometer 10. Thereafter, the rotation handle 13 is screwed along the threaded section 4 of the rod 3 to the support bearing 11.

By rotating the handle 13, the spring 9 of the load device is compressed by an amount controlled by the deformometer 10 and corresponding to the first stage of compressive axial force Pi on the ring plate 7.

After stabilization of the precipitation of the soil under the slab 7, the ring plate 7 is rotated with the handle 14 and the rotary slice of the soil under its support surface. At the same time, the flat belt of the grouser 8 cuts the soil along the perimeter of the annular plate with a commercial edge and spirals the soil with a sharply sharpened side. and cuts it off with the removal into the annular cavity. The maximum torque Mi of the rotational slice is recorded according to the readings of the deformeter 20.

Next, axial load PI is removed, idle rotation of the annular plate 7 is performed to clean the bottom of the cut soil and the next axial load stage Pz is created, after which a rotary cut is produced under the annular plate 7 with simultaneous fixation of the maximum moment Ma.

According to the obtained measurement results

determine the value of the soil resistivity slice TI, T2 f (Mi, M2). the Coulomb dependence is plotted and the angle of internal friction of the soil and its specific adhesion are calculated.

The device allows the soil to be tested for a rotational slice over the depth of the soil massif with a change at the test marks of the stress-strain state of the soil without disturbing its natural composition.

Claims (1)

Invention Formula A device for determining the strength of the soil, including an annular plate with grouts on a supporting surface, a tubular element fixed to it with a rotation handle, a rod with a rotation handle and a screw-nozzle, passed through the cavity of the tubular element, and an annular plate, characterized in that , in order to increase the information content, performance and accuracy of measurement, the lugs on the support surface of the ring plate are made in the form of a spiral-twisted flat tape with sharp internal sharpening outside its end face edge and a sharp outer edge sharpened top end. Compiled by N., Evstigneev Editor M.Kobyl nska Tehred M. MorgenKorrector O. Tsille Order 1499 Circulation: Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab. to9A ci