SU727758A1 - Failure detector - Google Patents

Description

(54) FAIL

I

The invention relates to devices for determining failure of elements immersed in the ground and can be used at construction sites during pile driving and control tests.

A fail-over is known, which includes a sensor with inertial mass, mounting and recording devices 1.

The fault meter is made with a flint stabilizer connected to an electrical circuit with a power source and a half bridge, the diagonal of which includes a milliammeter with shunt capacitance. The magnitude of the failures is measured by the arrow of a milliammeter, calibrated in millimeters of failure.

A known device does not have automatic recording of failure graphs and the accuracy of determining the magnitude of failure is insufficient.

Of the known failures, the closest in technical essence to the invention is a failuring device, comprising a yoke, a carriage with a recorder and a drum with chart paper 2

The disadvantage of the failure meter is the lack of kinematic connection between the recorder and the pile. This link works without

of the faults during lateral oscillations of the pile in only two planes parallel to the lateral facets of the rectangular pile. With diagonal oscillations of the pile (when hammered), reciprocal movements of the kinematic connection elements with off-center friction forces occur, and this entails both an inaccuracy in recording the failure of the pile and the failure of the part of the connection itself.

The purpose of the invention is to increase the accuracy of measurements.

The goal is achieved by the fact that the proposed refractor, which includes a collar, a carriage with a recorder and a drum with chart paper, is provided with a clip with chart paper and an additional recorder in contact with it with a traction spring, and the main recorder is equipped with a roller with a ball at one end, and the yoke is fixed on the yoke, the slider with ballon is housed in the yoke with the possibility of free movement, and the pull spring is connected to the drum.

FIG. 1 shows a diagram of the proposed device; in fig. 2 shows section A-A in FIG. one.

The base of the refusal meter contains the base 1. Two racks are welded to it - left 2 tubular and right 3 from a metal rod. A mounting bar 4 and a handle 5 are attached to the posts. A drum 6 is placed between the legs of the bed, which is centered by bolts 7 (below) and 8 (above). The drum is opened with graph paper. The upper part of the drum is a rotating disk 9 which is attached to the main drum by a bolt 10.

On the left tubular rack with a sliding fit, the carriage 11 carries the holder 12, the recorders 13 and 14 and the slider 15 with a ball 16 at the end. The pencil of the recorder 13 is pressed with a special spring to the chart paper on the drum, and the pencil of the recorder 14 - with the paper attached to the holder 17.

The cable 18 is connected at one end to a rotary disk with subsequent winding on a disk 10-20 revolutions, and the other end through guide blocks 19 and 20 to a spring 21 fixed with a lower end on the holder. The yoke 17 is rigidly attached to the pile 22 of a special BMG fixing yoke 23.

In a stationary position, the drum is held against rotation by a locking screw 24.

The automatic recording of the fault logs is obtained as follows.

When the hammer strikes the pile, it is loaded into the ground, together with it, the boom down and the yoke 17 (by the total failure value), which moves the carriage 11 (through the ball 16 on the slider 15) moves down. Together with the carriage, the pencil of the recorder 13 is also moved, which, being pressed against the chart paper, draws on it a vertical line equal to the complete failure of the pile.

At the same time, the carriage stretches (charges) the spring 21. After this, the reverse (elastic) movement of the soil and the pile occurs. Swa rises by the amount of elastic failure. Together with it, the carriage 11 with the recorder 13 rises, and the pencil automatically records it on the chart paper the return line, which exactly corresponds to the height of the elastic part of the failure.

After raising the pile by the size of the elastic part of the failure, the spring 21 is stretched by the amount of the residual part of the failure and, shortened (shortened) to the initial length, acts on the traction cable 18 and through it on the drum 6, and the pencil of the recorder 13 records a horizontal link, equal to the residual part of the failure. Such a cycle of automatic recording of a complete failure, elastic and residual part of it (vertically), as well as the residual part horizontally automatically follows each

hammer blows on a pile, and in sum these cycles form a complete schedule of pile movement, i.e., its failure pattern.

The kinematic scheme of the connection of the carriage 11 to the pile by means of the yoke 17 with parallel planes and ball 16 makes it possible to completely eliminate the influence of the total oscillations of the pile in the horizontal plane on the accuracy of the recording of the vertical failure of the pile. A well log of horizontal pile vibrations is recorded by the recorder 14 with lateral (horizontal) vibrations of the pile, together with the yoke 17. The pencil of the recorder draws on the chart paper, fixed | H1 on the plane of the yoke, the line showing the size and direction of vibrations

piles in the horizontal plane. The obtained data on the values and directions of pile deviation from the vertical axis significantly improve the quality control of the pile driving and the accuracy of determining its bearing capacity.

The technical and economic efficiency of the proposed device consists in increasing the accuracy of determining pile failure, which also increases the accuracy of determining the bearing capacity of the pile in dynamic tests.

Claims (2)

1. USSR Author's Certificate No. 249297, cl. E 02 D 13/06, 1967. 2. USSR author's certificate No. 487327, cl. E 02 D 13/06, 1972 (prototype).