SU1283285A1 - Apparatus for determining strength characteristics of soil - Google Patents

Abstract

The invention relates to the field of engineering and geological surveys in construction and is used as a laboratory automated device for determining the strength characteristics of the soil samples studied. In order to automate the processes of squeezing and cutting simultaneously several soil samples on the horizontal axis of the housing 2, an additional force is installed

Description

(/)

The second cylinder of the mechanism for compressing soil samples of a bilateral action, the rods 4 of which are pivotally connected to strainers 16, one ends of which are supported on dies 8, while others are rigidly connected to each other in a multi-beam star, with a shearing mechanism disk rotated on the hub 10 and on rolling bearings 9, split into equal-sized sectors, on the surface of which strain gauges 25 are mounted, and on the disk hub 10 — an annular current collector 24 and a gear wheel 21 interacting with the gear of the gearbox 22 of the shift mechanism with a drive 83285

the house is from an electric motor 23. The electrical signals from strain gauges 18 and 25 (through the current collector 24) are fed through amplifier 19 to a multichannel recorder 20, on which parameters of the resistance of soil samples 17 are fixed to the shear under various compressive loads. The device allows simultaneous testing of a shift in the n-number of soil samples, reducing its duration by more than three times by automating the process of reducing the soil samples, shifting them, and recording information about the strength properties of the studied soils. 2 Il.

The invention relates to the construction and can be used to determine the strength characteristics of the soil during geological engineering surveys for the construction of buildings and structures.

The purpose of the invention is to automate the testing of several soil samples simultaneously.

Fig, 1 and 2 shows the proposed device.

The device includes a frame 1 with a hollow cylindrical body 2, on the horizontal axis of which a two-sided power cylinder 3 is installed with rods 4 and fixed sleeves 5 are rigidly fixed in cups 6 with adjusting nuts 7 and dies 8 forming plunger pairs with stationary holders, and on rolling bearings 9, a movable holder 11 is mounted on the hub 10, made in the form of a rotary wheel on the shaft of the disk 12 (Fig. 2), cut with a gap into an integer number of equal-sized sectors 13 with holes 14 whose axes coincide at rotating the disk axes plunger disposed symmetrically relative to the disc. The rods 4 are connected to the strainer bar 16 (Fig. 1 and 2) of the mechanism for compressing the soil 17 by means of a normal pressure by means of a ball 15 (fig. 1), one ends of which are supported

stamps 8, while others are rigidly connected to each other in the form of a multipath star and strain gauges 18 of which, via an electrical bridge circuit, transmit data through amplifier 19 to a multichannel recorder 20 (or a speck oscilloscope) indicating the magnitude of the normal pressure on a soil sample. The hub 10 is rigidly connected to the gear wheel 21, which meshes with the gear of the gearbox 22 of the shift mechanism driven by the electric motor 23. The current collector 24 of the ring type, mounted on the hub 10, allows you to remove electrical signals from strain gauges 25 installed on sectors 13 and transmit them through an amplifier on a recorder 20, showing the resistivity of the soil sample to the shear. The drive of the soil compression mechanism with normal pressure, i.e. the power cylinder 3, is a pump station 26 with a pressure gauge 27 - and high and low pressure hoses 28. The control of the parameters of the normal pressure, pressing out the soil samples 17, is carried out by the pressure load cell 29 installed in the power cylinder 3.

The device works as follows.

Cylindrical samples of soil 17 of length C ЗЬ, where b is the thickness of disk 12, are placed in fixed holders 5 and in openings 14 coaxially mounted with them 14 of the movable sleeve 11. The gap between the movable sleeve 11 and the fixed holders 5 is set by rotating the adjusting nuts 7 on the threads of the glasses 6, rigidly connected with a hollow g (the cylindrical body 2 of the device and the frame 1. Stamps 8, like plungers, are inserted into the clips 5, the pump station 26 is turned on, and under the rods 4 of the power cylinder 3 they create pressure P, controlled by a pressure gauge 27 and fixed by a tenso the sensor 29, with the help of a working weave, distilled by the rods 28. In this case, the total force (compressive) T ,, developed by each rod of the power cylinder is transmitted through the hinges 15 and strain gauge 26 to the dies 8 equally and creates a normal for each soil sample 17 compressive pressure

With Ii.-.

where n is the number of soil samples;

d is the sample diameter.

The pressure (5, is controlled by strain gauges 18 that transmit signals via an electrical bridge circuit through amplifier 19 to a multichannel recorder 20 (or oscillating oscilloscope). Maintaining a constant pressure 6i until conditional stabilization of the samples of the soil type 17 is controlled by an hour-type indicator (not shown ) include an electric motor 23 transmitting torque through a gear 22 to a gear wheel 21 rigidly connected to the hub 10 of the yoke 11 rotating on the rolling bearings 9. Sectors 13 of the rotating disk 12 under the action of a circle the thrust moment Mj /, reduced from the electric motor 23, is cut by soil samples 17 by force Q, M, R, where R is the radius of the pitch circle from the axis of the power cylinder 3 to the axes of the hole 14 of the disk 12. At the same time, each soil sample 17 will have resistivity to shear

2 Oh,

C-j

Fri d

controlled by the sensor 25, transmitting electrical signals to the current collector 24 of the ring type and then through the amplifier 19 to the recorder 20. After

g fO 15 20

25

thirty

35

0

five

by cutting the soil sample 17 by sectors 13, cutting the soil out of the clips 5 and ejecting it from the holes 14 by pushers (not shown) installed, for example, on one side of the housing 2 of the device in the clips 5. The disk 12 is reset. The remaining parts of soil samples 17 are brought together by dies 8 and are crimped from the ends with normal pressure Oj until their sedimentation is stabilized. A torque Mj is created on the disk 12 and the resistivity of the soil samples 17 is set and so on until the soil is completely removed from the samples 17 from the clips 5. According to the control data taken from the oscillograms (G,, GJ, G,, t :,, Tj, Tj), build a graph of dependence and determine the specific adhesion and the angle of internal friction of the ground.

This device allows to increase the measurement accuracy by uniformly compressing soil samples from both ends with normal pressure and improve labor productivity in testing a soil sample by eliminating reloading operations in cages and preparing twin samples, as well as carrying out a simultaneous shear test. -number of soil samples, reducing its time by more than 3 times. Thus, it becomes possible to increase the automation of the process of soil samples squeezing with normal pressure, shift them and record information about the strength properties of the studied soils, and robotic manipulators can be used.

Claims (1)

Invention Formula G. A device for determining the strength characteristics of a ground, including a housing, a movable sleeve in the form of a disk with holes and with a hub capable of rotating around a horizontal axis, fixed rings with dies, symmetrically mounted with respect to the disk and coaxially with its holes, load mechanisms for compressing and shifting soil samples and measuring devices, characterized in that, in order to automate the testing of several soil samples, the device is equipped with additional fixed clips with dies, a double-acting power cylinder mounted on the horizontal axis of the housing, the load mechanism for compressing the samples is equipped with strain gages with strain gauges, the movable holders disk with strain gauges, and the disk hub is equipped with an annular current collector and gear wheel , interacting with the load shift mechanism, is made hollow and mounted coaxially to a two-way power cylinder with the possibility of rotation around 18 it, while the disk of the movable cage is made split into equal-sized sectors, on the surface of which strain gauges are installed, and fixed cages and stamps are arranged in pairs on both sides of the disk of the movable cage equidistant from its horizontal axis of rotation and from each other around the circumference, and the rods of the two-sided power cylinder actions are hingedly connected to strain grip, some ends of which are supported on stamps, while others are rigidly connected each other stars. in the form of multipath