SU89425A1 - Soil sample tester - Google Patents

Description

Instruments are known for testing soil samples that are placed in an outer shell covering the lateral surface of a sample placed in a chamber between porous disks and exposed to vertical loading and lateral compression. These instruments in the process of testing a sample determine only individual elements of the characteristics of the test sample.

The proposed device is intended to determine the dependencies between stresses and strains in samples of various types of soils under conditions of three-axis compression of the test sample. The device differs from those known in that it uses a regulating device to maintain a constant value of the lateral pressure on the sample during the test, as well as a device for measuring the free lateral expansion of the sample (volume meter) at vertical pressure on it.

Such a device design makes it possible in the process of testing a soil sample to produce a comprehensive definition of interdependent elements of the characteristics of the test soil: strength factor, filtration, etc.

The drawing shows the device in section.

The proposed device is a cylindrical chamber in which a sample / soil is placed for testing. The chamber above and below is bounded by porous disks 2 and 3 mounted in the base 4 of the device and in the loading piston 5. The elastic shell 6 tightly covers the lateral surface of the sample.

The device is installed under the punch of the loading device (not shown), and the annular space between the rubber diaphragm 6 and the walls 7 of the device body (which are made of transparent material to provide visibility of the test specimen) is filled with water pumped by the manual pump # 89425

with a syringe through the filling valve. 8. Emptying of this space is carried out through a drain pipe mounted into the base of the device. The receiving tubes 9 are connected to the diaphragm of the piston 5, which separates the chamber of the device from the atmosphere; an equalizing tank is attached to the bottom of the device.

Water, which fills the space between the rubber diaphragm 6 and the walls 7 of the housing, creates lateral pressure on the sample. The specified pressure on the side surface of the sample is kept constant by means of the regulating device 10. This device is set to the specified pressure by means of a spring / L sleeve 12 and a nut 13.

When the sample is compressed by a vertical load, it tends to expand and exerts pressure on the water. The lateral pressure is recorded by a manometer, the tank expansion of the sample is measured by the volume of water displaced by it with a volume meter 14, the vertical deformation of the sample is measured by massals attached to the loading piston 5.

When testing the soil for water resistance to one of the tubes 9, a piezometer filled with water is attached with a flexible rod, mounted independently on a tripod or body of the loading device.

Air is released through the second tube when water is filled between the surface of the test specimen in the tube and the piston diaphragm, after which the tube is sealed with a cap.

Subject of Invention

1. A device for testing soil samples placed in an elastic shell covering a side surface of a sample placed in a chamber between porous disks, characterized in that, in order to comprehensively determine the basic interdependent elements of the characteristics of the same sample of the soil tested, in the form of a working chamber equipped with a piston, installed under the punch of the loading device and filled with water between the rubber casing and the walls of the body, the pressure head as a result of lateral pressure sample during its deformation, is measured by manometer, and the vertical deformation of the sample-messuramk, bonded and loading opirayuschimis piston and on the housing.

2. Instrument No. 1, characterized in that, in order to test the soil sample for water resistance, a surge tank is attached to the lower part of the instrument, and receiving tubes separating the instrument's working chamber from the external atmosphere are attached to the instrument piston which is connected to the piezometer with a hose,

3. Device on PP. 1-2, characterized in that, in order to maintain in the process of testing a constant in magnitude of the specified lateral pressure on the sample, he used a regulating device, made in the form of a spring-loaded clan, regulating the tension nut and closing the hole, connecting the working chamber with the outside atmosphere.

4. Device on PP. 1-3, characterized in that, in order to measure the lateral expansion of the sample but the volume of water displaced by it, a volume meter attached from the outer side to the root is used in it. device.

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