SU973835A1 - Apparatus for measuring pressure in soil - Google Patents

Description

(54) DEVICE FOR MEASUREMENT OF D. GROUND IN GROUND

one

The invention relates to the mining industry and is intended to measure pressures in a given direction over time in the soil using instrument wells, for example, in the production of explosions.

Devices for measuring pressures in the soil using instrument wells are known, which include a rigid, in the form of a disk with a cavity, a base covered by a rubber membrane. A pressure sensor is installed on the base. The base cavity between the sensor and the membrane is filled with liquid. A cylinder case is rigidly connected to the base, which is equipped with a long mechanism. oriented fixing device in the well. This mechanism has a retractable stop and an escapement device interacting with it. The device is lowered into the well, when the bottom of the well is reached, the trigger device is triggered, the abutment is pulled out of the housing, and the device is fixed in a certain position 1.

The disadvantage of these devices is that the design of the mechanism of the fixation mechanism in the well, which contains seven

shaped parts connected functionally to each other. In addition, when the device is lowered into the well, as a result of accidentally touching the supporting rod behind the borehole wall or behind the cables passing through the well, the trigger mechanism may be triggered and the stop will be extended to lower the device to a predetermined depth.

It is also known a device for measuring pressure in the ground, comprising a housing, a receiving element with a pressure sensor placed at its base, filled with liquid and a closed membrane of elastic material, a threaded pin for fitting the receiving element, and spring brackets 2.

The drawback of the device is the low sensitivity of the instrument, therefore, three sensors are installed in the instrument well at predetermined horizons with the directions of the sensing elements at an angle of 90 ° to each other on the axes X, Y, Z.

20

The expediency of such an installation of devices is regulated by an appropriate method of experimental measurements. With such an installation, the devices are actually located at different horizons and it is difficult to maintain their exact mutual arrangement of the receiving parts, since it is necessary to orient each device separately. All this introduces certain errors in measurement. At the same time, the installation process of the devices has to be repeated three times to measure on one horizon — and to create for each device an independent supporting blockage, which requires additional time and material resources.

In addition, the manufacture of three independent instruments for measuring in three directions increases their cost, since in this case it is necessary to have three pairs of spring clips and three adapters.

The purpose of the invention is to improve the accuracy of measurements by making it possible to carry out measurements in three directions.

This goal is achieved by the fact that the device is additionally equipped with two receiving elements, threaded fingers and threaded bushings, while the axes of the threaded fingers with receiving elements placed on them and spring brackets are oriented at an angle of 90 ° with respect to each other, and the threaded bushings are mounted on the threaded fingers from the side opposite to receiving elements, with the possibility of interaction with spring clips.

FIG. 1 shows the device, obsh, iy kind; in fig. 2 is a view A of FIG. one; in fig. 3 shows the devices installed in the well; in fig. 4 - the same, top view.

The device comprises a housing 1, equipped with three receiving elements, the axes of which are located at an angle of 90 ° and coincide with the axes of the X, Y, Z coordinates. Each receiving element includes a base 2, a rubber membrane 3, a pressure sensor 4, a liquid 5. The density of the fluid is adjusted close to the density of the surrounding array. Cylinder 6 is rigidly connected to the base. The cavity of the cylinder in which the sensor is located is filled with a sealant, which protects the sensor from moisture. The base is made in the form of a disk with a cavity. The perimeter membrane is pressed to the base by a ring 7. The inductive sensor DDI-20 can be used as a sensor, for example.

The housing 1 has threaded pins 8 located on all its side surfaces along the axes X, Y, Z. The receiving parts of the device and the threaded bushings 9 are attached to these protrusions, to which in the X and Z directions are attached the springs Shie brackets 10, and in the Y direction, an adapter 11 is used to connect the device to the carrier element 12. Nuts 13 are provided for locking the bushings 9.

The brackets 10 have the shape of an ellipse and are made of spring steel wire. The rounded upper and lower edges of the brackets prevent them from cutting the open hole wall into the ground when lowering or removing the device. Staples are made so that they provide the force of pressing the receiving parts of the device to the well in the X direction and Z not less than the weight of the device as a whole, which ensures reliable fixation of the device in a given position even without reliance on the bottom. The required force of pressing the base to the wall is ensured by the fact that the dimensions of the device with brackets in the horizontal plane are larger than the cross-sectional dimensions of the well, as well as

diameter and spring properties of the material of staples.

The pressing force is provided by the deflection f of the clips (Fig. 3), the value of which is determined from the known expression

f - BP-,

where L is the distance from the clamping point of the clamp to the point of contact with the well wall; Р - required pressing force; d is the diameter of the staple material; E is the modulus of elasticity of the material. At the same time, the diameter of the staple material is taken at least 4-5 mm so that they do not cut into the soil of the borehole walls.

Thus, with elastic deformation 0 of one of the brackets of the magnitude f, the condition for fixing the device in the well is provided, and since two brackets are used, this force is greater and the fixing of the device is more reliable.

In the proposed device, thanks to the 5 threaded joint of the sleeves 9 with the fingers 8, it is possible to adjust the dimensions of the device in a horizontal plane, which allows for the necessary force of pressing the device to the well, as well as installing devices in wells of different diameters.

Prior to measurement, the device is connected with a support element 12 equipped with an electromagnetic uncoupler using adapter 11 and lowered into the well. 5 When lowering, the brackets are compressed and slide along the borehole wall. When stopping the lowering and detaching the carrier, the device is held on a given horizon due to the elastic properties of the clips. At experimental measurements in each well, several devices (usually 5-8 pcs) are installed in this way at different horizons. After that, a ground-cement solution is poured into the well, which is tightly attached on all sides to the j device and to the walls of the well.

Claims (2)

In an explosion, the pressure from the wall of the well 1-; s through the membrane, 3 and liquid 5 is transmitted to the sensitive element of the pressure sensor 4. The signal from each sensor is transmitted via cable to the appropriate recording equipment installed in the instrumentation facility. The cost of manufacturing a set of three devices (for measurements in the three directions X, Y, Z) is reduced by 10% due to the exclusion of two pairs of brackets and adapters. The time to install devices in the well is reduced, instead of three technological operations for installing three devices, only one is required. The accuracy of measurements is increased due to the fact that the proposed device provides measurements of n, in three directions at one point, while the use of three devices cannot provide this. In the proposed device, the strict mutual position of the receiving elements is maintained. In the proposed. the device, the measured pressure in three directions at one point is 1400 kPa, and the diameter of the wells, in which reliable fixation is possible, is 180-250 mm. Claims An apparatus for measuring pressure in a ground, comprising a housing, a receiving element with a pressure sensor located at its base filled with a liquid and closed with a membrane of a particulate material, a threaded pin for mounting the receiving element and spring brackets, characterized in that In order to increase the accuracy of measurements by making it possible to measure in three directions, the device is additionally equipped with two receiving elements, threaded fingers and threaded bushings, with this m threaded axis with the fingers placed on them and the spring receiving members staples are oriented at an angle of 90 ° with respect to each other and the threaded sleeve mounted on the threaded bolt on the side opposite the receiving elements, to cooperate with spring clips. Sources of information taken into account during the examination 1. USSR author's certificate No. 590453, cl. E 21 C 39/00, 1976. 2. USSR author's certificate on the factory, № 2822728/03, cl. E 21 C 39/00, 1979 (prototype). : i "r - - o V - f- AS I I p mL M 7.2 FigL