CN218496581U - Strain control type triaxial apparatus - Google Patents

Abstract

The utility model relates to a ground check out test set technical field discloses a strain control formula triaxial apparatus, including base, pressure chamber and drainage system, be provided with the drainage interface with soil sample intercommunication on the pressure chamber, drainage system includes the drain pipe, elevating gear, pressure sensors and controller, drain pipe and drainage interface intercommunication, and the drain pipe is arranged on elevating gear, and pressure sensors, elevating gear all with controller signal connection, pressure sensors give the controller with pressure signal transmission, controller control elevating gear action to adjust the height of drain pipe. When drainage in-process drain pipe pressure changes, pressure sensor gathers pressure signal and gives the controller for, and controller control elevating gear drives the drain pipe and reciprocates, makes the flood peak in the drain pipe go up and down to make the pressure value of drain pipe and begin the value and keep unanimous, promptly flood peak and pressure chamber keep unanimous, avoid influencing the experimental result because of drain pipe pressure, improve experimental precision and accuracy.

Description

Strain control type triaxial apparatus

Technical Field

The utility model relates to a ground check out test set technical field especially relates to a strain control formula triaxial apparatus.

Background

The construction of the engineering project cannot be supported by a large amount of geotechnical test data, in the conventional geotechnical test methods, the triaxial shear test is the most basic and important test method, geotechnical strength parameters under different stress paths can be obtained through the triaxial shear test, and the reliability of the parameters has extremely important influence on the safety reliability and economic rationality in the engineering project construction process.

The traditional strain triaxial apparatus mainly measures the deformation characteristics and the strength characteristics of a soil sample by applying pressure to the soil sample in a pressure chamber of the triaxial apparatus, but the strain triaxial apparatus still has some disadvantages in the actual use process: firstly, the degree of automation is low, the pressure stability precision is poor, and the error range reaches +/-10 kpa; and secondly, the output range of the air pressure triaxial apparatus is small, the measurement of the axial pressure is obtained by adopting water as a medium, and the test precision and the stability of the system are poor. The automatic control strain triaxial apparatus can perform axial pressure control, not only covers the functions of the strain triaxial apparatus, but also has the characteristics which the strain triaxial apparatus does not have, and is equipped in most domestic scientific research institutions.

The patent with the publication number of CN216309629U discloses a stress path detection triaxial apparatus with an axial loading mode, which comprises a pressure cavity, wherein the upper end of the pressure cavity is provided with a first flange, the lower end of the pressure cavity is provided with a second flange, and the first flange is fixedly connected with the second flange through a pull rod; the upper surface of the second flange is provided with a soil sample lifting seat, and the lower end of the soil sample lifting seat is connected with an axial loading mechanism at the lower end of the second flange through a force output shaft; a hole pressure connecting pipe is arranged in the soil sample lifting seat, the first end of the hole pressure connecting pipe is positioned on the upper surface of the lifting seat, and the second end of the hole pressure connecting pipe is connected with a first pressure sensor outside the pressure cavity; the lower end of the first flange is sequentially provided with a second pressure sensor and a crystal pressure head; the device also comprises a displacement sensor and a data acquisition controller; the displacement sensor is installed on the second flange, and the data acquisition controller is connected with the first pressure sensor, the second pressure sensor and the displacement sensor and is connected with the axial loading mechanism.

The triaxial apparatus adopts the axial ballast device to improve the stability of pressure, when the triaxial apparatus is used for testing soil, water is usually adopted as a medium for pressure output when pressure is applied to the pressure cavity, and moisture in a soil sample can be discharged by the drainage pipe under the action of pressure. The confining pressure in the pressure cavity is compensated based on the pressure at the underwater pressure sensor at the crystal pressure head, the confining pressure is the same as the pressure value at the underwater pressure sensor during the initial test, the water pressure in the drainage pipe can influence the increase of the pore pressure in the pressure chamber along with the discharge of water in soil into the drainage pipe, the increase of the pore pressure can lead to the increase of the pressure value at the position of the underwater pressure sensor, the confining pressure at the position of the underwater pressure sensor is constantly compensated, the actual compensation value at the position of the underwater pressure sensor is reduced, the actual value deviation of the confining pressure is caused, the pore pressure value deviation of the pressure chamber is also caused, and the test result is influenced.

SUMMERY OF THE UTILITY MODEL

The utility model discloses an aim at: the utility model provides a strain control formula triaxial apparatus to solve among the prior art water pressure increase in the drain pipe after influence experimental precision and accuracy.

In order to realize the above-mentioned purpose, the utility model provides a strain control formula triaxial apparatus, include the base, arrange pressure chamber on the base and with the drainage system that the pressure chamber is connected, be provided with the drainage interface with soil sample intercommunication on the pressure chamber, drainage system includes drain pipe, elevating gear, pressure sensors and controller, the drain pipe with drainage interface intercommunication, the drain pipe is kept away from the one end of drainage interface is the blind end, the drain pipe is arranged elevating gear is last, pressure sensors elevating gear all with controller signal connection, pressure sensors is used for detecting pressure in the drain pipe transmits pressure signal for the controller, the controller is used for receiving pressure signal and control the elevating gear action is with the regulation the height of drain pipe.

Preferably, the drain pipe comprises a horizontal section extending horizontally and a vertical section vertically connected with the horizontal section, the horizontal section is connected with the drain interface, the vertical section is arranged on the lifting device, and the pressure sensor is connected with the horizontal section to detect the water pressure on the horizontal section.

Preferably, the horizontal section is a deformable flexible tube and the vertical section is a glass tube.

Preferably, the lifting device comprises a lifting motor arranged on the base, a screw rod in transmission connection with the lifting motor, and a lifting platform assembled on the screw rod in a threaded manner, and the drain pipe is fixedly arranged on the lifting platform.

Preferably, a weighing sensor is arranged on the lifting platform, and the drain pipe is fixedly arranged on the weighing sensor.

Preferably, the lifting motor is a stepping servo motor.

The embodiment of the utility model provides a strain control formula triaxial apparatus compares with prior art, and its beneficial effect lies in: the water draining interface is arranged on the drainage pipe, the pressure sensor is used for acquiring pressure signals and transmitting the pressure signals to the controller when the pressure of the drainage pipe changes in the drainage process, the controller controls the lifting device to drive the drainage pipe to move up and down, and the water head in the drainage pipe is lifted.

Drawings

Fig. 1 is a schematic structural diagram of a strain-controlled triaxial apparatus according to the present invention;

fig. 2 is a schematic structural diagram of a confining pressure loading system of the strain-controlled triaxial apparatus of the present invention;

fig. 3 is a schematic structural diagram of a drainage system of the strain-controlled triaxial apparatus of the present invention.

In the figure, 1, a base; 2. a pressure chamber; 3. an axial loading device; 4. a confining pressure loading system; 5. a drain pipe; 51. a horizontal segment; 52. a vertical section; 6. a lifting device; 61. a lifting motor; 62. a screw rod; 63. a lifting platform; 7. a pressure sensor; 8. a controller; 9. and a weighing sensor.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

The utility model discloses a preferred embodiment of strain control formula triaxial apparatus, as shown in fig. 1 to 3, this strain control formula triaxial apparatus includes base 1, pressure chamber 2, drainage system, and pressure chamber 2 arranges on base 1, and drainage system is connected with pressure chamber 2 in order to discharge the moisture in the soil sample.

The base 1 is a supporting foundation of the strain control type triaxial apparatus, the axial loading device 3 is further arranged on the base 1, the axial loading device 3 is connected with the pressure chamber 2, and the axial loading device 3 is used for applying axial load to a soil sample in the pressure chamber 2. The pressure chamber 2 is also connected with a confining pressure loading system 4, and the confining pressure loading system 4 is used for providing continuous confining pressure for the pressure chamber 2. The specific structures of the pressure chamber 2, the axial loading device 3 and the confining pressure ballast system are the same as the prior art structure in the background art, and will not be described in detail here.

The pressure chamber 2 is provided with a drainage interface which is communicated with a soil sample to drain moisture in soil during a test, and the drainage interface is arranged at the bottom of the pressure chamber 2 to be connected with a drainage system. The drainage system comprises a drainage pipe 5, a lifting device 6, a pressure sensor 7 and a controller 8, wherein one end, far away from the drainage interface, of the drainage pipe 5 is a closed end so as to prevent water loss, and the drainage pipe 5 is communicated with the drainage interface on the pressure chamber 2 so as to store drained water.

The drain pipe 5 is arranged on the lifting device 6, and the lifting device 6 can drive the drain pipe 5 to move up and down when lifting, so that the height of the drain pipe 5 can be adjusted. Pressure sensor 7, elevating gear 6 all with controller 8 signal connection, pressure sensor 7 is used for the pressure in the drain pipe 5 and gives controller 8 with pressure signal transmission, and controller 8 is used for receiving pressure signal and controls elevating gear 6 action to the height of adjusting drain pipe 5.

Discharged moisture flows into in the drain pipe 5 through the drainage interface during soil test, when just beginning the drainage, pressure in the drain pipe 5 is the same with the pressure in the pressure chamber 2, pressure sensor 7 detects the initial pressure of drain pipe 5, when 5 pressure variations of drainage pipe in the drainage process, pressure sensor 7 gathers pressure signal and transmits for controller 8, controller 8 control elevating gear 6 drives drain pipe 5 and reciprocates, make the flood peak in the drain pipe 5 go up and down, thereby make the pressure value of drain pipe 5 and begin the value keep unanimous, promptly, flood peak and pressure chamber 2 keep unanimous, avoid influencing the experimental result because of drain pipe 5 pressure, improve experimental precision and accuracy.

Preferably, the water discharge pipe 5 includes a horizontal section 51 extending horizontally and a vertical section 52 connected vertically to the horizontal section 51, the horizontal section 51 is connected to the water discharge interface, the vertical section 52 is disposed on the elevating device 6, and the pressure sensor 7 is connected to the horizontal section 51 to detect the water pressure on the horizontal section 51.

When moisture enters the water discharge pipe 5, the moisture enters the vertical section 52 from the horizontal section 51, the position of the horizontal section 51 is the lowest, and the result that the pressure sensor 7 detects the water pressure on the horizontal section 51 is more accurate. The vertical section 52 is arranged on the lifting device 6, the lifting device 6 moves up and down, and the direction of the vertical section 52 is the same, so that the moisture in the moving process can be prevented from being supported by the pipe wall of the drain pipe 5 to influence the accuracy of the result.

Preferably, the horizontal section 51 is a deformable flexible tube and the vertical section 52 is a glass tube.

The flexible pipe can compensate the distance change between the water discharge pipe 5 and the pressure chamber 2 when lifting, and the vertical section 52 is a glass pipe, so that the water head height inside can be conveniently observed.

Preferably, the lifting device 6 comprises a lifting motor 61 arranged on the base 1, a screw rod 62 in transmission connection with the lifting motor 61, and a lifting platform 63 screwed on the screw rod 62, and the drain pipe 5 is fixedly arranged on the lifting platform 63.

The lifting motor 61 drives the screw rod 62 to rotate, the lifting platform 63 moves up and down under the action of the thread structure, so that the drain pipe 5 is driven to move up and down, the pressure value of the drain pipe 5 can be kept consistent with the starting value, and the water head position of the drain pipe 5 is kept consistent with the pressure chamber 2. The water draining pipe 5 is driven to lift by the screw rod 62 and the lifting platform 63, and the structure is simple.

Preferably, a load cell 9 is disposed on the elevating platform 63, and the drain pipe 5 is fixedly disposed on the load cell 9.

Because the end of the drain pipe 5 far away from the drain connector is a closed end, the drain pipe 5 is a one-way inlet, the water quantity is continuously increased in the draining process, and the weight of the drain pipe 5 is also increased. The weighing sensor 9 is connected with the drain pipe 5, the weight of the drain pipe 5 can be measured by the weighing sensor 9, namely the weight of the drained water, and the weight and the volume of the water can be converted, so that the volume value of the drained water can be calculated.

According to the measurement accuracy of the weighing sensor 9, the drainage system can accurately collect the drainage quantity, and the accuracy can be improved to 0.1mL.

Preferably, the lift motor 61 is a stepper servo motor.

The precision of the stepping servo motor is high, the moving height of the drain pipe 5 can be accurately calculated by calculating the step number of the stepping motor, so that the water head of the drain pipe 5 is consistent with that of the pressure chamber 2 in the test process, and the central position of the pressure chamber 2 is automatically tracked.

To sum up, the embodiment of the utility model provides a strain control formula triaxial apparatus, discharged moisture flows into in the drain pipe through the drainage interface during its soil test, when just beginning drainage, pressure in the drain pipe is the same with the pressure in the pressure chamber, pressure sensors detects the initial pressure of drain pipe, when drainage process drain pipe pressure variation, pressure sensors gathers pressure signal and transmits for the controller, controller control elevating gear drives the drain pipe and reciprocates, make the flood peak in the drain pipe go up and down, thereby make the pressure value of drain pipe keep unanimous with the starting value, the flood peak keeps unanimously with the pressure chamber promptly, avoid influencing the experimental result because of drain pipe pressure, improve experimental precision and accuracy.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and replacements can be made without departing from the technical principle of the present invention, and these modifications and replacements should also be considered as the protection scope of the present invention.

Claims (6)

1. The strain control type triaxial apparatus is characterized by comprising a base, a pressure chamber arranged on the base and a drainage system connected with the pressure chamber, wherein a drainage interface communicated with a soil sample is arranged on the pressure chamber, the drainage system comprises a drainage pipe, a lifting device, a pressure sensor and a controller, the drainage pipe is communicated with the drainage interface, one end, far away from the drainage interface, of the drainage pipe is a closed end, the drainage pipe is arranged on the lifting device, the pressure sensor and the lifting device are in signal connection with the controller, the pressure sensor is used for detecting the pressure in the drainage pipe and transmitting a pressure signal to the controller, and the controller is used for receiving the pressure signal and controlling the lifting device to act so as to adjust the height of the drainage pipe.

2. The strain controlled triaxial apparatus of claim 1, wherein the drain tube comprises a horizontally extending horizontal section and a vertical section vertically connected to the horizontal section, the horizontal section being connected to the drain interface, the vertical section being disposed on the lifting device, the pressure sensor being connected to the horizontal section to detect water pressure on the horizontal section.

3. The strain controlled triaxial apparatus of claim 2 wherein the horizontal segment is a deformable flexible tube and the vertical segment is a glass tube.

4. The strain controlled triaxial apparatus according to any one of claims 1 to 3, wherein the lifting device comprises a lifting motor disposed on the base, a lead screw in transmission connection with the lifting motor, and a lifting platform screwed on the lead screw, and the drain pipe is fixedly disposed on the lifting platform.

5. Strain controlled triaxial apparatus according to claim 4, wherein a load cell is arranged on the lifting table and the drain pipe is fixedly arranged on the load cell.

6. The strain controlled triaxial apparatus of claim 4, wherein the lift motor is a stepper servo motor.

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