CN213456452U - Soil body creep test system - Google Patents

Abstract

The utility model discloses a soil body creep test system, which comprises an air pump, a triaxial measurement and control cabinet, an axial pressure regulating cabinet, a test reaction frame, a pressure chamber, a multi-channel controller and a computer; the air pump is connected with the air inlet of the axial pressure regulating cabinet to provide axial pressure for the test; the air outlet of the axial pressure regulating cabinet is connected with the test reaction frame to apply axial pressure to the soil sample; the triaxial measurement and control cabinet is connected with the pressure device through a confining pressure pipeline and a counter pressure pipeline; and each channel of the multi-channel controller is respectively and correspondingly connected with the pore pressure interface and the deformation sensor, so that the deformation displacement and the pore pressure of the soil sample are collected in real time and transmitted to a computer for analysis. The utility model provides a triaxial creep compression test of soil body can be carried out to soil body creep test system, researches the creep performance of the soil body, and K0 lateral pressure coefficient creep test, pore pressure creep test, unipolar soil body creep and poisson ratio test etc. also can be done to the relevant test device of supporting simultaneously.

Description

Soil body creep test system

Technical Field

The utility model relates to a soil body test technical field especially relates to soil body creep test system.

Background

In the field of infrastructure construction, such as in the construction of buildings, traffic, water conservancy and mines, a large number of slope stability problems are involved. The prevention of the deformation and damage of the slope in different forms, such as landslide or collapse, during the construction process is a key research subject in the field, and the research of the subject has many problems, one of which is that the soil body creep condition cannot be simulated in real time.

At present, creep tests of soil bodies mainly comprise two major research subjects of micro and macro and the like, wherein the micro creep tests are researched by observing the microscopic structure of the soil body by means of an optical microscope or an electronic scanning microscope and explaining the creep characteristics of the soil body by using a microscopic mechanism, but only qualitative description and quantitative description are provided at present.

The macroscopic creep test comprises a field creep test and an indoor creep test, and is characterized in that the creep mechanical property of a soil body is obtained by researching the relation of stress-strain-time of the soil body through a series of test steps by means of a test instrument.

The on-site creep test is to test the creep of the on-site rock-soil medium material, such as long-term settlement of a foundation, displacement of a side slope and the like, the on-site creep test result can better reflect the influence of the characteristics of the rock-soil material, such as structure, cracks and the like, and instruments for carrying out the on-site creep test mainly comprise a bearing plate instrument, a large direct shear instrument, a convergence instrument, a station hole multipoint displacement meter, an inclinometer, a turbulence meter and the like. The field creep test can provide first-hand data, and therefore, the method has important guiding significance and value for specific engineering. Although the field creep test has the characteristic of simple instrument, the field test cost is high, the time consumption is long, the external interference is large, and particularly, the stress state, the stress path and the test boundary condition of a soil body cannot be actively controlled, so that the field test result is influenced.

The indoor creep test is to perform corresponding creep mechanical property test on a rock soil sample on a creep instrument in a test room. The indoor creep test can control the conditions of stress, strain, drainage and the like, and the in-situ creep test is difficult to control the conditions, so that the complex characteristics of the soil body can be researched only by the indoor creep test. The indoor test can strictly control the conditions of test stress, strain, drainage and the like, has the advantages of good repeatability, no external interference, relatively low cost and the like, and is thus valued by extensive researchers. Creep test instruments used for conducting creep tests indoors fall into two broad categories: one is a test instrument that applies shear directly, such as a direct shear apparatus and a torsional shear apparatus; one type of instrument for creep testing using tension or compression is a tensile and compressive creep gauge. The conventional creep devices have a series of problems of single instrument function, too simple test stress path, manual grading loading, irregular test reading mode and the like.

In many geotechnical engineering, cracks occur in the soil body during loading, and the cracks are often caused by tensile damage of the soil body. For example, a plurality of cohesive soils behind retaining walls and cohesive soil slope landslide bodies have cracking phenomena, when a slope soil body deforms to a certain extent, shearing damage or stretching damage can occur in the soil body, so that cracks are generated, the cracks are large in general scale and penetrate into the slope soil body, serious damage is caused to soil slope engineering, and particularly, catastrophic consequences can be caused due to the fact that the structural loess slope engineering has relatively small displacement deformation and sudden damage. Therefore, the long-term tensile creep and shear creep strength of the soil body have great influence on the stability of the geotechnical buildings and the side slopes. In the foundation, the soil body is loaded to cause the instability of the foundation, and the instability is caused by the shearing damage of the soil body under the pressure condition. For example, when a high-rise building is built, the foundation is subjected to compressive deformation, and shearing damage occurs in the soil body, so that the foundation fails. Therefore, the long-term compressive creep and shear creep strength of the soil body greatly influence the stability of the soil foundation. In the long-term movement of the geological structure, the deformation of the earth crust can be caused, so that the influence of certain torsional shear deformation on the surface soil body can be generated.

When the long-term creep strength of the soil body is researched, three aspects of research on long-term tensile creep strength, long-term compressive creep strength, long-term shear creep strength and the like should be paid attention to. At present, the research on the shear creep strength and the compressive creep strength of a soil body is relatively sufficient, but no corresponding research on the uniaxial tensile creep strength, the triaxial tensile creep strength, the uniaxial torsional shear creep strength and the triaxial torsional shear creep strength is carried out, and the research on the aspects is very meaningful for further carrying out.

SUMMERY OF THE UTILITY MODEL

To the problem that exists, the utility model aims at providing a whole set of triaxial creep test, infiltration creep and the dissipation creep test that can be used for carrying on the soil body to carry out the test system of collection analysis to the test result.

In order to achieve the above object, the utility model adopts the following technical scheme:

soil body creep test system, including pressure device, controlling means, experimental main part device and data acquisition device, its characterized in that: the control device comprises a triaxial measurement and control cabinet and an axial pressure regulating cabinet, and the data acquisition device comprises a multichannel controller and a computer;

the pressurizing device is connected with the air inlet of the axial pressure regulating cabinet and provides axial pressure for the test;

the test main body device comprises at least one test reaction frame, and each test reaction frame is provided with a pressure chamber for placing a soil sample; each test reaction frame is provided with a pressurizing rod and a deformation sensor;

the air outlet of the axial pressure regulating cabinet is connected with each test reaction frame through an air passage to apply axial pressure to the soil sample in the corresponding pressure chamber;

each pressure chamber is provided with a confining pressure interface, a back pressure interface, a pore pressure interface and a displacement applying unit; the displacement applying unit is matched with the deformation sensor to measure the deformation displacement of the soil sample;

the triaxial measurement and control cabinet is connected with the confining pressure interface and the back pressure interface on each pressure chamber through a confining pressure pipeline and a back pressure pipeline;

a piston rod is arranged at the top of the pressure chamber, and the pressurizing rod is positioned right above the piston rod;

the multi-channel controller comprises a plurality of displacement channels and pore pressure channels, each displacement channel is connected with a deformation sensor on a corresponding test reaction frame, and each pore pressure channel is connected with a pore pressure interface on a corresponding pressure chamber to acquire the deformation displacement and pore pressure of the soil sample in real time;

the multi-channel controller is connected with the computer through a lead to realize a data transmission function.

Furthermore, the test reaction frame comprises a reaction frame base, a support and a cross beam, the cross beam is sleeved on the support and can be adjusted up and down, a pressurizing rod and a deformation sensor are arranged on the cross beam, the deformation sensor can be in contact with a displacement applying unit, and the displacement applying unit prepresses the deformation sensor for a deformation value; the bottom of the pressurizing rod is provided with a ball head; the pressure rod is also provided with a trimmer;

the reaction frame base upper surface is equipped with the lifter plate, be equipped with the air film that goes up and down to the lifter plate in the reaction frame base, the air film with the gas circuit intercommunication.

Furthermore, the pressure chamber comprises a pressure chamber base and an upper cover, the pressure chamber base and the upper cover form a closed space, and the pressure chamber base is detachably connected with the upper cover;

the bottom of the pressure chamber base is provided with a concave platform matched with the lifting plate, and the concave platform is matched with the lifting plate, so that the pressure chamber is detachably connected with the test reaction frame;

a soil sample placing table is arranged at the center of the upper surface of the pressure chamber base; the top of the upper cover is provided with a piston rod, the piston rod extends into the upper cover, and the lower end surface of the piston rod is the same as the cross section of the soil sample in size; the center of the piston rod is positioned right below the ball head;

the piston rod is provided with a shaft pressure sensor which is positioned in the upper cover;

the top of the upper cover is provided with a pressure plate bracket, and a displacement applying unit is rotatably connected to the pressure plate bracket;

the pore pressure interface is positioned on one side of the pressure chamber base, a pore pressure sensor is arranged at the pore pressure interface, and the pore pressure channel is connected with the pore pressure sensor;

the upper cover is also provided with a box drainage air port.

Furthermore, the three-axis measurement and control cabinet comprises a water storage barrel, a back pressure body variable pipe, a pore space variable pipe and a measurement and control part;

the measurement and control part comprises a confining pressure adjusting pipeline measurement and control part, a back pressure adjusting pipeline measurement and control part and a pressure chamber drainage pipeline measurement and control part; the measurement and control part comprises a confining pressure regulating pipeline measurement and control part, a back pressure regulating pipeline measurement and control part and a pressure chamber drainage pipeline measurement and control part which are connected with the water storage barrel and the pressure chamber;

the back pressure body variable pipe, the body variable pipe and the pore space variable pipe are all connected with the pressure chamber.

Further, the pressurizing device is an air pump.

Furthermore, the axle pressure regulating cabinet is provided with a plurality of axle pressure regulating valves and axle pressure gauges, and each axle pressure regulating valve corresponds to one axle pressure gauge; each shaft pressure regulating valve is connected with the corresponding test reaction frame.

The utility model has the advantages that: compared with the prior art, the utility model has the improvement that,

1. the soil body creep test system of the utility model can simulate the triaxial creep compression condition of the soil body under the conditions of different confining pressures and different stress ratios, and quickly obtain the soil body porosity pressure and the deformation condition of the soil body under the conditions of different confining pressures and different stress ratios;

2. the soil body creep test system of the utility model can test a single soil sample, and can also test a plurality of soil samples simultaneously;

3. the utility model provides a soil body creep test system, axle load sensor are located the pressure chamber, can gather the true axial pressure that the soil sample received in real time, and cross-section such as compression bar and soil sample moreover owing to can influence the axle load when exerting the confined pressure, avoided the axial pressure that the axle load sensor was located the outdoor time of pressure to gather because the confined pressure influences and the wearing and tearing back of compression bar, the true axial pressure that receives with the soil sample deviation appears.

4. The utility model discloses a soil body creep test system can also be done K0 side pressure coefficient creep test, pore pressure creep test, unipolar soil body creep and poisson's ratio test etc..

Drawings

Fig. 1 is the connection schematic diagram of the soil body creep test system of the utility model.

Fig. 2 is the utility model discloses soil body creep test system triaxial observes and controls cabinet pipeline schematic diagram.

Fig. 3 is the structural schematic diagram of the pressure chamber of the soil body creep test system of the utility model.

Fig. 4 is the utility model discloses experimental reaction frame structure schematic diagram of soil body creep test system.

FIG. 5 is a front view of the control panel of the three-axis measurement and control cabinet of the present invention;

FIG. 6 is a back view of the control panel of the three-axis measurement and control cabinet of the present invention;

FIG. 7 is an interface screenshot displayed on the LCD screen when the triaxial test and control cabinet of the present invention is powered on;

fig. 8 is an interface screenshot displayed on the lcd screen after the control panel of the three-axis measurement and control cabinet of the present invention is pressed down the "set key";

fig. 9 is an interface screenshot displayed on the lcd screen after the "enter key" or "enter key" is pressed to select "time setting" and "enter key" in the interface of fig. 8 of the triaxial measurement and control cabinet of the present invention;

fig. 10 is an interface screenshot displayed on the lcd screen after the "key" or "key" is pressed to select "coefficient calibration" and "enter key" in the interface of fig. 8 of the triaxial test and control cabinet of the present invention;

fig. 11 is an interface screenshot displayed on the lcd screen after the triaxial measurement and control cabinet of the present invention is pressed down the "calibration key";

fig. 12 is an interface screenshot displayed on the lcd screen after the triaxial measurement and control cabinet of the present invention is pressed down the "test key";

fig. 13 is the utility model discloses after triaxial observes and controls cabinet and presses "settlement key" that confined pressure or back pressure fence correspond, the interface screenshot that shows on the LCD screen.

Wherein: 0-soil sample, 1-triaxial measurement and control cabinet, 101-water storage tank, 102-confining pressure water injection valve, 103-confining pressure valve, 104-pressure chamber water discharge valve, 105-counter pressure water injection valve, 106-counter pressure valve, 107-counter pressure water discharge valve, 108-pressure chamber valve, 109-volume change measuring valve, 110-pressure chamber water injection valve, 111-counter pressure volume change pipe, 112-volume change pipe, 113-pore volume pipe, 114-water pump, 115-confining pressure regulating valve, 116-confining pressure sensor, 117-counter pressure regulating valve, 118-counter pressure sensor, 119-confining pressure gauge, 120-counter pressure gauge, 121-confining pressure pipe, 122-counter pressure pipe, 123-pore pressure valve, 2-test counter force frame, 201-counter force frame base, 202-frame, 203-beam, 204-pressure rod, 205-deformation sensor, 206-fixing nut, 207-lifting plate, 208-ball head, 209-trimmer; 3-axial pressure regulating cabinet, 301-axial pressure regulating valve, 302-axial pressure gauge, 303-gas path, 4-multichannel controller, 401-displacement channel, 402-pore pressure channel, 5-computer, 6-pressure chamber, 601-pressure chamber base, 602-upper cover, 603-piston rod, 604-soil sample placing table, 605-confining pressure interface, 606-back pressure interface, 607-pore pressure interface, 608-displacement applying unit, 609-pressure plate support, 610-drainage air port, 611-axial pressure sensor, 612-pore pressure sensor and 7-air pump.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following describes the technical solution of the present invention with reference to the accompanying drawings and embodiments.

The first embodiment is as follows:

the soil body creep test system shown with reference to the attached figures 1-4 comprises a pressurizing device, a control device, a test main body device and a data acquisition device.

Specifically, the pressurizing device is an air pump 7, and the control device comprises a three-axis measurement and control cabinet 1 and an axial pressure regulating cabinet 3; the data acquisition device comprises a multi-channel controller 4 and a computer 5, and the test main body device comprises a test reaction frame 2 and a pressure chamber 6. The multi-channel controller 4 is connected with the computer 5 through a lead. In the present embodiment, three test reaction frames 2 and three pressure chambers 6 are provided. In actual use, only one or two test reaction frames 2 and pressure chambers 6 can be used, and the number of the test reaction frames 2 and the number of the pressure chambers 6 are required to be consistent.

Specifically, the air pump 7 is connected with an air inlet of the axial pressure regulating cabinet 3; the axial pressure regulating cabinet 3 is used for shunting the airflow and providing axial pressure;

the axle pressure regulating cabinet 3 is provided with three axle pressure regulating valves 301 and axle pressure gauges 302, and each axle pressure regulating valve 301 corresponds to one axle pressure gauge 302; the air outlet of the axle pressure regulating cabinet 3 is connected with the three test reaction frames 2 through air passages 303, and each air passage 303 corresponds to one axle pressure regulating valve 301 and one axle pressure gauge 302.

Further, the test reaction frame 2 comprises a reaction frame base 201, supports 202 and a cross beam 203, two open grooves are formed in the reaction frame base 201, one support 202 is connected into each open groove through a thread, threads are formed in the outer surfaces of the supports 202, and the bottoms of the supports 202 are fixed with the reaction frame base 201 through nuts; a cross beam 203 is arranged between the two brackets 202, openings are arranged at the positions of the cross beam 203 corresponding to the brackets 202, and the cross beam 203 is sleeved outside the brackets 202 through the openings; two fixing nuts 206 are arranged on each bracket 202, the two fixing nuts 206 are respectively positioned above and below the cross beam 203, the threads on the outer surface of the bracket 202 are matched with the fixing nuts 206 to fix the cross beam 203 on the bracket 202 at any height, and the height of the cross beam 203 can be adjusted by adjusting the fixing nuts 206.

Furthermore, a vertical pressure rod 204 is arranged in the middle of the cross beam 203, the height of the pressure rod 204 changes with the change of the height of the cross beam 203, a fine adjuster 205 is arranged on the pressure rod 204 and used for fine adjustment of the height of the pressure rod 204, and a ball head 208 is arranged at the bottom of the pressure rod 204; the cross beam 203 is further provided with a deformation sensor 205, and the deformation sensor 205 is positioned on one side of the pressurizing rod 204.

Further, a lifting plate 207 is arranged on the upper surface of the reaction frame base 201, a pressurizing cavity is arranged in the reaction frame base 201, an air film for lifting the lifting plate 207 is arranged in the pressurizing cavity, and the air film is communicated with a corresponding air passage 303; the air flow in the air path 303 flows into the air film, changes the size of the air film, and lifts the lifting plate 207.

Furthermore, each test reaction frame 2 is provided with a pressure chamber 6 for placing the soil sample 0. The pressure chamber 6 comprises a pressure chamber base 601 and an upper cover 602, the bottom of the upper cover 602 is a flange, three slots with threads are arranged on the pressure chamber base 601, and the upper cover 602 is detachably connected with the pressure chamber base 601 through a cover-shaped nut and a T-shaped bolt; the bottom of the upper cover 602 is also provided with a sealing groove, the pressure chamber base 601 is correspondingly provided with a sealing ring, the type of the sealing ring is phi 95 x 3.10, when the pressure chamber base 601 and the upper cover 602 are installed, the phi 95 x 3.10 type sealing ring on the base must be ensured to be in the sealing groove, otherwise, leakage and damage to the O-shaped rubber ring can be caused; meanwhile, the bottom surface of the upper cover needs not to be damaged, roughened and polished, so that the flatness of the sealing surface is ensured, otherwise, leakage is caused; when the upper cover 602 and the pressure chamber base 601 are mounted together, a closed space is formed inside the upper cover 602.

The bottom of the pressure chamber base 601 is provided with a concave matched with the lifting plate 207, the concave of the pressure chamber base 601 is correspondingly placed on the lifting plate 207 at the top of the reaction frame 201, the pressure chamber 6 is fixed on the test reaction frame 2, and the diameter of the pressure chamber 6 is smaller than the distance between the two brackets 202.

A soil sample placing table 604 is arranged at the center of the upper surface of the pressure chamber base 601; the soil sample placing table 604 is used for placing a soil sample 0 for testing. A piston rod 603 is arranged at the top of the upper cover 602, the piston rod 603 extends into the upper cover 602, the bottom of the piston rod 603 is higher than the soil sample placing table 604, the bottom of the piston rod 603 is positioned right above the soil sample placing table 604, the top of the piston rod 603 penetrates out of the upper cover 602, and the center of the piston rod 603 is positioned right below the ball head 208 at the bottom of the pressure rod 204; the lower end face of the piston rod 603 is the same as the cross section of the soil sample 0 in size; when mounting the pressure chamber base 601 and the upper housing 602, three M10 cap nuts are tightened uniformly to ensure the verticality of the piston rod 603.

Further, a sealing structure is arranged at the contact position of the piston rod 603 and the upper cover 602, and two types of sealing are adopted, namely, 7501 silicone grease is used for sealing and lubricating the gap; and the O-shaped oil-resistant rubber sealing ring is used for sealing and stopping water, and the mode is that the O-shaped oil-resistant rubber sealing ring is used for sealing and using after the piston matching part is worn for a long time, so that the gap is increased and the leakage is caused.

Further, a shaft pressure sensor 611 is arranged on the piston rod 603, the shaft pressure sensor 611 is located in the upper cover 602, and the shaft pressure sensor 611 acquires the shaft pressure of the soil sample 0 in real time.

Further, a pressurizing plate support 609 is further arranged on the top end face of the upper cover 602 upwards, and a displacement applying unit 608 is rotatably sleeved on the pressurizing plate support 609 close to the top end; the displacement applying unit 608 is located below the deformation sensor 205 on the test reaction frame 2, before the test, the deformation sensor 205 can contact with the displacement applying unit 608, and the displacement applying unit 608 preloads the deformation sensor 205 by a deformation value; during the test, the soil sample 0 generates deformation displacement under the action of confining pressure and axial pressure, the deformation is applied to the deformation sensor 205 through the displacement applying unit 608, the deformation sensor 205 collects the displacement deformation of the soil sample 0, the deformation sensor 205 is connected with the multi-channel controller 4 through the displacement channel 401, and the real-time displacement deformation is transmitted to the multi-channel controller 4.

Further, a box drain air port 610 is also arranged on the upper cover 602.

Further, the front portion of the pressure chamber 6 is provided with a confining pressure interface 605 and a back pressure interface 606, one side of the pressure chamber 6 is provided with a pore pressure interface 607, a pore pressure sensor 612 is arranged at the pore pressure interface 607, and the pore pressure sensor 612 is connected with the multi-channel controller 4 through the pore pressure channel 402 to transmit the value of the pore pressure to the multi-channel controller 4.

Further, the multichannel controller 4 is connected with the computer 5 through a USB data line, the multichannel controller 4 transmits the displacement deformation amount collected by the deformation sensor 205 and the pore pressure value collected by the pore pressure sensor 612 to the computer 5 through the USB data line, and the computer 5 records, stores, analyzes and maps the received data.

Further, the three-axis measurement and control cabinet 1 comprises a water storage barrel 101, a back pressure body variable pipe 111, a body variable pipe 112, a pore volume pipe 113 and a measurement and control part; the triaxial measurement and control cabinet 1 is connected with a confining pressure interface 605 and a back pressure interface 606 on each pressure chamber 6 through a confining pressure pipeline 121 and a back pressure pipeline 122; the back pressure body changing pipe 111 is used for measuring volume variation of a sample when back pressure is added, the volume changing pipe 112 is used for measuring volume variation of the sample when back pressure is not added, and the pore space pipe 113 is used for changing a measuring body and keeping a pore pressure measuring system filled with water so that air does not permeate into the system.

Furthermore, the measurement and control part comprises a confining pressure adjusting pipeline measurement and control part, a back pressure adjusting pipeline measurement and control part and a pressure chamber drainage pipeline measurement and control part;

the confining pressure regulating pipeline measurement and control comprises a confining pressure water injection valve 102, a confining pressure valve 103 and a confining pressure regulating valve 115; a confining pressure sensor 116 and a confining pressure gauge 119 are arranged on the confining pressure adjusting pipeline; the confining pressure regulating pipeline is provided with a confining pressure regulating cylinder, the confining pressure regulating cylinder is provided with a confining pressure water injection valve 102 and a confining pressure valve 103, the confining pressure regulating cylinder consists of a pressure regulating cylinder, a piston, a 70TDY permanent magnet type low-speed synchronous motor, a pair of worm gear pairs and a screw pair, the confining pressure regulating cylinder is controlled by a measurement and control instrument, and a sensor controls the synchronous motor to rotate in a feedback manner, so that the piston moves forward or backward to keep exerting surrounding pressure on a soil sample; the screw pin is loosened, the water can be filled into the pressure regulating cylinder by manually regulating the confining pressure water injection valve 102 and the confining pressure valve 103, the water is discharged and exhausted, and the surrounding pressure is roughly regulated. The confining pressure value can be directly read through a digital display window in a pressure gauge or a measurement and control instrument. When the pressure regulating cylinder piston moves to the front end, i.e. the hand wheel contacts with the travel switch, the power supply can be automatically cut off to protect the safety of the system. The confining pressure gauge 119 is a 0.4-grade 1Mpa precision pressure gauge.

The back pressure regulation pipeline is observed and controlled including back pressure water injection valve 105, backpressure valve 106 and back pressure air-vent valve 117, be equipped with back pressure sensor 118 and backpressure manometer 120 on the back pressure regulation pipeline, be equipped with a back pressure regulating section of thick bamboo on the back pressure regulation pipeline, be equipped with back pressure water injection valve 105 and backpressure valve 106 on the back pressure regulating section of thick bamboo, the structure of a back pressure regulating section of thick bamboo is the same with the structure of the above-mentioned confined pressure regulating section of thick bamboo, a back pressure regulating section of thick bamboo is used for applying backpressure to. The back pressure gauge 120 is a 0.4-grade 2.5Mpa precision gauge.

The pressure chamber drain pipeline measurement and control comprises a pressure chamber drain valve 104, a back pressure drain valve 107, a pressure chamber valve 108 and a pressure chamber water injection valve 110; the pressure chamber valve 108 is a three-way valve.

The measurement and control part also comprises a water pump 114 for pumping water and a body variation measuring valve 109 for opening and closing during body variation measurement.

Furthermore, a control panel is further arranged on the three-axis measurement and control cabinet 1, and the confining pressure, the back pressure and the pore pressure can be accurately measured and precisely controlled by adopting liquid crystal full Chinese character menu display and operation.

The front view of the control panel is shown in figure 5, the back view is shown in figure 6, and the control panel is provided with a liquid crystal screen.

Wherein, the power: the instrument power switch is used for switching on the power supply when the red light is on;

a power socket: the 220V alternating current power supply socket is connected with a power line, the lower part of the socket is provided with a fuse slot, and a replaceable fuse is drawn out;

pore pressure: a pore pressure sensor receptacle;

confining pressure: a confining pressure sensor socket;

back pressure: a back pressure sensor socket;

confining pressure control: a confining pressure control motor socket;

back pressure control: a back-pressure control motor socket;

the system adopts liquid crystal display full Chinese menu, and realizes various complex functions and control in the test with fewer function keys. Simple operation and convenient use.

The system control menu is arranged at the lowest part of the liquid crystal screen and corresponds to six function keys F1, F2, F3, F4, F5 and F6, and the functions of the menu can be realized by pressing the keys right below the menu. In the following, the "pressing a certain key corresponding to a certain menu" is directly expressed as "pressing a certain menu key". Such as: the "set" menu corresponds to the F2 key, and pressing the "set" key is pressing the F2 key.

The instrument was powered on and the interface shown in figure 7 was displayed on the lcd screen. Pressing the "set key" displays the interface shown in fig. 8 on the liquid crystal screen. Pressing the "back key" returns to the interface shown in FIG. 7; the key and the key are menus for selecting the coefficient calibration and the time setting up from top to bottom, and the selected menu is displayed in a reverse color; pressing the 'confirm key' realizes the function of selecting the menu.

In the interface shown in fig. 8, the "time setting" is selected by pressing the "key" or the "key", and the interface shown in fig. 9 is entered by pressing the "enter key" to set the time.

Pressing the "back key" will return to the previous level of interface (i.e., FIG. 8).

The specific method for setting time comprises the following steps:

pressing "← →" selection key to select the part to be modified (cycle in year, month, day, hour, minute and second), and modifying the corresponding numerical value through the addition and subtraction key. After the time is set, the 'start key' is pressed to start normal timing.

The utility model provides a soil body creep test system pressure unit is Kpa, adopts 20 some multiple spot marks, has eliminated the nonlinear error of sensor basically. In the interface shown in fig. 8, the "key" or the "key" is pressed to select "coefficient calibration", and the interface shown in fig. 10 can be entered by pressing the "confirm key" to perform coefficient calibration.

Pressing the "back key" will return to the previous level of interface (i.e., FIG. 8).

The interface terms are illustrated below:

a channel: and displaying the current channel. As shown, "01 confining pressure" means that the first channel is currently shown, which channel is used for the confining pressure sensor. The 'selection key' can circularly select channels, and each time the channel is pressed, the channel number is increased by one, and the channel is circularly reciprocated.

Measuring range: the range of the channel sensor is displayed. The range of the pressure sensor is 2000Kpa as shown in the figure "2000". The setting can be performed by a "range key".

The first point is that: the number of points currently being recorded during calibration is displayed, along with the pressure (or other) value for that point.

And (3) calibrating points: the number of points marked is shown, typically 20.

Current value: the display sensor outputs the converted digital quantity of the current analog quantity, the display can be refreshed in real time, and the display changes along with the change of the measured value of the channel.

Gain: the amplification factor of the display sensor signal can be set through a gain key. And an extensible platform is provided for upgrading the system and adapting to different types of sensors.

The specific method for calibrating the coefficient comprises the following steps: after entering the interface as shown in figure 10,

1. the "select key" selects the channel to be calibrated.

2. Pressing the gain key sets the appropriate gain for the selected channel sensor.

And each time the 'gain key' is pressed, the gain is increased by one step, the display is repeated from 1 to 128, and the displayed value is the current set value.

(Note: Only models with gain control can use this function)

3. Pressing "range key" sets the range of the selected channel sensor.

After pressing the "range key", the cursor will flash in the range column, select the part to be modified by the "← →" key, and then modify the corresponding numerical value by the "add-subtract key". After the input is correct, the 'confirm key' is pressed to complete the setting of the measuring range.

4. Pressing the 'calibration key' to start calibration.

When the "mark key" is pressed, the liquid crystal screen displays 0.0000 in the "dot" column and 20 in the mark column as shown in fig. 11, and the menu also changes. At this time, the pressure (or other measured value) of the pressure sensor (or other measured value) is unloaded to 0, and a 'record key' is pressed; then, the screen 'the 1 st point' is displayed, the original 0.0000 of the column becomes the next value to be calibrated, the pressure (or other measured values) is added to the displayed value, the record is pressed, and after 20 points are calibrated in sequence, the 'record key' becomes the 'save key'. Pressing the "save key" will save this calibration value. The system calculates the measured value of the channel based on the calibration in the test process.

Regarding the use of the "abort key": in order to solve the influence of the non-linear error of the sensor on the measurement, the system adopts 20-point multi-point calibration, and the 20-point calibration value is to divide the measurement range into 20 equal parts, and each time the measurement range is increased by one step, for example, the measurement range is 2000, the starting point is 0, the 1 st point is 100, the 2 nd point is 200, the 3 rd point is 300, and so on. If the standard measuring tool for calibration does not have the standard value of the point which we want to calibrate, if the standard measuring tool is 300, the measuring tool cannot measure actually, at the moment, the 'abandon key' can be pressed to abandon calibrating the point, and other points are calibrated continuously, so that the calibration process and the measurement of the sensor cannot be influenced. Meanwhile, the fixed 20-point calibration can be considered to be actually changed into the calibration of optional points and optional points, and for the occasions with low requirements, the calibration can be completed by calibrating 0 point and any other point, so that the measurement is realized.

With respect to "loading key" and "unloading key": when the confining pressure is calibrated, a standard pressure gauge can be added in the confining pressure pipeline, and the pressure of the pressure regulating cylinder is controlled to be pressurized and released by pressing the loading key and the unloading key so as to adjust the pressure value to be calibrated, so that the system provides the adjusting operation interface. However, for the calibration of other sensors, only the measured values are adjusted by other methods and then the calibration is recorded.

Note that: only after the steps 1, 2, 3 and 4 are correctly completed, the 'save key' is pressed to save the standard values including the range, the gain and each point. If an error occurs in the calibration process, please end at 20 points, and the 'abandon key' is pressed to abandon the storage when the 'save key' and the 'abandon key' appear on the screen, or the 'return key' is pressed in the calibration process and then enters the calibration interface from the beginning, the original stored range, gain and standard value of each point cannot be influenced.

When the sensor is recalibrated, the measuring range, the gain and the requirement do not change, and default values when leaving a factory are used as much as possible unless the sensor is replaced.

Further, when the confining pressure and the back pressure are controlled, the controller is powered on, and an interface as shown in fig. 7 is displayed on the liquid crystal screen. By pressing the "test key", an interface as shown in fig. 12 is displayed on the liquid crystal screen.

The first line of the screen displays date and time; the second line respectively displays the current set values of the wall and back pressure (the values needing to be stabilized); and the third line displays the current actually measured pressure values of the surrounding pressure and the back pressure in real time respectively.

The corresponding 'setting key' and 'voltage stabilizing key' are arranged below the confining pressure and back pressure bars.

When the "set key" corresponding to the column of the confining pressure or the back pressure is pressed, the cursor will flash in the column, as shown in the interface of fig. 13. The section to be modified is selected through the key "← →" and the corresponding numerical value is modified through the key addition and subtraction, and the setting of the setting value is completed by pressing the "enter key" after no error is input. After the setting is finished, a 'pressure stabilizing key' is pressed, the controller automatically pressurizes or releases pressure to a set value, and compensation is continuously carried out to enable the pressure to be stabilized at the set value. During the voltage stabilization process, the voltage stabilization key is changed into a stop key, and if the voltage stabilization is to be stopped, the voltage stabilization is stopped by pressing the stop key controller.

The confining pressure and the back pressure can be respectively set to different voltage stabilization values to stabilize the voltage simultaneously without mutual influence.

Note that:

when the air-water-saving type air conditioner is used for the first time or after the air-water-saving type air conditioner is not used for a long time, the air exhaust operation is required to be carried out on a pipeline, and the method is to use the functions of water injection and water drainage and repeatedly carry out the water injection and water drainage operations.

When the water pump is not used for a long time, the water in the controller needs to be completely discharged, and the water pump needs to be started for several times at irregular intervals to prevent rust.

The water in the water storage bottle is replaced frequently, the water storage bottle is kept clean and cannot be turbid or contain soil impurities, otherwise, the instrument can be broken down, and the service life of the instrument is shortened.

If the sample contains corrosive media such as acid, alkali and the like, after the test is finished, all water in the controller is discharged immediately, the water in the water storage bottle is replaced, and the pipeline is cleaned by using the functions of water injection and water discharge so as to avoid the corrosion phenomenon.

When the container is filled with water or drained, the water is not required to leave, so that the phenomenon that a large amount of water overflows or a water pump works for a long time is avoided.

Further, the utility model provides a main technical parameter of soil body creep test system is:

1. power supply: 220V 50Hz

2. Power: 2kW

3. Soil sample size: phi 61.8X 125mm

4. Confining pressure: F.S with the precision of 0-2 MPa +/-0.5%. Digital display, adjustable at will

5. Back pressure: F.S with the precision of 0-1 MPa +/-0.5%. Digital display, adjustable at will

6. Pore pressure: 0-1 MPa precision +/-0.5% F.S

7. Deformation: 0mm to 20mm +/-0.01 mm

8. Axial force: can be adjusted arbitrarily to be constant, and can be automatically charged with 0 to 18KN (0 to 2.5 MPa)

9. Can simultaneously make 3 samples and can also separately make

10. Computer software for collecting deformation, pore pressure, data storage and drawing graph

11. And (3) measuring the volume change: precision of 0-50 ml: 0.2ml

12. The working environment is as follows:

indoor special grounding wire without strong electromagnetic interference

The performance can be ensured under the conditions that the working temperature is 10-40 ℃ and the relative humidity is less than 85%; can be used under the conditions of 0-45 ℃ and relative humidity less than 85 percent.

Further, the test method of the soil body creep test system comprises the following steps:

s1, connecting the instrument: assembling the pressurizing device, the control device, the test main body device and the data acquisition device;

specifically, the air pump is connected with an air inlet of the axial pressure regulating cabinet, an air outlet of the axial pressure regulating cabinet is connected with the test reaction frame, a confining pressure pipeline and a counter pressure pipeline of the triaxial measurement and control cabinet are respectively connected with a confining pressure interface and a counter pressure interface of the pressure chamber, the deformation sensor is connected with a displacement channel of the multi-channel controller, the pore pressure sensor is connected with a pore pressure channel of the multi-channel controller, and the multi-channel controller is connected with the computer.

S2, testing pressure and electricity: checking the tightness of each pipeline and each valve and the tightness of each gas circuit; checking and setting computer software to communicate with a test host;

specifically, the confining pressure pipeline and the back pressure pipeline of the triaxial measurement and control cabinet are subjected to exhaust and pressure test, so that the confining pressure pipeline and the back pressure pipeline, and valves and pressure chambers are prevented from being leaked; and checking the air passage tightness of the axial pressure regulating cabinet and the test reaction frame, and checking and setting computer software to communicate with the test host.

Specifically, the confining pressure water injection valve 102 is opened, the hand wheel bolt of the confining pressure regulating valve 115 is screwed off, the hand wheel is rotated anticlockwise to pump water for the pressure regulating cylinder to be full, the confining pressure water injection valve 102 is closed, the confining pressure valve 103 is opened, the hand wheel of the confining pressure regulating valve 115 is rotated clockwise to discharge water to the confining pressure interface 605 outlet of the pressure chamber 6 along the confining pressure pipeline 121, the above operations are repeatedly carried out until the confining pressure interface 605 outlet of the pressure chamber 6 is discharged with water, then, the confining pressure water injection valve 102 and the confining pressure valve 103 are closed, the bolt on the confining pressure regulating valve 115 is inserted, and the confining pressure regulating cylinder can be normally used after the exhaust operation is finished.

Further, the back pressure water injection valve 105 is opened, the hand wheel bolt of the back pressure regulating valve 117 is unscrewed, the screw plug of the body variable measuring tube 112 is unscrewed, the hand wheel of the back pressure regulating valve 117 is rotated anticlockwise, the back pressure regulating cylinder is pumped to be full, the back pressure valve 106, the body variable measuring valve 109 are opened, the back pressure water injection valve 105 is closed, the hand wheel of the back pressure regulating valve 117 is rotated clockwise, the operations are repeated, filling water into the body variable pipe 112, filling the water into the back pressure interface 606 of the pressure chamber 6 through the body variable measuring valve 109 along the small glass pipe in the body variable pipe 112, until the water overflows from the outlet of the back pressure interface 606, closing the body variable measuring valve 109, continuing to clockwise rotate the hand wheel of the back pressure regulating valve 117 until the water in the body variable pipe 112 is full, screwing the screw plug on the body variable pipe 112, closing the drain valve 104 of the pressure chamber, closing the back pressure water filling valve 105, inserting the plug on the back pressure regulating valve 117, and then using the back pressure regulating cylinder normally after the air exhaust operation is finished.

The pore measuring pipe 113 is filled with water, the pore pressure valve 123 is opened, and the pore pressure valve 123 is closed when water overflows from the pressure chamber base 601, so that the pore measuring system can be normally used after the drainage operation is finished.

S3, mounting a soil sample: installing a soil sample in a pressure chamber;

specifically, S31: placing the latex film in a film bearing cylinder, turning and sleeving two ends of the latex film outside the cylinder, paying attention to the fact that the latex film is flat and cannot be crumpled, turning the latex film up and down to be equal in width and level, sleeving a rubber tube on an air nozzle of the film bearing cylinder, connecting an ear washing ball at the end of the rubber tube, sucking air between the latex film and the cylinder wall, and enabling the latex film to be tightly attached to the cylinder wall of the film bearing cylinder;

s32: a rubber tube is sleeved on an air nozzle of the film bearing barrel, and an ear washing ball is connected to the end part of the rubber tube to suck out air between the latex film and the barrel wall so that the latex film is tightly attached to the barrel wall of the film bearing barrel;

s33: sleeving a film bearing cylinder with a latex film on a pre-prepared soil sample, turning down the lower latex film to enable the lower latex film to hoop the soil sample placing table, and tying and sealing the soil sample placing table by using a rubber band; turning up the upper latex film, loosening the ear washing ball, and taking down the film bearing cylinder;

s34: pulling down the piston rod to contact with the top surface of the soil sample, and simultaneously tying the piston rod tightly by a rubber band for sealing; note that the air tap can not be broken in use.

S35: the upper cover is arranged on the pressure chamber base, attention is paid to the sealing ring of the pressure chamber base to be sealed in the groove, and attention is paid to the sealing of the upper cover, otherwise, leakage can be caused. When the soil sample is loaded, permeable stones and filter paper are sequentially placed at the bottom and the upper part of the soil sample, and impermeable plates are respectively placed above and below the soil sample 0.

Furthermore, the specification of the film bearing cylinder is shown in Table 1,

TABLE 1 film-bearing canister Specifications

Furthermore, most of the soil samples for the triaxial test are saturated soil, when the device is used, the soil samples are placed into a saturator for capillary saturation and air extraction saturation, the saturator comprises an upper cover, a base, a permeable stone and a three-petal cylinder, and the specification of the saturator is shown in table 2.

TABLE 2 saturator specification

The method specifically comprises the following steps: placing the cut sample in a three-piece barrel, sleeving a hoop, cutting off the upper and lower excessive soil, placing one piece of filter paper at each of two ends, placing the soil sample barrel on a permeable stone in a base, placing the other permeable stone on a barrel, installing a nylon upper cover, and screwing a disc-shaped nut to saturate in saturation equipment;

after the sample is saturated, the hoop is loosened, the three petals are sequentially pushed along the axis direction by hands, and then the soil can be taken out.

And each piece on the three-piece barrel is printed with a number. When the clothes are put together, the combination is matched according to the number without miscombination or exchange, and the edges of the clothes are not damaged by collision so as to avoid influencing the matching.

After use, the soil is cleaned, the metal piece is coated with oil for protection, and the residual soil on the permeable stone is cleaned.

The base and the upper cover are made of nylon materials, such as tightening a pull rod, and the force cannot be too large to avoid damage.

S4: placing the pressure chamber with the soil sample installed on a test reaction frame, and adjusting the height of the test sample reaction frame;

specifically, a fixing nut on the support is loosened, the height of the cross beam is adjusted, then the fixing nut is screwed, and then the fine adjuster is adjusted to enable the pressurizing rod to be in contact with a piston rod of the pressure chamber, and the piston rod is in contact with the top of the soil sample but is not stressed; and adjusting the displacement applying unit, prepressing a deformation value for the deformation sensor, checking the displacement data of a software interface on the computer, and ensuring that the sufficient displacement range exists in the test.

S5: starting the three-axis measurement and control cabinet and the axial pressure regulating cabinet to pressurize and stabilize the soil sample;

specifically, the three-axis measurement and control cabinet is started, the top drainage air port 610 of the pressure chamber 6 is opened, the pressure chamber valve 108 is arranged at a water injection position, the pressure chamber water injection valve 110 is opened, the water pump 114 is opened to inject water into the pressure chamber 6, when the pressure chamber 6 is nearly full of water, the pressure chamber valve 108 and the pressure chamber water injection valve 110 are closed, the confining pressure water injection valve 102 and the confining pressure valve 103 are opened, the pressure chamber 6 is naturally filled with water to be full of water, the top drainage air port 610 of the pressure chamber 6 is closed (can be closed by a screw plug), and the confining pressure water injection valve 102 is closed.

When the confining pressure is simultaneously applied to three soil samples, the confining pressure of three pressure chambers is required to be connected in series and pressurized simultaneously.

S6: inputting relevant parameters in a computer, starting a test, and recording and storing data and curve graphs in the test process;

specifically, carry out the triaxial creep test to soil sample 0, exert the confined pressure around to soil sample 0, simultaneously, start air pump 7, the air current of air pump 7 makes the air film inflation in the reaction frame base 201, it rises to drive lifter plate 207, the pressure bar 204 exerts axial pressure to soil sample 0, deformation sensor 205 gathers the deformation displacement of soil sample 0, pore pressure sensor 612 gathers the gap pressure, transmit to multichannel controller 4 through displacement passageway 401 and pore pressure passageway 402, then transmit to computer 5 through the USB wiring.

S7: and after the test is finished, removing the pressure, removing the soil sample, calculating and analyzing related data, and sorting the result.

Example two:

the soil body creep test system in the embodiment is completely the same as that in the first embodiment, in the test method of the soil body creep test system, after the soil sample is filled in the step S3, no watertight plates are arranged above and below the soil sample, in the step S6, the soil sample 0 is subjected to the seepage creep test, and the rest steps are the same.

Example three:

the soil body creep test system in the embodiment is completely the same as that in the first embodiment, in the test method of the soil body creep test system, after the soil sample is filled in the step S3, no watertight plates are placed above and below the soil sample, in the step S6, the pore pressure dissipation test is performed on the soil sample 0, and the rest steps are the same.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (6)

1. Soil body creep test system, including pressure device, controlling means, experimental main part device and data acquisition device, its characterized in that: the control device comprises a three-axis measurement and control cabinet (1) and an axial pressure regulating cabinet (3), and the data acquisition device comprises a multi-channel controller (4) and a computer (5);

the pressurizing device is connected with an air inlet of the axial pressure regulating cabinet (3) and provides axial pressure for a test;

the test main body device comprises at least one test reaction frame (2), and each test reaction frame (2) is provided with a pressure chamber (6) for placing a soil sample (0); each test reaction frame (2) is provided with a pressurizing rod (204) and a deformation sensor (205);

the air outlet of the axial pressure regulating cabinet (3) is connected with each test reaction frame (2) through an air passage (303) to apply axial pressure to the soil sample (0) in the corresponding pressure chamber (6);

each pressure chamber (6) is provided with a confining pressure interface (605), a back pressure interface (606), a pore pressure interface (607) and a displacement applying unit (608); the displacement applying unit (608) is matched with the deformation sensor (205) to measure the deformation displacement of the soil sample (0);

the triaxial measurement and control cabinet (1) is connected with a confining pressure interface (605) and a back pressure interface (606) on each pressure chamber (6) through a confining pressure pipeline (121) and a back pressure pipeline (122);

a piston rod (603) is arranged at the top of the pressure chamber (6), and the pressurizing rod (204) is positioned right above the piston rod (603);

the multi-channel controller (4) comprises a plurality of displacement channels (401) and pore pressure channels (402), each displacement channel (401) is connected with a deformation sensor (205) on a corresponding test reaction frame (2), each pore pressure channel (402) is connected with a pore pressure interface (607) on a corresponding pressure chamber (6), and deformation displacement and pore pressure of a soil sample (0) are collected in real time;

the multi-channel controller (4) is connected with the computer (5) through a lead to realize a data transmission function.

2. The soil mass creep test system of claim 1, wherein: the test reaction frame (2) comprises a reaction frame base (201), a support (202) and a cross beam (203), the cross beam (203) is sleeved on the support (202), the cross beam (203) can be adjusted up and down, a pressurizing rod (204) and a deformation sensor (205) are arranged on the cross beam (203), the deformation sensor (205) can be in contact with a displacement applying unit (608), and the displacement applying unit (608) pre-presses a deformation value for the deformation sensor (205); a ball head (208) is arranged at the bottom of the pressurizing rod (204); a fine adjuster (209) is also arranged on the pressurizing rod (204);

reaction frame base (201) upper surface is equipped with lifter plate (207), be equipped with the air film that goes on going up and down lifter plate (207) in reaction frame base (201), the air film with gas circuit (303) intercommunication.

3. The soil mass creep test system of claim 2, wherein: the pressure chamber (6) comprises a pressure chamber base (601) and an upper cover (602), the pressure chamber base (601) and the upper cover (602) form a closed space, and the pressure chamber base (601) is detachably connected with the upper cover (602);

the bottom of the pressure chamber base (601) is provided with a concave table matched with the lifting plate (207), and the concave table is matched with the lifting plate (207) to enable the pressure chamber (6) to be detachably connected with the test reaction frame (2);

a soil sample placing table (604) is arranged at the center of the upper surface of the pressure chamber base (601); a piston rod (603) is arranged at the top of the upper cover (602), the piston rod (603) extends into the upper cover (602), and the size of the lower end face of the piston rod (603) is the same as that of the cross section of the soil sample (0); the center of the piston rod (603) is positioned right below the ball head (208);

an axial pressure sensor (611) is arranged on the piston rod (603), and the axial pressure sensor (611) is positioned in the upper cover (602);

a pressurizing plate support (609) is arranged at the top of the upper cover (602), and a displacement applying unit (608) is rotatably connected to the pressurizing plate support (609);

the pore pressure interface (607) is positioned at one side of the pressure chamber base (601), a pore pressure sensor (612) is arranged at the pore pressure interface (607), and the pore pressure channel (402) is connected with the pore pressure sensor (612);

the upper cover (602) is also provided with a box drainage air port (610).

4. The soil mass creep test system of claim 1, wherein: the three-axis measurement and control cabinet (1) comprises a water storage barrel (101), a back pressure body variable pipe (111), a body variable pipe (112), a pore space variable pipe (113) and a measurement and control part;

the measurement and control part comprises a confining pressure adjusting pipeline measurement and control part, a back pressure adjusting pipeline measurement and control part and a pressure chamber drainage pipeline measurement and control part; the measurement and control part comprises a confining pressure regulating pipeline measurement and control part, a back pressure regulating pipeline measurement and control part and a pressure chamber drainage pipeline measurement and control part which are connected with the water storage barrel (101) and the pressure chamber (6);

the back pressure variable tube (111), the volume variable tube (112) and the pore volume tube (113) are all connected with the pressure chamber (6).

5. The soil mass creep test system of claim 1, wherein: the pressurizing device is an air pump (7).

6. The soil mass creep test system of claim 1, wherein: the shaft pressure regulating cabinet (3) is provided with a plurality of shaft pressure regulating valves (301) and shaft pressure gauges (302), and each shaft pressure regulating valve (301) corresponds to one shaft pressure gauge (302); each axial pressure regulating valve (301) is connected with the corresponding test reaction frame (2).

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