CN109238796B - Two-way pressurized triaxial sample preparation device - Google Patents

Abstract

The application relates to a bidirectional pressurized triaxial sample preparation device, which belongs to the field of indoor geotechnical engineering of the discipline of civil engineering. It includes seven parts: pressure mechanism, pressure transmission mechanism, upper pressure mechanism, lower pressure mechanism, sample preparation cylinder, upper support mechanism, and lower support mechanism. The application can intelligently control the sample preparation pressure and time of triaxial samples to simulate the actual soil consolidation process, and can form multiple samples at one time, reduce sample preparation time and disturbance to soil samples, and overcome traditional samples The defect of difficult sampling in the cylinder has certain engineering applicability.

Description

A bidirectional pressurized triaxial sample preparation device

technical field

The application relates to a bidirectional pressurized triaxial sample preparation device, which belongs to the field of indoor geotechnical engineering of the discipline of civil engineering.

Background technique

With the increasing number of construction projects on soft soil foundations in coastal areas, the testing of soft soil mechanical properties has become an important part of current civil engineering. Triaxial test is a common experimental method for measuring the mechanical properties of soft soil. Mechanical properties of soft soil under confining pressure. Usually, manual compaction is used to uniformly compact the soil sample to achieve the target soil sample compactness, and manual demoulding is used. Due to the low efficiency of making samples one by one, it is difficult to precisely control the uniformity and consistency of the samples, and manual demolding is difficult to avoid disturbance of the samples, thus affecting the mechanical properties testing of soft soil samples.

CN106568628A discloses a soil sample preparation experiment equipment, which can solve the problem of poor uniformity of soil sample preparation samples in the prior art; CN106769312A discloses a soil sample compactor, which adopts single-sided pressure, and performs the soil sampling process. optimized; CN106610353A discloses a device for preparing samples for triaxial experiments by using layered compaction method, which adopts manual layered compaction of soil samples according to the principle of leverage. The above cases have solved the problem of soil sample forming uniformity, but there are still three technical problems that need to be solved: 1. It cannot intelligently simulate the real stress process of foundation soil consolidation for a long time; 2. It cannot realize multiple tests at one time. 3. There is a defect that the sample is difficult to demould.

Based on this, the present application is made.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects in the existing sample preparation technology, the present application provides a bidirectional pressurized triaxial sample preparation device, which can not only intelligently control the triaxial sample preparation pressure and time to simulate the actual In the soil consolidation process, multiple samples can be formed at one time, which reduces the sample preparation time and the disturbance to the soil samples, and overcomes the defects of the traditional sample tube sampling difficulty, which has good engineering applicability.

In order to achieve the above-mentioned purpose, the technical scheme adopted in this application is as follows:

A two-way pressurized triaxial sample preparation device, comprising a pressure mechanism, a pressure transmission mechanism, an upper pressure mechanism, a lower pressure mechanism, a sample preparation cylinder and a plurality of pulleys, a pressure mechanism, an upper pressure mechanism, a sample preparation mechanism The barrel and the lower pressure mechanism are arranged in sequence from top to bottom, and a plurality of pulleys are fixedly arranged above the pressure mechanism. The pressure mechanism includes an upper power part, a lower power part, an upper time controller, a lower time controller, and an upper power part. It is connected with the lower power part through a soft conduit, an upper time controller is installed at the bottom of the upper power part, and a lower time controller is installed at the corresponding position of the lower power part and the upper time controller. The upper time controller and the lower time controller are respectively connected with the soft The two sides of the flexible conduit are connected to adjust the flow of the filler in the flexible conduit to achieve intelligent pressure control;

The pressure transmission mechanism includes an upper pressure wire rope and a lower pressure wire rope;

The upper compression mechanism includes an upper cross bar and several upper loading indenters, one end of the upper cross bar is connected with the upper compression wire rope, and swings with the movement of the upper compression wire rope. The lower power part is connected, and the other end is provided with an upper loading indenter, which is located above the sample preparation cylinder and moves up and down with the swing of the upper cross bar; the lower pressing mechanism includes a lower cross bar and several lower loading indenters. One end of the cross bar is connected with the lower pressure wire rope, and swings with the movement of the lower pressure wire rope. Below the sample cylinder, it is set corresponding to the upper loading pressure head; the upper pressure wire rope and the lower pressure wire rope change the operating state according to the pressure change, and then drive the upper loading pressure head and the lower loading pressure head to move up and down, that is, to realize the sample preparation time. Change.

Further, as a preference:

The upper pressure wire rope is provided with a stop spring buckle and a connection spring buckle, the upper pressure wire rope is movably connected with the upper cross bar through the connection spring buckle, and the position at the set height is fixed by the stop spring buckle. More preferably, the pulley is installed on the top of the door-type bracket, and the side of the door-type bracket is provided with fixing holes, and the fixing holes cooperate with the stop spring buckle to realize the control of the set height. When the experiment is over, stop the snap buckle into the fixing hole to achieve positioning.

The middle part of the upper cross bar is installed on the upper support rod through a rotating shaft, one end is connected to the upper pressure wire rope, the other end is installed with an upper limiter through the upper indenter, and a number of upper loading indenters are connected below the upper limiter; the middle part of the lower crossbar It is installed on the lower support rod through the rotating shaft, one end is connected to the lower pressure wire rope, and the other end is installed with a lower limiter through the lower pressure head. Several lower loading pressure heads are arranged above the lower stopper, and the upper support rod adopts the lever principle for the upper loading pressure The head provides power, and the lower support rod uses the principle of leverage to power the lower loading ram. More preferably, an upper compression spring is arranged below the lower compression head.

The sample preparation cylinder is installed on the lower support mechanism, the lower support mechanism includes a support panel and a plurality of accommodating holes arranged on the support panel, and the sample preparation cylinder is installed in the accommodating holes. More preferably, the sample preparation cylinder includes a cylinder body, a buckle and a collar, the cylinder body is composed of two pieces, at least one collar is provided, and is sleeved on the outer walls of the two cylinders, and the buckle is located on the outer side of the cylinder body to accommodate The outer side of the setting hole is provided with a buckle hole, which cooperates with the buckle to realize the lateral fixation of the cylinder; the lower support mechanism is fixed on the ground, the door-type bracket and the upper support rod are consolidated with the support panel, and the two cylinders pass through The accommodating hole and the snap hole are fixed on the support panel, the lower support rod is fixed at a position 10cm to the left in the middle of the support; the lower part of the upper pressure spring is fixed with the base.

The upper power piece is a hollow funnel-shaped device, preferably made of iron, and its volume is 0.1 m ³ , and the lower power piece and the upper power piece have the same shape and material.

The center of the upper power member is provided with a hole with a beam, and the lower pressurized steel wire rope is connected with the upper power member through the hole with a beam, so as to play the role of pressure conduction.

Two elliptical holes are arranged on the edge of the lower power piece, and the two elliptical holes are symmetrically arranged, and the upper pressure wire rope is connected with the lower power piece through the elliptical holes, which plays a role of pressure conduction.

The upper pressure mechanism is connected with the upper pressure wire rope through the hook, and the upper support rod adopts the lever principle to provide power for the upper loading indenter.

One side of the upper pressure wire rope of the pressure transmission mechanism is divided into two wire ropes with the same diameter and different lengths at the pulley. The tails of the two wire ropes are respectively connected with hooks, which are connected to the elliptical holes through the hooks; the other side of the upper pressure wire rope is connected by a connecting spring The buckle is connected with the upper cross bar to provide power for the upper pressurizing mechanism.

The connection spring buckle and the stop spring buckle are stainless steel spring buckles of the same material and size. The connecting spring buckle is located at the tail of the upper compression wire rope and is connected with the upper cross bar; the stop spring buckle is located 10cm above the connecting spring buckle, and the stop spring buckle is connected to the fixing hole at the end of the experiment.

The total length of the upper crossbar is 60cm, the length of the upper support rod is 20cm, and the upper support rod is arranged at 10cm at the end of the upper crossbar as a support point for pressure amplification.

The upper loading indenter has a height of 4cm, is connected to the upper cross bar at the end, and is located at the center of the upper limiter.

The thickness of the upper limiter is 2cm, the upper part is consolidated with the upper indenter to ensure the height of sample preparation, and the lower part is consolidated with three upper loading indenters, the height of the indenter is 3cm, and the diameter of the indenter is 3.91cm, which is used to press down the sample.

The total length of the lower crossbar is 60cm, and the length of the lower support rod is 15cm, which is connected to the lower crossbar at 10cm at the end of the lower crossbar as a support point for pressure amplification.

The height of the lower pressure head is 6cm, the lower part is fixed with the upper pressure spring, the upper part is fixed with the lower stopper, and the lower pressure head is located at the center of the lower stopper.

The thickness of the lower limiter is 2cm, and the lower part is consolidated with the lower indenter to ensure the height of sample preparation. There are three lower loading indenters fixed on the upper part of the lower limiter, the height of the pusher is 3cm, and the diameter of the indenter is 3.91cm, which is used for the upward compression test. Sample.

The inner diameter of the cylinder is 3.91 cm, the outer diameter is 4.5 cm, and the height is preferably 14.0 cm. The buckle is a cylindrical folded shape, preferably 0.5 mm in diameter, 1 cm long in the horizontal direction and 1.5 cm in the vertical direction, and is located at the midpoint of the side of the semicircular hollow sample preparation cylinder. The function of the buckle is to fix the cylinder on the support panel. The outer diameter of the collar is 4.7cm and the width is 20mm. The collar is used to fix the latex film, which is respectively fixed at the upper edge of the cylinder, and the lower collar is symmetrically fixed.

The height of the portal bracket is 1.3m and the width is 1.3m, which is used to support the pressure mechanism and the pressure transmission mechanism.

The fixed hole is 2cm high, 1.5cm wide, and 36cm from the upper part of the upper beam. At the end of the test, the stop spring buckle is fixed at the fixed hole.

The pulley is located above the portal bracket, which can support and turn the upper and lower pressure wire ropes.

The length of the support panel is 1.6m, the width is 1m, and the thickness is 2cm, which is used to fix the door type bracket and the upper support rod.

The diameter of the accommodating hole is 4.7cm, and the distance between the buckle hole and the accommodating hole is 0.8cm. Before the sample preparation begins, align the sample preparation cylinder and the buckle with the accommodation hole and the buckle hole respectively, and place the sample preparation cylinder vertically. .

The base is arranged on the ground as the support structure of the lower pressure mechanism and the upper pressure spring. The size of the base is consistent with the support panel, and the lower support rod and the upper pressure spring are fixed on the base.

The diameter of the upper pressure spring is 5cm, the length is 15cm when it is not under force, and the length is 5cm when it is under the action of 1000kpa pressure. When the upper compression spring is fully compressed, the top of the lower loading indenter protrudes 1mm into the sample preparation cylinder. The lower part of the upper pressure spring is fixed with the base, and the upper part is fixed with the lower pressure head. The upper compression spring converts the downward pressure exerted by the lower compression mechanism into an upward thrust for the lower pressure head, which exerts upward pressure on the sample.

The inner diameter of the cylinder is 3.91 cm, which is the same as that of the standard sample, the outer diameter is 4.5 cm, and the height is preferably 14.0 cm. The buckle is located at the center of the side of the cylinder, the outer diameter of the collar is 4.7cm, and the width is 20mm.

The total length of the upper rail is 60cm, the length of the upper support rod is 20cm, and the upper rail is connected to the upper rail at 10cm on the left side of the upper rail.

The height of the upper indenter is 4cm, which is fixed on the end of the upper cross bar and is located in the center of the upper surface of the upper limiter.

The thickness of the upper limiter is 2cm, and the lower part is consolidated with three lower loading indenters, with a height of 3cm and a diameter of 3.91cm.

The total length of the lower rail is 60cm, the length of the lower support rod is 15cm, and the lower rail is connected to the lower rail at 10cm on the left side of the lower rail.

The lower part of the lower limiter with a thickness of 2cm is consolidated with the lower indenter, the height of the lower indenter is 6cm, and the upper part of the lower limiter is consolidated with three lower loading indenters with a height of 3cm and a diameter of 3.91cm.

The height of the portal bracket is 1.3m and the width is 1.3m.

The fixed hole is 36cm from the bottom end of the beam, 2cm in length and 1.5cm in width.

The support panel has a length of 1.6m, a width of 1m and a thickness of 2cm.

The diameter of the accommodating hole is 4.7cm, and the distance between the center of the snap hole and the center of the accommodating hole is 3.6cm.

The diameter of the spring is 5cm, the length is 15cm in the unstressed state, and the length under the action of 1000kpa pressure is 5cm.

The above-mentioned device carries out the method for sample preparation as follows:

(1) Preparation before the experiment

According to the stress history, deposition conditions and particle composition of the soil used for the experiment, determine the amount of pressure to be applied during the experiment and the time required for the experiment.

(2) Instrument preparation

① First determine whether the filling amount in the upper power part of the pressure mechanism is sufficient, its gravity should make the upper pressure spring press to the exact design height, check whether there is filling in the lower power part, if there is no filling, the upper cross bar should be placed horizontal state.

②Fix the special latex film inside the cylinder, and try to keep the length of the latex film on both sides more than the length of the cylinder consistent when placing it, to ensure that there are no wrinkles and air at the contact between the interior of the cylinder and the latex film. The excess latex film on the side is fixed on the cylinder.

③ The sample preparation cylinder should be in the accommodating hole. If the sample preparation cylinder is not in this position, lightly press the right side of the upper horizontal bar to lift the upper loading indenter up to a proper position, and make the buckle enter the buckle hole.

④ Set the compaction time, set the upper time controller and the lower time controller, and control the pressure and sample preparation time by controlling the flow of the filler.

(3) soil sample placement

Weigh 3 soil samples of the design weight and put them into the sample preparation cylinder respectively. When placing, apply appropriate pressure to the right side of the upper cross bar to separate the upper loading indenter from the sample preparation cylinder with enough space to put the sample soil sample.

(4) Compaction completed

When the pressing time reaches the set time, the upper time controller will control the pressure mechanism to stop applying pressure to the sample soil. Connect the stop spring buckle and the fixing hole, and then separate the connecting spring buckle from the upper cross bar. At this time, the upper pressure mechanism is in a state of being free from external force.

(5) Take out the soil sample

Apply appropriate pressure to one side of the upper crossbar to separate the upper indenter from the sample preparation cylinder, take out the sample preparation cylinder, and demould. When demoulding, first remove the collar and separate the two cylinders to take out the sample wrapped in the latex film. At this time, the sample can be directly used for the next test.

(6) Instrument reset

Adjust the upper time controller and the lower time controller, and then reverse the position of the upper and lower pressure mechanisms, so that the lower power part is at the top, and connect the various parts on the pressure mechanism. Connect the connecting spring buckle to the upper cross bar, stop the spring buckle from separating from the fixing hole, and then follow the steps (1)-(5) for the next sample preparation.

The beneficial effects of this application are:

① The use of counter-pressure overcomes the defects of the traditional one-side sample preparation that cannot fully compact the soil and has poor uniformity.

② It can precisely control the pressing time and pressure, and can accurately simulate the stress process of the underground soil.

③ It can form multiple samples at one time, which saves sample preparation time and reduces sample preparation errors caused by batch sample preparation.

④ The latex film is installed in the sample preparation cylinder to facilitate sampling of the sample preparation cylinder, reduce the damage rate of the sample, and provide convenience for the next test, thereby improving the test efficiency.

Description of drawings

Fig. 1 is the state schematic diagram when the application starts to pressurize;

Fig. 2 is the structural representation of the pressure mechanism of the present application;

Fig. 3 is the structural schematic diagram of the pressure transmission mechanism of the present application;

Fig. 4 is the structural representation of the sample preparation cylinder of the present application;

FIG. 5 is a schematic structural diagram of the lower support mechanism of the present application.

Labels in the figure: 1. Pressure mechanism, 11. Upper power part, 12. Lower power part, 13. Soft conduit, 14. Upper time controller, 15. Lower time controller, 16. Hole with beam, 17. Ellipse Hole; 2. Pressure transmission mechanism, 21. Upper pressure wire rope, 22. Lower pressure wire rope, 23. Connection spring buckle, 24. Stop spring buckle; 3. Upper pressure mechanism, 31. Upper cross bar, 32. Upper Support rod, 33. Upper pressure head, 34. Upper limiter, 35. Upper loading pressure head; 4. Lower pressure mechanism, 41. Lower cross bar, 42. Lower support rod, 43. Lower pressure head, 44. Lower limit Positioner, 45. Lower loading pressure head, 46. Upper compression spring; 5. Sample preparation cylinder, 51. Buckle, 52. Cylinder body, 53. Collar; 6. Upper support mechanism, 61. Portal bracket, 62 .Fixed hole, 63. Pulley; 7. Lower support mechanism, 71. Support panel, 72. Receiving hole, 73. Buckle hole, 74. Wire rope hole, 75. Base.

Detailed ways

In this embodiment, a bidirectionally pressurized triaxial sample preparation device, with reference to FIG. 1 , includes a pressure mechanism 1 , a pressure transmission mechanism 2 , an upper pressure mechanism 3 , a lower pressure mechanism 4 , a sample preparation cylinder 5 and a plurality of The pulley 63, the pressure mechanism 1, the upper pressure mechanism 2, the sample preparation cylinder 5 and the lower pressure mechanism 4 are sequentially arranged from top to bottom, and a plurality of pulleys 63 are fixedly arranged above the pressure mechanism 1. With reference to FIG. 2, the pressure mechanism 1 It includes an upper power part 11, a lower power part 12, an upper time controller 14, and a lower time controller 15. The upper power part 11 and the lower power part 12 are connected by a soft conduit 13, and an upper time controller is installed at the bottom of the upper power part 11. 14, a lower time controller 15 is installed at the corresponding position of the lower power part 12 and the upper time controller 14, and the upper time controller 14 and the lower time controller 15 are respectively connected with the upper and lower sides of the soft conduit 13, and adjust the soft conduit 13. The flow of the filler to achieve intelligent control of the pressure;

3, the pressure transmission mechanism 2 includes an upper pressure wire rope 21 and a lower pressure wire rope 22;

1, the upper press 3 includes an upper cross bar 31 and a plurality of upper loading indenters 35. One end of the upper cross bar 31 is connected to the upper pressure wire rope 21, and swings with the movement of the upper pressure wire rope 21, and the upper pressure wire rope 21 moves. After the wire rope 21 is wound around at least one pulley 63, it is connected to the lower power member 12, and the other end is provided with an upper loading indenter 35, which is located above the sample preparation cylinder 5 and swings with the upper cross bar 21 relative to the sample preparation cylinder. 5. Move up and down; the lower pressure mechanism 4 includes a lower cross bar 41 and several lower loading indenters 45. One end of the lower cross bar 41 is connected with the lower pressure wire rope 22, and swings with the movement of the lower pressure wire rope 22. The lower pressure wire rope 22 after at least one pulley (preferably different from the pulley 63 on which the upper pressure wire rope 21 is wound), it is connected to the upper power part 21, and the other end is provided with a lower loading indenter 45, which is located in the sample preparation. The upper pressure wire rope 21 and the lower pressure wire rope 22 change the operating state according to the pressure change, and then drive the upper loading pressure head 35 and the lower loading pressure head 45 to move up and down, namely Realize changes in sample preparation time.

In order to achieve more use effects, the above scheme can also be added in the following way: in conjunction with FIG. 3 , the upper compression wire rope 21 is provided with a stop spring buckle 24 and a connection spring buckle 23, and the upper pressure wire rope 21 is connected with the spring buckle 23 and the upper pressure wire rope 21. The upper cross bar 31 is movably connected, and the position at the set height is fixed by stopping the spring buckle 24 . More preferably, the pulley 63 is installed on the top of the door-type bracket 61, and the side of the door-type bracket 61 is provided with fixed holes 62. The door-type bracket 61, the fixed hole 62 and the pulley 63 constitute the upper support mechanism 6, and the fixed hole 62 and the stop spring. The buckle 24 cooperates to realize the control of the set height. When the experiment is over, stop the snap buckle 24 and snap into the fixing hole 62 to achieve positioning.

In order to achieve more use effects, the above scheme can also be added in the following way: the middle part of the upper cross bar 31 is installed on the upper support bar 32 through a rotating shaft (not marked in the figure), one end is connected to the upper pressure wire rope 21, and the other end passes through the upper support rod 32. The indenter 33 is provided with an upper limiter 34, and a number of upper loading indenters 35 are connected below the upper limiter 34; the middle of the lower crossbar 41 is installed on the lower support rod 42 through a rotating shaft (not marked in the figure), and one end is connected to the lower pressure The other end of the steel wire rope 22 is provided with a lower limiter 44 through the lower pressure head 43, a number of lower loading pressure heads 45 are arranged above the lower limiter 44, and the upper support rod 32 adopts the lever principle to convert the swing of the upper cross bar 31 into an upper loading pressure The head 35 provides power, and the lower support rod 42 adopts the lever principle to convert the swing of the lower cross rod 41 into the lower loading ram 45 to provide power. More preferably, an upper pressure spring 46 is provided below the lower pressure head 43 .

In order to achieve more use effects, the above scheme can also be added in the following manner: in conjunction with FIG. 4 and FIG. 5 , the sample preparation cylinder 5 is installed on the lower support mechanism 7, and the lower support machine 7 includes a support panel 71 and is arranged on the support panel 71. There are several accommodating holes 72 on the upper part, and the sample preparation cylinder 5 is installed in the accommodating holes 72 . More preferably, referring to FIG. 4 , the sample preparation cylinder 5 includes a cylinder body 52 , a buckle 51 and a collar 53 , the cylinder body 52 is composed of two pieces, and at least one collar 53 is provided, which is sleeved on the outer walls of the two cylinder bodies 52 . , the buckle 51 is located on the outer side of the cylinder body 52, and the outer side of the accommodating hole 72 is provided with a buckle hole 73, and the buckle hole 73 cooperates with the buckle 51 to realize the side fixation of the cylinder body 52; the lower support mechanism 7 is fixed on the ground, and the door The type bracket 61 and the upper support rod 32 are fixed with the support panel 71, the two cylinders 52 are fixed on the support panel 71 through the accommodating holes 72 and the buckle holes 73, and the lower support rod 42 is fixed on the left side of the middle of the support 10cm position; the lower part of the upper pressure spring 46 is consolidated with the base 75 .

In order to achieve more use effects, the above scheme can also be added in the following way: the upper power part 11 is a hollow funnel-shaped device, the material is preferably iron, and its volume is 0.1m ³ , and the lower power part 12 and the upper power part 11 have The same shape and substance.

In order to achieve more use effects, the above scheme can also be added in the following way: the center of the upper power member 11 is provided with a hole 16 with a beam, and the lower pressure wire rope 22 is connected with the upper power member 11 through the hole 16 with a beam to conduct pressure transmission. effect.

In order to achieve more use effects, the above scheme can also be added as follows: two elliptical holes 17 are arranged at the edge of the lower power member 12, the two elliptical holes 17 are symmetrically arranged, and the upper pressure wire rope 21 passes through the elliptical holes 17 and the lower power. The parts 12 are connected to play the role of pressure conduction.

As a more specific solution: as shown in Figures 1 to 5 , in this embodiment, a bidirectional pressure triaxial sample preparation device includes a pressure mechanism 1 , a pressure transmission mechanism 2 , and an upper pressure mechanism 3 , The lower pressure mechanism 4, the sample preparation cylinder 5, the upper support mechanism 6, the lower support mechanism 7.

The pressure mechanism 1 includes an upper power member 11 , a lower power member 12 , a soft conduit 13 , an upper time controller 14 , a lower time controller 15 , a hole 16 with a beam, and an elliptical hole 17 . The upper power member 11 and the lower power member 12 are connected by a soft conduit 13 , an upper time controller 14 is installed at the bottom of the upper power member 11 , and a lower time controller 15 is installed at the corresponding position of the lower power member 15 .

The pressure transmission mechanism 2 includes an upper pressure wire rope 21, a lower pressure wire rope 22, a connecting spring buckle 23, and a stop spring buckle 24; the upper pressure wire rope 21 is equally divided into two wire ropes at the pulley 63, and the tail of one end is connected to a symmetrical ellipse through a hook. The hole 17 is connected, and the other end is connected with the upper cross bar 31 through the connecting spring buckle 23 .

The upper pressing mechanism 3 includes an upper cross bar 31 , an upper support rod 32 , an upper pressing head 33 , an upper limiter 34 , and an upper loading pressing head 35 . One side of the upper cross bar 31 is connected with the connecting spring buckle 23, the upper support rod 32 is arranged at one-sixth of it, and the other side is connected with the upper pressure head 33, and the upper support rod 32 is arranged at one sixth of the upper cross bar 31. At the length, the upper part of the upper limiter 34 is consolidated with the upper loading indenter 33 , and the lower part of the upper limiter 34 is consolidated with three uniformly distributed upper loading indenters 35 .

The lower pressing mechanism 4 includes a lower crossbar 41, a lower support rod 42, a lower pressing head 43, a lower limiter 44, a lower loading pressing head 45, and an upper pressing spring 46; the lower pressing mechanism 4 is integrally located on the base, and the lower crossbar One end of 41 is consolidated with the lower pressure wire rope 21, and the other end is connected with the lower pressure head 43; The upper part is consolidated with the lower limiter 44, and three evenly distributed lower loading indenters 45 are consolidated above the lower limiter 44.

The sample preparation cylinder 5 includes a buckle 51, a cylinder body 52, and a collar 53; the sample preparation cylinder 5 is fixed in the middle of the support panel, the buckle 51 is matched with the buckle hole 73, and the cylinder body 53 is matched with the accommodating hole 72. The upper hole of the sample cylinder 5 is matched with the upper loading pressure head 35 , the lower hole is matched with the lower loading pressure head 45 , and the collar 53 is symmetrically arranged on the cylinder body 52 .

The upper support mechanism 6 includes a door-type bracket 61, a fixing hole 62, and a pulley 63; the door-type bracket 61 is fixed above the support panel 71, the roller skating 63 is fixed on the door-type bracket 61, and the fixing hole 62 is located on the door-type bracket 61;

The lower support mechanism 7 includes a support panel 71, an accommodating hole 72, a buckle hole 73, a wire rope hole 74, and a base 75; , the two cylinders 52 are fixed on the support panel 71 through the accommodating hole 72 and the buckle hole 73, the lower support rod 42 is fixed to the left 10cm position in the middle of the support; the lower part of the upper pressure spring 46 is fixed to the base.

The upper power member 11 is a hollow funnel-shaped device, preferably made of iron, and its volume is 0.1 m ³ . The lower power member 12 and the upper power member 11 have the same shape and material.

The soft conduit 13 is a rubber conduit with a length of 46 mm, which is used to connect the upper power member 11 and the lower power member 12 .

The upper time controller 14 and the lower time controller 15 are respectively connected to both sides of the flexible conduit, and intelligently control the pressure and sample preparation time by adjusting the flow rate of the filler in the flexible conduit 13 .

The hole 16 with the beam is located at the center of the upper power member 11 , and is connected to the lower pressure wire rope 22 through a hook, which plays a role of pressure conduction. The same hole is arranged in the center of the lower power member 12 .

The elliptical holes 17 are symmetrically arranged on the edge of the lower power member 12, and are connected to the upper pressure wire rope 21 through hooks, which play the role of pressure conduction. There are oval holes 17 of the same size at corresponding positions of the upper power member 11 .

The upper pressure mechanism 11 is connected with the upper pressure wire rope 21 through a hook, and the upper support rod 32 uses the lever principle to provide power for the upper loading indenter 35 .

One side of the upper pressure wire rope 21 of the pressure transmission mechanism 2 is divided into two steel wire ropes with the same diameter and different lengths at the pulley. The side is connected with the upper cross bar 31 by the connecting spring buckle 23 . Power is provided to the upper pressurizing mechanism 3 .

The connection spring buckle 23 and the stop spring buckle 24 are stainless steel spring buckles of the same material and size. The connecting spring buckle 23 is located at the tail of the upper compression wire rope 21 and is connected with the upper cross bar 31 . The stop snap 24 is located 10 cm above the connecting snap. The stop snap 24 was connected to the fixing hole 62 at the end of the experiment.

The total length of the upper cross bar 31 is 60 cm, the length of the upper support bar 32 is 20 cm, and the upper support bar 32 is arranged at 10 cm of the end of the upper cross bar 31 as a support point for pressure amplification.

The upper loading indenter 35 has a height of 4 cm, is connected with the upper cross bar 31 at the end, and is located at the center of the upper limiter 34 .

The upper limiter 34 has a thickness of 2cm, the upper part is consolidated with the upper indenter 33 to ensure the height of sample preparation, and the lower part is consolidated with three upper loading indenters 35, the indenter height is 3cm, and the diameter is 3.91cm, which is used to press down the sample. .

The total length of the lower cross bar 41 is 60 cm, and the length of the lower support bar 42 is 15 cm. The lower cross bar 42 is connected to the lower cross bar 41 at the end 10 cm, as a support point for pressure amplification.

The height of the lower pressure head 43 is 6 cm, the lower part is fixed with the upper pressure spring 46 , the upper part is fixed with the lower stopper 44 , and the lower pressure head 43 is located at the center of the lower stopper 44 .

The thickness of the lower limiter 44 is 2cm, and the lower part is consolidated with the lower indenter 43 to ensure the height of sample preparation. Three lower loading indenters 45 are consolidated on the upper part of the lower limiter 44, the height of the pusher is 3cm, and the diameter is 3.91cm. Press the sample upwards.

The inner diameter of the cylindrical body 52 is 3.91 cm, the outer diameter is 4.5 cm, and the height is preferably 14.0 cm. The buckle 51 is cylindrical and folded, preferably 0.5 mm in diameter, 1 cm long in the horizontal direction and 1.5 cm long in the vertical direction, and is located at the midpoint of the side surface of the semicircular hollow sample preparation cylinder. The function of the buckle 51 is to fix the cylindrical body 52 on the support panel 71 . The outer diameter of the collar 53 is 4.7 cm and the width is 20 mm. The collar is used to fix the latex film, and is respectively fixed at the upper edge of the cylinder body, and the lower collar is symmetrically fixed.

The portal bracket 61 has a height of 1.3 m and a width of 1.3 m, and is used to support the pressure mechanism 1 and the pressure transmission mechanism 2 .

The fixing hole 62 is 2 cm high and 1.5 cm wide, and is 36 cm away from the upper part of the upper beam 31 .

The pulley 63 is located above the portal frame 61 and can support and turn the upper pressure wire rope 21 and the lower pressure wire rope 22 .

The length of the support panel 71 is 1.6 m, the width is 1 m, and the thickness is 2 cm, and is used for fixing the door-shaped bracket 61 and the upper support rod 32 .

The diameter of the accommodating hole 72 is 4.7cm, and the distance between the buckle hole 73 and the accommodating hole is 0.8cm. Before the sample preparation starts, the sample preparation cylinder 5 and the buckle 51 are aligned with the accommodating hole 72 and the buckle hole 73, respectively. The sample preparation cylinder 5 is placed vertically.

The base 75 is arranged on the ground as a support structure for the lower pressing mechanism 4 and the upper pressing spring 46 . The size of the base 75 is the same as that of the support panel 71 . The lower support rod 42 and the upper pressure spring 46 are fixed on the base.

The upper pressure spring 46 has a diameter of 5cm, a length of 15cm when it is not stressed, and a length of 5cm when subjected to a pressure of 1000kpa. When the upper compression spring 46 is fully compressed, the top of the lower loading indenter 45 protrudes into the sample preparation cylinder 5 by 1 mm. The lower part of the upper pressing spring 46 is fixed with the base 75 , and the upper part is fixed with the lower pressing head 43 . The upper pressing spring 46 converts the downward pressure applied by the lower pressing mechanism 4 into an upward pushing force on the lower pressing head 43, and applies pressure to the sample upward.

With reference to Figures 1 to 3, the working process of the above-mentioned device for sample preparation is as follows:

(1) Preparation before the experiment

According to the stress history, deposition conditions and particle composition of the soil used for the experiment, the magnitude of the applied pressure and the time required for the experiment were determined.

(2) Instrument preparation

① First determine whether the amount of filler in the upper power part 11 of the pressure mechanism 1 is sufficient, its gravity should make the upper pressure spring 46 press to the exact design height, check whether there is filler in the lower power part 12, if there is no filler, it should be The upper rail 31 is in a horizontal state.

②Fix the special latex film inside the cylinder body 52, and try to keep the length of the latex film on both sides longer than the length of the cylinder body 52 consistent when placing it, to ensure that there are no wrinkles and air at the contact point between the interior of the cylinder body 52 and the latex film, and use the sleeve after inspection. The ring 53 fixes the excess latex films on both sides on the cylinder body 52 .

③ The sample preparation cylinder 5 should be in the accommodating hole 72. If the sample preparation cylinder 5 is not in this position, lightly press the right side of the upper cross bar 31, so that the upper loading indenter 35 is lifted up to the proper position, and the buckle 51 is inserted. Snap hole 73.

④Set the compaction time. The upper time controller 14 and the lower time controller 15 are set to control the pressure and sample preparation time by controlling the flow rate of the filler.

(3) soil sample placement

Weigh 3 soil samples of the design weight and put them into the sample preparation cylinder 5 respectively. When placing, apply appropriate pressure to the right side of the upper cross bar to separate the upper loading indenter 35 and the sample preparation cylinder 5 into a sufficient space to put the sample soil sample.

(4) Compaction completed

When the pressing time reaches the set time, the upper time controller 14 will control the pressing mechanism to stop applying pressure to the sample soil. Connect the stop snap buckle 24 and the fixing hole 62, and then separate the connecting snap buckle 23 from the upper cross bar 31, at this time, the upper pressing mechanism 3 is in a state of being free from external force.

(5) Take out the soil sample

Appropriate pressure is applied to one side of the upper cross bar 31 to separate the upper indenter 33 from the sample preparation cylinder 5, and the sample preparation cylinder 5 is taken out and demolded. When demoulding, first remove the collar and separate the two cylinders 52 to take out the sample wrapped in the latex film. At this time, the sample can be directly used for the next test.

(6) Instrument reset

Adjust the upper time controller 14 and the lower time controller 15, and then reverse the position of the upper and lower pressure mechanisms, so that the lower power member 12 is at the top, and connect the various components on the pressure mechanism. Connect the connecting spring buckle 23 to the upper cross bar 31, stop the spring buckle 24 from separating from the fixing hole 62, and then follow steps (1)-(5) for the next sample preparation.

The comparison between the triaxial test sample preparation effect of the present application and the traditional sample preparation effect is shown in Table 1.

Table 1 Comparison of sample preparation effects in triaxial test

As can be seen from Table 1, the beneficial effects of the application are:

① The use of counter-pressure overcomes the defects of the traditional one-side sample preparation that cannot fully compact the soil and has poor uniformity.

② It can precisely control the pressing time and pressure, and can accurately simulate the stress process of the underground soil.

③ It can form 1 to 3 samples at a time, which saves sample preparation time and reduces the sample preparation error caused by batch sample preparation.

④ The latex film is installed in the sample preparation cylinder to facilitate sampling of the sample preparation cylinder, reduce the damage rate of the sample, and provide convenience for the next test, thereby improving the test efficiency.

The above content is a further detailed description of the provided technical solution in combination with the preferred embodiments of the present invention, and it cannot be assumed that the specific implementation of the present invention is limited to the above descriptions. On the premise of not departing from the inventive concept of the present invention, some simple deductions or substitutions can also be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (9)

1. a two-way pressurized triaxial sample preparation device is characterized in that: comprise pressure mechanism, pressure conduction mechanism, upper pressure mechanism, lower pressure mechanism and sample preparation cylinder and multiple pulleys, pressure mechanism, upper The pressurizing mechanism, the sample preparation cylinder and the lower pressurizing mechanism are sequentially arranged from top to bottom, and a plurality of pulleys are fixedly arranged above the pressure mechanism. The pressure mechanism includes an upper power part, a lower power part, an upper time controller, and a lower time controller. Controller, the upper power piece is connected with the lower power piece through a soft conduit, an upper time controller is installed at the bottom of the upper power piece, a lower time controller is installed at the corresponding position of the lower power piece and the upper time controller, the upper time controller and the lower The time controller is respectively connected with both sides of the soft conduit to adjust the flow rate of the filler in the soft conduit to achieve intelligent pressure control; The pressure transmission mechanism includes an upper pressure wire rope and a lower pressure wire rope; The upper compression mechanism includes an upper cross bar and several upper loading heads, one end of the upper cross bar is connected with the upper compression wire rope, and swings with the movement of the upper compression wire rope. The power part is connected, and the upper loading pressure head is set at the other end of the upper cross rod. The upper loading pressure head is located above the sample preparation cylinder and moves up and down with the swing of the upper cross rod. The middle part of the upper cross rod is installed on the upper support rod through the rotating shaft. The rod adopts the lever principle to convert the swing of the upper cross rod into the power of the upper loading indenter; the lower pressing mechanism includes the lower cross rod, several lower loading indenters, the lower indenter and the lower limiter. The pressure wire rope is connected, and swings with the movement of the lower pressure wire rope. The lower pressure wire rope is connected to the upper power piece after at least one pulley. A lower loading indenter, the lower loading indenter is located under the sample preparation cylinder, and is set corresponding to the upper loading indenter, and an upper compression spring is arranged under the lower indentation head, and the upper compression spring converts the downward pressure exerted by the lower compression mechanism into Push upward and apply pressure to the sample upward. The middle part of the lower cross bar is installed on the lower support rod through the rotating shaft. The lower support rod adopts the lever principle to convert the swing of the lower cross bar into the power of the lower loading indenter; The pressurized wire rope changes the operating state according to the pressure change, and then drives the upper and lower loading indenters to move up and down, that is, to change the sample preparation time. 2. A bidirectional pressurized triaxial sample preparation device according to claim 1, characterized in that: the upper pressurized wire rope is provided with a stop spring buckle and a connection spring buckle, and the upper pressurized wire rope is connected by The spring buckle is movably connected with the upper cross bar, and the position at the set height is fixed by stopping the spring buckle. 3. A bidirectional pressurized triaxial sample preparation device according to claim 2, characterized in that: the pulley is mounted on the top of the portal support, the side of the portal support is provided with fixed holes, and the fixed holes Cooperate with the stop spring buckle to realize the control of the set height. 4. A bidirectional pressurized triaxial sample preparation device according to claim 1, characterized in that: one end of the upper cross bar is connected to the upper pressurized steel wire rope, and the other end is provided with an upper limiter through the upper indenter , a number of upper loading indenters are connected below the upper limiter. 5. A bidirectional pressurized triaxial sample preparation device according to claim 1, characterized in that: the sample preparation cylinder is installed on a lower support mechanism, and the lower support mechanism comprises a support panel and is arranged on the support panel Several accommodating holes in the sample preparation cylinder are installed in the accommodating holes. 6. A bidirectional pressurized triaxial sample preparation device according to claim 5, characterized in that: the sample preparation cylinder comprises a cylinder body, a buckle and a collar, the cylinder body is composed of two pieces, and the sleeve is composed of two pieces. At least one ring is provided, which is sleeved on the outer walls of the two cylinders, the buckle is located on the outer side of the cylinder, and the outer side of the accommodating hole is provided with a buckle hole, and the buckle hole cooperates with the buckle to realize the side fixing of the cylinder. 7 . The triaxial sample preparation device for bidirectional pressurization according to claim 1 , wherein two elliptical holes are arranged at the edge of the lower power part, and the two elliptical holes are symmetrically arranged, and the upper part is pressurized. 8 . The wire rope is connected with the lower power part through the oval hole. 8. A bidirectional pressurized triaxial sample preparation device according to claim 1, characterized in that: the center of the upper power member is provided with a hole with a beam, and the lower pressurized wire rope passes through the hole with a beam and the upper power piece connection. 9. The bidirectional pressurized triaxial sample preparation device according to any one of claims 1-8, wherein the upper power part is a hollow funnel-shaped device with a filler in it; The lower power part and the upper power part have the same shape and are arranged symmetrically.

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