Indoor temperature-controlled crosshead shear instrument

Abstract

The application discloses an indoor temperature control vane shear apparatus, and relates to the technical field of soil testing, which comprises a sample cylinder with two open ends, wherein the sample cylinder is vertically placed, an insulating cylinder is sleeved outside the sample cylinder, and a drainage device is arranged at the lower end of the sample cylinder; a heating device is arranged at each end of the sample cylinder; a loading device is arranged above the sample cylinder to apply axial load to the soil sample in the sample cylinder; a testing assembly comprises a driving device and a vane, wherein the driving device is arranged above the sample cylinder, the vane is parallel to the axis of the sample cylinder, the vane is in transmission connection with the driving device to drive the vane to extend into the sample cylinder along the axial direction of the sample cylinder, and the driving device can also drive the vane to rotate around the axis. The indoor temperature control vane shear apparatus can determine the undrained shear strength and residual strength of the same soil sample under multiple different temperature conditions at a specified pressure in one test process, and greatly shortens the test period.

Description

Technical Field

[0001] This invention relates to the field of soil testing technology, and in particular to an indoor temperature-controlled vane shearing apparatus. Background Technology

[0002] In existing vane shear apparatuses, whether in situ or indoor, the main focus is on measuring the undrained shear strength of soil at room temperature. However, few shear apparatuses can quickly measure the undrained shear strength of soil under different temperatures and pressures.

[0003] When it is necessary to determine the undrained shear strength of a soil sample under a specified pressure at different temperatures, multiple samplings are generally required to conduct tests under different temperature conditions. The testing cycle lengthens with the increase in the number of tests, resulting in low efficiency. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an indoor temperature-controlled vane shear apparatus, which measures the undrained shear strength and residual strength of the same soil sample under a specified pressure and multiple different temperature conditions in a single test, greatly shortening the test cycle.

[0005] According to an embodiment of the present invention, an indoor temperature-controlled vane shear apparatus includes: a sample tube, the sample tube being open at both ends for loading a soil sample, the sample tube being placed vertically, an insulation cylinder being fitted around the outside of the sample tube, and a drainage device being provided at the lower end of the sample tube.

[0006] A heating device is respectively disposed at both ends of the sample cylinder;

[0007] A loading device is mounted above the sample cylinder to apply an axial load to the soil sample inside the sample cylinder.

[0008] The test assembly includes a drive device and a cross plate. The drive device is mounted above the sample cylinder. The cross plate is parallel to the axis of the sample cylinder. The cross plate is connected to the drive device for transmission, so as to drive the cross plate to extend into the sample cylinder along the axial direction of the sample cylinder. The drive device can also drive the cross plate to rotate around the axis.

[0009] The indoor temperature-controlled vane shear apparatus according to embodiments of the present invention has at least the following beneficial effects: the sample tube is open at both ends, allowing direct sampling at the test site, reducing stress release in the soil sample, and facilitating the preservation of the original soil sample structure; the heating device is used to heat the sample tube and the soil sample it contains, and the heating devices at both ends can be set to different target heating temperatures to obtain a gradient temperature zone along the axial direction within the sample tube; the loading device is used to apply a specified pressure load to the soil sample within the sample tube; the driving device drives the vane to perform testing at different positions within the sample tube, i.e., at different temperature zones to determine the undrained shear strength of the soil sample; the drainage device is used to control the drainage state of the soil sample within the sample tube, draining during the consolidation process when the loading device is working, and stopping drainage when the testing components are working to determine the undrained shear strength. By undergoing a single sampling, pressurization, and heating process, the undrained shear strength and residual strength of soil samples under the same pressure state at multiple temperature environments can be determined, greatly improving testing efficiency and shortening the testing cycle.

[0010] According to some embodiments of the present invention, the heating device includes an upper heating plate and a lower heating plate. The upper heating plate is disposed at the upper end of the sample cylinder and is connected to the loading device. The upper heating plate is movable inside the sample cylinder along the axial direction. A clearance hole is provided on the upper heating plate. The lower heating plate is disposed at the lower end of the sample cylinder.

[0011] According to some embodiments of the present invention, the upper heating plate is further connected to a sealing plug, the sealing plug being inserted into the relief hole, and the sealing plug being detachably connected to the upper heating plate.

[0012] According to some embodiments of the present invention, the sealing plug includes a plug post and a plug cap. The plug cap is disposed at one end of the plug post, and the plane of the plug cap is perpendicular to the axis of the plug post. The plug cap is provided with a first screw hole, and the surface of the upper heating plate is provided with a second screw hole. The plug post is inserted into the relief hole such that the first screw hole and the second screw hole are coaxial. The plug cap and the upper heating plate are connected by bolts.

[0013] According to some embodiments of the present invention, the loading device includes a hydraulic assembly and an axial pressure rod. The hydraulic assembly is disposed above the sample cylinder, and the axial pressure rod is drivenly connected to the hydraulic assembly. The axial pressure rod is parallel to the axis of the sample cylinder to control the movement of the axial pressure rod along the axial direction of the sample cylinder. One end of the axial pressure rod facing the sample cylinder abuts against the surface of the upper heating plate.

[0014] According to some embodiments of the present invention, the drainage device includes a drain pipe, a valve and a permeable stone, the lower heating plate is provided with a water outlet hole, the permeable stone is placed in the water outlet hole, the drain pipe is connected to the water outlet hole, and the valve is provided on the drain pipe.

[0015] According to some embodiments of the present invention, a temperature measuring device is provided inside the sample cylinder, and the temperature measuring device has multiple monitoring points, which are distributed at intervals along the axial direction of the sample cylinder.

[0016] According to some embodiments of the present invention, the temperature measuring device includes a temperature measuring rod and a plurality of temperature sensors. The temperature measuring rod is parallel to the axis of the sample cylinder and is placed inside the sample cylinder. The temperature sensors are disposed on the temperature measuring rod and are distributed at intervals along the axial direction of the temperature measuring rod.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0019] Figure 1 This is a schematic diagram of the structure of the indoor temperature-controlled vane shear device according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the heating device in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the axial pressure rod abutting and pushing the upper heating plate in an embodiment of the present invention.

[0022] Icon labels:

[0023] Sample cylinder 100, heat preservation cylinder 110, drainage device 200, drainage pipe 210, valve 220, permeable stone 230, heating device 300, upper heating plate 310, clearance hole 311, lower heating plate 320, water outlet hole 321, loading device 400, hydraulic component 410, axial pressure rod 420, test component 500, drive device 510, cross plate 520, sealing plug 600, plug column 610, plug cap 620, temperature measuring device 700, temperature measuring rod 710, temperature sensor 720. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0026] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0027] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0028] Reference Figure 1 As shown, an indoor temperature-controlled vane shear apparatus according to an embodiment of the present invention includes a sample cylinder 100, which is open at both ends for loading soil samples. The sample cylinder 100 is placed vertically, and an insulation cylinder 110 is fitted on the outside of the sample cylinder 100. A drainage device 200 is provided at the lower end of the sample cylinder 100.

[0029] Heating devices 300 are respectively installed at both ends of the sample cylinder 100;

[0030] The loading device 400 is mounted above the sample cylinder 100 to apply an axial load to the soil sample inside the sample cylinder 100.

[0031] The test assembly 500 includes a drive device 510 and a cross plate 520. The drive device 510 is mounted above the sample cylinder 100. The cross plate 520 is parallel to the axis of the sample cylinder 100. The cross plate 520 is connected to the drive device 510 for transmission, so as to drive the cross plate 520 to extend into the sample cylinder 100 along the axial direction of the sample cylinder 100. The drive device 510 can also drive the cross plate 520 to rotate around the axis.

[0032] The sample tube 100 has openings at both ends, allowing direct sampling from the test site, reducing stress release in the soil sample and facilitating preservation of the original soil sample structure. The heating device 300 heats the sample tube 100 and the soil sample it contains; different target temperatures can be set at both ends of the heating device 300 to create a gradient temperature zone along the axial direction within the sample tube 100. The loading device 400 applies a specified pressure load to the soil sample within the sample tube 100. The driving device 510 moves the vane 520 to different depths within the sample tube 100, i.e., different temperature zones, to determine the undrained shear strength and residual strength of the soil sample. The drainage device 200 controls the drainage state of the soil sample within the sample tube 100. It drains the soil during the consolidation process when the loading device 400 is operating, and stops drainage when the testing assembly 500 is operating, in order to determine the undrained shear strength and residual strength. By undergoing a single sampling, pressurization, and heating process, the undrained shear strength and residual strength of soil samples under the same pressure conditions at multiple temperature environments can be determined, greatly improving test efficiency and shortening the test cycle.

[0033] Specifically, a undisturbed soil sample is first taken using a sample tube 100, and the outside of the sample tube 100 is cleaned. In this embodiment, the sample tube 100 has a height of 200 mm, an inner diameter of 100 mm, and a wall thickness of 5 mm. The sample tube 100 is placed vertically below the loading device 400, and heating devices 300 are installed at both the upper and lower ends of the sample tube 100. Finally, an insulation cylinder 110 is fitted over it.

[0034] When the heating device 300 is activated, if it is only necessary to measure the undrained shear strength of a soil sample under one temperature condition, the heating devices 300 at the upper and lower ends can be set to the same heating target temperature. If it is necessary to measure the undrained shear strength of a soil sample under different temperature conditions, such as measuring the undrained shear strength of a soil sample under three temperature conditions, the heating devices 300 at the upper and lower ends can be set to different heating target temperatures to form a difference, and finally generate a gradient temperature zone in the sample tube 100.

[0035] Taking the determination of the undrained shear strength of a soil sample under three temperature conditions as an example, assuming the upper end of the sample cylinder 100 is the initial position, three points are selected at depths of 40mm, 100mm, and 160mm, corresponding to three different temperature conditions. After the soil sample temperature stabilizes, the loading device 400 is activated to apply a specified axial pressure to the soil sample inside the sample cylinder 100. Then, the drive device 510 controls the vane 520 to insert into the soil sample until it reaches a depth of 40mm. After standing for 2-3 minutes and waiting for the values ​​to stabilize, the drive device 510 applies torque to the vane 520 to shear the soil sample until it is sheared and fails, and the torque value M1 can be measured. Then, the vane 520 is rotated to fully disturb the soil, and after standing for 2-3 minutes, the vane 520 shears the soil sample again, and the torque value M2 is measured. According to the formula...

[0036]

[0037] This allows for the calculation of the undrained shear strength and residual strength of the soil sample under the specified temperature conditions. Here, M is the torque value measured by the vane 520; when M1 is taken, the calculated undrained shear strength C... u When M2 is taken, the residual strength value is calculated. D is the diameter of the vane 520, and H is the length of the vane 520.

[0038] Reference Figure 2 As shown, it can be understood that the heating device 300 includes an upper heating plate 310 and a lower heating plate 320. The upper heating plate 310 is disposed at the upper end of the sample cylinder 100. The upper heating plate 310 is connected to the loading device 400 in a transmission manner. The upper heating plate 310 can move inside the sample cylinder 100 along the axial direction. A clearance hole 311 is provided on the plate body of the upper heating plate 310. The lower heating plate 320 is disposed at the lower end of the sample cylinder 100.

[0039] The upper heating plate 310 and the lower heating plate 320 can be set to different target heating temperatures. For example, the upper heating plate 310 can be set to 20°C and the lower heating plate 320 can be set to 40°C. Then the temperature of the soil sample in the sample tube 100 will be distributed in a gradient between 20°C and 40°C. The upper heating plate 310 is provided with a relief hole 311 so that the cross plate 520 can pass through the relief hole 311 and extend into the soil sample.

[0040] Reference Figure 2 As shown, it can be understood that the upper heating plate 310 is also connected to a sealing plug 600, which is inserted into the relief hole 311 and is detachably connected to the upper heating plate 310.

[0041] Before the vane 520 is inserted into the soil sample, an axial load needs to be applied to the soil sample using the loading device 400. The sealing plug 600 is first inserted into the relief hole 311. When the loading device 400 applies the axial load, the soil sample is subjected to uniform force and will not overflow from the relief hole 311.

[0042] It is understood that the sealing plug 600 includes a plug 610 and a plug cap 620. The plug cap 620 is disposed at one end of the plug 610. The plane of the plug cap 620 is perpendicular to the axis of the plug 610. The plug cap 620 is provided with a first screw hole, and the surface of the upper heating plate 310 is provided with a second screw hole. The plug 610 is inserted into the relief hole 311, so that the first screw hole and the second screw hole are coaxial. The plug cap 620 and the upper heating plate 310 are connected by bolts.

[0043] The plug 610 is used to fill and block the relief hole 311. The plug cap 620 is detachably connected to the upper heating plate 310, and the sealing plug 600 can be quickly removed from the upper heating plate 310 when using the cross plate 520.

[0044] Reference Figure 3 As can be understood, the loading device 400 includes a hydraulic component 410 and an axial pressure rod 420. The hydraulic component 410 is disposed above the sample cylinder 100. The axial pressure rod 420 is connected to the hydraulic component 410 and is parallel to the axis of the sample cylinder 100 to control the movement of the axial pressure rod 420 along the axial direction of the sample cylinder 100. One end of the axial pressure rod 420 facing the sample cylinder 100 abuts against the surface of the upper heating plate 310.

[0045] The hydraulic component 410 drives the axial compression rod 420 to move toward the sample cylinder 100. The lower end of the axial compression rod 420 abuts against the surface of the upper heating plate 310 to push the upper heating plate 310 toward the lower heating plate 320. The soil sample is located between the upper heating plate 310 and the lower heating plate 320 and is compressed to the set pressure.

[0046] Reference Figure 2 As shown, it can be understood that the drainage device 200 includes a drainage pipe 210, a valve 220 and a permeable stone 230. The lower heating plate 320 is provided with a water outlet 321. The permeable stone 230 is placed in the water outlet 321. The drainage pipe 210 is connected to the water outlet 321. The valve 220 is provided on the drainage pipe 210.

[0047] When the loading device 400 applies an axial load to the soil sample, i.e., during the consolidation process, valve 220 opens, allowing water in the soil sample to drain through the permeable stone 230, the outlet hole 321, and the drain pipe 210. When the vane 520 applies torque shear, valve 220 remains closed to determine the undrained shear strength. The permeable stone 230 prevents the outlet hole 321 and drain pipe 210 from clogging during drainage, thus acting as a filter.

[0048] It is understood that a temperature measuring device 700 is provided inside the sample cylinder 100, and the temperature measuring device 700 has multiple monitoring points, which are distributed at intervals along the axial direction of the sample cylinder 100.

[0049] The temperature measuring device 700 is installed inside the sample tube 100 and is in contact with the soil sample to monitor the temperature at different locations on the soil sample.

[0050] Reference Figure 2 As shown, it can be understood that the temperature measuring device 700 includes a temperature measuring rod 710 and multiple temperature sensors 720. The temperature measuring rod 710 is parallel to the axis of the sample cylinder 100 and is placed inside the sample cylinder 100. The temperature sensors 720 are disposed on the temperature measuring rod 710 and are distributed at intervals along the axial direction of the temperature measuring rod 710.

[0051] After the temperature measuring rod 710 is inserted into the soil sample, the temperature sensor 720 can obtain the temperature of the soil sample at that location. For example, if three temperature sensors 720 are set at 40mm, 100mm and 160mm of the temperature measuring rod 710 respectively, the temperature at depths of 40mm, 100mm and 160mm of the soil sample can be monitored after the temperature measuring rod 710 is inserted into the soil sample.

[0052] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An indoor temperature-controlled vane shearing device, characterized in that, include: The sample tube (100) has openings at both ends for loading soil samples. The sample tube (100) is placed vertically. An insulation tube (110) is fitted on the outside of the sample tube (100). A drainage device (200) is provided at the lower end of the sample tube (100). Heating device (300) is respectively disposed at both ends of the sample tube (100). The heating device (300) includes an upper heating plate (310) and a lower heating plate (320). The upper heating plate (310) is disposed at the upper end of the sample tube (100). A clearance hole (311) is provided on the plate body of the upper heating plate (310). The lower heating plate (320) is disposed at the lower end of the sample tube (100). A loading device (400) is mounted above the sample cylinder (100) to apply an axial load to the soil sample inside the sample cylinder (100). An upper heating plate (310) is drivenly connected to the loading device (400). The loading device (400) includes a hydraulic assembly (410) and an axial pressure rod (420). The hydraulic assembly (410) is located above the sample cylinder (100). The axial pressure rod (420) is drivenly connected to the hydraulic assembly (410) and is parallel to the axis of the sample cylinder (100) to control the movement of the axial pressure rod (420) along the axial direction of the sample cylinder (100). One end of the axial pressure rod (420) facing the sample cylinder (100) abuts against the surface of the upper heating plate (310). The upper heating plate (310) is capable of moving inside the sample cylinder (100) along the axial direction. The test assembly (500) includes a drive device (510) and a cross plate (520). The drive device (510) is mounted above the sample tube (100). The cross plate (520) is parallel to the axis of the sample tube (100). The cross plate (520) is connected to the drive device (510) for transmission, so as to drive the cross plate (520) to extend into the sample tube (100) along the axial direction of the sample tube (100). The drive device (510) can also drive the cross plate (520) to rotate around the axis. as well as, The upper heating plate (310) is also connected to a sealing plug (600), which is inserted into the relief hole (311) and is detachably connected to the upper heating plate (310). The sealing plug (600) includes a plug post (610) and a plug cap (620). The plug cap (620) is disposed at one end of the plug post (610). The plane of the plug cap (620) is perpendicular to the axis of the plug post (610). The plug cap (620) is provided with a first screw hole, and the surface of the upper heating plate (310) is provided with a second screw hole. The plug post (610) is inserted into the relief hole (311) so that the first screw hole and the second screw hole are coaxial. The plug cap (620) and the upper heating plate (310) are connected by bolts.

2. The indoor temperature-controlled vane shearing device according to claim 1, characterized in that: The drainage device (200) includes a drain pipe (210), a valve (220) and a permeable stone (230). The lower heating plate (320) is provided with a water outlet (321). The permeable stone (230) is placed in the water outlet (321). The drain pipe (210) is connected to the water outlet (321). The valve (220) is set on the drain pipe (210).

3. The indoor temperature-controlled cross-blade shearing device according to claim 1, characterized in that: The sample tube (100) is equipped with a temperature measuring device (700), which has multiple monitoring points that are spaced apart along the axial direction of the sample tube (100).

4. The indoor temperature-controlled vane shearing device according to claim 3, characterized in that: The temperature measuring device (700) includes a temperature measuring rod (710) and a plurality of temperature sensors (720). The temperature measuring rod (710) is parallel to the axis of the sample cylinder (100) and is placed inside the sample cylinder (100). The temperature sensors (720) are disposed on the temperature measuring rod (710) and are spaced apart along the axial direction of the temperature measuring rod (710).

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