CN115219398A - Device and method for combined belt permeation and shear test under oblique shearing action - Google Patents
Device and method for combined belt permeation and shear test under oblique shearing action Download PDFInfo
- Publication number
- CN115219398A CN115219398A CN202210841525.2A CN202210841525A CN115219398A CN 115219398 A CN115219398 A CN 115219398A CN 202210841525 A CN202210841525 A CN 202210841525A CN 115219398 A CN115219398 A CN 115219398A
- Authority
- CN
- China
- Prior art keywords
- cylindrical shaft
- soil
- water
- soil sample
- cylindrical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000010008 shearing Methods 0.000 title claims abstract description 40
- 238000012360 testing method Methods 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims abstract description 27
- 230000009471 action Effects 0.000 title claims abstract description 21
- 239000002689 soil Substances 0.000 claims abstract description 160
- 238000006073 displacement reaction Methods 0.000 claims abstract description 62
- 230000007246 mechanism Effects 0.000 claims abstract description 43
- 230000008859 change Effects 0.000 claims abstract description 21
- 239000004816 latex Substances 0.000 claims abstract description 11
- 229920000126 latex Polymers 0.000 claims abstract description 11
- 230000035515 penetration Effects 0.000 claims abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 147
- 238000002156 mixing Methods 0.000 claims description 34
- 230000008569 process Effects 0.000 claims description 18
- 239000003638 chemical reducing agent Substances 0.000 claims description 13
- 230000035699 permeability Effects 0.000 claims description 13
- 230000008595 infiltration Effects 0.000 claims description 9
- 238000001764 infiltration Methods 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- 238000007789 sealing Methods 0.000 claims description 7
- 230000005484 gravity Effects 0.000 claims description 6
- 230000003204 osmotic effect Effects 0.000 claims description 6
- 238000000926 separation method Methods 0.000 claims description 5
- 210000003781 tooth socket Anatomy 0.000 claims description 4
- 230000001133 acceleration Effects 0.000 claims description 3
- 239000000443 aerosol Substances 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 3
- 230000005251 gamma ray Effects 0.000 claims description 3
- 238000002347 injection Methods 0.000 claims description 3
- 239000007924 injection Substances 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- OIGNJSKKLXVSLS-VWUMJDOOSA-N prednisolone Chemical compound O=C1C=C[C@]2(C)[C@H]3[C@@H](O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 OIGNJSKKLXVSLS-VWUMJDOOSA-N 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 2
- 230000000694 effects Effects 0.000 claims 2
- 238000010998 test method Methods 0.000 abstract description 3
- 239000011295 pitch Substances 0.000 description 7
- 239000010419 fine particle Substances 0.000 description 5
- 238000005192 partition Methods 0.000 description 5
- 239000002245 particle Substances 0.000 description 4
- 239000011435 rock Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000005325 percolation Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/24—Investigating strength properties of solid materials by application of mechanical stress by applying steady shearing forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/0003—Steady
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0025—Shearing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0676—Force, weight, load, energy, speed or acceleration
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0682—Spatial dimension, e.g. length, area, angle
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Dispersion Chemistry (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a combined belt penetration and shearing test device and a combined belt penetration and shearing test method under the action of oblique shearing, wherein the device comprises a pressure chamber, a cylindrical shaft is arranged in the pressure chamber along the axis, the upper end of the cylindrical shaft is connected with a vertical displacement driving mechanism, and the lower end of the cylindrical shaft is provided with a rotation driving mechanism; the middle part of the cylindrical shaft is wrapped with a concrete round bar, a short circular cylindrical soil sample is arranged outside the cylindrical shaft, a latex film is sleeved outside the soil sample, and the upper end and the lower end of the soil sample are respectively contacted with an annular upper cap connected with the upper cover and an annular lower cushion connected with the base; the upper cover is internally provided with a circulating channel communicated with the upper cap hole, the circulating channel is connected with a circulating system comprising a circulating pump, and the circulating system is connected with a measuring system. The method comprises steps S1-S11. The shear deformation oblique to the hydraulic gradient is decomposed, the shear deformation in the forward direction (vertical direction in the device) and the orthogonal direction (annular direction in the device) to the hydraulic gradient is independently provided, and the permeation and shear characteristic change of the soil body and rigid surface combined belt under any shear deformation condition can be inspected.
Description
Technical Field
The invention relates to the technical field of soil body permeability characteristic and shear characteristic measurement, in particular to a soil body permeability and shear test device and method under the oblique shear action.
Background
The seepage failure is the most common failure mode of the earth-rock dam with the soil impervious body except for overtopping, and mainly occurs on the combination belts of soil bodies and rigid surfaces, such as soil bodies and rock bank slopes or concrete bases on the bank slopes, soil bodies and concrete dam sections, concrete buried pipes and the like. In this connection zone, the osmotic hydraulic gradient in the plane tends from upstream to downstream in the river direction and in the vertical plane, while the shear deformation between the soil body and the rigid surface is mainly in the gradient direction of the rigid surface in the cross-river direction on the one hand and has a certain amount of deformation perpendicular to the gradient direction in the river direction on the other hand. The soil body on the combined belt of the soil body and the rigid surface is under the combined action of certain normal stress, the hydraulic power ratio drop and the shearing deformation which are mutually oblique. The permeability characteristic change processes of soil bodies at different positions of the bottom of the dam body are different in the shearing deformation process, so that the permeability characteristic distribution difference at the bottom of the dam body is caused, and the position with relatively low permeability coefficient and relatively low damage ratio drop becomes the position easy to be damaged by permeation.
In addition, with the change of the shear magnitude in each direction, the shear rate in each direction and the migration of fine particles in the seepage process, the shear strength of the soil body and the rigid surface combined belt may change due to the inherent viscous property and state correlation of the soil body, and the change also causes the change of the interaction and distribution between the bottom of the dam body and the bank slope.
The evolution conditions of the permeability characteristic and the shearing characteristic of the soil body and rigid surface combined zone under the combined action of certain normal stress, the hydraulic gradient of mutual skew and shearing deformation along with the change of the shearing deformation value, the shearing deformation rate and the fine particle content are mastered, and the method has great significance for predicting and guaranteeing the seepage prevention and the structure safety of the earth-rock dam.
The existing test device can not provide the conditions required by the penetration and shearing property test, can control the penetration property test combined with the normal stress, and generally can not provide shearing deformation; while the only test methods that can provide shear deformation are those in which the shear deformation direction is either parallel or orthogonal to the percolation direction. In addition, the existing test methods capable of providing shear deformation can only measure the change process of the permeability coefficient in the shearing process, cannot measure the osmotic failure rate drop, and cannot simultaneously measure the change of the strength.
The research and development of a test device capable of simulating the conditions of permeability coefficient, osmotic damage ratio drop and shear strength change of a soil body and a rigid surface combined belt under the conditions of shear deformation and arbitrary oblique crossing of seepage directions are urgently needed.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a soil body permeation and shearing test device and method under the oblique shearing action.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:
the device comprises a pressure chamber, wherein the upper end and the lower end of the pressure chamber are respectively packaged by an upper cover and a base, and a cylindrical shaft is arranged in the pressure chamber along the axis; the upper end of the cylindrical shaft penetrates through the upper cover, and the lower end of the cylindrical shaft is inserted into and penetrates through a cylindrical sleeve arranged on the base; the upper end of the cylindrical shaft is connected with a vertical displacement driving mechanism for driving the cylindrical shaft to vertically displace through a connector, the lower end of the cylindrical sleeve is provided with a rotary driving mechanism for driving the cylindrical sleeve and the cylindrical shaft to rotate, and a torque sensor is arranged between the cylindrical sleeve and the rotary driving mechanism.
The middle part of the cylindrical shaft is wrapped with a concrete rod with a circular cylindrical structure, a soil sample with a circular cylindrical structure is arranged outside the concrete rod, the length of the cylindrical shaft is greater than that of the concrete rod, the length of the concrete rod is greater than that of the soil sample, a latex film is sleeved outside the soil sample, and the upper end and the lower end of the latex film are respectively bound on the outer sides of the annular upper cap and the annular lower cushion; the annular upper cap and the annular lower pad are respectively connected with the upper cover and the base, a first tooth socket is arranged between the top surface of the upper cap and the soil sample, and a second tooth socket is arranged between the bottom surface of the lower pad and the soil sample; the upper cap and the lower pad are embedded into the surface of the soil sample, and the upper cap and the soil sample, and the lower pad and the soil sample are respectively matched through the first tooth groove and the second tooth groove; the distance between the upper surface of the concrete rod and the top cover and the distance between the lower surface of the concrete rod and the base are larger than the displacement of the up-and-down movement of the cylindrical shaft; the lengths of the upper surface and the lower surface of the concrete rod from the upper surface and the lower surface of the soil sample are respectively greater than the downward displacement and the upward displacement of the concrete rod.
A plurality of vertical channels are arranged in the upper cap, the lower pad, the first tooth groove and the second tooth groove, and the channels are respectively communicated with the bottom surface and the top surface of the soil sample; a seepage water inlet is arranged in the base and is communicated with the lower cushion through a seepage channel; the upper cover is provided with a circulating channel communicated with the upper cap, the circulating channel is connected with a circulating system comprising a circulating pump, and the circulating system is connected with an effusion soil and water measurement system; the upper cover is provided with a pressure chamber water inlet communicated with the pressure chamber.
Further, the lower extreme of cylindricality axle is provided with first hexagon post, the telescopic upper end of cylindricality and lower extreme are provided with hexagon hole in first and the second respectively, hexagon hole all is coaxial with the cylindricality axle in hexagon hole in first and the second, it is downthehole that first hexagon post inserts hexagon in first, and be provided with the clearance between the bottom in hexagon post and hexagon hole in first, the length in clearance is greater than the length of cylindricality axle displacement, be provided with second hexagon post in the hexagon hole in the second, second hexagon post is connected with torque sensor, be connected with the transmission of rotary driving mechanism again.
Furthermore, a through hole is formed in the base, the cylindrical sleeve penetrates through the through hole, and a dynamic sealing ring is arranged between the cylindrical sleeve and the base.
Furthermore, the upper cap and the lower pad are both of annular structures, the cylindrical shaft penetrates through the inner holes of the upper cap, the first tooth groove, the lower pad and the second tooth groove, the long concrete rod wrapped outside the middle part of the cylindrical shaft and the cylindrical shaft penetrate through the inner holes of the upper cap, the first tooth groove, the lower pad and the second tooth groove together, and a gap is formed between the concrete rod and the inner hole; the diameters of the upper cap, the first tooth groove, the lower pad and the second tooth groove are 2mm larger than the diameter of the concrete rod; the outer surface of the concrete rod is tightly attached to the inner surface of the cylindrical soil sample of the peripheral circular ring.
Furthermore, a through hole is also formed in the upper cover, the cylindrical shaft penetrates through the through hole in the upper cover, and a dynamic sealing ring is also arranged between the cylindrical shaft and the through hole in the upper cover.
Further, the vertical displacement driving mechanism comprises a linear motor, and the axis of the linear motor is coaxial with the cylindrical shaft; the lower end of the linear motor is connected with the upper end of the cylindrical shaft through a connector; the upper end of the linear motor is connected with the bearing frame through a ball bearing; the load-bearing frame is fixed to the upper cover or other stable position.
Further, the vertical displacement driving mechanism comprises a servo motor, a speed reducer, a threaded sleeve with an opening at one end and a screw rod; the end part of the threaded sleeve is connected with the speed reducer, and the threaded sleeve is coaxial with an output shaft of the speed reducer; the servo motor outputs rotation, and the rotation is output to the threaded sleeve after the speed is reduced by the speed reducer and the torque is amplified; the inner wall of the threaded sleeve is provided with internal threads, and the external threads of the screw are matched with the internal threads of the threaded sleeve; the lower end of the screw is connected with a force sensor through a connector, and the force sensor is connected with the upper end of the cylindrical shaft; the servo motor and the speed reducer are connected with a bearing frame, and the bearing frame is fixed on the upper cover or other stable positions.
Furthermore, the vertical displacement driving mechanism can also adopt a nut and screw rod combination with a set screw pitch, the screw rod is in threaded fit with the nut, the nut is installed on the upper cover through the bearing frame, the lower end of the screw rod is connected with the force sensor through the connector, and the force sensor is connected with the upper end of the cylindrical shaft.
For the nut and screw combination used, the screw rotates one revolution, i.e. moves one pitch vertically with the connector, the cylindrical shaft and the concrete bar.
Furthermore, a circulating channel is arranged in the upper cover, the circulating channel penetrates through two ends of the upper cover, two ends of the circulating channel are connected through an external pipeline, and a circulating pump is arranged on the external pipeline; the external pipeline and the internal circulation channel of the upper cover form a ring; the external pipeline is provided with a branch pipe, and the branch pipe is connected with the measuring system; and a valve is arranged on a branch pipe connected between the external pipeline and the measuring system.
The measuring system comprises a first balance and a second balance which are close to each other, wherein the first balance is provided with a water tank for containing seepage water with variable quantity, and the second balance is provided with a mixing tank for measuring a mixture containing seepage soil and seepage soil water with fixed volume; a second water inlet pipe is arranged in the mixing tank and extends into the bottom of the mixing tank from one side of the mixing tank; the second water inlet pipe is connected with a branch pipe of the external pipeline; the bottom of the separation plate is connected to a bottom plate on one side of the mixing tank, which is far away from the second water inlet pipe, and the separation plate is covered above the second water inlet pipe; a porous retaining plate is also arranged on the inner wall of the mixing tank close to one side of the second water inlet pipe, and the second water inlet pipe penetrates through the porous retaining plate; the upper end of the side wall of the mixing tank, which is far away from one side of the second water inlet pipe, is provided with a water outlet, the water outlet is connected with a water drain pipe, and the water drain pipe extends into the water tank.
The upper end of the upper cover is provided with an exhaust hole, a pressure chamber water inlet and a seepage water inlet are respectively connected with the first pressure volume controller and the second pressure volume controller, and the lower end of the pressure chamber water inlet extends into the bottom of the pressure chamber through a vertical first water inlet pipe.
The method for testing the penetration and shearing characteristics of the soil body and the rigid surface combined belt under the shearing deformation action of the hydraulic ratio declination by using the soil body penetration and shearing test device under the oblique shearing action comprises the following steps:
s1: placing a cylindrical shaft with a long concrete rod in a test device, manufacturing a circular cylindrical soil sample on the outer side of the concrete rod, sealing and binding the circular cylindrical soil sample between an upper cap and a lower pad by using a latex film, and assembling the circular cylindrical soil sample into a soil body penetration test device;
s2: opening an exhaust hole, injecting water into the pressure chamber through a water inlet of the pressure chamber by adopting a first pressure volume controller, closing the exhaust hole when the pressure chamber is filled with water and the water is discharged from the exhaust hole, and suspending water injection;
pressurizing the pressure chamber by a first pressure volume controller, detecting the pressure in the pressure chamber to reach a set pressure value P 1 (ii) a Keeping the first pressure volume controller on and the stable pressure P 1 ；
S3: opening a second pressure volume controller, injecting water into the soil sample through the seepage water inlet, keeping the water pressure of the seepage water inlet at 50kPa until the water is filled in the space below the lower surface and above the upper surface of the concrete rod, and is filled in the holes in the lower pad and the upper cover and the circulating system connected with the outer part of the upper cap, and flows into a mixing tank on a second balance; when the mixing tank on the second balance is filled with water and the water begins to overflow to the water tank on the first balance, preparing to carry out the next test;
s4: gradually increasing the pressure of the second pressure volume controller until the pressure of the seepage water inlet is increased to a set pressure value P 2 (ii) a After the water quantity increasing speed measured by the second balance is stable, the vertical displacement driving mechanism is used for pushing the cylindrical shaft to move along the up-down direction, and meanwhile, the rotary driving mechanism drives the cylindrical shaft to rotate; through the combination of the rotation and the vertical displacement of the cylindrical shaft, the shearing deformation between the soil body and the rigid surface of the concrete is realized on the inner side surface of the circular cylindrical soil sample;
s5: continuing to adopt a second pressure volume controller along the seepage water inlet to set a water pressure P 2 Continuously injecting water into the soil sample through the lower pad;
s6: measuring the weight change of the mixing tank to obtain the aerosol W of the soil material rushed out of the soil sample s And calculating the soil material loss (W) in the seepage process s /G s +W s ) Wherein G is s Is the specific gravity of the soil grains;
measuring the mass W of added water in a sink w0 And the displacement s of the cylindrical axis movement, with the cylindrical axial upward displacement as positive, calculates the amount W of water oozed during any shear deformation w ；
Wherein r is the radius of the concrete rod wrapped outside the cylindrical shaft, r 0 Is the radius of the cylindrical shaft; gamma ray w Is the volume weight of water, g is the acceleration of gravity;
s7: according to the width r of the combination band between the circular ring column-shaped soil sample and the concrete rod in the radius direction d Calculating the area A of a combined belt between the soil sample and the concrete rod:
A＝π(r+r d ) 2 -πr 2 ≈2πr·r d
calculating the loss of soil material (W) s /G s +W s ) Derivative over time q s Water mass W w Derivative over time q w Dividing the area A by the area of the combined zone to obtain the soil emergence speed V of the combined zone in the seepage process s The velocity V of the seepage water w ；
S8: calculating the permeability coefficient k of the binding band cont ：
Wherein i is the hydraulic power drop in the soil sample, P 2 The osmotic pressure at the bottom of the soil sample, and h is the height of the soil sample;
s9: measuring torque T through a torque sensor, and measuring thrust F of the vertical displacement driving mechanism to the cylindrical shaft through a force sensor; the cohesive force c of the soil and concrete combined belt is a constant; in the shearing deformation process, the shearing stress variation delta tau which can be provided in unit area between the soil sample and the concrete rod is as follows:
delta tau = sigma tan delta phi, wherein sigma is the normal pressure of the inner surface of the soil sample, and phi is the internal friction angle of the soil and concrete combined belt;
s10: the resistance variation of the vertical displacement of the concrete rod, namely the thrust variation delta F applied to the cylindrical shaft by the vertical displacement driving mechanism, is as follows:
ΔF＝σtanΔφ 1 ·2πr·h
calculating the state and speed related to the vertical displacement and the vertical displacement speed and the variation delta phi of the friction angle related to the fine grain content of the soil sample 1 ；
S11: the resistance variation in the concrete rod rotation process, namely the torque variation delta T applied to the cylindrical shaft by the rotation driving mechanism is as follows;
ΔT＝σtanΔφ 2 ·2πr·h·r
calculating the variation delta phi of the friction angle related to the state, speed and fine grain content of the soil sample related to the fine grain loss caused by horizontal displacement, horizontal displacement speed and seepage 2 。
The beneficial effects of the invention are as follows:
this device adopts soil sample and concrete stick simulation earth and rockfill dam heart wall and bank slope contact surface, through vertical displacement actuating mechanism and rotation driving mechanism combined action, provides the deformation of arbitrary direction for this contact surface. Adopt emulsion membrane to keep apart the stagnant water between soil sample and pressure chamber, go up cap and base and set up first tooth's socket and second tooth's socket respectively, avoid the sample to take place whole rotation along with the concrete stick. A circulating system is arranged to prevent soil particles from silting on the upper cover. And a first pressure volume controller is adopted to provide the contact surface normal stress for the sample, and a second pressure volume controller is adopted to provide the hydraulic pressure drop for the sample.
The measuring system can independently measure the soil particle loss quality and the seepage water amount in real time, the mixing tank is used for measuring the quality of the outflow soil particles, the water tank is used for measuring the quality of the seepage water, and the soil particles in the mixing tank are prevented from flowing into the water tank through the porous plate and the partition plate.
The scheme decouples the shear deformation obliquely crossed with the hydraulic ratio drop, independently provides the shear deformation in the forward direction (vertical direction in the device) and the orthogonal direction (circumferential direction in the device) of the hydraulic ratio drop, can independently control the positive and negative, speed, pause and magnitude of the orthogonal shear deformation and the forward shear deformation, generates any shear deformation path, and only adopts the combination of a nut and a screw rod with specific thread pitch, the proportion of the orthogonal shear deformation and the forward shear deformation is fixed, and the oblique shear angle is fixed; for the other two vertical displacement driving mechanisms, the two directions are independently controlled. The hydraulic power ratio drop is independently controlled besides the shear deformation in two directions, and the seepage soil and water weight and the acting force in two directions on the soil body and rigid surface combined belt in the shearing process are measured simultaneously, so that the seepage and shear characteristic change of the soil body and rigid surface combined belt under any shear deformation condition can be conveniently inspected.
Drawings
FIG. 1 is a schematic structural diagram of a soil body permeation and shear test device under the oblique shear action.
Fig. 2 is a structural view of a second embodiment of the vertical displacement drive mechanism.
Fig. 3 is a structural view of a third embodiment of the vertical displacement drive mechanism.
The device comprises a bearing 1, a ball bearing, a linear motor 2, a linear motor 3, a bearing frame 4, a connector 5, a circulating pump 6, a valve 7, a pressure chamber 8, a first tooth groove 9, a latex film 10, a soil sample 11, a second tooth groove 12, a seepage water inlet 13, a mixing groove 14, a water groove 15, a second hexagonal column 16, a cylindrical sleeve 17, a base 18, a first hexagonal column 19, a lower pad 20, a concrete rod 21, an upper cap 22, a cylindrical shaft 23, a pressure chamber water inlet 24, an exhaust hole 25, an upper cover 26, a partition plate 27, a threaded sleeve 28, a screw rod 29, a torque sensor 30, a porous retaining plate 31, a second water inlet pipe 32, a branch pipe 33, a first water inlet pipe 34, a force sensor 35 and a nut.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined by the appended claims, and all changes that can be made by the invention using the inventive concept are intended to be protected.
As shown in fig. 1, the soil infiltration and shear test device under the oblique shear action of the present scheme comprises a pressure chamber 7, wherein the upper end and the lower end of the pressure chamber 7 are respectively sealed by an upper cover 25 and a base 17, a cylindrical shaft 22 is arranged in the pressure chamber 7 along the axial line, the upper end of the cylindrical shaft 22 passes through the upper cover 25, and the lower end is inserted into a cylindrical sleeve 16 passing through the base 17; the upper end of the cylindrical shaft 22 is connected with a force sensor 34 through a connector 4, the force sensor 34 is connected with a vertical displacement driving mechanism for driving the cylindrical shaft 22 to vertically displace, and the lower end of the cylindrical sleeve 16 is provided with a rotary driving mechanism for driving the cylindrical sleeve 16 and the cylindrical shaft 22 to rotate; and a torque sensor 29 is arranged between the cylindrical sleeve 16 and the cylindrical shaft 22 for measuring the torque of the parameter.
The middle part of the cylindrical shaft 22 is wrapped with a concrete rod 20 with a circular cylindrical structure, a soil sample 10 with a circular cylindrical structure is arranged outside the concrete rod 20, the length of the concrete rod 20 is greater than that of the soil sample 10 and smaller than the net height in the pressure chamber, a latex film 9 is sleeved outside the soil sample 10, and the upper end and the lower end of the latex film 9 are respectively bound outside the annular upper cap 21 and the annular lower cushion 19; the bottom of the upper cap 21, the top of the soil sample 10, the top of the lower pad 19 and the bottom of the soil sample 10 are respectively provided with a first tooth groove 8 and a second tooth groove 11, and the upper cap 21 and the lower pad 19 are respectively embedded into the upper surface and the lower surface of the soil sample 10 through the first tooth groove 8 and the second tooth groove 11; the distance between the upper surface of the concrete rod 20 and the top cover and the distance between the lower surface of the concrete rod and the base are larger than the displacement of the up-and-down movement of the cylindrical shaft 22.
The upper cap 21 and the lower cushion 19 are respectively provided with a plurality of vertical channels which are respectively communicated with the top surface and the bottom surface of the soil sample 10, the base 17 is provided with a seepage water inlet 12, and the seepage water inlet 12 is communicated with the lower cushion 19 through a seepage channel; a pressure chamber water inlet 23 communicated with the pressure chamber 7 is arranged on the upper cover 25, a circulating channel communicated with the upper cap 21 is arranged in the upper cover 25, the circulating channel is connected with a circulating system containing a circulating pump 5, the circulating system is provided with a branch pipe 32, and the branch pipe 32 is connected with a measuring system; the upper cover is provided with a pressure chamber water inlet communicated with the pressure chamber 7.
In this embodiment, the lower extreme of cylindricality axle 22 is provided with first hexagon post 18, hexagonal hole in hexagon hole and the second in hexagon hole in the first is provided with respectively to the upper end and the lower extreme of cylindricality sleeve 16, hexagonal hole in hexagon hole and the second in hexagon hole are all coaxial in hexagon hole and the second in the first, first hexagon post 18 inserts in hexagon hole in the first, and be provided with the clearance between the bottom in hexagon post 18 and the first interior hexagonal hole, the length in clearance is greater than the length of cylindricality axle 22 downward displacement, be provided with second hexagon post 15 in the hexagon hole in the second, second hexagon post 15 is connected with the rotation driving mechanism transmission.
In this embodiment, a through hole is formed in the base 17, the cylindrical sleeve 16 extends into the through hole, and a dynamic seal ring is arranged between the cylindrical sleeve 16 and the base 17. The upper cover 25 is also provided with a through hole, the cylindrical shaft 22 passes through the through hole on the upper cover 25, and a dynamic sealing ring is also arranged between the cylindrical shaft 22 and the through hole on the upper cover 25.
In this embodiment, the upper cap 21 and the lower pad 19 are both annular structures, the cylindrical shaft 22 passes through inner holes of the upper cap 21 and the lower pad 19, and a gap is arranged between the cylindrical shaft 22 and the inner holes; the circular cylindrical concrete rod 20 is fixedly sleeved outside the cylindrical shaft 22, the circular cylindrical soil sample 10 is sleeved outside the concrete rod 20, the length of the concrete rod 20 is smaller than that of the cylindrical shaft 22, and the length of the soil sample 10 is smaller than that of the concrete rod 20. The distance between the upper surface and the lower surface of the concrete rod 20 and the upper cover 25 and the base 17 of the pressure chamber is larger than the upward and downward displacement of the concrete rod; the distance between the upper surface and the lower surface of the concrete rod 20 and the upper surface and the lower surface of the soil sample 10 is respectively greater than the downward displacement and the upward displacement of the concrete rod 20.
In this embodiment, the vertical displacement driving mechanism includes a linear motor 2, the upper end of the cylindrical shaft 22 is connected to the linear motor 2 through a connector 4, and the linear motor 2 is connected to the bearing frame 3 through a ball bearing 1. The carrying frame 3 can be fixed on the upper cover 25 or in another stable position.
As shown in fig. 2, in this embodiment, the vertical displacement driving mechanism may further include a servo motor, a speed reducer, a threaded sleeve 27 with an opening at one end, and a screw 28, wherein an inner thread is provided on an inner wall of the threaded sleeve 27, the screw 28 is matched with the threaded sleeve 27, a lower end of the screw 28 is connected to a force sensor 34 through a connector 4, the force sensor 34 is connected to an upper end of the cylindrical shaft 22, an end of the threaded sleeve 27 is connected to the servo motor through the speed reducer, and the servo motor and the speed reducer are fixed to the support frame 3. The carrying frame 3 can be fixed on the upper cover 25 or in another stable position.
In the embodiment shown in fig. 3, the vertical displacement driving mechanism may further include a nut 35 and a screw 28, the screw 28 is threadedly engaged with the nut 35, and the nut 35 is fixed on the supporting frame 3. The lower end of the screw 28 is connected with a force sensor 34 through a connector 4, the force sensor 34 is connected with the upper end of the cylindrical shaft 22, the rotation is driven by a rotation driving mechanism, and the rotating screw 28 is matched with a fixed nut 35 to ascend or descend. The carrying frame 3 can also be fixed on the upper cover 25 or in another stable position.
The screw rod 28 and the nut 35 that adopt different screw pitches as required are screw-thread fit, and screw rod 28 and nut 35 combination have and set for the screw pitch, and the screw pitch is the vertical shear deformation that hoop shear deformation a week corresponds, can provide the slant shear deformation different with the hoop contained angle through the screw pitch change, realizes different with the proportional combination of hydraulic ratio descending direction (vertical) shear deformation and the orthogonal to hydraulic ratio descending direction (hoop) shear deformation.
The circulating channel is arranged in the upper cover 25 and penetrates through two ends of the upper cover 25, two ends of the circulating channel are connected through an external pipeline, the circulating pump 5 is arranged on the external pipeline, the external pipeline is provided with a branch pipe 32, the branch pipe 32 leads to the measuring system, and a valve 6 is arranged between the branch pipe 32 and the measuring system.
In the embodiment, the measuring system comprises a first balance and a second balance which are close to each other, a water tank 14 for measuring water quantity is arranged on the first balance, a mixing tank 13 for measuring a mixture containing the seeped soil and the seeped soil with a fixed volume is arranged on the second balance, a second water inlet pipe 31 is arranged in the mixing tank 13, the second water inlet pipe 31 extends into the bottom of the mixing tank 13 from one side of the mixing tank 13, the second water inlet pipe 31 is communicated with a branch pipe 32, an inverted L-shaped partition plate 26 is arranged in the mixing tank 13, the partition plate 26 covers the upper side of the second water inlet pipe 31, a water outlet is arranged at the upper end of the mixing tank 13 at one side of the partition plate 26, and the water outlet extends into the water tank 14; and the inner wall of the mixing tank 13 on the side away from the water outlet is also provided with a perforated retaining plate 30, and a second water inlet pipe 31 penetrates into the water tank 14 through the holes.
The upper end of the upper cover 25 is provided with an exhaust hole 24, the pressure chamber water inlet 23 and the seepage water inlet 12 are respectively connected with a pressure control system containing a pressure water pump, and the lower end of the pressure chamber water inlet 23 extends into the bottom of the pressure chamber 7 through a vertical first water inlet pipe 33.
The method for testing the permeability and shearing characteristics of the soil body and the rigid surface combined belt under the shearing action of the hydraulic ratio reduction oblique crossing by using the soil body permeability and shearing test device under the oblique shearing action comprises the following steps:
s1: placing a cylindrical shaft 22 with a long concrete rod 20 in a test device, manufacturing a circular cylindrical soil sample 10 outside the concrete rod 20, sealing and binding the circular cylindrical soil sample between an upper cap 21 and a lower pad 19 by using a latex film 9, and assembling the circular cylindrical soil sample into a soil body penetration test device;
s2: opening the vent hole 24, injecting water into the pressure chamber 7 through the pressure chamber water inlet 23 by adopting a first pressure volume controller, closing the vent hole 24 when the pressure chamber 7 is filled with water and the water is discharged from the vent hole 24, and suspending water injection;
pressurizing the pressure chamber 7 by a first pressure volume controller, detecting the pressure in the pressure chamber to reach a set pressure value P 1 (ii) a Keeping the pressure water pump on and the stable pressure P 1 ；
S3: opening a second pressure volume controller, injecting water into the soil sample 10 through the seepage water inlet 12, keeping the water pressure of the seepage water inlet 12 at 50kPa until the water is filled in the space below the lower surface and above the upper surface of the concrete rod 20, and is filled in the lower cushion 19, the holes in the upper cover and the circulating system connected with the outer part of the upper cap, and flows into a mixing tank 13 on a second balance; when the mixing tank 13 on the second balance is filled with water and begins to overflow the water tank 14 on the first balance, preparing to carry out the next test;
s4: the pressure of the second pressure volume controller is increased step by step until the pressure of the seepage water inlet 12 is increased to a set pressure value P 2 (ii) a After the water quantity increasing speed measured by the second balance is stable, the vertical displacement driving mechanism is used for pushing the cylindrical shaft 22 to move along the up-down direction, and meanwhile, the rotary driving mechanism drives the cylindrical shaft 22 to rotate; through the combination of the rotation and the vertical displacement of the cylindrical shaft 22, the shearing deformation between the soil body and the rigid concrete surface is realized on the inner side surface of the circular cylindrical soil sample 10;
s5: using a second pressure volume controller along the seepage water inlet 12 at a set water pressure P 2 Injecting water into the soil sample 10 through the lower pad;
s6: the weight change of the mixing tank 13 is measured to obtain the aerosol W of the soil material rushed out of the soil sample 10 s And calculating the soil material loss (W) in the seepage process s /G s +W s ) Wherein G is s Is the specific gravity of the soil grains;
measuring the mass W of added water in the tank 14 w0 And the displacement s of the cylindrical shaft 22 in the upward direction, the cylindrical shaft 22 being displaced positively, the amount W of water oozed out during any shear deformation is calculated w ；
Wherein r is the radius of the concrete rod 20 wrapped outside the cylindrical shaft, r 0 Is the radius of the cylindrical shaft; gamma ray w Is the volume weight of water, g is the acceleration of gravity;
s7: according to the width r of the combination band between the circular column-shaped soil sample 10 and the concrete rod 20 in the radius direction d Calculating the area A of the bonding zone between the soil sample 10 and the concrete rod 20:
A＝π(r+r d ) 2 -πr 2 ≈2πr·r d
calculating the loss of soil material (W) s /G s +W s ) Derivative over time q s Water mass W w Derivative over time q w Dividing the area A by the area of the combined zone to obtain the soil emergence speed V of the combined zone in the seepage process s The velocity V of the seepage water w ；
S8: calculating the permeability coefficient k of the binding band cont ：
Wherein i is the hydraulic power drop in the soil sample 10, P 2 Is the osmotic pressure at the bottom of the soil sample 10, and h is the height of the soil sample 10.
S9: the torque T is measured by the torque sensor and the thrust F of the vertical displacement drive mechanism to the cylindrical shaft is measured by the force sensor 34.
The cohesive force c of the soil and concrete combined belt is assumed to be constant. In the shear deformation process, the shear stress variation Δ τ provided in a unit area between the soil sample 10 and the concrete rod 20 is:
delta tau = sigma tan delta phi, wherein sigma is the normal pressure of the inner surface of the soil sample, and phi is the internal friction angle of the soil and concrete combined belt;
s10: the resistance variation of the vertical displacement of the concrete rod 20, i.e., the thrust variation Δ F applied to the cylindrical shaft 22 by the vertical displacement driving mechanism, is:
ΔF＝σtanΔφ 1 ·2πr·h
the state, speed and fine particle content related friction angle change delta phi related to the vertical displacement and the vertical displacement speed can be calculated by adopting the formula 1 ；
S11: the amount of change in resistance during rotation of the concrete rod 20, i.e., the amount of change Δ T in torque applied to the cylindrical shaft 22 by the rotary drive mechanism, is.
ΔT＝σtanΔφ 2 ·2πr·h·r
The friction angle change delta phi relevant to the state, speed and fine particle content of the fine particle loss caused by the horizontal displacement (horizontal shear deformation caused by rotation), the horizontal displacement rate (horizontal shear deformation rate caused by rotation) and the seepage can be calculated by the above formula 2 。
The scheme decouples the shear deformation obliquely crossed with the hydraulic ratio drop, independently provides the shear deformation in the forward direction (vertical direction in the device) and the orthogonal direction (annular direction in the device) of the hydraulic ratio drop, and can independently control the positive and negative, speed, pause and magnitude of the orthogonal shear deformation and the forward shear deformation to generate any shear deformation path. The hydraulic power ratio drop is independently controlled besides the shear deformation in two directions, and the seepage soil and water weight and the acting force in two directions on the soil body and rigid surface combined belt in the shearing process are measured simultaneously, so that the seepage and shear characteristic change of the soil body and rigid surface combined belt under any shear deformation condition can be conveniently inspected.
Claims (10)
1. The device for the combined belt permeation and shear test under the oblique shearing action is characterized by comprising a pressure chamber, wherein the upper end and the lower end of the pressure chamber are respectively encapsulated by an upper cover and a base; the upper end of the cylindrical shaft penetrates through the upper cover, and the lower end of the cylindrical shaft is inserted into a cylindrical sleeve arranged on the base; the upper end of the cylindrical shaft is connected with a vertical displacement driving mechanism for driving the cylindrical shaft to vertically displace through a connector, the lower end of the cylindrical sleeve is provided with a rotary driving mechanism for driving the cylindrical sleeve and the cylindrical shaft to rotate, and a torque sensor is arranged between the cylindrical sleeve and the rotary driving mechanism.
The middle part of the cylindrical shaft is wrapped with a circular cylindrical concrete rod, a circular cylindrical soil sample is arranged outside the concrete rod, the length of the cylindrical shaft is greater than that of the concrete rod, the length of the concrete rod is greater than that of the soil sample, a latex film is sleeved outside the soil sample, and the upper end and the lower end of the latex film are respectively bound to the outer sides of the annular upper cap and the annular lower cushion; the annular upper cap and the annular lower pad are respectively connected with the upper cover and the base, a first tooth socket is arranged between the top surface of the upper cap and the soil sample, and a second tooth socket is arranged between the bottom surface of the lower pad and the soil sample; the upper cap and the lower pad are embedded into the surface of the soil sample, and the upper cap and the soil sample, and the lower pad and the soil sample are respectively matched through the first tooth groove and the second tooth groove; the distance between the upper surface of the concrete rod and the top cover and the distance between the lower surface of the concrete rod and the base are larger than the displacement of the up-and-down movement of the cylindrical shaft; the lengths of the upper surface and the lower surface of the concrete rod from the upper surface and the lower surface of the soil sample are respectively greater than the downward displacement and the upward displacement of the concrete rod.
A plurality of vertical channels are arranged in the upper cap, the lower pad, the first tooth groove and the second tooth groove, and the channels are respectively communicated with the bottom surface and the top surface of the soil sample; a seepage water inlet is formed in the base and is communicated with the lower cushion through a seepage channel; the upper cover is provided with a circulating channel communicated with the upper cap, the circulating channel is connected with a circulating system comprising a circulating pump, and the circulating system is connected with an earth and water seepage measuring system; the upper cover is provided with a pressure chamber water inlet communicated with the pressure chamber.
2. The soil infiltration and shear test device under oblique shearing action of claim 1, wherein the lower end of the cylindrical shaft is provided with a first hexagonal column, the upper end and the lower end of the cylindrical sleeve are respectively provided with a first inner hexagonal hole and a second inner hexagonal hole, the first inner hexagonal hole and the second inner hexagonal hole are coaxial with the cylindrical shaft, the first hexagonal column is inserted into the first inner hexagonal hole, a gap is arranged between the first hexagonal column and the bottom of the first inner hexagonal hole, the length of the gap is greater than the displacement length of the cylindrical shaft, a second hexagonal column is arranged in the second inner hexagonal hole, and the second hexagonal column is connected with the torque sensor and then is in transmission connection with the rotation driving mechanism.
3. The soil infiltration and shear test device under oblique shearing action of claim 2, wherein the base is provided with a through hole, the cylindrical sleeve passes through the through hole, and a dynamic sealing ring is arranged between the cylindrical sleeve and the base.
4. The soil infiltration and shear test device under oblique shearing action of claim 1, wherein the upper cap and the lower pad are both of annular structures, the cylindrical shaft passes through the inner holes of the upper cap, the first tooth groove, the lower pad and the second tooth groove, the long concrete rod wrapped outside the middle part of the cylindrical shaft and the cylindrical shaft pass through the inner holes of the upper cap, the first tooth groove, the lower pad and the second tooth groove together, and a gap is arranged between the concrete rod and the inner holes; the diameters of the upper cap, the first tooth groove, the lower pad and the second tooth groove are 2mm larger than the diameter of the concrete rod; the outer surface of the concrete rod is tightly attached to the inner surface of the externally-arranged circular-ring cylindrical soil sample.
5. The soil infiltration and shear test device under oblique shear of claim 1, wherein the upper cover is also provided with a through hole, the cylindrical shaft passes through the through hole of the upper cover, and a dynamic seal ring is also arranged between the cylindrical shaft and the through hole of the upper cover.
6. The soil infiltration and shear test device under oblique shearing action of claim 1, wherein the vertical displacement drive mechanism comprises a linear motor, and the axis of the linear motor is coaxial with the cylindrical shaft; the lower end of the linear motor is connected with the upper end of the cylindrical shaft through a connector; the upper end of the linear motor is connected with the bearing frame through a ball bearing; the load-bearing frame is fixed to the upper cover or other stable position.
7. The soil infiltration and shear test device under oblique shearing action of claim 1, wherein the vertical displacement driving mechanism comprises a servo motor, a speed reducer, a threaded sleeve with an opening at one end and a screw; the end part of the threaded sleeve is connected with a speed reducer, and the threaded sleeve is coaxial with an output shaft of the speed reducer; the servo motor outputs rotation, and the rotation is output to the threaded sleeve after the speed is reduced by the speed reducer and the torque is amplified; the inner wall of the threaded sleeve is provided with internal threads, and external threads of the screw are matched with the internal threads of the threaded sleeve; the lower end of the screw is connected with a force sensor through a connector, and the force sensor is connected with the upper end of the cylindrical shaft; the servo motor and the speed reducer are connected with a bearing frame, and the bearing frame is fixed on the upper cover or other stable positions.
8. The soil infiltration and shear test device under oblique shear of claim 1, wherein the vertical displacement driving mechanism further comprises a nut and screw combination with a set pitch, the nut is mounted on the upper cover through a bearing frame, the lower end of the screw is connected with a force sensor through a connector, and the force sensor is connected with the upper end of the cylindrical shaft;
the screw rod is in threaded fit with the nut, the screw rod and nut combination has a set screw pitch, the screw pitch is vertical shear deformation corresponding to one circle of circumferential shear deformation, oblique shear deformation different from a circumferential included angle can be provided through screw pitch change, and different proportional combinations of shear deformation in the downstream direction and shear deformation in the orthogonal direction to the hydraulic ratio and the drop direction are achieved.
9. The soil infiltration and shear test device under oblique shearing action of claim 1, wherein the circulation channel is arranged in the upper cover, the circulation channel penetrates through two ends of the upper cover, two ends of the circulation channel are connected through an external pipeline, and the circulation pump is arranged on the external pipeline; the external pipeline and the internal circulation channel of the upper cover form a ring shape; the external pipeline is provided with a branch pipe, and the branch pipe is connected with a measuring system; and a valve is arranged on a branch pipe connected between the external pipeline and the measuring system.
The measuring system comprises a first balance and a second balance which are close to each other, wherein a water tank for containing seepage water in a non-constant amount is arranged on the first balance, and a mixing tank for measuring a mixture containing seepage soil and seepage soil water with a fixed volume is arranged on the second balance; a second water inlet pipe is arranged in the mixing tank and extends into the bottom of the mixing tank from one side of the mixing tank; the second water inlet pipe is connected with a branch pipe of the external pipeline; the mixing tank is internally provided with an inverted L-shaped separation plate, the bottom of the separation plate is connected to a bottom plate on one side of the mixing tank, which is far away from the second water inlet pipe, and the separation plate is covered above the second water inlet pipe; a porous retaining plate is also arranged on the inner wall of the mixing tank close to one side of the second water inlet pipe, and the second water inlet pipe penetrates through the porous retaining plate; the upper end of the side wall of the mixing tank, which is far away from one side of the second water inlet pipe, is provided with a water outlet, the water outlet is connected with a water drainage pipe, and the water drainage pipe extends into the water tank.
The upper end of the upper cover is provided with an exhaust hole, the pressure chamber water inlet and the seepage water inlet are respectively connected with the first pressure volume controller and the second pressure volume controller, and the lower end of the pressure chamber water inlet extends into the bottom of the pressure chamber through the vertical first water inlet pipe.
10. A method for testing the penetration and shear characteristics of a soil mass and a rigid surface combined belt under the shear deformation effect obliquely crossed with hydraulic ratio reduction by using the soil mass penetration and shear testing device under the oblique shear effect of any one of claims 1 to 9, which is characterized by comprising the following steps:
s1: placing a cylindrical shaft with a long concrete rod in a test device, manufacturing a circular cylindrical soil sample on the outer side of the concrete rod, sealing and binding the circular cylindrical soil sample between an upper cap and a lower pad by using a latex film, and assembling the circular cylindrical soil sample into a soil body penetration test device;
s2: opening an exhaust hole, injecting water into the pressure chamber through a water inlet of the pressure chamber by adopting a first pressure volume controller, closing the exhaust hole when the pressure chamber is filled with water and the water is discharged from the exhaust hole, and suspending water injection;
pressurizing the pressure chamber via the first pressure volume controller, detecting the pressure in the pressure chamber to reach a set pressure value P 1 (ii) a Keeping the first pressure volume controller open and the stable pressure P 1 ；
S3: opening a second pressure volume controller, injecting water into the soil sample through the seepage water inlet, keeping the water pressure of the seepage water inlet at 50kPa until the water is filled in the space below the lower surface and above the upper surface of the concrete rod, and is filled in the holes in the lower pad and the upper cover and the circulating system connected with the outer part of the upper cap, and flows into a mixing tank on a second balance; when the mixing tank on the second balance is full of water and the water begins to overflow to the water tank on the first balance, preparing to carry out the next test;
s4: the pressure of the second pressure volume controller is increased step by step until the pressure of the seepage water inlet is increased to a set pressure value P 2 (ii) a After the water quantity increasing speed measured by the second balance is stable, the vertical displacement driving mechanism is used for pushing the cylindrical shaft to move along the up-down direction, and meanwhile, the rotary driving mechanism drives the cylindrical shaft to rotate; through the combination of the rotation and the vertical displacement of the cylindrical shaft, the shearing deformation between the soil body and the rigid surface of the concrete is realized on the inner side surface of the circular cylindrical soil sample;
s5: continuing to adopt a second pressure volume controller along the seepage water inlet to set a water pressure P 2 Continuously injecting water into the soil sample through the lower pad;
s6: measuring the weight change of the mixing tank to obtain the aerosol mass W of the soil material rushed out of the soil sample s And calculating the soil material loss (W) in the seepage process s /G s +W s ) Wherein G is s Is the specific gravity of the soil grains;
measuring the mass W of added water in a sink w0 And the displacement s of the cylindrical axis movement, with the cylindrical axial upward displacement as positive, calculates the amount W of water oozed during any shear deformation w ；
Wherein r is the radius of the concrete rod wrapped outside the cylindrical shaft, r 0 Is the radius of the cylindrical shaft; gamma ray w Is the volume weight of water, g is the acceleration of gravity;
s7: according to the width r of the combination belt between the annular cylindrical soil sample and the concrete rod in the radius direction d Calculating the area A of the combination belt between the soil sample and the concrete rod:
A＝π(r+r d ) 2 -πr 2 ≈2πr·r d
calculating the loss of soil material (W) s /G s +W s ) Derivative over time q s Water quality W w Derivative over time q w Dividing the area A by the area of the combined zone to obtain the soil emergence speed V of the combined zone in the seepage process s The velocity V of the seepage water w ；
S8: calculating the permeability coefficient k of the binding band cont ：
Wherein i is water in the soil sampleDecrease of force ratio, P 2 The osmotic pressure at the bottom of the soil sample, and h is the height of the soil sample;
s9: measuring torque T through a torque sensor, and measuring thrust F of the vertical displacement driving mechanism to the cylindrical shaft through a force sensor; the cohesive force c of the soil and concrete combined belt is a constant; in the shearing deformation process, the shearing stress variation delta tau which can be provided on the unit area between the soil sample and the concrete rod is as follows:
Δτ＝σtanΔφ
wherein, sigma is the normal pressure of the inner surface of the soil sample, phi is the internal friction angle of the combination belt of the soil body and the concrete;
s10: the resistance variation of the vertical displacement of the concrete rod, namely the thrust variation delta F applied to the cylindrical shaft by the vertical displacement driving mechanism, is as follows:
ΔF＝σtanΔφ 1 ·2πr·h
calculating the state and speed related to the vertical displacement and the vertical displacement speed and the variation delta phi of the friction angle related to the fine grain content of the soil sample 1 ；
S11: the resistance variation in the concrete rod rotation process, namely the torque variation delta T applied to the cylindrical shaft by the rotation driving mechanism is as follows;
ΔT＝σtanΔφ 2 ·2πr·h·r
calculating the variation of the friction angle delta phi in relation to the state, rate and fines content of the soil sample in relation to the loss of fines by horizontal displacement, horizontal displacement rate and seepage 2 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210841525.2A CN115219398B (en) | 2022-07-18 | 2022-07-18 | Device and method for combined belt permeation and shear test under oblique shearing action |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210841525.2A CN115219398B (en) | 2022-07-18 | 2022-07-18 | Device and method for combined belt permeation and shear test under oblique shearing action |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115219398A true CN115219398A (en) | 2022-10-21 |
| CN115219398B CN115219398B (en) | 2023-04-07 |
Family
ID=83612240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210841525.2A Active CN115219398B (en) | 2022-07-18 | 2022-07-18 | Device and method for combined belt permeation and shear test under oblique shearing action |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115219398B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117517174A (en) * | 2023-12-29 | 2024-02-06 | 中铁十七局集团第二工程有限公司 | Building concrete water-resistant permeability test device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104142277A (en) * | 2014-08-08 | 2014-11-12 | 重庆大学 | Soil body torsion shear seepage testing device and testing method |
| CN106932284A (en) * | 2017-05-16 | 2017-07-07 | 清华大学 | Seepage flow test device and its application method are sheared in a kind of contact surface large deformation |
| CN108593519A (en) * | 2018-04-27 | 2018-09-28 | 中国水利水电科学研究院 | Rotary shear type soil and structure contact surface mechanical property test device |
| CN109187312A (en) * | 2018-10-29 | 2019-01-11 | 重庆大学 | A kind of Novel pole cuts pervasion test device and its test method |
| CN111482127A (en) * | 2020-05-29 | 2020-08-04 | 广东粤港供水有限公司 | Algae removal equipment, unmanned ship and automatic medicine feeding system |
| CN111896447A (en) * | 2020-07-09 | 2020-11-06 | 河海大学 | Contact surface large-deformation rotary shear seepage test device and method considering temperature effect |
| CN113916739A (en) * | 2021-08-24 | 2022-01-11 | 河海大学 | Soil-concrete contact seepage test device and method considering contact surface shearing |
| WO2022142671A1 (en) * | 2021-01-04 | 2022-07-07 | 青岛理工大学 | Triaxial shear and seepage integrated experimental method and device for hydrate-bearing sediment |
-
2022
- 2022-07-18 CN CN202210841525.2A patent/CN115219398B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104142277A (en) * | 2014-08-08 | 2014-11-12 | 重庆大学 | Soil body torsion shear seepage testing device and testing method |
| CN106932284A (en) * | 2017-05-16 | 2017-07-07 | 清华大学 | Seepage flow test device and its application method are sheared in a kind of contact surface large deformation |
| CN108593519A (en) * | 2018-04-27 | 2018-09-28 | 中国水利水电科学研究院 | Rotary shear type soil and structure contact surface mechanical property test device |
| CN109187312A (en) * | 2018-10-29 | 2019-01-11 | 重庆大学 | A kind of Novel pole cuts pervasion test device and its test method |
| CN111482127A (en) * | 2020-05-29 | 2020-08-04 | 广东粤港供水有限公司 | Algae removal equipment, unmanned ship and automatic medicine feeding system |
| CN111896447A (en) * | 2020-07-09 | 2020-11-06 | 河海大学 | Contact surface large-deformation rotary shear seepage test device and method considering temperature effect |
| WO2022142671A1 (en) * | 2021-01-04 | 2022-07-07 | 青岛理工大学 | Triaxial shear and seepage integrated experimental method and device for hydrate-bearing sediment |
| CN113916739A (en) * | 2021-08-24 | 2022-01-11 | 河海大学 | Soil-concrete contact seepage test device and method considering contact surface shearing |
Non-Patent Citations (1)
| Title |
|---|
| 雷红军;刘中阁;于玉贞;吕禾;: "黏土-结构接触面大剪切变形后渗流特性试验研究" * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117517174A (en) * | 2023-12-29 | 2024-02-06 | 中铁十七局集团第二工程有限公司 | Building concrete water-resistant permeability test device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115219398B (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115219398B (en) | Device and method for combined belt permeation and shear test under oblique shearing action | |
| CN107632116B (en) | A kind of three-dimensional grouting model test servo-control system and test method | |
| WO2021143229A1 (en) | Test system for measuring gas permeation parameters of ultra-low permeability medium in multi-field and multi-phase coupling conditions | |
| CN109374855B (en) | Test device and test method for simulating railway roadbed slurry-rolling mud-pumping disease phenomenon | |
| CN105223087B (en) | Coarse-grained soil seepage flow direct shear test device and method | |
| CN107290501B (en) | Crack fault type geological structure internal filling medium seepage instability water inrush experiment device and method | |
| US10472788B2 (en) | Devices used in laboratories to measure horizontal displacement of soil around a foundation to be treated by vacuum preloading, and measurement methods | |
| CN110426337B (en) | Rock-soil body osmotic deformation testing device under low stress condition and testing method thereof | |
| CN111157363B (en) | Earth pressure balance shield muck workability and improvement optimization evaluation test method | |
| CN106769752A (en) | Rotatable imbibition experimental provision | |
| CN111896447A (en) | Contact surface large-deformation rotary shear seepage test device and method considering temperature effect | |
| CN114279818B (en) | Bidirectional flexible loading and unloading ring shear device and test method thereof | |
| CN105651677A (en) | Geotechnical parameter and property tester capable of simultaneously testing specific yield and osmotic coefficient | |
| CN1737530B (en) | Method for testing permeability coefficient and anti-pervasion gradient ratio | |
| CN102879315B (en) | Multifunctional seepage experiment device | |
| CN212540400U (en) | Multifunctional frost heaving test system | |
| CN108593519A (en) | Rotary shear type soil and structure contact surface mechanical property test device | |
| CN111912760A (en) | Test device and test method for simulating contact surface seepage coupling characteristics | |
| CN114295492B (en) | Rock mass multi-field coupling rotary cutting drilling testing device and method | |
| CN108534985A (en) | Intertidal zone sediment incipient motion measuring device and its measurement method | |
| CN103091372B (en) | On-board seepage flow and outflow concentration real-time monitoring device and method of geotechnical centrifuge | |
| CN105672378B (en) | Simulate the excavation of foundation pit model test apparatus of artesian head lifting | |
| CN114354486A (en) | Device and method for testing bonding performance of geomembrane | |
| CN104568696A (en) | Device for quickly determining permeability coefficient of coarse-grained soil and determination method | |
| CN101975727B (en) | High-temperature static mixed plugging agent initial setting time detection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |