CN113049342B - Direct shear test device and method considering mud skin formation conditions and interface normal displacement - Google Patents
Direct shear test device and method considering mud skin formation conditions and interface normal displacement Download PDFInfo
- Publication number
- CN113049342B CN113049342B CN202110395530.0A CN202110395530A CN113049342B CN 113049342 B CN113049342 B CN 113049342B CN 202110395530 A CN202110395530 A CN 202110395530A CN 113049342 B CN113049342 B CN 113049342B
- Authority
- CN
- China
- Prior art keywords
- mud
- shear
- shear box
- box
- sleeve
- 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.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- 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
Abstract
The invention relates to a direct shear test device considering mud skin forming conditions and interface normal displacement, which comprises a mud skin sample preparation mechanism and a shear test mechanism, wherein the mud skin sample preparation mechanism comprises a shear box and a water storage tank arranged on one side of the shear box, the shear box comprises a shear box base, a shear box sleeve fixed on the shear box base, a mud casing fixed on the shear box sleeve and a mud casing upper cover fixed on the mud casing, a spring is arranged between the bottom end of the shear box sleeve and the shear box base, and a water inlet communicated with the interior of the shear box sleeve is arranged in the shear box base and is connected with the bottom of the water storage tank through a water pipe. The invention realizes the integration of mud skin sample preparation and direct shear test, can control the preparation of mud dip dyeing soil samples under different pressure difference conditions and the normal displacement in the interface shear test, and the preparation of mud dip dyeing soil samples is completed in the shear box sleeve, thus avoiding the disturbance of soil samples, being more close to the engineering practice and effectively improving the reliability of test results.
Description
Technical Field
The invention relates to the technical field of geotechnical test research, in particular to a direct shear test device considering mud skin formation conditions and interface normal displacement and a use method thereof.
Background
Reservoir dams are an important infrastructure of China and are commonly used for flood control, irrigation, hydroelectric power generation and the like, and more than 87000 reservoir dams are reported to be built in places of China in recent years, wherein 95% of the reservoir dams are earth and rockfill dams. In western regions of China, the rivers are vertical and horizontal, the hydropower resources are rich, but a plurality of rivers have super-thick coverage layers, in order to achieve the aim of seepage prevention, a concrete seepage-proofing wall core wall is generally built on a coverage layer dam foundation, the seepage-proofing wall is used as an important component part of a reservoir dam, the mechanical property research between the seepage-proofing wall and a soil body interface also becomes one of important problems in geotechnical engineering, and particularly the interface between the seepage-proofing wall containing mud skin and the super-thick coverage layers. The research on the interaction between soil and a structural interface is mainly focused on two aspects of an interface shear test and an interface drawing test at present, and the interface shear test is a means for intuitively reflecting the actual characteristics of engineering. The traditional experimental research on the interface shear characteristics mostly stays in the influence of interface roughness and water content, sample size, load size and speed, the forming process of the interface is not considered, and the influence of normal displacement is not considered. However, in practical engineering, especially in the ultra-thick coverage soil dam foundation, as most of the coverage soil body is sandy soil or sand gravel, the coverage soil body is loose, the porosity is large, mud can dip dye the soil body under the action of high water pressure difference, mud skin is formed between the concrete impervious wall and the soil body interface, and the mud skin has larger normal deformation, so that the mechanical characteristics of the concrete impervious wall and the soil body interface can be seriously affected. Therefore, it is needed to provide a test device integrating the preparation of clay sample containing clay skin and considering the normal deformation of the interface, in particular to a direct shear test device considering the clay skin forming condition and the normal displacement of the interface.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a direct shear test device considering mud skin forming conditions and interface normal displacement and a use method thereof, which realize the integration of mud skin sample manufacturing and direct shear test.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the utility model provides a consider mud skin formation condition and interface normal direction displacement's direct shear test device, includes mud skin sample preparation mechanism and shear test mechanism, mud skin sample preparation mechanism includes shear box and the aqua storage tank of setting in shear box one side, the shear box includes shear box base, fixes the shear box sleeve on the shear box base, fixes the thick liquid section of thick bamboo of protecting on the shear box sleeve, fixes the thick liquid section of thick bamboo upper cover of protecting on the thick liquid section of thick bamboo, is equipped with transparent window on the lateral wall of shear box sleeve, install the spring between shear box sleeve's bottom and the shear box base, be equipped with the inlet valve with the water inlet hole of the inside intercommunication of shear box sleeve in the shear box base, the inlet valve is connected with the inlet tube through the air-plug, and the inlet tube links to each other with the bottom of aqua storage tank, be equipped with inlet and gas vent on the thick liquid inlet valve department, external mud injection device on the mud control valve, vent department installs vent valve, shear test mechanism includes the force transmission frame that fixes on the shear box soil body base, the thick liquid that makes, dipstick, is used for covering on the upper cover and the shear box upper cover horizontal shear box and the shear box, and the shear box is equipped with the horizontal shear box and is equipped with the load meter.
The shearing box base, the shearing box sleeve, the mud casing and the mud casing upper cover are fixed together through the screw rod and the screw cap, wherein one end of the screw rod is fixed on the shearing box base, the mud casing upper cover is provided with a perforation corresponding to the screw rod, and the other end of the screw rod passes through the perforation and then fastens the screw cap so as to fix the shearing box base, the shearing box sleeve, the mud casing and the mud casing upper cover together.
The shearing box sleeve is a cylindrical tetragonal body, the shearing box base is in a convex shape, four bottom ends of the shearing box sleeve are connected with the shearing box base through springs, first screw holes are formed in the side walls of the protruding portions of the shearing box base, second screw holes corresponding to the first screw holes are formed in the side walls of the shearing box sleeve, screws are installed in the first screw holes and the second screw holes, the shearing box sleeve is fixed on the shearing box base through the screws, the first screw holes and the second screw holes during sample preparation, water stop gaskets are arranged between the inner wall of the shearing box sleeve and the outer wall of the protruding portions of the shearing box base, water permeable stones, filter paper and soil bodies are sequentially placed in the shearing box sleeve from top to bottom, and mud is placed in the mud protection barrel.
The mud casing and the shearing box sleeve are cylindrical tetragonal bodies with the same size, water stopping grooves are formed in the upper ends of the four sides of the shearing box sleeve, and water stopping belts corresponding to the water stopping grooves are arranged at the lower ends of the four sides of the mud casing.
The lower surface of the slurry casing upper cover is provided with a slurry casing clamping groove, and a rubber sealing ring is placed in the clamping groove.
A water outlet is arranged on one side wall of the water storage tank, and a water draining valve is arranged at the water outlet.
The force transmission frame is fixed on the base of the shear box through a lower screw and an upper screw.
The shearing box base, the shearing box sleeve, the mud casing upper cover and the force transmission frame are all made of stainless steel materials.
The application method of the direct shear test device considering mud skin forming conditions and interface normal displacement comprises the following steps:
(a) Drying the soil body, taking a proper amount of dried soil body, and carrying out specific gravity G s Measuring and then based on the measured specific gravity G s Calculating the mass m of the soil body required to be dried according to the soil body volume V and the void ratio e s As shown in formula (1):
weighing the soil mass with required mass by using an electronic balance for standby;
(b) Placing a water stop gasket at a screw hole of the shear box sleeve, then installing a spring below the shear box sleeve, fixing the lower end of the spring on the shear box base, and fastening the shear box sleeve and the shear box base by using a screw;
(c) Placing permeable stone and filter paper in the shearing box sleeve, compacting soil body in the shearing box sleeve for three times, scraping the soil body surface, installing a mud protection barrel, placing a rubber sealing ring in a groove of an upper cover of the mud protection barrel, and integrally fastening the upper cover of the mud protection barrel, the shearing box sleeve and a base of the shearing box by utilizing a screw rod and a screw cap;
(d) The water inlet valve, the mud control valve and the exhaust valve on the upper cover of the mud protection cylinder and the water discharging valve on the water storage tank are arranged on the base of the shearing box, the water storage tank and the water inlet valve are connected well by the water inlet pipe and the air plug, the water storage tank is filled with water at a certain height, the water inlet valve is opened, after the soil body is saturated, the water inlet valve is closed, and the water storage tank is placed at the same height position of the liquid level and the mud-soil interface;
(e) Opening a mud control valve and an exhaust valve, adjusting an external mud injection device, injecting mud at low pressure, closing the exhaust valve when the exhaust valve has mud flowing out, adjusting the pressure of the mud injection device to be a set value, observing the mud dip dyeing process through a camera, and stopping injection after the mud dip dyeing process is completed;
(f) Removing a screw rod and a screw cap, removing the upper cover of the mud casing and the mud casing, removing screws on a sleeve of the shearing box and a base of the shearing box, installing a force transmission frame on the base of the shearing box, placing the shearing box on a sliding guide rail of a direct shear apparatus, connecting the force transmission frame, placing a concrete slab on the shearing box, placing and opening the PIV device, setting the direct shear apparatus, setting the normal stress to be a set value, setting the shearing rate to be 1mm/min, starting a test, and ending the test when a preset result is reached;
(g) Removing the shear box, changing the soil body void ratio, pressure difference, normal load, shear rate and the like, and repeating the steps, so that the clay-bearing soil-concrete interface characteristic rules under the conditions of different soil body void ratios, pressure difference, normal load, shear rate and the like can be obtained.
The soil body is sandy soil or sand gravel, the porosity ratio of the sandy soil is selected to be 0.50 or 0.5 or 0.60, and the porosity ratio of the sand gravel is selected to be 0.30 or 0.35 or 0.40.
According to the invention, the mud skin sampling mechanism is used for simulating the mud skin forming process of mud dyeing soil body, and making a soil sample with mud skin on the surface, and the shear test mechanism is used for completing the direct shear test with normal displacement of an interface, so that the integration of making the soil sample with mud skin and the direct shear test is realized, the making of the mud dyeing soil sample under different pressure difference conditions and the control of normal displacement in the interface shear test can be realized, and the making of the mud dyeing soil sample is completed in the shear box sleeve, thus the disturbance of the soil sample is avoided, the engineering reality is more similar, the reliability of the test result is effectively improved, and the device is simple to make, low in cost and convenient to operate.
Drawings
FIG. 1 is a schematic diagram of a mud skin sample preparation apparatus according to the present invention.
FIG. 2 is a schematic diagram of an interfacial direct shear test according to the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
Example 1
As shown in fig. 1 and 2, the direct shear test device considering mud skin forming conditions and interface normal displacement comprises a mud skin sample preparation mechanism and a shear test mechanism, wherein the mud skin sample preparation mechanism comprises a shear box and a water storage tank 24 arranged on one side of the shear box, the shear box comprises a shear box base 8, a shear box sleeve 12 fixed on the shear box base, a mud casing 22 fixed on the shear box sleeve and a mud casing upper cover 13 fixed on the mud casing, transparent windows are arranged on the side walls of the shear box sleeve, and can be made of organic glass windows for convenient observation. A spring 2 is arranged between the bottom end of the shearing box sleeve and the shearing box base, normal displacement in the interface shearing process can be controlled through the spring, a water inlet hole 4 communicated with the interior of the shearing box sleeve is arranged in the shearing box base, a water inlet valve 6 is arranged at the inlet of the water inlet hole 4, the water inlet valve is connected with a water inlet pipe 23 through an air plug 7, the water inlet pipe 23 adopts a high-pressure-resistant hose, and the water inlet pipe 23 is connected with the bottom of a water storage tank 24. The upper cover 13 of the mud casing is provided with a mud inlet and an exhaust port, the mud inlet is provided with a mud control valve 16, the mud control valve 16 is externally connected with a mud injection device, the mud injection device can adopt a pressure-adjustable injection pump, and the exhaust port is provided with an exhaust valve 17. The shear test mechanism comprises a force transmission frame 9 fixed on a shear box base, a manufactured mud skin 28, a dip-dyed soil body 30, a concrete slab 32 and a direct shear device, wherein the concrete slab 32 and the direct shear device are used for covering the upper part of a shear box sleeve, a force transmission frame connecting screw hole is formed in the force transmission frame 9, the force transmission frame 9 is fixedly connected with a horizontal loading device of the direct shear device, the shear box base is slidably mounted on a sliding guide rail of the direct shear device, during a shear test, a mud casing upper cover and a mud casing are detached, the concrete slab is covered on the shear box sleeve and the mud skin, a vertical load loading device of the direct shear device acts on the middle position of the upper surface of the concrete slab to fix the concrete slab, and the horizontal loading device of the direct shear device can drive the shear box base to move along the horizontal direction of the sliding guide rail of the direct shear device through the force transmission frame 9 so as to move along the horizontal direction of the whole sample to realize shear.
The shear box base 8, the shear box sleeve 12, the mud casing 22 and the mud casing upper cover 13 are fixed together through the screw rod 14 and the screw cap, wherein one end of the screw rod 14 is fixed on the shear box base 8, the shear box base 8 is provided with a fastening bolt hole 29 for installing the screw rod, the mud casing upper cover 13 is provided with a perforation corresponding to the screw rod, and the other end of the screw rod 14 passes through the perforation and then fastens the screw cap so as to fix the shear box base 8, the shear box sleeve 12, the mud casing 22 and the mud casing upper cover 13 together.
The shear box sleeve 12 is a cylindrical tetragonal body, the shear box base 8 is in a convex shape, four bottom ends of the shear box sleeve are connected with the shear box base through springs, first screw holes are formed in the side walls of the protruding portions of the shear box base, second screw holes 27 corresponding to the first screw holes are formed in the side walls of the shear box sleeve, screws 11 are installed in the first screw holes and the second screw holes, the shear box sleeve 12 is fixed on the shear box base 8 through the screws 11, the first screw holes and the second screw holes during sample preparation, a water stop gasket 18 is arranged between the inner wall of the shear box sleeve and the outer wall of the protruding portions of the shear box base, water permeable stones 3, filter papers 5 and soil bodies 19 are sequentially placed in the shear box sleeve from bottom to top, mud 21 is placed in the mud protection barrel, and the water permeable stones and the filter papers can prevent mud from blocking water inlet holes in the shear box base.
The mud casing and the shearing box sleeve are cylindrical tetragonal bodies with the same size, water stopping grooves 31 are formed in the upper ends of the four sides of the shearing box sleeve, and water stopping belts 20 corresponding to the water stopping grooves are arranged at the lower ends of the four sides of the mud casing.
The lower surface of the upper cover of the mud casing is provided with a mud casing clamping groove, and a rubber sealing ring 15 is placed in the clamping groove.
A water outlet 26 is arranged on one side wall of the water storage tank, a water discharge valve 25 is arranged at the water outlet, the height of the water storage tank is adjustable, and the water storage tank is used for observing the soil body of the covering layer at the lower part of the cylinder.
The force transmission frame is fixed on the shear box base 8 through the lower screw 1 and the upper screw 10, so that the assembly and the disassembly are convenient.
The shearing box base, the shearing box sleeve, the mud casing upper cover and the force transmission frame are all made of stainless steel, so that the test sample is not polluted by rust during the test, and the service life of the device is prolonged.
Example 2
The soil body is sand or sand gravel, the porosity ratio of the sand is selected to be 0.50 or 0.5 or 0.60, the porosity ratio of the sand gravel is selected to be 0.30 or 0.35 or 0.40, and the sand gravel is graded and scaled to the maximum grain diameter of 50mm which is met by the test equipment according to the geotechnical test procedure (SL 237-1999) because the grain size of the sand gravel of the covering layer is larger. The pressure differential may be 50kPa to 600kPa, such as 100kPa, 200kPa, 300kPa, 400kPa, and the normal stress may be 50 to 1000kPa, such as 200kPa, 500kPa, 700kPa, 1000kPa, to take into account the different depth positions, the maximum permeation time is set to 72 hours.
In this example, 100kPa shear displacement is 60mm pressure difference, the sand with a pore ratio of 0.6 is taken as an example, normal stress is 200kPa, shear rate is 1mm/min, shear displacement is taken as an example, and pressure difference is the difference between mud pressure and formation pressure. The slurry used in the test adopts novel positive sealant slurry for the impervious wall, and is fully stirred in the manufacturing process and is fully hydrated and swelled after being placed for 24 hours; before use, the density, the March funnel viscosity and other performances of the slurry are tested, so that the slurry meets the requirements of technical Specification for concrete diaphragm wall construction of Water conservancy and hydropower engineering (SL 174-2014).
The application method of the direct shear test device considering mud skin forming conditions and interface normal displacement comprises the following steps:
(a) Drying the soil body, taking a proper amount of dried soil body, and carrying out specific gravity G s Measuring and then based on the measured specific gravity G s Calculating the mass m of the soil body required to be dried according to the soil body volume V and the void ratio e s As shown in formula (1):
weighing the soil mass with required mass by using an electronic balance for standby;
(b) Placing a water stop gasket 18 at a screw hole of the shear box sleeve, then installing a spring 2 below the shear box sleeve, fixing the lower end of the spring 2 on the shear box base 8, and fastening the shear box sleeve 12 and the shear box base 8 by using a screw 11;
(c) Placing the permeable stone 3 and the filter paper 5 in the shear box sleeve 12, compacting the soil body 19 in the shear box sleeve for three times, scraping the surface of the soil body, installing the slurry casing 22, placing the rubber sealing ring 15 in the groove of the upper cover of the slurry casing, and integrally fastening the upper cover of the slurry casing, the shear box sleeve and the shear box base by utilizing the screw 14 and the screw cap;
(d) The water inlet valve 6 on the base of the shearing box, the mud control valve 16 and the exhaust valve 17 on the upper cover of the mud casing and the water discharge valve 25 on the water storage tank are arranged, the water storage tank 24 and the water inlet valve 6 are connected well by the water inlet pipe 23 and the air plug 7, the water storage tank 24 is filled with water to be at a certain height, the water inlet valve 6 is opened, after the soil body 19 is saturated, the water inlet valve 6 is closed, and the water storage tank 24 is placed at the same height position of the liquid level and the mud-soil interface;
(e) The mud control valve 16 and the exhaust valve 17 are opened, an external mud injection device is regulated, mud 21 is injected at low pressure, when the exhaust valve 17 has mud flowing out, the exhaust valve 17 is closed, the pressure of the mud injection device is regulated to 100kPa, a camera can be adopted in the process to record the whole mud dip dyeing process, and the injection is stopped after the whole mud dip dyeing process is completed;
(f) Removing the screw rod 14 and the screw cap, removing the upper cover 13 of the mud casing and the mud casing 22, removing the screw 11 on the sleeve of the shearing box and the base of the shearing box, mounting the force transmission frame 9 on the base 8 of the shearing box, then placing the base of the shearing box on a sliding guide rail of a direct shear apparatus, connecting the force transmission frame, placing the concrete slab 32 on the shearing box, placing and opening the PIV device according to the concrete slab, setting the direct shear apparatus, enabling a vertical load loading device of the direct shear apparatus to act on the concrete slab with a normal stress of 200kPa, enabling a monotonic shearing rate of a horizontal loading device of the direct shear apparatus to be 1mm/min, enabling the shearing displacement to be 60mm, starting the test by the direct shear apparatus, and ending the test when a preset result is reached;
(g) Removing the shear box, changing the soil body void ratio, pressure difference, normal load, shear rate and the like, and repeating the steps, so that the clay-bearing soil-concrete interface characteristic rules under the conditions of different soil body void ratios, pressure difference, normal load, shear rate and the like can be obtained.
During the test, high-precision linear displacement sensors can be arranged at the upper and lower positions of the interface, the top and the bottom of the shear box, and the influence of monotone and cyclic loading on interface deformation and strength such as mud skin, mud skin thickness, bridge plug area range, soil type, filling compactness, concrete surface roughness and the like can be studied around key mechanical characteristics of the interface such as initial modulus, peak strength, residual strength, normal deformation and the like. And (3) researching the dynamic characteristics of the interface under the cyclic load, and analyzing the influence rules of the initial shear level, the cyclic vibration frequency and the loading amplitude. The method comprises the steps of photographing a direct shearing process in real time through an organic glass 'observation window', analyzing the change rule of a soil body particle displacement field by adopting an PIV test technology, researching the normal deformation rule and the shearing sliding band range of an interface, analyzing the progressive destruction process of the interface, researching the relation between the destruction position of the interface and the mud skin forming condition, and revealing the destruction mechanism of the interface. On the basis of researching the mechanical properties of the mud skin, the influence rule of the mud skin on the mechanical properties of the interface is analyzed.
Claims (8)
1. The direct shear test device is characterized by comprising a mud skin sample preparation mechanism and a shear test mechanism, wherein the mud skin sample preparation mechanism comprises a shear box and a water storage tank arranged on one side of the shear box, the shear box comprises a shear box base, a shear box sleeve fixed on the shear box base, a mud casing fixed on the shear box sleeve and a mud casing upper cover fixed on the mud casing, a transparent window is arranged on the side wall of the shear box sleeve, a spring is arranged between the bottom end of the shear box sleeve and the shear box base, a water inlet valve is arranged at the inlet of the water inlet valve and connected with a water inlet pipe through an air plug, the water inlet pipe is connected with the bottom of the water storage tank, a slurry inlet and an exhaust port are arranged on the upper cover of the mud casing, a slurry control valve is externally connected with a slurry injection device, an exhaust valve is arranged at the exhaust port, the shear test mechanism comprises a force transmission frame fixed on the shear box base, a made mud immersion cover, a dye-level sensor and a shear box and a vertical shear device which are used for loading a concrete slab, and a direct shear tester is arranged on the upper surface of the shear box base, and a horizontal shear box is fixedly arranged on the upper cover, and a shear tester is arranged on the upper surface of the shear box is arranged on the shear box base, and a horizontal shear box is fixedly arranged on the shear box, and a guide rail is fixedly arranged on the shear box is mounted on the shear box, and a vertical shear tester is mounted on the upper cover, and a vertical shear box is mounted on a vertical shear box, and a vertical shear tester is mounted on a vertical shear box and a vertical guide device is mounted on a vertical shear box;
the shearing box base, the shearing box sleeve, the slurry protection cylinder and the slurry protection cylinder upper cover are fixed together through a screw rod and a screw cap, wherein one end of the screw rod is fixed on the shearing box base, a through hole corresponding to the screw rod is formed in the slurry protection cylinder upper cover, and the screw cap is fastened after the other end of the screw rod passes through the through hole so as to fix the shearing box base, the shearing box sleeve, the slurry protection cylinder and the slurry protection cylinder upper cover together;
the shearing box sleeve is a cylindrical tetragonal body, the shearing box base is in a convex shape, four bottom ends of the shearing box sleeve are connected with the shearing box base through springs, first screw holes are formed in the side walls of the protruding portions of the shearing box base, second screw holes corresponding to the first screw holes are formed in the side walls of the shearing box sleeve, screws are installed in the first screw holes and the second screw holes, the shearing box sleeve is fixed on the shearing box base through the screws, the first screw holes and the second screw holes during sample preparation, water stop gaskets are arranged between the inner wall of the shearing box sleeve and the outer wall of the protruding portions of the shearing box base, water permeable stones, filter paper and soil bodies are sequentially placed in the shearing box sleeve from top to bottom, and mud is placed in the mud protection barrel.
2. The direct shear test device considering mud skin formation conditions and interface normal displacement according to claim 1, wherein the mud casing and the shear box sleeve are cylindrical tetragonal bodies with equal size, water stopping grooves are arranged at the upper ends of four sides of the shear box sleeve, and water stopping belts corresponding to the water stopping grooves are arranged at the lower ends of four sides of the mud casing.
3. The direct shear test device considering mud skin formation conditions and interface normal displacement according to claim 1, wherein a mud casing clamping groove is formed in the lower surface of the mud casing upper cover, and a rubber sealing ring is placed in the clamping groove.
4. The direct shear test device considering mud skin formation conditions and interface normal displacement according to claim 1, wherein a water outlet is arranged on one side wall of the water storage tank, and a water drain valve is arranged at the water outlet.
5. The direct shear test device of claim 1, wherein the force-transmitting frame is fixed to the shear box base by a lower screw and an upper screw, taking into account mud skin formation conditions and interface normal displacement.
6. The direct shear test device considering mud skin formation conditions and interface normal displacement according to claim 1, wherein the shear box base, the shear box sleeve, the mud casing upper cover and the force transmission frame are all made of stainless steel.
7. The method of using a direct shear test device according to any of claims 1-6, wherein the conditions for mud skin formation and normal displacement of the interface are considered, comprising the steps of:
(a) Drying the soil body and taking a proper amount of the soil bodyThe dried soil body has specific gravity G s Measured and then based on the measured specific gravity G s Calculating the mass m of the soil body required to be dried according to the soil body volume V and the void ratio e s As shown in formula (1):
weighing the soil mass with required mass by using an electronic balance for standby;
(b) Placing a water stop gasket at a screw hole of the shear box sleeve, then installing a spring below the shear box sleeve, fixing the lower end of the spring on the shear box base, and fastening the shear box sleeve and the shear box base by using a screw;
(c) Placing permeable stone and filter paper in the shearing box sleeve, compacting soil body in the shearing box sleeve for three times, scraping the soil body surface, installing a mud protection barrel, placing a rubber sealing ring in a groove of an upper cover of the mud protection barrel, and integrally fastening the upper cover of the mud protection barrel, the shearing box sleeve and a base of the shearing box by utilizing a screw rod and a screw cap;
(d) The water inlet valve, the mud control valve and the exhaust valve on the upper cover of the mud protection cylinder and the water discharging valve on the water storage tank are arranged on the base of the shearing box, the water storage tank and the water inlet valve are connected well by the water inlet pipe and the air plug, the water storage tank is filled with water at a certain height, the water inlet valve is opened, after the soil body is saturated, the water inlet valve is closed, and the water storage tank is placed at the same height position of the liquid level and the mud-soil interface;
(e) Opening a mud control valve and an exhaust valve, adjusting an external mud injection device, injecting mud at low pressure, closing the exhaust valve when the exhaust valve has mud flowing out, adjusting the pressure of the mud injection device to be a set value, observing the mud dip dyeing process through a camera, and stopping injection after the mud dip dyeing process is completed;
(f) Removing a screw rod and a screw cap, removing the upper cover of the mud casing and the mud casing, removing screws on a sleeve of the shearing box and a base of the shearing box, installing a force transmission frame on the base of the shearing box, placing the shearing box on a sliding guide rail of a direct shear apparatus, connecting the force transmission frame, placing a concrete slab on the shearing box, placing and opening the PIV device, setting the direct shear apparatus, setting the normal stress to be a set value, setting the shearing rate to be 1mm/min, starting a test, and ending the test when a preset result is reached;
(g) And removing the shear box, changing the soil body pore ratio, the pressure difference, the normal load and the shear rate, and repeating the steps, so that the clay-bearing soil-concrete interface characteristic rules under the conditions of different soil body pore ratios, pressure differences, normal loads and shear rates can be obtained.
8. The method of claim 7, wherein the soil is sand or gravel, the void ratio of the sand is selected to be 0.50 or 0.60, and the void ratio of the gravel is selected to be 0.30 or 0.35 or 0.40.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110395530.0A CN113049342B (en) | 2021-04-13 | 2021-04-13 | Direct shear test device and method considering mud skin formation conditions and interface normal displacement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110395530.0A CN113049342B (en) | 2021-04-13 | 2021-04-13 | Direct shear test device and method considering mud skin formation conditions and interface normal displacement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113049342A CN113049342A (en) | 2021-06-29 |
| CN113049342B true CN113049342B (en) | 2023-09-22 |
Family
ID=76519206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110395530.0A Active CN113049342B (en) | 2021-04-13 | 2021-04-13 | Direct shear test device and method considering mud skin formation conditions and interface normal displacement |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113049342B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11303301A (en) * | 1998-04-17 | 1999-11-02 | Kajima Corp | Shearing specimen and manufacture of shearing specimen |
| CN106124341A (en) * | 2016-06-20 | 2016-11-16 | 三峡大学 | The field direct shear test sample preparation of a kind of Tu Yan interface and assay device |
| CN108106949A (en) * | 2017-12-04 | 2018-06-01 | 深圳大学 | Method and symmetrical direct shear apparatus for stake Soil Interface shearing strength in-situ test |
| CN108828195A (en) * | 2018-03-14 | 2018-11-16 | 同济大学 | It is a kind of to simulate the laboratory testing rig returned on pile-end post-grouting slurries and test method |
| CN208206694U (en) * | 2018-03-23 | 2018-12-07 | 深圳宏业基岩土科技股份有限公司 | A kind of pile-soil interface direct shear test device of multilayer |
| CN110895233A (en) * | 2019-12-16 | 2020-03-20 | 西南交通大学 | Dynamic penetration film forming test device and measurement method for slurry balance shield slurry |
| CN111323315A (en) * | 2020-03-23 | 2020-06-23 | 郑州大学 | Direct shear test device |
| WO2021042322A1 (en) * | 2019-09-04 | 2021-03-11 | 浙江大学 | Visual interface-based direct shear apparatus capable of taking temperature and seepage effect into consideration |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105973722B (en) * | 2016-07-26 | 2017-03-15 | 山东科技大学 | The constant normal stiffness shearing test device of rock discontinuum and its test method |
-
2021
- 2021-04-13 CN CN202110395530.0A patent/CN113049342B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11303301A (en) * | 1998-04-17 | 1999-11-02 | Kajima Corp | Shearing specimen and manufacture of shearing specimen |
| CN106124341A (en) * | 2016-06-20 | 2016-11-16 | 三峡大学 | The field direct shear test sample preparation of a kind of Tu Yan interface and assay device |
| CN108106949A (en) * | 2017-12-04 | 2018-06-01 | 深圳大学 | Method and symmetrical direct shear apparatus for stake Soil Interface shearing strength in-situ test |
| CN108828195A (en) * | 2018-03-14 | 2018-11-16 | 同济大学 | It is a kind of to simulate the laboratory testing rig returned on pile-end post-grouting slurries and test method |
| CN208206694U (en) * | 2018-03-23 | 2018-12-07 | 深圳宏业基岩土科技股份有限公司 | A kind of pile-soil interface direct shear test device of multilayer |
| WO2021042322A1 (en) * | 2019-09-04 | 2021-03-11 | 浙江大学 | Visual interface-based direct shear apparatus capable of taking temperature and seepage effect into consideration |
| CN110895233A (en) * | 2019-12-16 | 2020-03-20 | 西南交通大学 | Dynamic penetration film forming test device and measurement method for slurry balance shield slurry |
| CN111323315A (en) * | 2020-03-23 | 2020-06-23 | 郑州大学 | Direct shear test device |
Non-Patent Citations (5)
| Title |
|---|
| Shear Behavior of Wheat-Concrete Interface during Monotonic and Cyclic Loading;Changnv Zeng et al.;Complexity;全文 * |
| 不同含水率泥皮对接触面力学特性影响的试验研究;张治军;饶锡保;丁红顺;吴良平;;长江科学院院报(第05期);全文 * |
| 不同泥皮厚度下黄土—混凝土接触面剪切试验;张磊等;地下空间与工程学报;第16卷(第增刊2期);全文 * |
| 土-结构物接触面试验研究进展综述;陈海康等;材料与技术(第9期);全文 * |
| 水泥土泥皮下土与结构接触面的单剪特性;彭凯;朱俊高;冯树荣;蔡昌光;朱晟;;重庆大学学报(第08期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113049342A (en) | 2021-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102175585B (en) | Method for testing permeability stability of sand gravel material | |
| CN101603913B (en) | Device and method for testing permeability coefficient of cement soil | |
| CN111982699B (en) | Unsaturated soil compression characteristic and permeability characteristic test device | |
| CN108036985B (en) | Device and method for manufacturing split grouting slurry vein and detecting permeability coefficient | |
| CN107167410B (en) | Periodic round-trip seepage experimental device and method | |
| CN110672497A (en) | Multifunctional infiltration piping tester | |
| CN109001098B (en) | Soil instantaneous permeability characteristic tester and soil permeability characteristic calculation method | |
| CN108918390B (en) | Device and method for forming mud film and measuring consolidation amount and air inflow of mud film | |
| CN206618667U (en) | It is a kind of to be used for the experimental rig of property evolution under simulation concrete cut-pff wall Service Environment | |
| CN109959553A (en) | Consolidation-infiltration-shear wave velocity coupling experiment device | |
| CN113218841A (en) | Device and method for testing reverse filtration characteristic of geotextile | |
| CN113049342B (en) | Direct shear test device and method considering mud skin formation conditions and interface normal displacement | |
| CN103033460B (en) | The determinator of soil body horizontal osmotic coefficient and method thereof | |
| CN212459324U (en) | Coarse sand horizontal seepage model box | |
| CN106768153B (en) | A kind of slurry consolidation cubical contraction test device and method of testing | |
| CN116907972A (en) | Coarse-grained soil large triaxial tester with seepage pressure control function | |
| CN112195986A (en) | Offshore barrel type foundation simulation test model device and penetration test method | |
| CN217605591U (en) | Simulation device for broken stone reverse filter material clogging test | |
| CN115290533A (en) | Centrifugal model test device and method for simulating soil body permeation | |
| CN212459323U (en) | Vertical seepage model box for coarse-grained calcareous sand | |
| CN113640188B (en) | Testing device and method for simulating in-situ stress field of clay stratum around pile | |
| CN108507929A (en) | The pervious concrete pervasion test device and its test method of level pressure gas-flow closure | |
| CN110082182B (en) | Preparation device of saturated clay samples at different depths and determination method of pore water types and content of saturated clay samples | |
| CN112504939A (en) | Device and method for measuring compressibility and permeability of dredged mud with high water content | |
| CN114354451A (en) | Unsaturated soil high-pressure grouting test device and measuring system thereof |
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 |