CN109269910B - Triaxial freeze thawing test device for piles and anchor rods - Google Patents
Triaxial freeze thawing test device for piles and anchor rods Download PDFInfo
- Publication number
- CN109269910B CN109269910B CN201811367399.1A CN201811367399A CN109269910B CN 109269910 B CN109269910 B CN 109269910B CN 201811367399 A CN201811367399 A CN 201811367399A CN 109269910 B CN109269910 B CN 109269910B
- Authority
- CN
- China
- Prior art keywords
- soil sample
- pressure
- simulation chamber
- pile
- sample
- 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
- 238000012360 testing method Methods 0.000 title claims abstract description 74
- 238000010257 thawing Methods 0.000 title claims abstract description 39
- 239000002689 soil Substances 0.000 claims abstract description 104
- 238000004088 simulation Methods 0.000 claims abstract description 54
- 238000006073 displacement reaction Methods 0.000 claims abstract description 34
- 238000012806 monitoring device Methods 0.000 claims abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 81
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 26
- 238000002347 injection Methods 0.000 claims description 17
- 239000007924 injection Substances 0.000 claims description 17
- 229910052742 iron Inorganic materials 0.000 claims description 13
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000002474 experimental method Methods 0.000 description 16
- 238000000034 method Methods 0.000 description 12
- 239000011148 porous material Substances 0.000 description 10
- 230000008014 freezing Effects 0.000 description 9
- 238000007710 freezing Methods 0.000 description 9
- 238000004873 anchoring Methods 0.000 description 7
- 238000011065 in-situ storage Methods 0.000 description 5
- 238000012544 monitoring process Methods 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005429 filling process Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
Classifications
-
- 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
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/18—Performing tests at high or low temperatures
-
- 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
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
-
- 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
- G01N3/60—Investigating resistance of materials, e.g. refractory materials, to rapid heat changes
-
- 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
- G01N2203/022—Environment of the test
- G01N2203/0222—Temperature
- G01N2203/0224—Thermal cycling
-
- 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
- G01N2203/022—Environment of the test
- G01N2203/023—Pressure
- G01N2203/0232—High pressure
-
- 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
- G01N2203/025—Geometry of the test
- G01N2203/0256—Triaxial, i.e. the forces being applied along three normal axes of the specimen
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a triaxial freeze thawing test device for piles and anchor rods, which comprises a supporting platform, wherein a dynamic load monitoring device is arranged above the supporting platform, a soil sample environment simulation chamber is arranged on the upper surface of the supporting platform, a soil body is arranged in the soil sample environment simulation chamber, and a test piece is inserted into the soil body. The pile triaxial test device has the beneficial effects that the load force application mode is more in line with the actual working condition compared with the existing pile triaxial test. Through set up power loading device in supporting beam's lower bottom surface, the device can provide vibrations load to when simulating actual stake received vibration load and the repeated load of vehicle, additional displacement and the accumulated deformation volume of arousing the stake can carry out dynamic drawing to the stock simultaneously, solves in the past stock and draws testing arrangement, only can exert the problem of linear pulling force or impact load to the stock, makes experimental data more persuade.
Description
Technical Field
The invention relates to the field of rock and soil reinforcement engineering, in particular to a triaxial freeze-thawing test device for piles and anchor rods.
Background
The pile is used as a structure for increasing the bearing capacity of the foundation, and is widely applied to underground roadbed engineering, foundation engineering, bridge engineering and the like. And the application range of the piles is wider and wider, the piles are more and more applied in cold areas, and the bearing capacity change of the piles under the freezing and thawing cycle condition is considered to be a focus of attention.
Along with the continuous expansion of the application scope of the pile, the pile is applied to various engineering fields, the influence of freeze thawing cycle, vibration load and repeated load on the pile bearing capacity is also proposed, when the pile is applied to roadbed engineering in cold areas, the roadbed and other structures generate frost heaving, thawing and sinking after the freeze thawing cycle, and when the pile is subjected to vibration load and repeated load of vehicles, the additional displacement and accumulated deformation of the pile can be caused. Therefore, when the bearing capacity of the pile is calculated, the bearing capacity and displacement of the pile under the static load in the initial state are unreasonable, the actual requirements cannot be met, and the bearing capacity and displacement research of the pile under the freeze thawing cycle or under the dynamic load is extremely meaningful. The pile body has different confining pressures and bearing capacities, and the pile body has different confining pressures and bearing capacities, so that the pile bearing capacity research under different confining pressures by adopting the freezing and thawing cycle times is of great practical engineering significance.
The anchor bolt support is used as an economic and effective reinforcement mode and is widely applied to underground engineering, slope engineering, structural anti-floating engineering and deep foundation pit engineering. The anchor bolt support is increasingly applied in cold areas, and the influence of freeze thawing cycles on the shear strength generated by the adhesion of the anchor bolt and surrounding soil is also increasingly noticed. The anchor rod can be successfully anchored on the stratum, and depends on the resistance of the bottom layer to the anchor rod being pulled out, wherein the resistance is not only related to the type of soil body, but also related to the stress state of the soil body, and after the freeze thawing cycle, the soil body structure is changed, so that the cohesive force between the two is different. Therefore, the anchor rod pulling resistance test under different freeze thawing cycles and in different confining pressure states is very necessary.
Whether the bearing capacity of the pile, the anchoring performance of the anchor rod or the dynamic response under different freezing and thawing conditions or under different stress states is researched, the in-situ test and the model test are the most direct and effective means. However, in-situ test is often affected by environmental conditions and various unstable factors, so that the in-situ test is difficult to develop, and compared with in-situ test, the in-situ test has strong experiment controllability and small external interference, and is favorable for finding rules. For the model test of the bearing capacity performance and the dynamic response of the pile in the soil body under the action of dynamic load and the model test of the anchoring performance and the dynamic response of the anchor rod in the soil body under different stress states, the existing test device can not well simulate the actual situation and is not provided with the test device for effectively combining the freeze thawing cycle and the confining pressure, so the invention is extremely significant.
Disclosure of Invention
The invention aims to solve the problem that the existing test instrument cannot completely simulate surrounding soil body confining pressure of a pile or an anchor rod in actual engineering after repeated freeze thawing cycles, so that bearing capacity or pulling resistance is affected.
The technical scheme of the invention for achieving the purpose is that the triaxial freeze thawing test device for the piles and the anchor rods comprises a supporting platform, wherein a dynamic load monitoring device is arranged above the supporting platform, a soil sample environment simulation chamber is arranged on the upper surface of the supporting platform, a soil body is arranged in the soil sample environment simulation chamber, and a test piece is inserted into the soil body;
the support platform includes: the base and the plurality of support columns are uniformly distributed on the outer ring of the upper surface of the base;
the dynamic load monitoring device comprises: the device comprises a base, a supporting beam, a power loading device, a pressure sensor, a ring buckle and a displacement sensor, wherein the supporting beam is arranged above the base and connected with a plurality of supporting columns, the power loading device is fixed at the center position of the lower bottom surface of the supporting beam, the pressure sensor is connected with the power loading device and positioned below the power loading device, the ring buckle is arranged at the tail end of the pressure sensor, and the displacement sensor is fixed at the lower bottom surface of the supporting beam and positioned at one side of the power loading device;
The soil sample environment simulation chamber comprises: the simulation chamber comprises an outer annular wall, an inner annular wall which is coaxial with the outer annular wall and is positioned in the outer annular wall, and a simulation chamber top cover which is arranged at the tops of the outer annular wall and the inner annular wall, wherein an outer cavity water filling port and an inner cavity water filling port are formed in the simulation chamber top cover;
the soil body comprises: the device comprises a soil sample, a rubber film wrapping the outer layer of the soil sample, a sample chassis arranged on the lower bottom surface of the soil sample, and a sample cover arranged on the upper surface of the soil sample;
specifically, the test piece is inserted in the center of the soil sample and is in direct or indirect contact with the power loading device.
Specifically, the supporting cross beam is connected with a plurality of supporting upright posts through nuts.
Specifically, be the outer chamber between outer rampart with interior rampart, outer chamber water injection mouth set up in on the simulation room top cap and with the position that the outer chamber corresponds, interior rampart's inside is the inner chamber, the inner chamber water injection mouth set up in on the simulation room top cap and with the position that the inner chamber corresponds.
Further, the upper equipartition of outer rampart has the dead lever, the lower bottom surface of simulation room top cap is fixed with the sample lid dead lever, the sample lid dead lever is located simulation room top cap with between the sample lid, peg graft on the simulation room top cap and have temperature sensor, temperature sensor is located the inner chamber, the inner chamber is provided with the drain pipe, the drain pipe intercommunication the sample lid with the sample chassis.
Further, the lower surface of the sample cover and the middle position contacting the soil sample are hollow.
One embodiment is that the test piece is a pile, the pile is located inside the soil sample, a dowel bar is arranged above the pile, the top end of the dowel bar is in contact with the pressure sensor, and the bottom end of the dowel bar is in contact with the pile.
Specifically, the position that one end of dowel steel just with pressure sensor is close to is fixed with the iron sheet, the iron sheet with displacement sensor's terminal contact, and remain throughout in the experimentation with displacement sensor contacts, the dowel steel with pressure sensor contacts but does not connect.
In another embodiment, the test piece is an anchor rod, the lower end of the anchor rod is located inside the soil sample, the upper end of the anchor rod passes through the top cover of the simulation chamber to be in contact with the pressure sensor, and the top of the anchor rod is connected with the pressure sensor through the ring buckle.
Specifically, the confining pressure back pressure device comprises: the device comprises a pressure control base, a slideway arranged on the pressure control base, a motor and a sliding rod arranged on the slideway, a pressure control cavity arranged at the tail end of the sliding rod and connected with the sliding rod, and a pressure control water inlet and a pressure control water outlet arranged at one end of the pressure control cavity.
Specifically, the lateral surface of base has seted up intercommunication the confined pressure controller connecting hole, hole pressure sensor connecting hole, pressure hole and the inner chamber wash port of soil sample environment simulation room inner chamber, and intercommunication the outer chamber wash port, the water bath temperature controller interface of the outdoor chamber of soil sample environment simulation.
The pile triaxial test device has the beneficial effects that 1. The load force application mode is more in line with the actual working condition compared with the existing pile triaxial test. Through set up power loading device in supporting beam's lower bottom surface, the device can provide vibrations load to when simulating actual stake received vibration load and the repeated load of vehicle, additional displacement and the accumulated deformation volume of arousing the stake can carry out dynamic drawing to the stock simultaneously, solves in the past stock and draws testing arrangement, only can exert the problem of linear pulling force or impact load to the stock, makes experimental data more persuade.
2. The structural design of the sample cover is more reasonable, and the accuracy of experimental data is improved. The cavity is reserved in the middle of the lower bottom surface of the sample cover, the sample cover adopts a variable cross section, the top surface of the sample is kept to be adjacent to a pile or an anchor rod within a certain range and is not constrained, the whole sample cover adopts a ring shape, the situation that the surrounding soil body is constrained by external force and the load drawing stress of the anchor rod is disturbed in the experimental process is avoided, and therefore the anchoring performance of the experimental device when the anchor rod is detected to bear the pulling resistance is more scientific.
3. The setting of outer chamber water bath circulation makes the range of application of the data that this experimental apparatus obtained more extensive. The temperature of the outer cavity is changed through the water bath circulation of the outer cavity, so that the times of freezing and thawing cycle of a soil sample and different temperatures can be controlled, and experiments are carried out under different environmental conditions, so that the reliability of experimental data is higher, and the application range of the experimental data is wider.
Drawings
FIG. 1 is a schematic structural view of a pile freeze thawing experimental device of the invention;
FIG. 2 is a schematic structural diagram of an anchor rod freeze thawing experimental device of the invention;
FIG. 3 is a schematic view of the whole structure of the confining pressure back pressure device of the invention;
FIG. 4 is a schematic view of the structure of the sample cover of the present invention;
FIG. 5 is a schematic top plan view of the simulated room roof structure of the present invention;
FIG. 6 is a schematic top view of a sample chassis structure of the present invention;
in the figure, 1, a supporting platform; 101. a base; 102. a support column; 103. an outer cavity drain hole; 104. a pressure hole; 105. an inner cavity drain hole; 106. a water bath temperature controller interface; 107. a hole pressure sensor is connected with the hole; 108. a confining pressure controller connecting hole; 2. a dynamic load monitoring device; 201. a support beam; 202. a power loading device; 203. a pressure sensor; 204. a ring buckle; 205. a displacement sensor; 206. a nut; 3. a soil sample environment simulation chamber; 301. an outer annular wall; 302. an inner annular wall; 303. simulating a roof; 304. an outer cavity water filling port; 305. an inner cavity water filling port; 306. an outer cavity; 307. an inner cavity; 308. a fixed rod; 309. a sample cover fixing rod; 4. soil mass; 401. a soil sample; 402. a rubber film; 403. a sample chassis; 404. a sample cover; 5. a test piece; 501. a pile; 502. a dowel bar; 503. iron sheet; 504. a bolt; 6. a temperature sensor; 7. a drain pipe; 8. a confining pressure back pressure device; 801. a pressure control base; 802. a slideway; 803. a motor; 804. a slide bar; 805. a pressure control cavity; 806. controlling the pressure into the water gap; 807. and the pressure control water outlet.
Detailed Description
The invention is specifically described below with reference to the accompanying drawings, as shown in fig. 1-6, a triaxial freeze thawing test device for piles and anchor rods comprises a supporting platform 1, wherein a dynamic load monitoring device 2 is arranged above the supporting platform 1, the dynamic load monitoring device 2 can apply load to the piles or the anchor rods and detect the counter force of the dynamic load monitoring device, the dynamic load monitoring device can be used for simulating the vibration load of the piles or the anchor rods in practice, the load bearing capacity of the piles or the anchor rods under the vibration load is detected, the upper surface of the supporting platform 1 is provided with a soil sample environment simulation chamber 3, the soil sample environment simulation chamber 3 is used for simulating the surrounding environment of a soil sample, the load bearing capacity of the piles and the anchor rod anchoring force change under different freeze thawing cycles in different depths in cold regions, a soil body 4 is arranged in the soil sample environment simulation chamber 3, a test piece 5 is inserted into the soil body 4, the test piece 5 is the pile or the anchor rod in practice, and one side of the supporting platform 1 is provided with a back pressure device 8; the support platform 1 comprises: the power loading device comprises a base 101 and a plurality of supporting columns 102 which are uniformly distributed on the outer ring of the upper surface of the base 101, wherein the supporting columns 102 are used for supporting the power loading device 202 and enabling the power loading device to be capable of adjusting the height of the supporting columns 102; the dynamic load monitoring device 2 includes: the test piece test device comprises a support beam 201, a power loading device 202, a pressure sensor 203, a ring buckle 204 and a displacement sensor 205, wherein the support beam 201 is arranged above a base 101 and connected with a plurality of support columns 102, the power loading device 202 is fixed at the center position of the lower bottom surface of the support beam 201, the pressure sensor 203 is connected with the power loading device 202 and is positioned below the power loading device 202, the ring buckle 204 is arranged at the tail end of the pressure sensor 203, the displacement sensor 205 is fixed at the lower bottom surface of the support beam 201 and is positioned at one side of the power loading device 202, the pressure sensor 203 is of a model number of TKA-10000kg, the support beam 201 is used for providing a suspended platform for other elements, the height of all elements connected with the support beam 201 is changed through adjusting the height of the support beam 201, the power loading device 202 is used for applying load to the test piece 5, the vibration load applied to the test piece under the actual condition of the test engineering is simulated, the pressure sensor 203 is used for monitoring the load force of the power loading device 202, the ring buckle 204 is used for connecting the test piece with a rod under the test requirement, the test piece under the condition, the test piece 205 is provided with the test piece with the measuring range accuracy of 200mm and the test piece under the test piece displacement is 0.01;
As shown in fig. 1 to 6, the soil sample environment simulation chamber 3 includes: the soil sample environment simulation chamber comprises an outer annular wall 301, an inner annular wall 302, a simulation chamber top cover 303, an outer cavity water injection port 304 and an inner cavity water injection port 305, wherein the inner annular wall 302 is coaxial with the outer annular wall 301 and is positioned in the outer annular wall 301, the simulation chamber top cover 303 is arranged at the top of the outer annular wall 301 and the inner annular wall 302, the outer annular wall 301 and the inner annular wall 302 are coaxially arranged, the soil sample environment simulation chamber 3 is divided into a plurality of spaces, and water with different temperatures or pressures is added through the outer cavity water injection port 304 or the inner cavity water injection port 305, so that simulation experiments with different environment temperatures or pressures are carried out on soil 4 at the center position of the soil mass; The soil body 4 comprises: the soil sample 401, the rubber film 402 wrapping the outer layer of the soil sample 401, the sample chassis 403 arranged on the lower bottom surface of the soil sample 401 and the sample cover 404 arranged on the upper surface of the soil sample 401, because the soil components in different areas are different, in order to ensure that the experimental result is more fit with the actual requirement, the same soil sample as the actual field can be adopted, the accuracy of the experiment is ensured, and the rubber film 402 is used for gathering and forming the loose soil sample, so that the loose distribution of the loose soil sample is avoided from being unfavorable for the experiment; the test piece 5 is inserted in the center of the soil sample 401 and is in direct or indirect contact with the power loading device 202, the power loading device 202 generates vibration load to give the test piece 5, and the bearing capacity or anchoring force of the test piece with different depths under different freezing and thawing conditions is judged by monitoring the displacement and counter force of the test piece 5 under the action of the vibration load. The supporting beam 201 is connected with a plurality of supporting columns 102 through nuts, through holes corresponding to the supporting columns 102 are formed in the periphery of the supporting beam 201, threads are formed at the part, which is in contact with the supporting beam 201, of one end of the supporting beam 102, as shown in fig. 1-2, the supporting beam 201 passes through the supporting columns 102, and meanwhile, the upper bottom surface and the lower bottom surface of the supporting beam 201 are connected with the supporting columns 102 through nuts 206, so that the height of the supporting beam 201 is fixed between the upper nut 206 and the lower nut 206, and when the height of the supporting beam 201 needs to be adjusted, The nut 206 is loosened, the height of the supporting beam 201 is redetermined, and then the nut 206 is tightened, so that the height of the supporting beam 201 can be arbitrarily adjusted. an outer cavity 306 is arranged between the outer annular wall 301 and the inner annular wall 302, the outer cavity water injection port 304 is arranged on the top cover 303 of the simulation chamber and corresponds to the outer cavity 306, water is injected into the outer cavity 306, the temperature of the water is controlled, so that the environment temperature of soil samples at different freezing and thawing temperatures is simulated, an inner cavity 307 is arranged inside the inner annular wall 302, the inner cavity water injection port 305 is arranged on the top cover 303 of the simulation chamber and corresponds to the inner cavity 307, water is injected into the inner cavity 307, and the water pressure is controlled, so that the environment pressure of the soil samples at different geological pressure states is simulated; The outer annular wall 301 is provided with a fixing rod 308 for ensuring the stability of the outer annular wall 301 and providing a firm and stable experimental environment for the soil sample environment simulation chamber, the lower bottom surface of the simulation chamber top cover 303 is provided with a sample cover fixing rod 309, the sample cover fixing rod 309 is positioned between the simulation chamber top cover 303 and the sample cover 404 and is used for pressing the sample cover 404 to ensure that the sample cover 404 is tightly fastened on the soil sample 401, the sample chassis 403 is provided with a plurality of threaded holes corresponding to the fixing rod 309, the fixing rod passes through the simulation chamber top cover 303 from top to bottom and is connected on the sample chassis 403 through threads, The temperature sensor 6 is inserted into the top cover 303 of the simulation room, the temperature sensor 6 is located in the inner cavity 307 and used for monitoring the temperature change of the inner cavity, the inner cavity 307 is used for simulating the freezing and thawing condition, so that the inner cavity 307 is provided with the temperature sensor 6 for better monitoring the freezing and thawing temperature change, the inner cavity 307 is provided with the drain pipe 7, the drain pipe 7 is communicated with the sample cover 404 and the sample chassis 403, and the drain pipe 7 is used for draining water generated by a soil sample in the experimental process into a drain hole of the sample chassis 403 and then draining the experimental equipment, so that the experimental effect is prevented from being influenced; The middle position of the lower surface of the sample cover 404, which is in contact with the soil sample 401, is a cavity, namely, the sample cover 404 is annular, and because the position is the interface between the test piece 5 and the soil sample 401, which is in contact with the air, the soil sample 401 at the position inevitably affects the experimental result if being constrained by the external force of the sample cover 404, so that the surrounding soil body is prevented from being constrained by the external force, and the anchoring performance of the test piece under the pulling resistance is more scientific.
As shown in fig. 1, the test piece 5 is a pile 501, the pile 501 is located inside the soil sample 401, a dowel bar 502 is arranged above the pile 501, the top end of the dowel bar 502 is in contact with the pressure sensor 203, and the bottom end of the dowel bar 502 is in contact with the pile 501; an iron sheet 503 is fixed at one end of the dowel bar 502 and is close to the pressure sensor 203, the iron sheet 503 is in contact with the tail end of the displacement sensor 205, and is always in contact with the displacement sensor 205 in the experimental process, because the iron sheet 503 is fixed with the dowel bar 502, the dowel bar 502 is in contact with the pile 501, the motion displacement of the iron sheet 503 is the motion displacement of the pile 501, the displacement of the pile 501 is monitored in the process of applying a vibration load to the pile 501, and the bearing capacity change of piles with different depths under different freeze thawing conditions can be known, the dowel bar 502 is in contact with the pressure sensor 203 but not connected, and only is in contact with and not connected with the displacement sensor 205 because the pile is only subjected to a pressure load in the actual use, and therefore the pile 501 and the dowel bar 502 are required to be in contact with and not connected with the displacement sensor 205.
As shown in fig. 2, the test piece 5 is an anchor rod 504, the lower end of the anchor rod 504 is located inside the soil sample 401, and the upper end of the anchor rod 504 passes through the top cover 303 of the simulation chamber and contacts with the pressure sensor 203, the top of the anchor rod 504 is connected with the pressure sensor 203 through the loop 204, and the anchor rod 504 is not only subjected to a load force but also to an upward tensile force in practical application, so that the anchor rod 504 is connected with the pressure sensor 203, and the anchor rod 504 is pulled in the process of vibrating the power loading device 202, so that the anchor force variation of the anchor rod at different depths can be monitored under different freezing and thawing conditions.
As shown in fig. 3, the confining pressure back pressure device 8 may directly adopt the confining pressure control system of the gds company in the united kingdom, which includes: the device comprises a pressure control base 801, a slideway 802 arranged on the pressure control base 801, a motor 803 and a sliding rod 804 arranged on the slideway 802, a pressure control cavity 805 arranged at the tail end of the sliding rod 804 and connected with the sliding rod, a pressure control water inlet 806 and a pressure control water outlet 807 arranged at one end of the pressure control cavity 805, wherein the pressure control water inlet 806 is used for supplementing water in the pressure control cavity 805 in the early stage of an experiment, and it is required to adopt two confining pressure counter-pressure devices 8 at the same time in the practical experiment, and the two devices independently work, wherein one of the devices is used as a confining pressure device, the pressure control water outlet 807 is communicated with a confining pressure controller connecting hole 108 through a rubber hose, the motor 803 rotates positively to drive the sliding rod 804 to squeeze the pressure control cavity 805, and water in the pressure control cavity 805 enters the inner cavity 307 through the confining pressure controller connecting hole 108, so that the water pressure in the inner cavity 307 is increased, confining pressure is applied to a soil sample (the working principle is equivalent to medical needle tube, the motor provides power, and the sliding rod is a push rod presses the water in the pressure control cavity; the other is used as a back pressure device, a pressure control water outlet 807 is communicated with a pressure hole 104 through a rubber hose, a motor 803 is reversed to drive a sliding rod 804 to draw out a pressure control cavity 805, water generated by extrusion in a soil sample enters the pressure control cavity 805 through the pressure hole 104, so that the hyperstatic pore water pressure in the soil sample (soil body is subjected to confining pressure to generate hyperstatic pore water pressure, the hyperstatic pore water pressure is completely dissipated through adjustment of the back pressure device, the current hyperstatic pore water pressure can be monitored through a pore pressure sensor at a pore pressure sensor connecting hole 107), wherein the motor is a servo stepping motor, the model can be TKA-TTS-200, and the specification of a corresponding confining pressure volume controller (namely the sliding rod and the pressure control cavity) is specifically 6MPa/8000ml.
As shown in fig. 1-2, the outer side surface of the base 101 is provided with a confining pressure controller connecting hole 108, a hole pressure sensor connecting hole 107, a pressure hole 104 and an inner cavity water draining hole 105 which are communicated with the inner cavity of the soil sample environment simulation chamber 3, an outer cavity water draining hole 103 and a water bath temperature controller interface 106 which are communicated with the outer cavity of the soil sample environment simulation chamber 3, the confining pressure controller connecting hole 108 is used for being connected with an external confining pressure device, the confining pressure device supplements water to the inner cavity so as to increase the water pressure of the inner cavity, the effect of confining pressure applied to the soil sample by the inner cavity water body is achieved, the hole pressure sensor connecting hole 107 is used for being connected with an external hole pressure sensor (the hole pressure sensor can be used for measuring the range of 0-2 MPa, the precision of 0.1% and the power supply of 10 VDC), the pore water pressure of the soil sample is monitored, the pressure hole 104 is used for being connected with an external back pressure device, the pore pressure of the soil sample is adjusted through the back pressure device, the inner cavity water draining hole 105 is used for draining water in the inner cavity after an experiment, the outer cavity water draining hole 103 is used for being connected with an external constant temperature box (the water bath experiment box is used for being connected with a water bath experiment box through the water bath interface of a water bath of a conventional constant temperature controller, the constant temperature box is used for adjusting the water bath experiment box, and the temperature box is used for being connected with an external constant temperature box is used for a water bath box.
Working principle:
the pile freeze thawing experiment using process comprises the following steps:
1. The preparation work is carried out in the early stage of the experiment. After the soil sample is prefabricated successfully in advance, the rubber mould is sleeved on the sample chassis, meanwhile, the soil body is fixed on the sample chassis through the fixing rod, the position of the experimental part is adjusted to enable the experimental part to be propped against the bottom of the sample cover, the inspection and the sealing are good, and the dowel bar is pressed down to enable the dowel bar to be in good contact with the pile. And the tightness is checked, and the position of the iron sheet on the dowel bar is adjusted, so that the displacement sensor has initial reading and is ensured to always contact the iron sheet in the test process. The height of the dynamic load monitoring device is adjusted through up-and-down rotation of the nut, and the upper device is just in good contact with the dowel bar through display of data reading display of a display screen (data of the pressure sensor and the displacement sensor are displayed through an external display screen).
2. And (5) water injection pressurization experiment. The inner cavity water filling port and the outer cavity water filling port are used for filling water into the inner cavity and the outer cavity, and the air tightness of the soil sample environment simulation chamber is observed in the water filling process. After the test is completed, the test is started, confining pressure is applied to the soil body through the inner cavity (water is injected through the inner cavity water injection port, certain water pressure exists in the inner cavity, then the inner cavity water injection port is closed, water in the pressure control cavity is extruded to the pressure hole through the confining pressure device, the purpose of controlling the pressure of the inner cavity through the confining pressure device can be achieved because the pressure hole is communicated with the inner cavity), the super-static pore water pressure in the soil sample is regulated and controlled through the back pressure device while the confining pressure is applied, the super-static pore water pressure disappears, the water temperature in the outer cavity is regulated and controlled through the constant-temperature water bath box, the pile is loaded through the power loading device after the confining pressure and the temperature are stabilized, a displacement time curve of the pile under vibration load is obtained, and the cycle-displacement curve and the amplitude displacement curve are output through changing the load cycle and the load amplitude. The stress condition and the displacement condition of the soil pile under different freeze thawing cycle times, different temperatures and different stress states of the pile are obtained, and the stress condition of the pile at different embedding depths is obtained through confining pressure adjustment.
The anchor rod freeze thawing experiment using process comprises the following steps:
1. The preparation work is carried out in the early stage of the experiment. When the anchor rod test is carried out, after the soil sample is layered and compacted, the simulation site construction technology is used for pouring a special anchor rod into the soil sample through concrete, covering a rubber mold on a sample chassis with the well-maintained soil sample, covering a sample cover, removing a dowel bar, enabling the anchor rod to be coaxially placed with a pressure sensor, adjusting the height of a power loading device, enabling the anchor rod to be connected with the pressure sensor above through a ring buckle, and adjusting the contact between the sample cover and a fixing rod of the sample cover. Fixing an iron sheet on the anchor rod, so that the displacement sensor has initial reading and is ensured to always contact the iron sheet in the test process. And meanwhile, the confining pressure is maintained by injecting water into the indoor cavity of the soil sample environment simulation chamber, the maintenance temperature is regulated by water bath circulation of the outer cavity, and the air tightness of the soil sample environment simulation chamber is observed in the water injection process.
2. And (5) water injection pressurization experiment. After the test is complete, the test is started, confining pressure is applied to the soil body, after the soil body is stable, the anchor rod is loaded through the power loading device, a displacement time course curve of the anchor rod under vibration load is obtained, and a cycle-displacement curve and an amplitude displacement curve are output through changing the load cycle and the load amplitude. The method is used for researching the anchoring performance and dynamic response of the anchor rod in the soil body in the dynamic drawing under different freeze thawing cycles and different temperature conditions under different stress states.
The invention solves the problem that the vibration confining pressure of the base is unstable in the existing pile triaxial test process, and the actual working condition is simulated through the vibration of the power loading device, so that the invention is more in line with the actual condition, and experimental data is more convincing.
Claims (9)
1. The pile and anchor rod triaxial freeze thawing test device is characterized by comprising a supporting platform (1), wherein a dynamic load monitoring device (2) is arranged above the supporting platform (1), a soil sample environment simulation chamber (3) is arranged on the upper surface of the supporting platform (1), a soil body (4) is arranged in the soil sample environment simulation chamber (3), a test piece (5) is inserted into the soil body (4), and a confining pressure back pressure device (8) is arranged on one side of the supporting platform (1); the support platform (1) comprises: the device comprises a base (101) and a plurality of supporting columns (102) uniformly distributed on the outer ring of the upper surface of the base (101); the dynamic load monitoring device (2) comprises: the device comprises a supporting beam (201) arranged above a base (101) and connected with a plurality of supporting columns (102), a power loading device (202) fixed at the center of the lower bottom surface of the supporting beam (201), a pressure sensor (203) connected with the power loading device (202) and positioned below the power loading device, a ring buckle (204) arranged at the tail end of the pressure sensor (203), and a displacement sensor (205) fixed at the lower bottom surface of the supporting beam (201) and positioned at one side of the power loading device (202); the soil sample environment simulation chamber (3) comprises: the simulation chamber comprises an outer annular wall (301), an inner annular wall (302) which is coaxial with the outer annular wall (301) and is positioned in the outer annular wall, a simulation chamber top cover (303) which is arranged at the tops of the outer annular wall (301) and the inner annular wall (302), an outer cavity water injection port (304) and an inner cavity water injection port (305) which are arranged on the simulation chamber top cover (303), an outer cavity (306) is arranged between the outer annular wall (301) and the inner annular wall (302), the outer cavity water injection port (304) is arranged on the simulation chamber top cover (303) and corresponds to the outer cavity (306), an inner cavity (307) is arranged in the inner cavity water injection port (305) and is arranged on the simulation chamber top cover (303) and corresponds to the inner cavity (307); the soil body (4) comprises: the device comprises a soil sample (401), a rubber film (402) wrapped on the outer layer of the soil sample (401), a sample chassis (403) arranged on the lower bottom surface of the soil sample (401), and a sample cover (404) arranged on the upper surface of the soil sample (401); the test piece (5) is inserted in the center of the soil sample (401) and is in direct or indirect contact with the power loading device (202).
2. A triaxial freeze-thaw test device for piles and anchor rods according to claim 1, wherein the supporting beam (201) is connected with a plurality of supporting columns (102) through nuts (206).
3. The triaxial freeze thawing test device for piles and anchor rods according to claim 1, wherein a plurality of fixing rods (308) are arranged at the position of the outer annular wall (301), a sample cover fixing rod (309) is arranged on the lower bottom surface of the simulation chamber top cover (303), the sample cover fixing rod (309) is located between the simulation chamber top cover (303) and the sample cover (404), a temperature sensor (6) is inserted into the simulation chamber top cover (303), the temperature sensor (6) is located in the inner cavity (307), a drain pipe (7) is arranged in the inner cavity (307), and the drain pipe (7) is communicated with the sample cover (404) and the sample chassis (403).
4. The triaxial freeze-thawing test device for piles and anchor rods according to claim 1, wherein a lower surface of the specimen cover (404) and a middle position contacting the soil sample (401) are hollow.
5. The pile and anchor rod triaxial freeze-thawing test device according to claim 1, characterized in that the test piece (5) is a pile (501), the pile (501) is located inside the soil sample (401), a dowel (502) is arranged above the pile, the top end of the dowel (502) is in contact with the pressure sensor (203), and the bottom end of the dowel (502) is in contact with the pile (501).
6. The triaxial freeze-thawing test device for piles and anchor rods according to claim 5, wherein an iron sheet (503) is fixed at one end of the dowel bar (502) and at a position close to the pressure sensor (203), the iron sheet (503) is in contact with the tail end of the displacement sensor (205), and is always in contact with the displacement sensor (205) during the test, and the dowel bar (502) is in contact with but not connected to the pressure sensor (203).
7. The pile and anchor rod triaxial freeze thawing test device according to claim 1, characterized in that the test piece (5) is an anchor rod (504), the lower end of the anchor rod (504) is located inside the soil sample (401), the upper end of the anchor rod passes through the simulation chamber top cover (303) to be in contact with the pressure sensor (203), and the top of the anchor rod (504) is connected with the pressure sensor (203) through the ring buckle (204).
8. A pile and bolt triaxial freeze-thaw test apparatus according to claim 1, wherein the confining pressure counter-pressure device (8) comprises: the device comprises a pressure control base (801), a slideway (802) arranged on the pressure control base (801), a motor (803) and a sliding rod (804) arranged on the slideway (802), a pressure control cavity (805) arranged at the tail end of the sliding rod (804) and connected with the sliding rod, and a pressure control water inlet (806) and a pressure control water outlet (807) arranged at one end of the pressure control cavity (805).
9. The triaxial freeze thawing test device for piles and anchor rods according to claim 1, wherein an outer side surface of the base (101) is provided with a confining pressure controller connecting hole (108), a hole pressure sensor connecting hole (107), a pressure hole (104) and an inner cavity draining hole (105) which are communicated with an inner cavity of the soil sample environment simulation chamber (3), and an outer cavity draining hole (103) and a water bath temperature controller interface (106) which are communicated with an outer cavity of the soil sample environment simulation chamber (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811367399.1A CN109269910B (en) | 2018-11-16 | 2018-11-16 | Triaxial freeze thawing test device for piles and anchor rods |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811367399.1A CN109269910B (en) | 2018-11-16 | 2018-11-16 | Triaxial freeze thawing test device for piles and anchor rods |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109269910A CN109269910A (en) | 2019-01-25 |
| CN109269910B true CN109269910B (en) | 2024-06-25 |
Family
ID=65189120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811367399.1A Active CN109269910B (en) | 2018-11-16 | 2018-11-16 | Triaxial freeze thawing test device for piles and anchor rods |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109269910B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109540690B (en) * | 2018-11-13 | 2021-10-15 | 河海大学 | Pile-soil contact surface mechanical property testing device based on temperature control triaxial apparatus |
| CN110186760A (en) * | 2019-06-13 | 2019-08-30 | 河北建筑工程学院 | A kind of soil property anchor rod drawing test method for considering to change confining pressure condition |
| CN110567811B (en) * | 2019-09-26 | 2024-03-08 | 河南理工大学 | Concrete body confining pressure loading device for anchor cable drawing experiment |
| CN111122350A (en) * | 2020-01-03 | 2020-05-08 | 同济大学 | Triaxial apparatus for synchronously loading high-frequency cyclic load under static load |
| CN111721612B (en) * | 2020-06-04 | 2023-11-24 | 河北建筑工程学院 | Anchor rod drawing test device and test method considering temperature and pressure influence |
| CN113670749B (en) * | 2021-08-20 | 2022-06-14 | 湖南大学 | Indoor accelerated degradation test device for performance of anchor-soil interface and using method |
| CN113916667B (en) * | 2021-10-11 | 2024-03-29 | 辽宁工业大学 | Dynamic load simulated tunneling/roadway newly-installed anchor rod physical response test device and method |
| CN114441341A (en) * | 2022-01-24 | 2022-05-06 | 西南交通大学 | Soil shearing device for testing dynamic performance of tillite |
| CN114755092B (en) * | 2022-03-23 | 2023-02-03 | 哈尔滨商业大学 | Special device and method for seasonal frozen soil indoor test |
| CN115876608B (en) * | 2023-03-09 | 2023-05-16 | 成都理工大学 | Rock-soil mechanical test equipment and method in-situ freeze thawing-dry-wet circulating environment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN210071552U (en) * | 2018-11-16 | 2020-02-14 | 河北建筑工程学院 | Triaxial confining pressure test device for pile and anchor rod |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2644615C1 (en) * | 2016-12-02 | 2018-02-13 | Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский технологический университет "МИСиС" | Method for determining the thermal resistance of coals to their cyclic freezing and thawing |
| CN106644750B (en) * | 2016-12-07 | 2019-07-05 | 凌贤长 | Open system Thawing soil sound triaxial tester |
| CN106769563A (en) * | 2016-12-12 | 2017-05-31 | 中国科学院武汉岩土力学研究所 | The Triaxial tester and its method of soil body Frozen-thawed cycled dynamic load coupling |
-
2018
- 2018-11-16 CN CN201811367399.1A patent/CN109269910B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN210071552U (en) * | 2018-11-16 | 2020-02-14 | 河北建筑工程学院 | Triaxial confining pressure test device for pile and anchor rod |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109269910A (en) | 2019-01-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109269910B (en) | Triaxial freeze thawing test device for piles and anchor rods | |
| CN210071552U (en) | Triaxial confining pressure test device for pile and anchor rod | |
| CN106769478A (en) | A kind of pile-soil interface shearing test device | |
| CN106284443B (en) | A kind of test method for simulating bottom-grouting-enlarged Zhuan Kang order bearing capacities | |
| CN108828195B (en) | Indoor test method for simulating upward return of post-grouting slurry at pile end | |
| CN110987607B (en) | Nested multi-coupling model test system and test method for dam body of coal mine underground reservoir | |
| CN111794293B (en) | Drawing test device for compacted grouting soil nails | |
| CN106645637A (en) | Freeze thawing thermal cycle tri-axial seepage multifunctional pressure chamber for geotechnical material | |
| CN104458428A (en) | Large-sized fluid-solid-heat multi-field coupling test loading system | |
| CN107831009A (en) | Coal mine roadway side portion's anchor pole or anchorage cable anchoring analogue experiment installation and its experimental method | |
| CN206523371U (en) | Pile-soil interface shearing test device | |
| CN114199686B (en) | Model test device and method for operating highway tunnel lining disease evolution law | |
| CN111622277B (en) | Test device and test method for simulating influence of pile end cavities on bearing performance of pile foundation | |
| CN108693019A (en) | Liquid-heat-stress coupling acts on roadbed bridge response to forced vibration device and method | |
| CN105696636B (en) | Can in Simulation of Excavation Process WATER LEVEL CHANGES excavation models experimental rig | |
| CN110441159A (en) | The simulation test device and method of borehole wall bearer properties under hydraulic coupling action | |
| CN102478472A (en) | Test apparatus used for simulating influence of three-axis loading and unloading on engineering pile | |
| CN107843553A (en) | A kind of coal body and Anchor Agent interface binding intensity method of testing | |
| CN104990659B (en) | A kind of swelled ground area slurry balance shield tunnel tunnel face expansive force experimental rig | |
| CN105181463A (en) | Water-containing gangue compression testing device and testing method thereof | |
| CN111006951A (en) | Indoor grouting test device and simulated grouting test method | |
| CN106018271A (en) | Method and device for testing resin anchoring interface adhesion damage under water action | |
| CN108914998B (en) | Reinforced soil retaining wall damage mechanism experimental device and working method | |
| CN111721612B (en) | Anchor rod drawing test device and test method considering temperature and pressure influence | |
| CN107621415A (en) | A kind of true triaxial multifunctional large-scale Deep Mine Roadway model testing machine |
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 |