Sandy soil stratum freezing model experimental device and use method thereof

Abstract

The invention discloses a sandy soil stratum freezing model experimental device and a use method thereof, and relates to the field of sandy soil freezing models. The device comprises a bearing base, a soil sample loading mold, a vibration assembly, a plurality of groups of monitoring assemblies, a seepage water supply assembly, a freezing assembly, an excavation hole protection door and a controller, the soil sample loading mold comprises a bearing support, a mold box, a box cover and a vibration connecting plate, the mold box is mounted at the top of the bearing support, and the top of the mold box is open; excavating holes are symmetrically formed in the two opposite side walls of the mold box, the box cover covers the top opening of the mold box, the vibration connecting plate is fixed to the outer bottom wall of the mold box, and a groove is formed in the center of the top of the vibration connecting plate. According to the device, the vibration assembly can be used for driving the vibration connecting plate to vibrate, vibration is transmitted from the side of the mold box to sandy soil in the mold box through the grooves in the vibration connecting plate, a soil sample in the mold box can be evenly vibrated and tamped, a sandy soil model is constructed, and seepage experiments, freezing experiments and excavation experiments of a sandy soil stratum are conducted.

Description

Technical Field

[0001] The invention relates to the technical field of sand freezing models, and in particular to a sand layer freezing model experimental device and a use method thereof. Background Art

[0002] The geotechnical engineering freezing construction method is a foundation consolidation construction method that uses artificial refrigeration technology to temporarily reinforce the natural rock and soil into frozen soil. It is widely used in mine construction, subways, foundation pits, foundations, water conservancy projects, tunnels and other municipal construction projects. When the freezing project is in a water-rich stratum, the underground high-velocity seepage will have a great impact on the freezing temperature field of the traditional freezing scheme, resulting in the phenomenon of out-of-control of the freezing wall handover sequence, displacement of the freezing wall handover position, increased freezing wall handover time or even no handover, causing huge safety accidents and economic losses to the freezing method foundation consolidation project.

[0003] In order to proactively prevent ground freezing accidents under seepage and actively respond to engineering problems of ground freezing under seepage, it is of great significance to study the development law of freezing temperature field under high-velocity seepage conditions, which can provide theoretical support and practical reference for actual engineering.

[0004] The geotechnical engineering freezing construction method needs to determine the specific construction method according to the actual terrain and soil structure, so the geological structure needs to be simulated in the laboratory before the construction method is determined. However, the existing sandy soil layer freezing model experimental device has a relatively complex structure, and the soil layer geological model construction box can only be loaded with soil from the top, and the model needs to be compacted manually, which is time-consuming and laborious for the construction of the freezing experimental model, and the compaction is uneven. At the same time, the existing freezing experimental device is not convenient for excavation experimental testing after freezing, and the specific effect of the freezing experimental model cannot be intuitively reflected. Summary of the invention

[0005] The purpose of the present invention is to provide a sandy soil stratum freezing model experimental device and a method of using the same, so as to solve the technical problems in the prior art that the sandy soil stratum freezing model experimental device has a complex structure, is laborious and uneven in compaction, and cannot perform excavation experiments.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A sandy soil layer freezing model experimental device, comprising:

[0008] Load-bearing base;

[0009] A soil sample loading mold, the soil sample loading mold comprising a bearing support, a mold box, a box cover and a vibration connecting plate, the bearing support is mounted on the top of the bearing base, the mold box is mounted on the top of the bearing support and its top is open, and digging holes are symmetrically opened on two oppositely arranged side walls; the box cover is arranged on the open top of the mold box and a water injection pipe joint is installed on its top, the vibration connecting plate is fixed to the outer bottom wall of the mold box, and a groove is opened at the center of its top;

[0010] A vibration component, the vibration component is mounted on the top of the bearing support and the output end of the vibration component is connected to the bottom of the vibration connecting plate;

[0011] A plurality of groups of monitoring components, each group of the monitoring components is arranged along the height direction of the mold box and installed in the inner cavity of the mold box;

[0012] A seepage water supply component, wherein the seepage water supply component is installed on the top of the bearing base on one side of the bearing support, and the water outlet end thereof is connected to the water injection pipe joint;

[0013] A freezing assembly, the freezing assembly comprising a freezing water circulation assembly and a freezing pipe, the freezing water circulation assembly being mounted on the top of the bearing base on one side of the bearing support, a plurality of freezing pipes being mounted in the mold box along the height direction of the mold box or along the excavation direction of the excavation hole, the water inlet end of the freezing water circulation assembly being connected to the water outlet end of the freezing water circulation assembly, and the water outlet end being connected to the water return end of the freezing water circulation assembly;

[0014] An excavation hole protection door, wherein the inner side wall of each excavation hole is slidably mounted with the excavation hole protection door;

[0015] A controller is mounted on the top of the bearing base and is electrically connected to the vibration assembly, each group of the monitoring assembly, the seepage water supply assembly and the freezing water circulation assembly.

[0016] The beneficial effects of the present invention are as follows: the device can utilize the vibration component to drive the vibration connecting plate to vibrate, and utilize the grooves on the vibration connecting plate to transmit the vibration from the side of the mold box to the sand inside, so that the soil sample in the mold box can be vibrated and compacted evenly, a sand model can be constructed, and seepage experiments, freezing experiments and excavation experiments of the sand stratum can be carried out.

[0017] Preferably, the bearing support includes a base plate, a plurality of pillars and a tray, the base plate is installed on the top of the bearing base, the plurality of pillars are circumferentially evenly arranged on the top of the base plate, the tray is fixed on the top of the plurality of pillars, and a vibration hole is opened in the center of the tray, the lower end of the mold box is connected to the inner wall of the tray, and the output end of the vibration assembly is connected to the vibration connecting plate through the vibration hole.

[0018] Preferably, the vibration assembly includes a telescopic motor, a vibration impact plate, a plurality of impact columns and a plurality of noise reduction gaskets, the telescopic motor is fixed on the top of the base plate, the vibration impact plate is fixed on the top of the output shaft of the telescopic motor, the plurality of impact columns are evenly fixed on the top of the vibration impact plate, the plurality of noise reduction gaskets correspond one by one to the plurality of impact columns and are connected to the top of the impact columns, and the bottom of the vibration connecting plate abuts against the top of the noise reduction gasket.

[0019] Preferably, a discharge port is provided at the lower portion of the side wall of the mold box, and a discharge plate is installed in the discharge port.

[0020] Preferably, it also includes a positioning connection component, which includes a plurality of upper connection cylinders of the monitoring component, a plurality of water injection cylinders, a plurality of upper sealing cylinders, a plurality of lower connection cylinders of the monitoring component and a plurality of lower sealing cylinders, wherein the plurality of upper connection cylinders of the monitoring component, the plurality of water injection cylinders and the plurality of upper sealing cylinders are evenly distributed on the box cover and the bottom ends thereof are all connected with the inner cavity of the mold box; the lower connection cylinder of the monitoring component is arranged corresponding to the upper connection cylinder of the monitoring component and is fixed to the inner bottom wall of the mold box, and the lower sealing cylinder is arranged corresponding to the upper sealing cylinder and the water injection cylinder and is fixed to the inner bottom wall of the mold box;

[0021] The upper end of each group of monitoring components is connected to the upper connecting tube of the monitoring component, and the lower end is connected to the lower connecting tube of the monitoring component. The water injection pipe joint is installed on the top of the water injection tube. The top cover of the upper sealing tube is provided with an upper sealing cover, and the top cover of the lower sealing tube is provided with a lower sealing cover.

[0022] Preferably, a plurality of positioning holes are provided on the outer peripheral side of each excavation hole, and the positioning holes on the two opposite side walls of the mold box correspond to each other, and side sealing covers are installed at the outer ends of the positioning holes;

[0023] Among them, when the freezing pipe is arranged along the excavation direction of the excavation hole, its two ends are respectively connected to the positioning holes on both sides; when the freezing pipe is arranged along the height direction of the mold box, the lower end of the freezing pipe is connected to the lower sealing cylinder, and the upper end is connected to the corresponding upper sealing cylinder.

[0024] Preferably, each group of the monitoring components includes a monitoring tube and multiple groups of sensor components, the upper end of the monitoring tube is connected to the upper connecting tube of the monitoring component, and the lower end is connected to the corresponding lower connecting tube of the monitoring component; the multiple groups of sensor components are arranged at intervals along the height direction of the monitoring tube, and each group of the sensor components includes a humidity sensor, a temperature sensor, a density sensor and a seepage rate sensor.

[0025] Preferably, the inner wall of the freezing pipe is installed with a partition arranged along its length direction to divide its inner cavity into an inlet channel and a return channel, the water inlet end of the inlet channel is connected to the water outlet end of the freezing water circulation component, the water inlet end of the return channel is connected to the water outlet end of the inlet channel, and the water outlet end is connected to the return water end of the freezing water circulation component.

[0026] Preferably, the excavation hole protection door includes an inner door panel, a rubber insulation panel, an outer door panel and a slider which are connected in sequence from the inside to the outside. The inner wall of the inner door panel is flush with the inner wall of the mold box. The slider is slidably connected to the inner wall of the excavation hole, and a limiting block is formed on the outer wall away from one end of the inner door panel. The limiting block is limitedly connected to the outer wall of the mold box.

[0027] A method for using a sandy soil layer freezing model experimental device comprises the following steps:

[0028] S1: Assemble the sand layer freezing model experimental device, install the soil sample loading mold, the seepage water supply component, the freezing component and the controller on the upper surface of the bearing base, and then install the vibration component at the bottom of the freezing mold box according to the experimental plan, install the monitoring component and the freezing pipe inside, and connect the vibration component, each group of the monitoring components, the seepage water supply component and the freezing water circulation component to the controller through wires;

[0029] S2: Filling the inside of the freezing mold box with sand and soil: manually use tools to fill the inside of the mold box with experimental sand and soil samples, and start the vibration component during the filling process to compact the experimental sand and soil inside the mold box by vibration, and finally install the box cover, and then according to the experimental plan, install the water injection pipe joint on the corresponding water injection cylinder, connect the water injection pipe joint with the water outlet of the seepage water supply component, connect the water outlet of the freezing water circulation component with the water inlet of the freezing pipe, and connect the return water end with the water outlet of the freezing pipe;

[0030] S3: Seepage simulation of sand model: determine the seepage data of the sand model according to the experimental plan, inject water into the sand model by controlling the water output of the seepage water supply component, use the monitoring component to detect the seepage data of the sand model, and the controller performs data statistics;

[0031] S4: Sand model freezing simulation, determine the freezing data of the sand model according to the experimental plan, adjust the temperature and water outlet speed of the freezing water circulation component, and adjust the seepage parameters of the sand model during the freezing experiment; start the freezing water circulation component to introduce freezing circulating water into the freezing pipe, perform a freezing experiment on the sand model with continuous seepage, detect the parameter changes at various positions of the sand model through the monitoring component, and perform data statistics by the controller;

[0032] S5: Conduct an excavation experiment to determine the effect of the sand model freezing experiment, maintain continuous seepage of the sand model, remove the excavation hole protection door inside the excavation hole, and conduct an excavation test on the frozen sand model from the excavation hole to determine whether there is collapse or seepage inside the pit of the sand model after excavation, and record the data during the sand model excavation test through the monitoring component, and the controller performs data statistics.

[0033] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a sandy soil layer freezing model experimental device and a method of using the same, which has the following beneficial effects:

[0034] 1. A sand layer freezing model experimental device, which continuously impacts the vibrating connecting plate at the bottom of the mold box through a telescopic motor and a vibrating impact plate, and then quickly compacts the sand inside the mold box to form a sand model, reducing the operating difficulty and labor intensity of the experimenters.

[0035] 2. Multiple sets of monitoring components are set in the mold box. Each set of monitoring components is equipped with multiple sets of sensor components to conduct all-round monitoring of the sand model, so as to fully understand the temperature changes, humidity changes, soil density changes, seepage conditions of the sand model, and freezing conditions of the sand model before and after the experiment.

[0036] 3. Set up positioning connection components, which can change the positions of monitoring components, water injection pipe joints and freezing pipes according to the needs of the experimental plan. It is easy to assemble and disassemble, saving installation time.

[0037] 4. Setting up seepage water supply components, freezing components and excavation holes can carry out seepage experiments, freezing experiments and excavation experiments on sandy soil strata, so as to more intuitively understand the freezing effect of the sandy soil model and facilitate comprehensive analysis and statistics of the sandy soil model.

[0038] 5. A discharge port and a detachable discharge plate are set at the bottom of the mold box to facilitate the quick cleaning of the sand and soil inside the frozen mold box after the experiment, speed up the experiment, reduce the difficulty of experimental operation, and ensure the experimental effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The present invention is a three-dimensional structural schematic diagram of a sand layer freezing model experimental device at one angle.

[0040] Figure 2 The figure is a three-dimensional structural schematic diagram from another angle of a sand layer freezing model experimental device of the present invention.

[0041] Figure 3 It is a schematic diagram of the three-dimensional structure of the bearing base of the present invention.

[0042] Figure 4 It is a schematic diagram of the three-dimensional structure of the soil sample loading mold of the present invention.

[0043] Figure 5 It is a schematic diagram of the partial cross-sectional structure of the soil sample loading mold of the present invention.

[0044] Figure 6 For the present invention Figure 5 Schematic diagram of the enlarged structure at point A in the middle.

[0045] Figure 7 For the present invention Figure 5 Schematic diagram of the enlarged structure at point B in the middle.

[0046] Figure 8 For the present invention Figure 5 Schematic diagram of the enlarged structure at point C in the middle.

[0047] Fig. 9 It is a schematic diagram of the three-dimensional structure of the controller of the present invention.

[0048] Fig.10 It is a schematic diagram of the three-dimensional structure of the seepage water supply assembly of the present invention.

[0049] Fig.11 It is a schematic diagram of the three-dimensional structure of the freezing water circulation component of the present invention.

[0050] Fig.12 For the present invention Fig.11 Schematic diagram of the enlarged structure at D in the middle.

[0051] Fig.13 A schematic diagram of the test points, water injection points and soil freezing points of the present invention.

[0052] Fig.14 Another schematic diagram of the test points, water injection points and soil freezing points of the present invention.

[0053] In the figure: 1, bearing base, 101, bearing bottom plate, 102, supporting leg, 103, protective rubber sleeve, 104, mold positioning frame, 105, seepage component positioning frame, 106, freezing component positioning frame, 107, controller positioning frame, 108, connecting rod;

[0054] 2. Soil sample loading mold, 201. Bearing support, 2011. Bottom plate, 2012. Pillar, 2013. Pallet, 202. Mold box, 2021. Protective outer box, 2022. Gypsum insulation layer, 2023. Rock wool insulation layer, 2024. Bearing inner box, 2025. Excavation hole, 2026. Positioning hole, 203. Box cover, 2031. Cover body, 2032. Glass wool insulation layer, 2033. Extruded pressing plate, 204. Vibration connecting plate;

[0055] 3. Vibration assembly, 301. Telescopic motor, 302. Vibration impact plate, 303. Impact column, 304. Noise reduction gasket;

[0056] 4. Monitoring component, 401. Monitoring tube, 402. Sensor component;

[0057] 5. Seepage water supply assembly, 501. Seepage water tank, 502. Seepage water supply pump, 503. Seepage outlet pipe, 504. Seepage diversion pipe joint, 505. First plugging head, 506. First water injection valve, 507. Flow regulating valve;

[0058] 6. Freezing assembly, 601. Freezing water circulation assembly, 6011. Circulating water tank, 6012. Circulating water pump, 6013. Outlet pipe, 6014. Cooler, 6015. Outlet shunt pipe, 6016. Return shunt pipe, 6017. Return pipe, 6018. Second water injection valve, 6019. Outlet shunt pipe joint, 60191. Outlet conduit, 6020. Return pipe joint, 60201. Return conduit, 6021. Second plugging head, 602. Freezing pipe;

[0059] 7. Excavation hole protection door, 701. Inner door panel, 702. Rubber insulation board, 703. Outer door panel, 704. Sliding block, 705. Limiting block;

[0060] 8. Controller, 801, electric control box, 802, computer;

[0061] 9. Unloading plate;

[0062] 10. Positioning connection assembly, 1001. upper connection cylinder of monitoring assembly, 1002. water injection cylinder, 1003. upper sealing cylinder, 1004. lower connection cylinder of monitoring assembly, 1005. lower sealing cylinder;

[0063] 11. Water injection pipe joint;

[0064] 12. Upper sealing cover;

[0065] 13. Side sealing cover. DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] Embodiment 1:

[0068] like Figures 1 to 14As shown, this embodiment provides a sandy soil stratum freezing model experimental device, including: a bearing base 1, a soil sample loading mold 2, a vibration component 3, multiple monitoring components 4, a seepage water supply component 5, a freezing component 6, an excavation hole protection door 7 and a controller 8. This device can use the vibration component 3 to vibrate and compact the soil sample in the mold box 202, build a sand model, and conduct seepage experiments, freezing experiments and excavation experiments on sandy soil strata.

[0069] like Figure 3 As shown, the supporting base 1 includes a supporting bottom plate 101, supporting legs 102 and a protective rubber sleeve 103. A mold positioning frame 104, a seepage component positioning frame 105, a freezing component positioning frame 106 and a controller positioning frame 107 are fixed on the top of the supporting bottom plate 101. Multiple supporting legs 102 are supported at the bottom of the supporting bottom plate 101. The protective rubber sleeve 103 is sleeved on the bottom end of the supporting legs 102 to improve the stability of the overall supporting base 1.

[0070] A plurality of connecting rods 108 are welded on two oppositely arranged side walls of the bearing base plate 101 , and the connecting rods 108 are used to facilitate the movement of the entire device.

[0071] like Figure 4 , Figure 5 The soil sample loading mold 2 includes a bearing support 201, a mold box 202, a box cover 203 and a vibration connecting plate 204. The bearing support 201 is clamped in the mold positioning frame 104, the mold box 202 is installed on the top of the bearing support 201 and its top is open, and digging holes 2025 are symmetrically opened on its two oppositely arranged side walls; the box cover 203 is set on the open top of the mold box 202 and a water injection pipe joint 11 is installed on its top, the vibration connecting plate 204 is fixed to the outer bottom wall of the mold box 202, and a groove is opened in the center of its top. By setting the groove, the vibration is transmitted from the side of the mold box 202 to the sand and soil inside, so that the sand and soil vibrates evenly and is fully compacted.

[0072] The bearing support 201 includes a base plate 2011, multiple pillars 2012 and a tray 2013. The base plate 2011 is installed on the top of the bearing base 1. The multiple pillars 2012 are evenly arranged on the top of the base plate 2011 in the circumferential direction. The tray 2013 is fixed on the top of the multiple pillars 2012, and a vibration hole is opened in the center of the tray 2013. The lower end of the mold box 202 is connected to the inner wall of the tray 2013, and the output end of the vibration component 3 is connected to the bottom wall of the vibration connecting plate 204 through the vibration hole. The tray 2013 of this embodiment is composed of multiple angle plates.

[0073] See also Figure 6 The mold box 202 includes a protective outer box 2021, a gypsum insulation layer 2022, a rock wool insulation layer 2023 and a load-bearing inner box 2024 which are sequentially connected from the outside to the inside, and has good insulation effect and load-bearing capacity.

[0074] The box cover 203 includes a cover body 2031 and a glass wool insulation layer 2032 and an extruded pressing plate 2033 installed on the bottom of the cover body 2031 from the outside to the inside. The lower surface of the extruded pressing plate 2033 is a smooth plane. The glass wool insulation layer 2032 and the extruded pressing plate 2033 jointly play a role in heat preservation.

[0075] See also Figure 1-Figure 2 , Figure 4-Figure 7 , and also includes a positioning connection component 10, which includes a plurality of monitoring component upper connection cylinders 1001, a plurality of water injection cylinders 1002, a plurality of upper sealing cylinders 1003, a plurality of monitoring component lower connection cylinders 1004 and a plurality of lower sealing cylinders 1005, wherein the plurality of monitoring component upper connection cylinders 1001, the plurality of water injection cylinders 1002 and the plurality of upper sealing cylinders 1003 are evenly distributed on the box cover 203 and the bottom ends thereof are all connected with the inner cavity of the mold box 202; the monitoring component lower connection cylinder 1004 is arranged corresponding to the monitoring component upper connection cylinder 1001 and fixed to the inner bottom wall of the mold box 202, and the lower sealing cylinder 1005 is arranged corresponding to the upper sealing cylinder 1003 and the water injection cylinder 1002 and fixed to the inner bottom wall of the mold box 202;

[0076] The upper end of each monitoring assembly 4 is connected to the upper connection tube 1001 of the monitoring assembly, and the lower end is connected to the lower connection tube 1004 of the monitoring assembly. The water injection pipe joint 11 is installed on the top of the water injection tube 1002. The top cover of the upper sealing tube 1003 is provided with an upper sealing cover 12, and the top cover of the lower sealing tube 1005 is provided with a lower sealing cover. When in use, according to the requirements of the experimental plan, the installation position and installation quantity of the monitoring assembly 4, the water injection pipe joint 11 and the upper sealing cover 12 can be changed, and the position and quantity of the lower sealing cover can be changed accordingly, so as to meet the experimental requirements of different test points.

[0077] See also Figure 8 A plurality of positioning holes 2026 are provided on the outer peripheral side of each excavation hole 2025 , and the positioning holes 2026 on the opposite side walls of the mold box 202 correspond to each other, and a side sealing cover 13 is installed on the outer end of the positioning hole 2026 .

[0078] When the freezing pipe 602 is arranged along the excavation direction of the excavation hole 2025, the side sealing cover 13 of the corresponding installation point is opened, so that the two ends of the freezing pipe 602 are respectively connected to the positioning holes 2026 on both sides. When the freezing pipe 602 is arranged along the height direction of the mold box 202, the upper sealing cover 12 and the lower sealing cover of the corresponding point are opened, so that the lower end of the freezing pipe 602 is connected to the lower sealing cylinder 1005, and the upper end is connected to the upper sealing cylinder 1003. The freezing pipe 602 is not only convenient for adjusting the installation point, but also convenient for changing the installation direction to conduct different experiments.

[0079] like Figure 7The vibration assembly 3 includes a telescopic motor 301, a vibration impact plate 302, a plurality of impact columns 303 and a plurality of noise reduction gaskets 304. The telescopic motor 301 is fixed on the top of the bottom plate 2011, the vibration impact plate 302 is fixed on the top of the output shaft of the telescopic motor 301, and a plurality of impact columns 303 are evenly fixed on the top of the vibration impact plate 302. Each noise reduction gasket 304 is connected to the top of the impact column 303 one by one. The bottom of the corresponding groove of the vibration connecting plate 204 abuts against the top of the noise reduction gasket 304, transmits vibration to the mold box 202, and at the same time prevents the mold box 202 from being damaged.

[0080] like Figure 6 Each group of monitoring components 4 corresponds to the upper connecting tube 1001 of the monitoring component one by one. Each group of monitoring components 4 includes a monitoring tube 401 and multiple groups of sensor components 402. The upper end of the monitoring tube 401 is plugged into the upper connecting tube 1001 of the monitoring component, and the lower end is threadedly connected to the corresponding lower connecting tube 1004 of the monitoring component; the multiple groups of sensor components 402 are arranged at intervals along the height direction of the monitoring tube 401. Each group of sensor components 402 includes a humidity sensor, a temperature sensor, a density sensor and a seepage velocity sensor, which perform real-time detection of various soil experimental data, which is convenient for studying the experimental results of the soil model.

[0081] See also Fig.10 The seepage water supply assembly 5 includes a seepage water tank 501, a seepage water supply pump 502, a seepage water outlet pipe 503 and a plurality of seepage diversion pipes. The seepage water tank 501 is clamped in the seepage assembly positioning frame 105, and a first water injection valve 506 is installed on its side wall. The seepage water supply pump 502 is electrically connected to the controller 8, and its water inlet end is connected to the inner cavity of the seepage water tank 501. The water inlet end of the seepage water outlet pipe 503 is connected to the water outlet end of the seepage water supply pump 502, and a seepage diversion pipe joint 504 is installed at the water outlet end. The seepage diversion pipe joint 504 is provided with a plurality of water diversion conduits. The seepage diversion pipe adopts a hose. The water inlet ends of the plurality of seepage diversion pipes are connected to the water diversion conduit, and the water outlet ends are connected to a plurality of water injection pipe joints 11. A flow regulating valve 507 is installed on the seepage water outlet pipe 503. The water supply flow rate can be adjusted according to the need for water supply, and a first plugging head 505 is installed at the water outlet end of the water diversion conduit that is not connected to the seepage diversion pipe.

[0082] See also Fig.11 , Fig.12 The freezing component 6 includes a freezing water circulation component 601 and a freezing pipe 602. The freezing water circulation component 601 is installed on the top of the bearing base 1 on one side of the bearing support 201. Both ends of multiple freezing pipes 602 are respectively inserted into the freezing pipe 602 installation holes on the two side walls of the mold box 202. The water inlet end is connected to the water outlet end of the freezing water circulation component 601, and the water outlet end is connected to the return water end of the freezing water circulation component 601.

[0083] The freezing water circulation component 601 includes a circulating water tank 6011, a circulating water pump 6012, a water outlet pipe 6013, a cooler 6014, a water outlet shunt pipe 6015, a return water shunt pipe 6016 and a return water pipe 6017. The circulating water tank 6011 is installed in the freezing component positioning frame 106 and a second water injection valve 6018 is installed on its side wall. The water inlet end of the circulating water pump 6012 is connected to the water outlet of the circulating water tank 6011, the water inlet end of the water outlet pipe 6013 is connected to the water outlet end of the circulating water pump 6012, the cooler 6014 is installed at the water outlet end of the water outlet pipe 6013, and the water outlet end of the cooler 6014 is connected to the water outlet end of the circulating water tank 6011. The outlet water shunt pipe 6015 is provided with an outlet water shunt pipe joint 6019 at the outlet end of the outlet water shunt pipe 6015, and the outlet water shunt pipe joint 6019 includes a plurality of outlet water conduits, and the outlet ends of the plurality of outlet water conduits are connected to the water inlet ends of the plurality of freezing pipes 602 through a hose, and the water inlet end of the return water shunt pipe 6016 is provided with a return pipe joint 6020, and the return pipe joint 6020 includes a plurality of return water conduits, and the plurality of return water conduits are connected to the water outlet ends of the plurality of freezing pipes 602 through a hose, and the water inlet end of the return water pipe 6017 is connected to the water outlet end of the return water shunt pipe 6016, and the water outlet end is connected to the return port of the circulating water tank 6011. When in use, according to experimental needs, the outlet ends of the unconnected water shunt pipe and the return water conduit are both provided with a second plug 6021.

[0084] like Figure 8 , each excavation hole 2025 is slidably installed with an excavation hole protection door 7 on the inner wall, and the excavation hole protection door 7 includes an inner door panel 701, a rubber insulation panel 702, an outer door panel 703 and a slider 704 which are sequentially connected from the inside to the outside, and the inner wall of the inner door panel 701 is flush with the inner wall of the mold box 202, one end of the slider 704 is slidably connected to the inner wall of the excavation hole 2025, and a limiting block 705 is formed on the outer wall of the other end, and the limiting block 705 is limitedly connected to the outer wall of the mold box 202, which can not only play a role in heat preservation but also is convenient for disassembly, is convenient for excavation experiments, and more intuitively understands the freezing effect of the sand model, and is convenient for comprehensive analysis and statistics of the sand model.

[0085] like Figure 1 , Figure 4 A discharge port is provided on the lower side wall of the mold box 202, and a discharge plate 9 is detachably installed in the discharge port. After the experiment is completed, the discharge plate is removed and the sand and soil inside the inner box 2024 are taken out to reduce the difficulty of separating the sand and soil model.

[0086] See also Fig. 9, controller 8, controller 8 includes an electric control box 801 and a computer 802. The electric control box 801 is installed in the controller positioning frame 107 and is electrically connected to the telescopic motor 301, the humidity sensor, the temperature sensor, the density sensor and the seepage velocity sensor, the seepage water supply pump 502, the flow meter, the circulating water pump 6012, and the cooler 6013. The computer 802 is installed on the top of the electric control box 801 to send instructions to the electric control box 801, and to count and calculate the feedback data received by the electric control box 801, and then determine the experimental results.

[0087] Embodiment 2:

[0088] This embodiment provides a method for using a sand layer freezing model experimental device, comprising the following steps:

[0089] S1: Assemble the sand layer freezing model experimental device, install the soil sample loading mold 2, the seepage water supply component 5, the freezing component 6 and the controller 8 on the upper surface of the bearing base 1, and then install the vibration component 3 at the bottom of the freezing mold box 202 according to the experimental plan, install the monitoring component 4 inside and install the freezing pipe 602 along the excavation direction of the excavation hole 2025, and connect the vibration component 3, each group of monitoring components 4, the seepage water supply component 5 and the freezing water circulation component 601 to the controller 8 through wires;

[0090] The computer 802 sends instructions to the control box, and the control box adjusts the cooling temperature of the cooler 6013, the water supply speed of the circulating water pump 6012, the working power of the telescopic motor 301, and the water supply speed of the seepage water supply pump 502;

[0091] S2: Fill the freezing mold box 202 with sand and soil, and use tools to manually fill the experimental sand and soil samples into the mold box 202. In the process of filling the soil samples, start the telescopic motor 301, so that the telescopic motor 301 drives the vibration impact plate 302 to reciprocate up and down, so that the impact column 303 continuously impacts the vibration connecting plate 204 through the noise reduction gasket 304, and the vibration connecting plate 204 transmits the vibration to the mold box 202, and the experimental sand and soil are compacted inside the mold box 202 by vibration, and then install the box cover 203, and according to the experimental plan, install the water injection pipe joint 11 on the corresponding water injection cylinder 1002, connect the water injection pipe joint 11 to the water outlet end of the seepage water supply component 5, and then connect the water outlet end of the freezing water circulation component 601 to the water inlet end of the freezing pipe 602, and connect the return water end to the water outlet end of the freezing pipe 602, connect the current loop of the sensor component 402, and perform preliminary temperature, humidity, and soil density measurements on the sand model;

[0092] S3: Seepage simulation of sand model, determine the seepage data of the sand model according to the experimental plan, then inject water into the sand model by controlling the water output and water output speed of the seepage water supply component 5, detect the seepage data of the sand model by the seepage speed sensor of the monitoring component 4, and perform data statistics by the controller 8 to calculate the seepage time, seepage water volume, seepage speed, soil density change and soil temperature change during the seepage process;

[0093] S4: freezing simulation of the sand model, determining the freezing data of the sand model according to the experimental plan, adjusting the temperature and water outlet speed of the freezing water circulation component 601, and adjusting the seepage parameters of the sand model during the freezing experiment, and then starting the freezing water circulation component 601 to introduce freezing circulating water into the freezing pipe 602, and performing a freezing experiment on the sand model with continuous seepage; detecting parameter changes at various positions of the sand model through the sensor component 402, and performing data statistics by the controller 8, and calculating soil temperature changes, soil density changes, and soil seepage state changes at different points;

[0094] S5: Conduct an excavation experiment to determine the effect of the freezing experiment of the sand soil model, maintain the continuous seepage of the sand soil model, remove the excavation hole protection door 7 inside the excavation hole 2025, and then conduct an excavation test on the frozen sand soil model from inside the excavation hole 2025 to determine whether there is collapse or seepage inside the pit of the sand soil model after excavation, and record the data during the excavation test of the sand soil model through the sensor component 402; the controller 8 performs data statistics, and judges the freezing effect of the sand soil model according to the actual situation of the excavation pit, and finally performs pit support and thaw of the sand soil model to complete the whole process of the experiment, and conducts comprehensive statistics on the freezing experiment of the sand soil model. This experimental method is suitable for tunnel excavation and foundation pit excavation of air-raid shelter projects, such as subway tunnel excavation, mountain tunnel excavation, etc.

[0095] Embodiment 3:

[0096] On the basis of Example 2, the installation method of the freezing pipe 602 is changed, and the freezing pipe 602 is inserted into the mold box 202 through the upper sealing cylinder 1003 and the lower sealing cylinder 1005 along the height direction of the mold box 202, and then filled with sand. According to the experimental design plan, the point position of the monitoring component 4 and the water injection pipe joint 11 is adjusted, and then the seepage and freezing experiments of the sand model are carried out. After the freezing experiment is completed, the box cover 203 is removed, and the sand model excavation experiment is carried out from the top of the mold box 202 to determine whether the inside of the sand model pit after excavation collapses and seepage occurs. The data in the sand model excavation test process is recorded by the sensor component 402, and the computer 802 performs data statistics. According to the actual situation of the excavation pit, the freezing effect of the sand model is judged, and finally the pit support and sand model thawing are carried out to complete the whole process of the experiment, and the freezing experiment of the sand model is comprehensively counted. This experimental method is suitable for projects such as foundation pit excavation and deep mine excavation, such as bridge pier foundation pit excavation with high water content soil and continuous excavation work in the depth of the mine.

[0097] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A sandy soil layer freezing model experimental device, characterized in that: include: A bearing base (1); A soil sample loading mold (2), the soil sample loading mold (2) comprising a bearing support (201), a mold box (202), a box cover (203) and a vibration connecting plate (204), the bearing support (201) being mounted on the top of the bearing base (1), the mold box (202) being mounted on the top of the bearing support (201) and having an open top, and having excavation holes (2025) symmetrically provided on two oppositely arranged side walls; the box cover (203) being arranged to cover the open top of the mold box (202) and having a water injection pipe joint (11) installed on the top, the vibration connecting plate (204) being fixed to the outer bottom wall of the mold box (202), and having a groove provided at the center of the top; A vibration component (3), the vibration component (3) being mounted on the top of the bearing support (201) and having an output end connected to the vibration connecting plate (204); A plurality of groups of monitoring components (4), each group of the monitoring components (4) being arranged along the height direction of the mold box (202) and installed in the inner cavity of the mold box (202); A seepage water supply component (5), the seepage water supply component (5) being installed on the top of the bearing base (1) on one side of the bearing support (201), and the water outlet end of the seepage water supply component (5) being connected to the water injection pipe joint (11); A freezing assembly (6), wherein the freezing assembly (6) comprises a freezing water circulation assembly (601) and a freezing pipe (602), wherein the freezing water circulation assembly (601) is mounted on the top of the bearing base (1) on one side of the bearing support (201), and a plurality of freezing pipes (602) are mounted in the mold box (202) along the height direction of the mold box (202) or along the excavation direction of the excavation hole (2025), wherein the water inlet end thereof is connected to the water outlet end of the freezing water circulation assembly (601), and the water outlet end is connected to the water return end of the freezing water circulation assembly (601); An excavation hole protection door (7), wherein the inner wall of each excavation hole (2025) is slidably mounted with the excavation hole protection door (7); A controller (8), wherein the controller (8) is mounted on the top of the supporting base (1) and is electrically connected to the vibration component (3), each group of the monitoring components (4), the seepage water supply component (5) and the freezing water circulation component (601).

2. A sandy soil layer freezing model experimental device according to claim 1, characterized in that: The bearing support (201) comprises a base plate (2011), a plurality of pillars (2012) and a tray (2013); the base plate (2011) is mounted on the top of the bearing base (1); the plurality of pillars (2012) are evenly spaced circumferentially arranged on the top of the base plate (2011); the tray (2013) is fixed on the top of the plurality of pillars (2012); a vibration hole is provided at the center of the tray (2013); the lower end of the mold box (202) is connected to the inner wall of the tray (2013); and the output end of the vibration component (3) is connected to the vibration connecting plate (204) through the vibration hole.

3. A sandy soil layer freezing model experimental device according to claim 2, characterized in that: The vibration component (3) comprises a telescopic motor (301), a vibration impact plate (302), a plurality of impact columns (303) and a plurality of noise reduction pads (304); the telescopic motor (301) is fixed to the top of the bottom plate (2011); the vibration impact plate (302) is fixed to the top of the output shaft of the telescopic motor (301); the plurality of impact columns (303) are evenly fixed to the top of the vibration impact plate (302); the plurality of noise reduction pads (304) correspond to the plurality of impact columns (303) one by one and are connected to the top of the impact columns (303); and the bottom of the vibration connecting plate (204) abuts against the top of the noise reduction pad (304).

4. The sandy soil layer freezing model experimental device according to claim 1, characterized in that: A discharge port is provided at the lower part of the side wall of the mold box (202), and a discharge plate (9) is installed in the discharge port.

5. The sandy soil layer freezing model experimental device according to claim 1, characterized in that: It also includes a positioning connection component (10), the positioning connection component (10) including a plurality of monitoring component upper connection cylinders (1001), a plurality of water injection cylinders (1002), a plurality of upper sealing cylinders (1003), a plurality of monitoring component lower connection cylinders (1004) and a plurality of lower sealing cylinders (1005); the plurality of monitoring component upper connection cylinders (1001), the plurality of water injection cylinders (1002) and the plurality of upper sealing cylinders (1003) are evenly distributed on the box cover (203) and the bottom ends thereof are all connected to the inner cavity of the mold box (202); the monitoring component lower connection cylinder (1004) is arranged corresponding to the monitoring component upper connection cylinder (1001) and is fixed to the inner bottom wall of the mold box (202); the lower sealing cylinder (1005) is arranged corresponding to the upper sealing cylinder (1003) and the water injection cylinder (1002) and is fixed to the inner bottom wall of the mold box (202); The upper end of each group of monitoring components (4) is connected to the upper connecting tube (1001) of the monitoring components, and the lower end is connected to the lower connecting tube (1004) of the monitoring components. The water injection pipe joint (11) is installed on the top of the water injection tube (1002). The top cover of the upper sealing tube (1003) is provided with an upper sealing cover (12), and the top cover of the lower sealing tube (1005) is provided with a lower sealing cover. When the freezing tube (602) is arranged along the height direction of the mold box (202), the lower end of the freezing tube (602) is connected to the lower sealing tube (1005), and the upper end is connected to the corresponding upper sealing tube (1003).

6. A sandy soil layer freezing model experimental device according to claim 5, characterized in that: A plurality of positioning holes (2026) are provided on the outer peripheral side of each excavation hole (2025), and the positioning holes (2026) on the opposite side walls of the mold box (202) correspond to each other, and a side sealing cover (13) is installed at the outer end of the positioning hole (2026); Wherein, when the freezing pipe (602) is arranged along the excavation direction of the excavation hole (2025), its two ends are respectively connected to the positioning holes (2026) on both sides.

7. The sandy soil layer freezing model experimental device according to claim 5, characterized in that: Each group of the monitoring components (4) comprises a monitoring tube (401) and a plurality of groups of sensor components (402); the upper end of the monitoring tube (401) is connected to the upper connecting tube (1001) of the monitoring component, and the lower end is connected to the corresponding lower connecting tube (1004) of the monitoring component; the plurality of groups of sensor components (402) are arranged at intervals along the height direction of the monitoring tube (401), and each group of the sensor components (402) comprises a humidity sensor, a temperature sensor, a density sensor and a seepage velocity sensor.

8. The sandy soil layer freezing model experimental device according to claim 1, characterized in that: The inner wall of the freezing pipe (602) is installed with a partition (6021) arranged along its length direction to divide its inner cavity into an inlet channel (6022) and a return channel (6023), the inlet end of the inlet channel (6022) is connected to the outlet end of the freezing water circulation component (601), the inlet end of the return channel (6023) is connected to the outlet end of the inlet channel (6022), and the outlet end is connected to the return end of the freezing water circulation component (601).

9. The sandy soil layer freezing model experimental device according to claim 1, characterized in that: The excavation hole protection door (7) comprises an inner door panel (701), a rubber insulation panel (702), an outer door panel (703) and a slider (704) which are sequentially connected from the inside to the outside, wherein the inner wall of the inner door panel (701) is flush with the inner wall of the mold box (202), the slider (704) is slidably connected to the inner wall of the excavation hole (2025), and a limiting block (705) is formed on the outer wall of the end away from the inner door panel (701), and the limiting block (705) is connected to the outer wall of the mold box (202) in a limiting manner.

10. A method for using a sandy soil layer freezing model experimental device according to any one of claims 1 to 9, characterized in that: The steps include: S1: Assemble a sand layer freezing model experimental device, install a soil sample loading mold (2), a seepage water supply component (5), a freezing component (6) and a controller (8) on the upper surface of a bearing base (1), and then install a vibration component (3) at the bottom of the freezing mold box (202) according to the experimental plan, install a monitoring component (4) and a freezing pipe (602) inside, and connect the vibration component (3), each group of the monitoring components (4), the seepage water supply component (5) and the freezing water circulation component (601) to the controller (8) through wires; S2: Filling the interior of the freezing mold box (202) with sand and soil: manually using tools to fill the interior of the mold box (202) with experimental sand and soil samples, and starting the vibration component (3) during the process of filling the soil samples, using vibration to compact the experimental sand and soil inside the mold box (202), and finally installing the box cover (203); then, according to the experimental plan, installing a water injection pipe joint (11) on the corresponding water injection cylinder (1002), connecting the water injection pipe joint (11) to the water outlet end of the seepage water supply component (5), connecting the water outlet end of the freezing water circulation component (601) to the water inlet end of the freezing pipe (602), and connecting the return water end to the water outlet end of the freezing pipe (602); S3: seepage simulation of the sand model, determining the seepage data of the sand model according to the experimental plan, injecting water into the sand model by controlling the water output of the seepage water supply component (5), detecting the seepage data of the sand model by using the monitoring component (4), and performing data statistics by the controller (8); S4: freezing simulation of the sand model, determining the freezing data of the sand model according to the experimental plan, adjusting the temperature and water outlet speed of the freezing water circulation component (601), and adjusting the seepage parameters of the sand model during the freezing experiment; starting the freezing water circulation component (601) to introduce freezing circulating water into the freezing pipe (602), performing a freezing experiment on the sand model with continuous seepage, detecting parameter changes at various positions of the sand model through the monitoring component (4), and performing data statistics by the controller (8); S5: Conducting an excavation experiment to determine the effect of the freezing experiment on the sand soil model, maintaining continuous seepage of the sand soil model, removing the excavation hole protection door (7) inside the excavation hole (2025), and conducting an excavation test on the frozen sand soil model from the excavation hole (2025) to determine whether collapse or seepage occurs inside the pit of the sand soil model after excavation, and recording data during the excavation test of the sand soil model through the monitoring component (4). The controller (8) performs data statistics and judges the freezing effect of the sand soil model based on the actual situation of the excavation pit.

Images