Prefabricated slope soil nailing pipe based on self-circulating heat exchange technology and its construction method

Abstract

This invention belongs to the field of geotechnical slope engineering technology, and provides a prefabricated slope soil nailing pipe based on self-circulating heat exchange technology and its construction method. The pipe includes a soil nail shell; a heat exchange assembly, which is disposed inside the soil nail shell and includes a thermosiphon rod and a heat exchange mechanism. The thermosiphon rod is located at the bottom of the soil nail shell, and the heat exchange mechanism is connected to the thermosiphon rod. The heat exchange mechanism absorbs and releases the heat transferred by the thermosiphon rod outward through the soil nail shell. A gravity-promoting drive component is installed inside the heat exchange mechanism to accelerate the flow of the heat exchange medium within the mechanism, ensuring heat exchange between the soil nail shell and the heat exchange mechanism even when the shell is not vertical; and a heat dissipation assembly, which is disposed inside the soil nail shell and connected to the heat exchange mechanism. The heat dissipation assembly releases the heat dissipated by the heat exchange mechanism into the air. This invention can provide stable support for slopes in cold regions and frozen soil beneath the slope.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical slope engineering technology, and particularly relates to prefabricated slope soil nailing pipes and construction methods based on self-circulating heat exchange technology. Background Technology

[0002] In the cold regions of Tibet, the soil and rock masses repeatedly experience freeze-thaw cycles as the seasons change. During this process, the soil suffers varying degrees of deformation and damage due to frost heave and thaw settlement.

[0003] As winter approaches in cold regions, temperatures gradually decrease, causing the previously flowing water inside slopes to freeze. The freezing process progresses slowly from the slope surface inwards. We know that water has a unique physical property: below 4°C, its temperature changes with temperature, exhibiting thermal expansion and contraction. Due to this property, when the rock mass has a high water content and numerous crisscrossing fissures, the expanding ice is constrained by the fixed boundaries of the rock slope, exerting sufficient pressure on the surface rock mass and generating a tremendous frost heave force. This causes the fissures to expand further, and combined with continuous weathering, the surface rock mass collapses and falls, ultimately leading to slope instability and failure.

[0004] Currently, some countries have adopted engineering facilities for slope protection against freeze-thaw cycles and slope stabilization in cold regions, including anchor bolts, heat pipes, ventilation ducts, anti-slide piles, and retaining walls, which have achieved some success. However, research and solutions to problems related to slope stability analysis and instability prevention under freeze-thaw cycles in cold regions are still insufficient, and such issues are only superficially addressed. Therefore, there is currently a lack of independent, economical, and environmentally friendly engineering facilities that can support and reinforce slopes in cold regions and prevent damage caused by freeze-thaw cycles. Summary of the Invention

[0005] The purpose of this invention is to provide prefabricated slope soil nailing pipes and construction methods based on self-circulating heat exchange technology to solve the above-mentioned problems and achieve the purpose of stabilizing slopes and frozen soil below slopes in cold regions.

[0006] To achieve the above objectives, the present invention provides the following solution: a prefabricated slope soil nailing pipe based on self-circulating heat exchange technology, comprising:

[0007] Soil nail shell;

[0008] A heat exchange assembly is disposed within the soil nail shell. The heat exchange assembly includes a thermosiphon rod and a heat exchange mechanism. The thermosiphon rod is disposed at the bottom of the soil nail shell, and the heat exchange mechanism is connected to the thermosiphon rod. The heat exchange mechanism is used to absorb and release the heat transferred by the thermosiphon rod through the soil nail shell. A gravity-promoting drive is disposed within the heat exchange mechanism. The gravity-promoting drive can accelerate the flow of the heat exchange medium within the heat exchange mechanism, so that the soil nail shell can still exchange heat with the heat exchange mechanism when it is in a non-vertical state.

[0009] A heat dissipation component is disposed inside the soil nail housing and is connected to the heat exchange mechanism. The heat dissipation component is used to release the heat dissipated by the heat exchange mechanism into the air.

[0010] Preferably, the heat exchange mechanism includes an evaporator and a condenser, which are connected by a gas pipe and a liquid pipe. The evaporator and condenser are filled with a heat exchange medium. The thermosiphon rod is fixedly connected to the evaporator. The gravity-driven component is disposed between the gas pipe and the liquid pipe. The main function of the gravity-driven component is to promote the flow of the heat exchange medium between the evaporator and the condenser.

[0011] Preferably, the gravity-driven component includes a driving wheel rotatably connected in the gas pipe and a driven wheel rotatably connected in the liquid pipe. The driving wheel and the driven wheel are connected by a transmission. The gaseous working fluid in the gas pipe can drive the driving wheel to rotate, and the driven wheel can drive the liquid in the liquid pipe to flow.

[0012] Preferably, the heat dissipation assembly includes a ventilation pipe, the thermosiphon rod, the evaporator and the condenser are respectively disposed inside the ventilation pipe, the ventilation opening of the ventilation pipe is located on the top outer side of the soil nail shell, and the ventilation tail pipe of the ventilation pipe is connected to the tail of the thermosiphon rod.

[0013] Preferably, the ventilation duct is made of metal or bamboo.

[0014] Preferably, it also includes a data monitoring component, which includes a plurality of sensor placement slots formed on the side wall of the soil nail housing. The plurality of sensor placement slots are evenly arranged along the axial side wall of the soil nail housing, and strain gauges and sensors are disposed in the sensor placement slots.

[0015] The construction method for prefabricated slope soil nailing pipes based on self-circulating heat exchange technology includes the following steps:

[0016] S1. Precast soil nails and transport several precast soil nail pipes to the construction site;

[0017] S2. Carry out earthwork excavation and slope trimming. While trimming the slope, simultaneously drive several soil nails into the predetermined positions on the slope.

[0018] S3. After the earthwork excavation reaches the specified elevation, immediately spray concrete to protect the excavation surface.

[0019] Preferably, in step S3, after spraying concrete, the ventilation opening should be located on the outside of the concrete layer.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] 1. This invention is an integrated construction facility for supporting and reinforcing slopes and the underlying frozen soil in high-altitude and cold regions under freeze-thaw cycles.

[0022] 2. The heat exchange mechanism and gravity-driven component of the present invention complement each other, which can reduce the impact of terrain and inclination on its function during installation, and solve the defect that the original thermosiphon rod itself can only rely on vertical placement for gravity circulation, so it can be applied to slope and other projects.

[0023] 3. The internal heat dissipation components of this device can assist the heat exchange mechanism in its operation, and make the heat dissipation of the device more efficient and stable. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the soil nailing tube of the present invention;

[0026] Figure 2 This is a schematic diagram of the heat exchange mechanism of the present invention;

[0027] Figure 3 This is a schematic diagram of the gravity-driven component of the present invention;

[0028] Figure 4 This is a cross-sectional schematic diagram of the gravity-driven component of the present invention;

[0029] Figure 5 This is a cross-sectional view of the soil nailing tube of the present invention;

[0030] Figure 6 This is a construction effect diagram of the present invention;

[0031] Figure 7 This is another construction effect diagram of the present invention;

[0032] The components are as follows: 1. Evaporator; 2. Gas pipe; 3. Liquid pipe; 4. Driving wheel; 5. Driven wheel; 6. Condenser; 7. Connecting housing; 8. Soil nail housing; 9. Sensor placement slot; 10. Soil nail fixing ring; 11. Ventilation tailpipe; 12. Ventilation opening; 13. Soil nail pipe; 14. Ventilation pipe; 16. Slope drilling hole; 17. Bevel gear; 18. Intermediate bevel gear; 19. Thermosiphon rod. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figures 1-7 This invention provides a prefabricated slope soil nailing pipe based on self-circulating heat exchange technology, comprising:

[0036] 8. Soil nail shell;

[0037] A heat exchange assembly is disposed inside the soil nail shell 8. The heat exchange assembly includes a thermosiphon rod 19 and a heat exchange mechanism. The thermosiphon rod 19 is disposed at the bottom of the soil nail shell 8. The heat exchange mechanism is connected to the thermosiphon rod 19 and is used to absorb the heat transferred by the thermosiphon rod 19 and release it to the outside through the soil nail shell 8. A gravity-promoting drive is provided inside the heat exchange mechanism. The gravity-promoting drive can accelerate the flow of the heat exchange medium inside the heat exchange mechanism, so that the soil nail shell 7 can still exchange heat with the heat exchange mechanism when it is in a non-vertical state.

[0038] The heat dissipation component is installed inside the soil nail housing 8 and is connected to the heat exchange mechanism. The heat dissipation component is used to release the heat dissipated by the heat exchange mechanism into the air.

[0039] The main function of the thermosiphon 19 is to directly absorb heat from the soil layer and transfer it to the heat exchange mechanism. The main function of the heat exchange mechanism is to release the heat absorbed by the thermosiphon 19 to the outside, thereby reducing the temperature of the frozen soil. The main function of the gravity-driven component is to ensure that the heat exchange mechanism can still operate and exchange heat even when the soil nail shell 8 is tilted. The main function of the heat dissipation component is to accelerate the release of the heat dissipated by the heat exchange mechanism into the air. Overall, this invention can achieve a self-circulating heat exchange process with the frozen soil layer under different terrains and angles, maintaining the temperature of the frozen soil layer within a certain range, while providing stable support for slopes and frozen soil below the slope in cold regions.

[0040] Further optimization of the scheme: The thermosiphon rod 19 is an existing technology. Liquid ammonia is injected into the thermosiphon tube. The liquid ammonia absorbs heat from the frozen soil layer, evaporates and becomes gaseous ammonia. It rises to one end near the heat exchange mechanism, releases heat to the heat exchange structure, and then becomes liquid ammonia again and flows down the thermosiphon tube to achieve cyclic heat absorption.

[0041] The scheme is further optimized. The heat exchange mechanism includes an evaporator 1 and a condenser 6, which are connected by a gas pipe 2 and a liquid pipe 3. The evaporator 1 and the condenser 6 are filled with heat exchange working fluid. The thermosiphon rod 19 is fixedly connected to the evaporator 1. The gravity-driven component is set between the gas pipe 2 and the liquid pipe 3. The main function of the gravity-driven component is to promote the flow of heat exchange working fluid between the evaporator 1 and the condenser 6.

[0042] The scheme is further optimized so that the gravity drive component includes a driving wheel 4 rotatably connected in the gas pipe 2 and a driven wheel 5 rotatably connected in the liquid pipe 3. The driving wheel 4 and the driven wheel 5 are connected by transmission. The gaseous working medium in the gas pipe 2 can drive the driving wheel 4 to rotate, and the driven wheel 5 can drive the liquid in the liquid pipe 3 to flow.

[0043] In a further optimized design, a connecting housing 7 is provided between the driving wheel 4 and the driven wheel 5. Bevel gears 17 are fixedly connected to the driving wheel 4 and the driven wheel 5 on the same axis. The two sets of bevel gears 17 are located inside the connecting housing 7. An intermediate bevel gear 18 is rotatably connected inside the connecting housing 7. The two sets of bevel gears 17 mesh with the intermediate bevel gear 18.

[0044] The scheme was further optimized, and Freon and coolant were selected as the heat exchange medium.

[0045] like Figures 2-4As shown, after the thermosiphon rod 19 transfers heat to the evaporator 1, due to the high temperature of the evaporator 1 and the relatively low temperature of the condenser 6, the working fluid in the evaporator 1 becomes gaseous. Because of the thermal potential difference (corresponding to the saturation pressure difference) between the evaporator 1 and the condenser 6, the gaseous working fluid flows to the condenser 6 through the gas pipe 2. The gaseous working fluid in the gas pipe 2 drives the drive wheel 4 to rotate. Since the two bevel gears 17 mesh with the same intermediate bevel gear 18, and the two bevel gears 17 rotate in opposite directions, the rotation of the drive wheel 4 drives the driven wheel 5 to rotate in the opposite direction through the transmission of the bevel gears 17 and the intermediate bevel gear 18. The rotation of the driven wheel 5 drives the liquid working fluid in the liquid pipe 3 to flow into the evaporator 1. Because the volumetric flow rate of the gaseous working fluid in gas pipe 2 is much greater than the volumetric flow rate (density) of the liquid working fluid in liquid pipe 3, when the driving wheel 4 and the driven wheel 5 rotate at the same power, the pressure head obtained by the liquid working fluid is much greater than the pressure head lost by the gaseous working fluid. This pressure head can overcome the flow resistance throughout the entire flow process, enabling continuous heat exchange between the evaporator 1 and the condenser 6.

[0046] Further optimization of the scheme: the heat dissipation component includes a ventilation pipe 14, a thermosiphon rod 19, an evaporator 1 and a condenser 6 respectively installed inside the ventilation pipe 14, the ventilation port 12 of the ventilation pipe 14 is located on the top outer side of the soil nail shell 8, and the ventilation tail pipe 11 of the ventilation pipe 14 is connected to the tail of the thermosiphon rod 19.

[0047] like Figure 5 As shown, the ventilation duct 14 can promote the dissipation of heat from the condenser 6 into the air. Specifically, the heat emitted by the condenser 6 is released into the air through the ventilation port 12 to promote the realization of the heat exchange function between the evaporator 1 and the condenser 6.

[0048] Further optimization of the design: ventilation duct 14 can be made of metal or bamboo.

[0049] Further optimization of the scheme also includes a data monitoring component, which includes several sensor placement slots 9 opened on the side wall of the soil nail housing 8. The several sensor placement slots 9 are evenly arranged along the axial side wall of the soil nail housing 8, and strain gauges and sensors are installed in the sensor placement slots 9.

[0050] like Figure 1 and Figure 7 As shown, strain gauges are arranged longitudinally along the slope. When placing the strain gauges and corresponding sensors into the sensor placement slot 9, they must also be evenly distributed along the circumference of the member. The corresponding sensors are arranged perpendicular to the member. By placing the sensors in the sensor placement slot 9, parameters such as temperature, acceleration, pressure, and displacement can be selectively monitored to observe the slope and the development of the underlying frozen soil in real time during the test. The strain gauges and sensors allow for real-time monitoring of some field data of the slope, facilitating subsequent maintenance and improvement work.

[0051] The design has been further optimized by installing a soil nail fixing ring 10 on the top of the soil nail shell 8.

[0052] The main function of the soil nail fixing ring 10 is to fix the soil nail shell 8 to the slope after the soil nail shell 8 is inserted into the predetermined borehole.

[0053] Further optimizations include a photovoltaic power generation system, which provides power to several strain gauges and to power the condenser during startup.

[0054] Since photovoltaic power generation systems are existing technology, they will not be described in detail here.

[0055] The construction method for prefabricated slope soil nailing pipes based on self-circulating heat exchange technology includes the following steps:

[0056] S1. Precast soil nails and transport several precast soil nail pipes 13 to the construction site;

[0057] S2. Excavate earthwork and trim the slope. While trimming the slope, simultaneously drive several soil nails 13 into the predetermined positions on the slope and grout between the soil nails 13 and the soil.

[0058] like Figure 6 and Figure 7 As shown, the construction of the soil nailing pipe 13 of the present invention is carried out simultaneously with the slope repair. After the excavation of one layer of soil and the slope repair are completed, the soil nailing pipe 13 is drilled into the slope soil using a drilling rig.

[0059] Among them, 16 slope boreholes were drilled according to the points, depths, and angles required by the design drawings, and the positions of each slope borehole 16 were marked with red paint. A pneumatic down-the-hole hammer was used for drilling, and the drilling angle should be carefully controlled during drilling.

[0060] After all the soil nail tubes 13 have been placed in their designated positions, the soil nail tubes are fixed to the upper end of the slope borehole 16 using the soil nail fixing ring 10.

[0061] Grouting is uniformly injected into the borehole using a grouting pump. The grouting pipe must be inserted 50cm from the bottom of borehole 16 on the slope to ensure grouting quality. Plain cement grout is prepared using ordinary Portland cement No. 42.5. Grouting is performed from the bottom of borehole 16 on the slope using a soft plastic pipe, with each borehole receiving at least 1-2 additional grouting passes after initial grouting. Bottom-hole grouting should be used to ensure full grouting. A secondary grouting process is also employed, using pure cement grout for the secondary grouting.

[0062] S3. After the earthwork excavation reaches the specified elevation, immediately spray concrete to protect the excavation surface.

[0063] Once the earthwork has been excavated to the specified elevation, shotcrete is applied to protect the surface and prevent the soil from loosening and collapsing.

[0064] When starting a shotcrete operation, air should be supplied first, then the machine should be started, and then the material should be fed. When finishing, the air should be turned off only after all the material has been sprayed. The material supply to the shotcrete machine should be continuous and uniform, and sufficient material should be kept in the hopper.

[0065] To further optimize the scheme, in step S3, after spraying concrete, ensure that the ventilation opening 12 is located on the outside of the concrete layer.

[0066] Ventilation opening 12 must be exposed on the outside of the protective cover to ensure that the heat from ventilation duct 14 is dissipated smoothly into the air.

[0067] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An assembled slope soil nailing pipe based on self-circulation heat exchange technology, characterized in that, include: Soil nail shell (8); A heat exchange assembly is disposed inside the soil nail shell (8). The heat exchange assembly includes a thermosiphon rod (19) and a heat exchange mechanism. The thermosiphon rod (19) is disposed at the bottom of the soil nail shell (8). The heat exchange mechanism is connected to the thermosiphon rod (19). The heat exchange mechanism is used to absorb and release the heat transferred by the thermosiphon rod (19) through the soil nail shell (8). A gravity-promoting drive is disposed inside the heat exchange mechanism. The gravity-promoting drive can accelerate the flow of the heat exchange medium inside the heat exchange mechanism, so that the soil nail shell (8) can still exchange heat with the heat exchange mechanism when it is in a non-vertical state. A heat dissipation component is disposed inside the soil nail shell (8), and the heat dissipation component is connected to the heat exchange mechanism. The heat dissipation component is used to release the heat dissipated by the heat exchange mechanism into the air. The heat exchange mechanism includes an evaporator (1) and a condenser (6). The evaporator (1) and the condenser (6) are connected by a gas pipe (2) and a liquid pipe (3). The evaporator (1) and the condenser (6) are filled with heat exchange working fluid. The thermosiphon rod (19) is fixedly connected to the evaporator (1). The gravity-driven component is disposed between the gas pipe (2) and the liquid pipe (3). The gravity-driven component includes a drive wheel (4) rotatably connected in the gas pipe (2) and a driven wheel (5) rotatably connected in the liquid pipe (3). The drive wheel (4) and the driven wheel (5) are connected by transmission. The gaseous working medium in the gas pipe (2) can drive the drive wheel (4) to rotate, and the driven wheel (5) can drive the liquid in the liquid pipe (3) to flow. The heat dissipation assembly includes a ventilation pipe (14), the thermosiphon rod (19), the evaporator (1) and the condenser (6) are respectively disposed in the ventilation pipe (14), the ventilation port (12) of the ventilation pipe (14) is located on the top outer side of the soil nail shell (8), and the ventilation tail pipe (11) of the ventilation pipe (14) is connected to the tail of the thermosiphon rod (19).

2. The prefabricated slope soil nailing pipe based on self-circulating heat exchange technology according to claim 1, characterized in that: The ventilation duct (14) is made of metal or bamboo.

3. The prefabricated slope soil nailing pipe based on self-circulating heat exchange technology according to claim 1, characterized in that: It also includes a data monitoring component, which includes a plurality of sensor placement slots (9) formed on the side wall of the soil nail housing (8). The plurality of sensor placement slots (9) are evenly arranged along the axial side wall of the soil nail housing (8). Strain gauges and sensors are provided in the sensor placement slots (9).

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