CN117071575A - Method for protecting surrounding soil body or building during foundation pit construction - Google Patents
Method for protecting surrounding soil body or building during foundation pit construction Download PDFInfo
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- CN117071575A CN117071575A CN202310923471.9A CN202310923471A CN117071575A CN 117071575 A CN117071575 A CN 117071575A CN 202310923471 A CN202310923471 A CN 202310923471A CN 117071575 A CN117071575 A CN 117071575A
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- 239000002689 soil Substances 0.000 title claims abstract description 150
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000010276 construction Methods 0.000 title claims abstract description 31
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 118
- 238000010438 heat treatment Methods 0.000 claims abstract description 73
- 239000004568 cement Substances 0.000 claims abstract description 63
- 239000003673 groundwater Substances 0.000 claims abstract description 57
- 238000005086 pumping Methods 0.000 claims abstract description 55
- 239000002002 slurry Substances 0.000 claims abstract description 34
- 238000007710 freezing Methods 0.000 claims description 31
- 230000008014 freezing Effects 0.000 claims description 31
- 238000001816 cooling Methods 0.000 claims description 6
- 238000005553 drilling Methods 0.000 claims description 6
- 239000003507 refrigerant Substances 0.000 claims description 6
- 229910000851 Alloy steel Inorganic materials 0.000 claims description 5
- 230000000694 effects Effects 0.000 abstract description 4
- 238000009792 diffusion process Methods 0.000 description 9
- 238000009833 condensation Methods 0.000 description 5
- 230000005494 condensation Effects 0.000 description 5
- 239000003651 drinking water Substances 0.000 description 5
- 235000020188 drinking water Nutrition 0.000 description 5
- 239000011440 grout Substances 0.000 description 5
- 238000007569 slipcasting Methods 0.000 description 5
- 239000002023 wood Substances 0.000 description 3
- 230000001112 coagulating effect Effects 0.000 description 2
- 238000005485 electric heating Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D19/00—Keeping dry foundation sites or other areas in the ground
- E02D19/06—Restraining of underground water
- E02D19/10—Restraining of underground water by lowering level of ground water
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/11—Improving or preserving soil or rock, e.g. preserving permafrost soil by thermal, electrical or electro-chemical means
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Structural Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Civil Engineering (AREA)
- Paleontology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Agronomy & Crop Science (AREA)
- Soil Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The application discloses a method for protecting surrounding soil or buildings during foundation pit construction, which comprises the steps of firstly measuring the water level of groundwater between a foundation pit and a protected building; heating the soil above the groundwater between the foundation pit and the protected building for a set heating time period; grouting soil above groundwater between the foundation pit and the protected building, and enabling the injected cement slurry to enter the heated soil; after the cement paste injected into the heated soil is coagulated, the soil in the groundwater between the foundation pit and the protected building is grouted and pumped, the pumping and grouting are synchronously carried out, and grouting positions are positioned around the pumping position. The application has the effect of reducing the influence on the surrounding soil body and the building during the construction of the foundation pit.
Description
Technical Field
The application relates to the technical field of foundation pit construction, in particular to a method for protecting surrounding soil bodies or buildings during foundation pit construction.
Background
The foundation pit construction needs to excavate the soil body in the pit, and the original balance of water and soil pressure in the foundation pit and outside the foundation pit is damaged, so that the deformation of the surrounding soil body or the movement of water in the soil body is caused, the deformation of surrounding buildings is caused, and the damage of the buildings is caused seriously. In order to ensure the safety of foundation pit construction, supporting structures for maintaining the stability of the foundation pit, such as bored piles, steel piles, various retaining walls, anchor rods, underground continuous walls and the like, are generally designed, and the large foundation pit is designed with inner supports and is assisted with soil reinforcement, precipitation, monitoring and other means. However, foundation pit construction has a great influence on surrounding soil and buildings, and even the situation that the surrounding soil collapses and the surrounding buildings are askew occurs in severe cases.
With respect to the related art in the above, the applicant believes that the following drawbacks exist: foundation pit construction has a large adverse effect on surrounding soil and buildings.
Disclosure of Invention
In order to reduce the influence on the surrounding soil body and the building during the construction of the foundation pit, the application provides a method for protecting the surrounding soil body or the building during the construction of the foundation pit.
The method for protecting the surrounding soil body or the building during foundation pit construction provided by the application adopts the following technical scheme:
a method for protecting surrounding soil mass or building during foundation pit construction comprises the following steps:
measuring the level of groundwater between the foundation pit and the protected building;
heating the soil body above the groundwater between the foundation pit and the protected building for a set heating time period;
grouting soil above groundwater between the foundation pit and the protected building, and enabling the injected cement slurry to enter the heated soil;
after the cement paste injected into the heated soil is coagulated, the soil in the groundwater between the foundation pit and the protected building is grouted and pumped, the pumping and grouting are synchronously carried out, and grouting positions are positioned around the pumping position.
By adopting the technical scheme, the soil above the underground water is heated, so that the moisture in the soil is evaporated into water vapor, the soil is cracked, the generated water vapor can enlarge the gap of the soil, the injected cement paste can more effectively enter the gap of the soil, and the diffusion range of the cement paste is wide, so that a layer of cement paste condensed soil layer connected into a sheet is formed above the underground water, the strength of the cement paste condensed soil layer is higher, and the bearing capacity of the cement paste condensed soil layer is higher; then extracting the groundwater of the cement paste condensation soil layer, grouting, replacing part of the groundwater by cement paste, and forming a layer of cement paste condensation soil layer connected into a piece again to improve the bearing capacity of soil body; the cement paste coagulating soil layer is formed in the soil body between the foundation pit and the protected building, so that the strength of the soil body between the foundation pit and the protected building is improved, and the influence on the surrounding soil body and the building during foundation pit construction is reduced.
Preferably, the method of heating the soil above the groundwater between the foundation pit and the protected building comprises:
drilling a heating pipe made of alloy steel into the soil body above the groundwater between the foundation pit and the protected building, wherein the lower end of the heating pipe is 1-5m above the water surface of the groundwater;
lifting the heater into the heating pipe to a set depth, and then starting the heater, wherein the heater generates heat and conducts the heat to soil around the heating pipe through the pipe wall of the heating pipe;
and after the heating time reaches the set heating time, turning off the heater, and taking the heater out of the heating pipe.
By adopting the technical scheme, the heating pipe is made of alloy steel, the heat conductivity is good, and the heater is placed in the heating pipe, so that the height of the heater can be adjusted according to the requirement, and the soil body with the set height is heated; after the heating is completed, the heater can be taken out for heating the soil body next time.
Preferably, the lower end of the heating pipe is closed, a plurality of side holes are formed in the side wall of the heating pipe, and after the soil body is heated, the heated soil body is grouted through the heating pipe.
By adopting the technical scheme, the heating pipe is used as a heat conductor of the heater and a grouting pipeline, when the heating pipe is used for heating, the soil body close to the heating pipe has better heating effect, the faster and more water in the soil body evaporates, and part of formed water vapor can enter the heating pipe through the side hole and then be discharged out of the soil body, so that the air pressure in a soil body gap is reduced, and the subsequent grouting is facilitated; in addition, no grouting pipe is needed, so that the cost is saved.
Preferably, before grouting the soil above the groundwater between the foundation pit and the protected building, the cement paste is heated to a set temperature, and then the heated cement paste is injected into the soil.
By adopting the technical scheme, as part of water vapor stays in the heated soil gap, if normal-temperature cement slurry is adopted for grouting, the normal-temperature cement slurry can quickly cool the soil with higher temperature and the water vapor, so that the gap between the soil is quickly contracted, the diffusion speed of the cement slurry is reduced, the diffusion difficulty of the cement slurry is improved, and the diffusion range of the cement slurry is reduced, therefore, in order to improve the diffusion range of the injected cement slurry, the cement slurry is heated first and then grouting is carried out.
Preferably, the method for grouting and pumping the soil in the groundwater between the foundation pit and the protected building comprises the following steps: the method comprises the steps of respectively drilling a plurality of grouting pipes and water pumping pipes into a set depth of soil according to a designed position, distributing the plurality of grouting pipes around the water pumping pipes, connecting the grouting pipes with a slurry pump, connecting the water pumping pipes with a water pump, starting the water pump and the slurry pump, and synchronously pumping water and grouting.
Through adopting above-mentioned technical scheme, the water pump draws water through the drinking-water pipe, forms a rivers that flows to the drinking-water pipe by the slip casting pipe between slip casting pipe and drinking-water pipe, and after the slip casting pipe pours into the grout of certain pressure into, the grout flows along the rivers to the drinking-water pipe, replaces cement slurry with the water between slip casting pipe and the drinking-water pipe, improves the intensity of soil body.
Preferably, the lower ends of the grouting pipe and the water pumping pipe are respectively provided with a section of heat conducting pipe, after the grouting pipe and the water pumping pipe are drilled into the set depth of soil body, the refrigerating pipe is lowered into the heat conducting pipe, then the refrigerating machine is installed, two ports of the refrigerating pipe are respectively connected to the refrigerating machine, then the refrigerating machine is started, refrigerants of the refrigerating machine circulate between the refrigerating pipe and the refrigerating machine, heat exchange is carried out at the heat conducting pipe, groundwater around the heat conducting pipe is frozen into ice, after the starting time of the refrigerating machine reaches the set time, the refrigerating machine is closed, the refrigerating machine is removed, the refrigerating pipe is taken out, and finally grouting and water pumping are carried out.
By adopting the technical scheme, when the water pumping pipe pumps water outwards, the underground water around and below the water pumping pipe can flow to the water pumping pipe, the underground water below the water pumping pipe is limited to move to the water pumping pipe, only the underground water around the water pumping pipe is reserved to flow, cold energy is generated at the heat conducting pipe through the refrigerator and the refrigerating pipe, and then the cold energy is conducted to the underground water around the heat conducting pipe through the heat conducting pipe, so that the underground water around the heat conducting pipe is condensed into ice, a layer of ice is formed below the grouting pipe, the underground water below the water pumping pipe is blocked from moving to the water pumping pipe, the efficiency of the underground water around the water pumping pipe in moving to the water pumping pipe is improved, the efficiency of replacing the underground water between the grouting pipe and the water pumping pipe by cement paste is improved, and meanwhile, the drainage of the underground water can be reduced.
Preferably, the method for taking out the freezing tube comprises the following steps: after the refrigerator is closed, the freezing pipe is detached from the refrigerator, the refrigerant in the freezing pipe is recovered, then the two ports of the freezing pipe are placed at two positions with different heights, hot water is continuously filled into the freezing pipe from the port with the high position, so that ice on the periphery of the freezing pipe is melted, and after the cooling pipe is loosened, the cooling pipe is pulled upwards.
Through adopting above-mentioned technical scheme, the freezer pipe takes out and need melts the ice around the freezer pipe, but can not wear the ice layer hole again, lets in the melting rate of ice around the freezer pipe that hot water can conveniently be controlled in the freezer pipe.
Preferably, the portion of the freezer pipe located outside the heat pipe is covered with a heat insulating film.
Through adopting above-mentioned technical scheme, the thermal-insulated membrane can make cold volume spread in heat pipe department, avoids freezing the groundwater of heat pipe top and causes unable pumping and slip casting's condition to take place.
In summary, the application at least comprises the following beneficial technical effects: the soil above the underground water is heated, so that moisture in the soil is evaporated into water vapor, the soil is cracked, the water vapor can expand the gap of the soil, then injected cement paste can effectively enter the gap of the soil, the diffusion range of the cement paste is wide, a layer of cement paste condensed soil layer connected into a sheet is formed above the underground water, the strength of the cement paste condensed soil layer is higher, and the bearing capacity is higher; then extracting the groundwater of the cement paste condensation soil layer, grouting, replacing part of the groundwater by cement paste, and forming a layer of cement paste condensation soil layer connected into a piece again to improve the bearing capacity of soil body; the cement paste coagulating soil layer is formed in the soil body between the foundation pit and the protected building, so that the strength of the soil body between the foundation pit and the protected building is improved, and the influence on the surrounding soil body and the building during foundation pit construction is reduced.
Drawings
Fig. 1 is a construction schematic diagram of a method of protecting a surrounding soil body or a building during foundation pit construction according to an embodiment of the present application.
Fig. 2 is another construction schematic of a method of protecting surrounding soil or a building during foundation pit construction according to an embodiment of the present application.
Reference numerals illustrate:
1. a building envelope; 2. heating pipes; 3. a heater; 4. the heated soil body; 5. groundwater; 6. a water pumping pipe; 7. grouting pipe; 8. cement slurry coagulates the soil layer.
Detailed Description
The application is described in further detail below with reference to fig. 1-2.
The embodiment of the application discloses a method for protecting surrounding soil bodies or buildings during foundation pit construction.
The method for protecting the surrounding soil body or the building during the foundation pit construction comprises the following steps:
s1, after the construction of the enclosure structure 1 of the foundation pit is completed, drilling holes in the soil body between the designed foundation pit and the protected building to the depth of the groundwater 5, and then measuring the water level of the groundwater 5 between the foundation pit and the protected building.
S2, referring to FIG. 1, according to the measured water level of the groundwater 5, a heating pipe 2 made of alloy steel is drilled into the soil body above the groundwater 5 between the foundation pit and the protected building, the lower end of the heating pipe 2 is drilled to a position 1-5m above the water surface of the groundwater 5, namely, the position is stopped, and preferably, the position 3m above the water surface of the groundwater 5. The lower end of the heating pipe 2 is closed, and the side wall of the heating pipe 2 is provided with a plurality of side holes. Then the heater 3 is connected by a power line, the heater 3 is an electric heating wire, the heating temperature of the electric heating wire is 800 ℃, and the power line is made of a high temperature resistant cable and can bear the temperature of not lower than 850 ℃, preferably 1000 ℃. Then the water is hung into the heating pipe 2 to a set depth through the power line, the power line is connected, the heater 3 is started, the heater 3 generates heat and is conducted to soil around the heating pipe 2 through the pipe wall of the heating pipe 2, the temperature of the soil around the heating pipe 2 is increased, moisture in the soil is evaporated, and cracks are generated due to soil body dry cracks. After the heating time reaches the set heating time, the heater 3 is turned off, the heater 3 is taken out of the heating pipe 2, and at the moment, the heated soil body 4 has a certain crack, so that the follow-up grouting is facilitated. The heating duration of the embodiment is obtained through experiments, and the specific method is as follows: when the water level of the groundwater 5 is measured by drilling, a sample of one kilogram of soil is taken out from a position 5m above the water surface of the groundwater 5, the sample is placed in a bottle for compaction, the sample is heated by using high temperature of 500 ℃, when the soil cracks or gaps between the soil and the inner wall of the bottle are larger than 0.2mm, the heating time at the moment is recorded, the heating time is twice the heating time of the embodiment, and the heating time of the embodiment is 20 minutes.
S3, grouting the heated soil body 4 through the heating pipe 2 after the soil body is heated, wherein the grouting pressure is 2-5Mpa, the preferable grouting pressure is 3.5 Mpa, the grouting time is 20 minutes, the injected cement paste enters the heated soil body through the side holes, then the cement paste diffuses in a direction away from the heating pipe 2 through gaps and cracks between the soil bodies, after grouting, the upper end of the heating pipe 2 is plugged by using a wood plug, and a cement paste condensed soil layer 8 is formed after cement paste is condensed.
S4, referring to FIG. 2, after the cement paste injected into the heated soil is condensed, a plurality of grouting pipes 7 and water pumping pipes 6 are respectively drilled into the position 5-8 meters below the water surface of the groundwater 5 in the soil according to the designed position, the grouting pipes 7 and the water pumping pipes 6 can be drilled into the heating pipe 2 or the soil at other positions, and the grouting pipes 7 are not less than 4 and uniformly distributed around the water pumping pipes 6. And then connecting a plurality of grouting pipes 7 with the same slurry pump, connecting a water suction pipe 6 with a water pump, starting the water pump to pump water, starting the slurry pump to perform grouting, performing grouting synchronously with the water pumping, wherein the grouting pressure is 3-6Mpa, preferably 4Mpa, until the pumped water contains cement slurry, and closing the water pump and the slurry pump. The water pump and the water suction pipe 6 are disconnected, the slurry pump and the grouting pipe 7 are disconnected, then the upper end of the grouting pipe 7 is plugged by a wood plug, and the water suction pipe 6 is connected with the slurry pump. And (3) starting the slurry pump to inject cement slurry into the water pumping pipe 6, keeping the grouting pressure for 2-5 minutes, then closing the slurry pump, disconnecting the slurry pump from the water pumping pipe 6, and plugging the upper end of the water pumping pipe 6 by using a wood plug.
It should be noted that when heating the soil body, the heating pipes 2 at different positions can be simultaneously performed, the distance between two adjacent heating pipes 2 is 3-6 meters, the heating area of each heating pipe 2 is calculated according to 3 square meters, the area of each time heating the soil body is not more than 10 square meters, and collapse accidents caused by overlarge area of the soil body heated simultaneously are avoided. The distance between the heating pipe 2 and the building is not less than 10 meters, and the distance between the heating pipe 2 and the building support structure 1 of the foundation pit is not less than 5 meters, so that the influence of heating soil on the building and the building support structure 1 of the foundation pit is reduced. The distance between the grouting pipe 7 and the water pumping pipe 6 is 1-4 meters, when pumping water below the water surface of the underground water 5, only one position is pumped at a time, and the soil around the water pumping pipe 6 is monitored at any time to perform sedimentation monitoring.
In another embodiment, before grouting the heated soil body, the cement paste is heated to 80 ℃ first, and then the heated cement paste is injected into the soil body through the heating pipe 2. Because part of water vapor stays in the heated soil gap, if normal-temperature cement slurry grouting is adopted, the normal-temperature cement slurry can quickly cool the soil with higher temperature and the water vapor, so that the gap between the soil is quickly contracted, the diffusion range of the cement slurry is reduced, and the diffusion range of the injected cement slurry can be improved by heating the cement slurry.
In another embodiment, the inner walls of the grouting pipe 7 and the pumping pipe 6 are coated with a layer of heat-insulating coating, grouting holes are formed in the side wall of the lower end of the grouting pipe 7, the grouting holes are distributed along the circumferential direction and the axial direction of the grouting pipe 7, a plurality of pumping holes are formed in the side wall of the lower end of the pumping pipe 6, and the pumping holes are distributed along the circumferential direction and the axial direction of the pumping pipe 6. The lower ends of the grouting pipe 7 and the water suction pipe 6 are respectively provided with a section of heat conduction pipe made of alloy steel, after the grouting pipe 7 and the water suction pipe 6 are drilled into a set depth of soil body, the freezing pipe is lowered into the heat conduction pipe, the part of the freezing pipe outside the heat conduction pipe is wrapped by a heat insulation film, then a refrigerator is installed, two ports of the freezing pipe are respectively connected to the refrigerator, then the refrigerator is started, refrigerant of the refrigerator circularly flows between the freezing pipe and the refrigerator, heat exchange is carried out at the heat conduction pipe, groundwater 5 around the heat conduction pipe is frozen into ice, after the starting time of the refrigerator reaches the set time, the refrigerator is closed, the refrigerator is removed, the freezing pipe is taken out, and finally grouting and water pumping are carried out. The refrigerating machine and the refrigerating pipe generate cold energy at the heat-conducting pipe, and then the cold energy is conducted into the groundwater 5 around the heat-conducting pipe through the heat-conducting pipe, so that the groundwater 5 around the heat-conducting pipe is condensed into ice, a layer of ice is formed below the grouting pipe 7, the groundwater 5 below the water pumping pipe 6 is blocked from moving towards the water pumping pipe 6, the efficiency of the groundwater 5 around the water pumping pipe 6 for moving towards the water pumping pipe 6 is improved, the efficiency of replacing the groundwater 5 between the grouting pipe 7 and the water pumping pipe 6 by cement paste is improved, and meanwhile, the drainage of the groundwater 5 can be reduced. Since the water is frozen to cause the volume to become larger and possibly cause the soil body to bulge, the surrounding soil body needs to be monitored in the freezing process, and if the soil body bulges, the refrigerator is immediately turned off. For the position with less water 5 upwelling, the step of freezing the groundwater 5 is not performed, and the step of freezing the groundwater 5 in this embodiment is considered to be performed when the pumping time of the pump reaches 30 minutes or when no cement slurry is discharged from the pump. The method for taking out the freezing tube comprises the following steps: after the refrigerator is closed, the freezing pipe is detached from the refrigerator, the refrigerant in the freezing pipe is recovered, then the two ports of the freezing pipe are placed at two positions with different heights, hot water is continuously filled into the freezing pipe from the port with the high position, so that ice on the periphery of the freezing pipe is melted, and after the cooling pipe is loosened, the cooling pipe is pulled upwards.
The implementation principle of the method for protecting the surrounding soil body or the building during foundation pit construction in the embodiment of the application is as follows: the method of the embodiment can be implemented before the foundation pit is excavated, and can also be implemented simultaneously with the foundation pit excavation. The soil above the groundwater 5 is heated, so that moisture in the soil is evaporated into steam, the soil is cracked, the generated steam can expand gaps of the soil, then injected cement paste can more effectively enter the gaps of the soil, the diffusion range of the cement paste is wide, a layer of cement paste condensed soil layer 8 connected into a sheet is formed above the groundwater 5, the strength of the cement paste condensed soil layer 8 is high, and the cement paste condensed soil layer has high bearing capacity. And then extracting the groundwater 5 of the cement paste coagulated soil layer 8, grouting, replacing part of the groundwater 5 by cement paste, and forming a layer of cement paste coagulated soil layer 8 connected into a sheet again to improve the bearing capacity of soil bodies, wherein the soil bodies above the groundwater 5 are not collapsed when the groundwater 5 is extracted, so that the cement paste can smoothly replace part of the groundwater 5 and strengthen the soil bodies. It should be emphasized that the grout condensate layer 8 of the present application may be double-layered, and that a plurality of grout condensate layers 8 may be constructed above the water surface of the groundwater 5, or a plurality of grout condensate layers 8 may be constructed below the water surface of the groundwater 5. By forming the cement paste condensation soil layer 8 in the soil body between the foundation pit and the protected building, the strength of the soil body between the foundation pit and the protected building is improved, so that the influence on the surrounding soil body and the building during foundation pit construction is reduced.
The above embodiments are not intended to limit the scope of the present application, so: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.
Claims (8)
1. A method for protecting a surrounding soil body or a building during foundation pit construction, comprising the steps of:
measuring the level of groundwater between the foundation pit and the protected building;
heating the soil body above the groundwater between the foundation pit and the protected building for a set heating time period;
grouting soil above groundwater between the foundation pit and the protected building, and enabling the injected cement slurry to enter the heated soil;
after the cement paste injected into the heated soil is coagulated, the soil in the groundwater between the foundation pit and the protected building is grouted and pumped, the pumping and grouting are synchronously carried out, and grouting positions are positioned around the pumping position.
2. A method of protecting a surrounding soil body or a building in a foundation pit construction according to claim 1, wherein the method of heating the soil body above groundwater between the foundation pit and the protected building comprises:
drilling a heating pipe made of alloy steel into the soil body above the groundwater between the foundation pit and the protected building, wherein the lower end of the heating pipe is 1-5m above the water surface of the groundwater;
lifting the heater into the heating pipe to a set depth, and then starting the heater, wherein the heater generates heat and conducts the heat to soil around the heating pipe through the pipe wall of the heating pipe;
and after the heating time reaches the set heating time, turning off the heater, and taking the heater out of the heating pipe.
3. The method for protecting a surrounding soil body or a building during foundation pit construction according to claim 2, wherein the lower end of the heating pipe is closed, the side wall of the heating pipe is provided with a plurality of side holes, and after the soil body is heated, grouting is performed on the heated soil body through the heating pipe.
4. A method of protecting a surrounding earth or a building in a foundation pit according to claim 3, wherein the cement slurry is heated to a predetermined temperature prior to grouting the earth above the groundwater between the foundation pit and the protected building, and the heated cement slurry is injected into the earth.
5. A method of protecting a surrounding soil body or a building in a foundation pit construction according to claim 1, wherein the method of grouting and pumping soil body in groundwater between the foundation pit and the protected building comprises: the method comprises the steps of respectively drilling a plurality of grouting pipes and water pumping pipes into a set depth of soil according to a designed position, distributing the plurality of grouting pipes around the water pumping pipes, connecting the grouting pipes with a slurry pump, connecting the water pumping pipes with a water pump, starting the water pump and the slurry pump, and synchronously pumping water and grouting.
6. The method according to claim 5, wherein a section of heat-conducting pipe is provided at the lower ends of the grouting pipe and the water suction pipe, respectively, the grouting pipe and the water suction pipe are drilled into the soil body to a set depth, the freezing pipe is lowered into the heat-conducting pipe, then the refrigerating machine is installed, two ports of the freezing pipe are respectively connected to the refrigerating machine, then the refrigerating machine is started, refrigerant of the refrigerating machine circulates between the freezing pipe and the refrigerating machine, heat exchange is performed at the heat-conducting pipe, groundwater around the heat-conducting pipe is frozen into ice, after the starting time of the refrigerating machine reaches the set time, the refrigerating machine is turned off, the refrigerating pipe is removed, and finally grouting and water pumping are performed.
7. The method for protecting a surrounding soil body or a building during foundation pit construction according to claim 6, wherein the method for taking out the freezing pipe is as follows: after the refrigerator is closed, the freezing pipe is detached from the refrigerator, the refrigerant in the freezing pipe is recovered, then the two ports of the freezing pipe are placed at two positions with different heights, hot water is continuously filled into the freezing pipe from the port with the high position, so that ice on the periphery of the freezing pipe is melted, and after the cooling pipe is loosened, the cooling pipe is pulled upwards.
8. A method of protecting a surrounding earth or a building in a pit construction according to claim 6, wherein the portion of the freezing pipe located outside the heat transfer pipe is covered with a heat insulating film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310923471.9A CN117071575A (en) | 2023-07-25 | 2023-07-25 | Method for protecting surrounding soil body or building during foundation pit construction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310923471.9A CN117071575A (en) | 2023-07-25 | 2023-07-25 | Method for protecting surrounding soil body or building during foundation pit construction |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117071575A true CN117071575A (en) | 2023-11-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310923471.9A Pending CN117071575A (en) | 2023-07-25 | 2023-07-25 | Method for protecting surrounding soil body or building during foundation pit construction |
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| Country | Link |
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| CN (1) | CN117071575A (en) |
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2023
- 2023-07-25 CN CN202310923471.9A patent/CN117071575A/en active Pending
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