Deep foundation pit construction technology

Abstract

The invention provides a deep foundation pit construction technology, and belongs to the technical field of foundation pit construction. According to the deep foundation pit construction technology, flow lofting is conducted, lime or timber piles are used for marking the contour line of a foundation pit, it is ensured that paying-off is accurate, a slope entry is provided with a ditch for construction, rainwater on the slope top is effectively collected and drained, water and soil loss and slope surface erosion are prevented, a foundation pit slope is excavated, the angle of the slope surface is determined according to design requirements, and the slope surface is trimmed through an excavator or manual work. A firm supporting structure is formed by shotcreting an anchor on a side slope, shotcreting concrete on the surface of the side slope and combining with an anchor rod so as to enhance the stability and the safety of the side slope, and a continuous enclosure structure is formed by driving a steel sheet pile into soil so as to enhance the stability and the safety of a foundation pit. The foundation pit construction technical standard is updated, and the method adapts to new technologies and new processes.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit construction, and in particular to a deep foundation pit construction process. Background Art

[0002] The retaining structure, groundwater control, environmental protection and other measures required to ensure the safety and stability of the underground space formed by excavating downward from the ground during the construction of underground structures are called foundation pit engineering. Foundation pit engineering is a systematic engineering that integrates geological engineering, geotechnical engineering, structural engineering and geotechnical testing technology.

[0003] The existing deep foundation pit construction requires a large number of professional technicians and workers, with high labor costs. The technical standards for foundation pit construction are updated slowly, making it difficult to adapt to the development of new technologies and new processes. The construction efficiency is low and the construction period is increased. Summary of the invention

[0004] In order to make up for the above shortcomings, the present invention provides a deep foundation pit construction process, which aims to improve the problems of slow updating of foundation pit construction technical standards, difficulty in adapting to the development of new technologies and new processes, low construction efficiency and increased construction period.

[0005] The present invention is achieved in that:

[0006] The present invention provides a deep foundation pit construction process, comprising the following steps:

[0007] S1: Flow setting out, use white lime or wooden stakes to mark the outline of the foundation pit to ensure that the setting out is accurate;

[0008] S2: Construction of drainage ditches on the top of the slope to effectively collect and discharge rainwater on the top of the slope to prevent soil erosion and slope erosion;

[0009] S3: Excavation of foundation pit slope. Determine the slope angle according to the design requirements. Use an excavator or manually trim the slope to ensure that the slope is flat and smooth without obvious bumps.

[0010] S4: Slope spray anchor, spraying concrete on the slope surface and combining it with anchor rods to form a solid support structure to enhance the stability and safety of the slope;

[0011] S5: Steel sheet pile injection: driving steel sheet piles into the soil to form a continuous retaining structure to enhance the stability and safety of the foundation pit;

[0012] S6: The sequence and method of foundation pit excavation and earthwork excavation shall be consistent with the design conditions;

[0013] S7: Monitoring and measurement, including measuring elevations and monitoring measurements;

[0014] S8: Basement construction, clearing loose soil and debris from the base, compacting the base, structural construction, and pouring concrete;

[0015] S9: Backfill the foundation pit. Use an excavator or manual labor to evenly spread the backfill material in the foundation pit and compact it.

[0016] Preferably, the flow sampling in step S1 includes laying out well points, installing flow meters and collecting data to realize well point precipitation detection. Multiple well points are laid out around the foundation pit, each well point is connected to the water collection main through a pipeline, and a flow meter, such as an electromagnetic flow meter or an ultrasonic flow meter, is installed on the pipeline of each well point. The flow data of each well point is regularly recorded to monitor the pumping and drainage of groundwater.

[0017] Preferably, the slope ditch in step S2 is constructed with prefabricated steel intercepting ditches, water collection wells in the pit, and drainage at the bottom of the pit is also in the form of steel pressure downward pressure. The pipeline is arranged around the foundation pit, and the points are arranged at a spacing of 3m. The water collection piles at the points are made of steel, with a sponge water absorption layer and a water storage pipe inside. After each deepening of the excavation, only all water needs to be collected downward to ensure timely and convenient drainage at the bottom of the pit. The water at the water collection point is pumped from the water collection well position pressure.

[0018] Preferably, the excavation of the foundation pit slope in step S3 should follow the principle of excavation from top to bottom and in layers to avoid damaging the slope foot and causing landslides. During excavation, the foundation pit slope should adopt a safe slope according to the backfill situation and environmental conditions. The width of the exposed part of each excavation step should be controlled within 20m, and the excavation height of each layer should be controlled not to exceed 2m. It is strictly forbidden to excavate to the bottom at one time under one working condition.

[0019] Preferably, the slope spray anchor in step S4 adopts a lattice stabilizing layer to be laid around the foundation pit at a position 5m around the excavation line, which can stabilize the layer and evenly bear the force, reduce the local settlement caused by uneven force caused by heavy trucks transporting soil, and be set to a reverse slope angle, which becomes a good way of drainage and waterproofing, ensuring that the outer side of the top of the foundation pit is not disturbed. The lattice stabilizing layer is actually a combination of a geogrid plastic type and a waterproof layer on the top.

[0020] Preferably, the steel sheet pile driving in step S5 is performed by setting up auxiliary guide frames along the line, which can be assembled, and all fastener styles are adjustable, which can be used to adjust the steel sheet pile driving process to prevent displacement interference, and a wearable steel sheet pile pointed hat is set, which is made of high-strength 355 steel and can effectively protect the resistance of breaking deep into the rock formation.

[0021] Preferably, the foundation pit excavation in step S6 is performed by setting a light-emitting device on the front end bucket of the excavator, indicating scales at the positions of each steel sheet pile to ensure that the last 0.3m is not over-excavated, and the excavation line is considered to have reached the specified depth by the coincidence of the light-emitting line and the marked scale, thus avoiding multiple manual over-leveling and being convenient for mechanical excavation personnel to quickly determine the excavation depth.

[0022] Preferably, the step S7 includes measuring elevation and monitoring measurement. After measuring the elevation, if the excavation is not in place, the excavation can continue. The monitoring measurement is used to measure the quality of the foundation pit excavation process. If there is any unqualified phenomenon, it is necessary to stop the work in time and make rectifications.

[0023] Preferably, the basement construction in step S8 is to process the basement, including cleaning, compacting and leveling, waterproofing, and welding pipes with plum blossom holes at the side seams of the steel sheet piles. Steel pipe piles with a spacing of 1m need to be welded, and those near the river need to be welded. According to the geological drawings, the positions where groundwater exists need to be welded. The spacing of the pipe holes is 0.3m, and the opening diameter is 2cm. After the insertion and driving, the steel pipe piles are pressure grouting, and the grouting process follows the anchor grouting process. The device to protect the insertion and driving process from damage is the aforementioned assembled pile tip with a pointed cap.

[0024] Preferably, the backfilling of the foundation pit in step S9 is carried out according to the properties of the backfilling material and the capacity of the compaction equipment to determine the thickness of each backfilling layer, and the backfilling material is evenly spread in the foundation pit using an excavator or manually, and after each layer of the backfilling material is spread, it is compacted using a rammer or a vibrating roller, and a temporary drainage ditch is set around the foundation pit to prevent rainwater and surface water from flowing into the foundation pit, and drainage pipes are laid in the backfilling material to ensure that the groundwater can be discharged smoothly, and vegetation is restored on the ground after backfilling to enhance the stability of the soil, and the road surface is restored on the ground to ensure the traffic capacity of the road.

[0025] The beneficial effects of the present invention are as follows: the present invention obtains a deep foundation pit construction process through the above design, through flow surveying, the outline of the foundation pit is marked with lime or wooden stakes to ensure that the line is accurately laid out, the slope is constructed with a ditch to effectively collect and discharge rainwater on the top of the slope to prevent soil erosion and slope erosion, the foundation pit slope is excavated, the angle of the slope is determined according to the design requirements, the slope is trimmed by an excavator or manually to ensure that the slope is flat and smooth without obvious bumps, the slope is sprayed with anchors, concrete is sprayed on the slope surface and combined with anchor rods to form a solid support structure to enhance the stability and safety of the slope Safety, steel sheet pile injection, driving the steel sheet piles into the soil to form a continuous retaining structure to enhance the stability and safety of the foundation pit, foundation pit excavation, the order and method of earth excavation must be consistent with the design conditions, monitoring and measurement, including measuring elevations and monitoring measurements, basement construction, removing loose soil and debris from the base, compacting the base, structural construction, pouring concrete, backfilling the foundation pit, using an excavator or manually spreading the backfill material evenly in the foundation pit and compacting it, updating the technical standards for foundation pit construction, adapting to the development of new technologies and new processes, improving construction efficiency, and shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of a deep foundation pit construction process flow provided by an implementation method of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0029] Example

[0030] The present invention provides a deep foundation pit construction process, comprising the following steps:

[0031] S1: Flow setting out, use white lime or wooden stakes to mark the outline of the foundation pit to ensure that the setting out is accurate;

[0032] S2: Construction of drainage ditches on the top of the slope to effectively collect and discharge rainwater on the top of the slope to prevent soil erosion and slope erosion;

[0033] S3: Excavation of foundation pit slope. Determine the slope angle according to the design requirements. Use an excavator or manually trim the slope to ensure that the slope is flat and smooth without obvious bumps.

[0034] S4: Slope spray anchor, spraying concrete on the slope surface and combining it with anchor rods to form a solid support structure to enhance the stability and safety of the slope;

[0035] S5: Steel sheet pile injection: driving steel sheet piles into the soil to form a continuous retaining structure to enhance the stability and safety of the foundation pit;

[0036] S6: The sequence and method of foundation pit excavation and earthwork excavation shall be consistent with the design conditions;

[0037] S7: Monitoring and measurement, including measuring elevations and monitoring measurements;

[0038] S8: Basement construction, clearing loose soil and debris from the base, compacting the base, structural construction, and pouring concrete;

[0039] S9: Backfill the foundation pit. Use an excavator or manual labor to evenly spread the backfill material in the foundation pit and compact it.

[0040] In this embodiment, the flow sampling in step S1 includes laying out well points, installing flow meters and collecting data to realize well point precipitation detection. Multiple well points are laid out around the foundation pit, and each well point is connected to the water collection main through a pipeline. A flow meter, such as an electromagnetic flow meter or an ultrasonic flow meter, is installed on the pipeline of each well point. The flow data of each well point is recorded regularly to monitor the pumping and drainage of groundwater.

[0041] In this embodiment, the slope ditch in step S2 is constructed with prefabricated steel intercepting ditches, water collection wells in the pit, and drainage at the bottom of the pit is also in the form of steel pressure downward pressure. The pipeline is arranged around the foundation pit, and the points are arranged at a spacing of 3m. The water collection piles at the points are made of steel, with a sponge water absorption layer and a water storage pipe inside. After each deepening of the excavation, it is only necessary to press down all the water to ensure timely and convenient drainage at the bottom of the pit. The water at the water collection point is pumped from the water collection well position pressure.

[0042] In this embodiment, the excavation of the foundation pit slope in step S3 should follow the principle of excavation from top to bottom and in layers to avoid damaging the slope foot and causing landslides. During excavation, the foundation pit slope should adopt a safe slope according to the backfill situation and environmental conditions. The width of the exposed part of each excavation step should be controlled at 20m, and the excavation height of each layer should be controlled not to exceed 2m. It is strictly forbidden to excavate to the bottom at one time under one working condition.

[0043] In this embodiment, the slope spray anchor in step S4 adopts a lattice stabilizing layer to be laid around the foundation pit at a position 5m around the excavation line, which can stabilize the layer and evenly bear the force, reduce the local settlement caused by uneven force caused by heavy trucks transporting soil, and set it to a reverse slope angle, which becomes a good way of drainage and waterproofing, ensuring that the outer side of the top of the foundation pit is not disturbed. The lattice stabilizing layer is actually a combination of geogrid plastic and a waterproof layer on the top.

[0044] In this embodiment, the steel sheet pile driving in step S5 is to set up an auxiliary guide frame along the line, which can be assembled, and all fastener styles are adjustable. It can be used to adjust the steel sheet pile driving process to prevent displacement interference, and a wearable steel sheet pile pointed hat is set. The material is high-strength 355 steel, which can effectively protect the resistance of penetrating into the rock formation.

[0045] 1. Steel sheet piles are placed using crawler excavators. Before placement, you must be familiar with the underground pipeline structure and lay out the accurate center line of the support piles.

[0046] 2. Before piling, check each steel sheet pile one by one, and remove those with rusted or severely deformed connection locks. Those that fail the test can only be used after being repaired.

[0047] 3. Before piling, apply grease inside the lock mouth of the steel sheet pile to facilitate driving in and out.

[0048] 4. During the driving process, measure and monitor the slope of each pile at any time to ensure it does not exceed 2%. When the deviation is too large and cannot be adjusted by pulling it in line, pull it up and drive it again.

[0049] 5. The steel sheet piles are driven in a screen-type driving method. The screen-type driving method is not easy to cause the sheet piles to bend, twist, tilt, and wall surface unevenness. It has high driving accuracy and is easy to achieve closure. During construction, 10-20 steel sheet piles are inserted into the guide frame in a row to make it screen-shaped, and then driven. Usually, a group of steel sheet piles at both ends of the screen wall are driven to the designed elevation or a certain depth, and the verticality is strictly controlled. They are fixed on the purlin by electric welding, and then driven in the middle in sequence at 1 / 3 or 1 / 2 of the sheet pile height.

[0050] The expansion and contraction in the axial direction, the convexity and concavity of the sheet pile wall and the pile driving efficiency have a direct impact. Therefore, the order of injection is one of the keys to the sheet pile construction process. The selection principle is: when the sheet piles installed at both ends of the screen wall are tilted in the opposite direction, the forward sequence should be used; otherwise, the reverse sequence should be used; when the sheet piles at both ends of the screen wall remain vertical, the reciprocating sequence can be used; when the length of the sheet pile wall is very long, the composite sequence can be used.

[0051] During construction, the injection sequence should be changed according to the specific situation. One or more injection sequences should be adopted to gradually drive the sheet piles to the designed elevation. The depth of one injection is generally 0.5-3.0m.

[0052] The tolerance standards for steel sheet pile driving are as follows:

[0053] The allowable deviation of the sheet pile axis is ±10cm; the allowable deviation of the pile top elevation is ±10cm; the allowable deviation of the sheet pile verticality is 5‰.

[0054] 6. Make sure the steel sheet piles are tightly fastened and not less than 2m into the soil after excavation to ensure smooth closure of the steel sheet piles. In particular, the four corners of the working pit should use corner steel sheet piles. If there are no such steel sheet piles, use old tires or rags to fill the seams and other auxiliary measures to seal them.

[0055] 7. After driving the steel sheet piles, promptly check the water tightness of the steel sheet pile body, repair the leaks by welding, and assign a special person to check the pile body every day.

[0056] 8. In order to achieve closed closure at the corners, reinforced special corner piles are used at the corners on site to ensure the stability and safety of the steel sheet piles.

[0057] In this embodiment, the foundation pit excavation in step S6 is to set a light-emitting device on the front end bucket of the excavator, and indicate a scale at the position of each steel sheet pile to ensure that the last 0.3m is not over-excavated. When the light-emitting line coincides with the marked scale, it is considered that the excavation line has reached the specified depth, avoiding multiple manual over-leveling, and can be used for mechanical excavation personnel to quickly determine the excavation depth.

[0058] In this embodiment, step S7 includes measuring elevation and monitoring measurement. After measuring the elevation, if the excavation is not in place, the excavation can continue. The monitoring measurement is used to measure the quality of the foundation pit excavation process. If there is any unqualified phenomenon, it is necessary to stop the work in time and make rectifications.

[0059] Monitoring points are arranged in batches on the slopes and supporting structures according to the progress of the on-site foundation pit excavation construction. During the excavation process, the slopes and supporting structures are monitored strictly in accordance with the monitoring requirements.

[0060] 1. Vertical and horizontal displacement of pile (slope) top

[0061] Along the foundation pit support structure, a vertical displacement and horizontal displacement observation point is arranged at intervals of about 15 to 20 meters at the top of the first-level slope and the top of the steel sheet pile. The horizontal displacement monitoring point is also used as a settlement monitoring point for observation. The monitoring point is buried with a spike about 7 cm long and with a cross mark on the top.

[0062] 2. Requirements for the layout of vertical displacement monitoring points outside the pit

[0063] Two rows are arranged along the parallel perimeter of the foundation pit, with a row spacing of 3m. The first row is 2m away from the edge of the foundation pit, and the distance between each row of measuring points is 20m. The horizontal section spacing is 40m, and each short side of the foundation pit has no less than 1 section. Monitoring sections should be added at the positive corners; each monitoring section has no less than 5 points, and the distance between measuring points is 2m, 3m, 5m, 7m, and 11m.

[0064] 3. The entire foundation pit monitoring should include complete monitoring record sheets, data reports, complete and intuitive charts and curves, and finally a comprehensive monitoring report.

[0065] 4. After the foundation pit monitoring is completed, the monitoring plan, measurement point details, data record sheets, monitoring reports and other materials shall be provided to the supervision unit and the construction unit for organization and archiving.

[0066] In this embodiment, the basement construction in step S8 is to process the basement, including cleaning, compacting and leveling, waterproofing, and welding pipes with plum blossom holes at the side seams of the steel sheet piles. Steel pipe piles with a spacing of 1m need to be welded, and those near the river need to be welded. According to the geological drawings, the locations where groundwater exists need to be welded. The spacing of the pipe holes is 0.3m, and the opening diameter is 2cm. After the insertion and driving, the steel pipe piles are pressure grouting, and the grouting process follows the anchor grouting process. The device to protect the insertion and driving process from damage is the aforementioned assembled pile tip with a pointed cap.

[0067] In this embodiment, the foundation pit backfill in step S9 is determined according to the properties of the backfill material and the capacity of the compaction equipment to determine the thickness of each backfill layer. The backfill material is evenly spread in the foundation pit using an excavator or manually. After each layer of backfill material is laid, it is compacted using a rammer or vibratory roller. A temporary drainage ditch is set around the foundation pit to prevent rainwater and surface water from flowing into the foundation pit. Drainage pipes are laid in the backfill material to ensure that groundwater can be discharged smoothly. Vegetation is restored on the ground after backfilling to enhance soil stability. The road surface is restored on the ground to ensure the road's traffic capacity.

[0068] Technical advantages: 1. Easy to understand: Rules are usually based on expert knowledge and experience, easy to understand and explain. 2. Flexibility: Different rules can be defined according to specific needs and scenarios. 3. Customizability: Rules can be customized according to specific performance standards to meet different evaluation needs.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent substitution, and improvement made within the spirit and principle of the present invention are acceptable.

Claims

1. A deep foundation pit construction process, characterized in that: The steps include: S1: Flow setting out, use white lime or wooden stakes to mark the outline of the foundation pit to ensure that the setting out is accurate; S2: Construction of drainage ditches on the top of the slope to effectively collect and discharge rainwater on the top of the slope to prevent soil erosion and slope erosion; S3: Excavation of foundation pit slope. Determine the slope angle according to the design requirements. Use an excavator or manually trim the slope to ensure that the slope is flat and smooth without obvious bumps. S4: Slope spray anchor, spraying concrete on the slope surface and combining it with anchor rods to form a solid support structure to enhance the stability and safety of the slope; S5: Steel sheet pile injection: driving steel sheet piles into the soil to form a continuous retaining structure to enhance the stability and safety of the foundation pit; S6: The sequence and method of foundation pit excavation and earthwork excavation shall be consistent with the design conditions; S7: Monitoring and measurement, including measuring elevations and monitoring measurements; S8: Basement construction, clearing loose soil and debris from the base, compacting the base, structural construction, and pouring concrete; S9: Backfill the foundation pit. Use an excavator or manual labor to evenly spread the backfill material in the foundation pit and compact it.

2. A deep foundation pit construction process according to claim 1, characterized in that: The flow sampling in step S1 includes laying out well points, installing flow meters and collecting data to realize well point precipitation detection. Multiple well points are laid out around the foundation pit, each well point is connected to the water collection main through a pipeline, and a flow meter, such as an electromagnetic flow meter or an ultrasonic flow meter, is installed on the pipeline of each well point. The flow data of each well point is regularly recorded to monitor the pumping and drainage of groundwater.

3. A deep foundation pit construction process according to claim 2, characterized in that: The slope ditch construction in step S2, prefabricated steel intercepting ditch, water collection well in the pit, and the bottom drainage of the pit are also in the form of steel pressure downward pressure. The pipeline is arranged around the foundation pit, and the points are arranged at a spacing of 3m. The water collection piles at the points are made of steel, with a sponge water absorption layer and a water storage pipe inside. After each deepening of the excavation, only all water needs to be pressed down to ensure timely and convenient drainage of the bottom of the pit. The water at the water collection point is pumped from the water collection well position pressure.

4. A deep foundation pit construction process according to claim 1, characterized in that: The excavation of the foundation pit slope in step S3 should follow the principle of excavation from top to bottom and in layers to avoid damaging the slope foot and causing landslides. During excavation, the foundation pit slope should adopt a safe slope according to the backfill situation and environmental conditions. The width of the exposed part of each excavation step should be controlled at 20m, and the excavation height of each layer should be controlled not more than 2m. It is strictly forbidden to excavate to the bottom at one time under one working condition.

5. A deep foundation pit construction process according to claim 1, characterized in that: The slope spray anchor in step S4 adopts a lattice stabilizing layer to be laid around the foundation pit at a position 5m around the excavation line, which can stabilize the layer and evenly bear the force, reduce the local settlement caused by uneven force caused by heavy trucks transporting soil, and set it to a reverse slope angle, which becomes a good way of drainage and waterproofing, ensuring that the outer side of the top of the foundation pit is not disturbed. The lattice stabilizing layer is actually a combination of geogrid plastic and a waterproof layer on the top.

6. A deep foundation pit construction process according to claim 1, characterized in that: The steel sheet pile driving in step S5 is to set up auxiliary guide frames along the line, which can be assembled, and all fastener styles are adjustable, which can be used to adjust the steel sheet pile driving process to avoid displacement interference, and set a wearable steel sheet pile tip hat made of high-strength 355 steel, which can effectively protect the resistance of penetrating into the rock formation.

7. A deep foundation pit construction process according to claim 1, characterized in that: The foundation pit excavation in step S6 is to set a light-emitting device on the front end bucket of the excavator, and indicate scales at the positions of each steel sheet pile to ensure that the last 0.3m is not over-excavated. By coinciding the light-emitting line with the marked scale, it is considered that the excavation line has reached the specified depth, avoiding multiple manual over-leveling, and can be convenient for mechanical excavation personnel to quickly determine the excavation depth.

8. A deep foundation pit construction process according to claim 1, characterized in that: The step S7 includes measuring the elevation and monitoring the measurement. After measuring the elevation, if the excavation is not in place, the excavation can continue. The monitoring measurement is used to measure the quality of the foundation pit excavation process. If there is any unqualified phenomenon, it is necessary to stop the work in time and make rectifications.

9. A deep foundation pit construction process according to claim 1, characterized in that: The basement construction in step S8 is to process the basement, including cleaning, compacting and leveling, waterproofing, and welding pipes with plum blossom holes at the side seams of the steel sheet piles. Steel pipe piles with a spacing of 1m need to be welded, and those near the river need to be welded. According to the geological drawings, the locations where groundwater exists need to be welded. The spacing of the pipe holes is 0.3m, and the opening diameter is 2cm. After the insertion and driving, the steel pipe piles are pressure grouting, and the grouting process follows the anchor grouting process. The device to protect the insertion and driving process from damage is the aforementioned assembled pile tip with a pointed cap.

10. A deep foundation pit construction process according to claim 1, characterized in that: The backfilling of the foundation pit in step S9 is to determine the thickness of each backfill layer according to the properties of the backfill material and the capacity of the compaction equipment. The backfill material is evenly spread in the foundation pit using an excavator or manually. After each layer of the backfill material is laid, it is compacted using a rammer or a vibrating roller. A temporary drainage ditch is set around the foundation pit to prevent rainwater and surface water from flowing into the foundation pit. Drainage pipes are laid in the backfill material to ensure that groundwater can be discharged smoothly. Vegetation is restored on the ground after backfilling to enhance soil stability. The road surface is restored on the ground to ensure the road's traffic capacity.

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