Foundation bottom negative pressure drainage device and using method

Abstract

The invention discloses a foundation bottom negative-pressure drainage device and a using method, and relates to the technical field of foundation engineering construction drainage. A water collecting pipe is buried in the lower portion of a foundation, a water inlet is formed in the lower portion of the water collecting pipe, an inverted filter support is arranged on the lower portion of the water inlet, and a pressure sensor and a drainage pipe valve are arranged at the position, close to a mixer, of each drainage pipe; the air compressor is connected with the mixer through the air delivery pipe, one end of the mixer is connected to the main drainage pipe, and the other end of the mixer is connected to the drainage pipes. The pressure sensor is in signal connection with the valve controller, and the grouting pump is used for reversely pressing filling grout into the drainage pipe after drainage. Compared with the prior art, the drainage device has the advantages that the inverted filter support filters impurities, negative pressure drainage prevents the electric water pump from being damaged, the drainage process is monitored and controlled in real time, reverse grouting is adopted to reinforce the foundation bottom after drainage, and the problems of equipment damage, pipeline blockage and foundation treatment in the drainage process of residual underground water at the foundation bottom are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of drainage in foundation engineering construction, and particularly to a negative pressure dewatering drainage device at the bottom of a foundation and a using method thereof. Background Art

[0002] In foundation excavation projects, it is a common phenomenon that residual groundwater appears at the bottom of the foundation. The sources of this residual groundwater are extensive, such as the continuous infiltration of groundwater and the rainfall infiltration during construction. Although the amount of water is not large, it gushes out continuously, bringing many troubles to foundation construction. The traditional electric water pump drainage method exposes obvious defects when dealing with such problems of small flow rate but continuous water gushing. The water pump is prone to pumping dry the groundwater in a short time and then entering a no-water idling state. Due to the lack of water cooling, the motor temperature will rise sharply and is extremely easy to be damaged due to overheating. This not only increases the equipment maintenance and replacement costs but also seriously affects the construction progress. Moreover, the existing drainage equipment lacks effective filtering and anti-blocking measures when dealing with water gushing containing impurities such as sediment, and the drainage pipeline is easily blocked by mud, sand and gravel, resulting in poor drainage or even complete interruption. In addition, after the drainage is completed, the treatment process for the bottom of the foundation is not perfect enough to effectively ensure the stability and compactness of the foundation, leaving potential safety hazards for subsequent projects.

[0003] After retrieval, the patent with the publication number of CN119163047A realizes the effective backwashing and cleaning of the drainage system through the annular array arrangement of the branch nozzles and the installation of one-way valves, prevents the occurrence of blockage, improves the drainage efficiency, and ensures the long-term stable operation of the system. However, the problem is that when there is small-flow continuous water gushing, the water pump is prone to pumping dry the groundwater in a short time and then entering a no-water idling state. Due to the lack of water cooling, the motor temperature will rise sharply and is extremely easy to be damaged due to overheating.

[0004] After retrieval, the patent with the publication number of CN106836232B can continuously drain water during the foundation construction stage by laying a drainage ditch secretly in the foundation bearing stratum, and it is convenient for the maintenance of the drainage pump, can prevent potential water leakage hazards in the later stage, and further eliminates quality and safety hazards through grouting filling, but it is not convenient to solve the problem of pipeline blockage.

[0005] The information disclosed in this background art section is only intended to increase the understanding of the overall background of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art already known to those of ordinary skill in the art. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above technical defects and provide a negative pressure dewatering drainage device at the bottom of a foundation and a using method thereof.

[0007] To solve the above problems, the technical solution of the present invention is: a negative pressure dewatering and drainage device at the bottom of a foundation, comprising an anti-filter support, a collecting pipe, a drain pipe, gravel, a pressure sensor, a drain pipe valve, a valve controller, an air compressor, an air delivery pipe, a mixer, a main drain pipe, a main drain pipe valve, and a grouting pump;

[0008] The collecting pipe is buried in a trench excavated inside the foundation soil at the bottom of the foundation. The lower part of the collecting pipe is provided with a water inlet. The anti-filter support is arranged below the water inlet. The gravel is filled in the gap between the collecting pipe, the anti-filter support and the trench. One end of the drain pipe located outside the foundation is connected to the collecting pipe, and the other end of the drain pipe is connected to the mixer. A pressure sensor and a drain pipe valve are arranged near the mixer for each group of drain pipes. The air compressor is connected to the mixer through an air delivery pipe. One end of the mixer is connected to the main drain pipe, and the other end is connected to multiple groups of drain pipes. A main drain pipe valve is arranged on the main drain pipe; the pressure sensor is signal-connected to the valve controller, and the grouting pump is used to reversely press filling slurry into the drain pipe after dewatering.

[0009] Further, the anti-filter support comprises a support hoop, a support outer wall, a first-stage anti-filter filler, a first-stage anti-filter net, a second-stage anti-filter filler, a second-stage anti-filter net, a third-stage anti-filter net, and a water inlet grille. The support hoop surrounds the outside of the collecting pipe. The support outer wall is in a funnel shape and connects the support hoop and the water inlet. The water inlet grille is arranged at the bottom of the support outer wall. The first-stage anti-filter net, the first-stage anti-filter filler, the second-stage anti-filter net, the second-stage anti-filter filler, and the third-stage anti-filter net are sequentially installed inside the support outer wall.

[0010] Further, a method for using a negative pressure dewatering and drainage device at the bottom of a foundation comprises the following steps:

[0011] Step 1, installation preparation stage: plan the positions and quantities of the trenches, select appropriate components, excavate the trenches, place the collecting pipe, the anti-filter support, and the drain pipe and backfill with gravel, connect the pipes and connect them to the mixer, and install each component to ensure firm connection and unobstructed pipes;

[0012] Step 2, negative pressure dewatering stage: start the air compressor to input high-pressure compressed air into the mixer. The mixer generates negative pressure to drive the drain pipe to discharge groundwater. The groundwater is filtered by the anti-filter support and then enters the collecting pipe and the drain pipe, is sucked into the mixer, mixed with the compressed air, and then discharged through the main drain pipe. The pressure sensor monitors in real time, and the valve controller controls the drain pipe valve according to the pressure change to ensure continuous drainage;

[0013] When the groundwater within the influence range of a certain group of collecting pipes and drain pipes is drained dry, air will enter the collecting pipes, causing the negative pressure in the drain pipes to drop sharply. The pressure sensor transmits a signal to the valve controller, which immediately closes the drain valves of this group. Repeat the above steps and simultaneously open the drain valves of the next group to ensure continuous drainage work and continuously drain the residual groundwater at the bottom of the foundation.

[0014] Step 3: Backwashing and slag discharging stage: When it is determined that the collecting pipes and drain pipes are blocked due to the decrease in the groundwater discharge flow rate, close the drain main pipe valve and all drain pipe valves, start the air compressor to input compressed air into the mixer, and sequentially open the drain valves of each group to input high-pressure compressed air in the reverse direction to impact and clean the mud residues in the collecting pipes and drain pipes, and then restart normal drainage.

[0015] Step 4: Grouting and compaction stage: After the drainage and dewatering meet the design requirements, remove some components, retain the drain pipes and collecting pipes, connect the drain pipes to the grouting pump, start the grouting pump to reverse-press the filling slurry into the drain pipes after debugging the parameters, pay attention to the change of the grouting pressure, and adjust the parameters in a timely manner to ensure sufficient filling. Wait for the filling slurry to solidify to improve the compactness and stability of the bottom of the foundation.

[0016] The advantages of the present invention compared with the existing technologies are as follows:

[0017] (1) The device of the present invention is composed of an anti-filter support, collecting pipes, gravel, drain pipes, pressure sensors, drain pipe valves, valve controllers, air compressors, air pipes, mixers, drain main pipes, drain main pipe valves, grouting pumps, etc. The impurities are filtered through the uniquely designed anti-filter support, the negative pressure drainage is used to avoid damage to the electric water pumps, the drainage process is monitored and controlled in real time, and the bottom of the foundation is reinforced by reverse grouting after drainage. During use, it is operated through stages such as installation preparation, negative pressure dewatering, backwashing and slag discharging, and grouting and compaction. The present invention effectively solves the problems of equipment damage, pipeline blockage and foundation treatment during the dewatering process of the residual groundwater at the bottom of the foundation, ensures the smooth progress of the foundation construction, and improves the project quality and safety. Description of the Drawings

[0018] Figure 1 It is a large-scale drawing of the anti-filter support of the present invention.

[0019] Figure 2 It is a sectional view of the bottom negative pressure dewatering device of the present invention.

[0020] Figure 3 It is a schematic diagram of the group working of the bottom negative pressure dewatering device of the present invention.

[0021] Figure 4 It is a schematic diagram of the single-group working of the bottom negative pressure dewatering device of the present invention.

[0022] Figure 5It is the schematic diagram of backwashing of the base negative pressure dewatering device of the present invention.

[0023] Figure 6 It is the schematic diagram of filling slurry of the base negative pressure dewatering device of the present invention.

[0024] As shown in the figure: 1. Filter support; 1-1. Support hoop; 1-2. Outer wall of the support; 1-3. First-stage filter packing; 1-4. First-stage filter screen; 1-5. Second-stage filter packing; 1-6. Second-stage filter screen; 1-7. Third-stage filter screen; 1-8. Inlet grille; 2. Collection pipe; 2-1. Inlet; 3. Drain pipe; 4. Gravel; 5. Pressure sensor; 6. Drain pipe valve; 7. Valve controller; 8. Air compressor; 9. Air delivery pipe; 10. Mixer; 11. Drain main pipe; 12. Drain main pipe valve; 13. Grouting pump; 001. Groundwater; 002. Foundation soil; 003. Foundation; 004. Compressed air; 005. Filling slurry. Specific embodiments

[0025] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Among them, the same parts are denoted by the same reference numerals.

[0026] It should be noted that the terms "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0027] In order to make the content of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] As Figures 1-6 shown, a negative pressure dewatering and drainage device at the bottom of a foundation is composed of components such as a filter support 1, a collection pipe 2, gravel 4, a drain pipe 3, a pressure sensor 5, a drain pipe valve 6, a valve controller 7, an air compressor 8, an air delivery pipe 9, a mixer 10, a drain main pipe 11, a drain main pipe valve 12, and a grouting pump 13.

[0029] The collecting pipe 2 is buried under the foundation 003. A strip-shaped trench is excavated in the foundation soil 002 under the foundation 003. The collecting pipe 2 and the filter support 1 are installed in the area with groundwater 001, and the drain pipe 3 is set in the area without groundwater 001. Then, the trench is backfilled with gravel 4 and compacted. The particle size of the gravel 4 is strictly screened. It not only has good water permeability and can filter some impurities in the water, but also has a certain bearing capacity and can provide support for the construction of the foundation 003 structure. According to the actual working conditions, several strip-shaped trenches can be excavated under the foundation 003, and multiple collecting pipes 2 and drain pipes 3 can be laid at the same time. The collecting pipes 2 and the drain pipes 3 in the same trench are connected into a group, and the drain pipe 3 is extended to exceed the plane range of the foundation 003 and is connected to the mixer 10 after collection.

[0030] An inlet 2-1 is arranged at the lower part of the collecting pipe 2, which is used to collect the groundwater 001 at the bottom of the foundation 003 and introduce it into the collecting pipe 2 and the drain pipe 3. The filter support 1 is installed at the lower part of each inlet 2-1. The filter support 1 is composed of a support hoop 1-1, a support outer wall 1-2, a first-stage filter packing 1-3, a first-stage filter screen 1-4, a second-stage filter packing 1-5, a second-stage filter screen 1-6, a third-stage filter screen 1-7, and an inlet grille 1-8. The support hoop 1-1 tightly surrounds the collecting pipe 2 to firmly fix the filter support 1; the support outer wall 1-2 is in a funnel shape with the large mouth facing down and the small mouth facing up to connect the inlet 2-1 of the collecting pipe 2, guiding the water flow and providing support for the internal filter structure. The inlet grille 1-8 is installed at the bottom opening of the support outer wall 1-2 and is composed of evenly spaced strip-shaped structures, which can prevent larger debris from entering and guide the water flow to flow in evenly; the first-stage filter screen 1-4 is installed above the inlet grille 1-8 and uses a filter screen with a slightly larger pore size to block larger particle impurities and confine the first-stage filter packing 1-3; the first-stage filter packing 1-3 is selected as gravel with a larger particle size and is installed above the first-stage filter screen 1-4 to initially filter larger particle impurities; the second-stage filter screen 1-6 is installed above the first-stage filter packing 1-3 and uses a filter screen with a medium pore size, which can not only confine the first-stage filter packing 1-3 but also further filter fine particles; the second-stage filter packing 1-5 is selected as coarse sand with a moderate particle size and is installed above the second-stage filter screen 1-6 for secondary filtration; the third-stage filter screen 1-7 is installed above the second-stage filter packing and uses a filter screen with a smaller pore size to finely filter the water.

[0031] One end of the mixer 10 is connected to multiple groups of radially distributed drain pipes 3, and these drain pipes 3 are used to collect the groundwater 001 seeping out from different areas at the bottom of the foundation 003. The other end is connected to the main drain pipe 11, and the main drain pipe 11 is responsible for transporting the mixed groundwater 001 and compressed air 004 out. In the middle of the mixer 10, there is a connection port for the air delivery pipe 9. The air compressor 8 is firmly connected to the mixer 10 through the air delivery pipe 9, and its function is to continuously supply high-pressure compressed air 004 to the mixer 10. The mixer 10 is in the shape of a Venturi tube as a whole, and its appearance is approximately dumbbell-shaped. When the high-pressure compressed air 004 enters the mixer 10 through the air delivery pipe 9, based on the Venturi tube effect, a negative pressure area will be formed inside the mixer 10. This negative pressure area is like a powerful suction pump, which can effectively extract the groundwater 001 in the drain pipe 3. One end of the main drain pipe 11 is closely connected to the mixer 10, and its function is to transport the mixed water and compressed air 004 to a designated location for discharge. To facilitate the control of the water flow and air flow on-off, a main drain pipe valve 12 is specifically installed on the main drain pipe 11.

[0032] Each group of drain pipes 3 is equipped with a high-precision pressure sensor 5 and an intelligent drain pipe valve 6 near the mixer 10. The pressure sensor 5 continuously and real-time monitors the slight changes in the pressure inside the drain pipe 3, and transmits accurate pressure signals to the valve controller 7. The valve controller 7 has an internal algorithm program, which can quickly and accurately control the opening and closing actions of the drain pipe valve 6 according to the received pressure signals, so as to ensure that the drainage system always maintains a stable and efficient operating state.

[0033] After the negative pressure drainage and dewatering operation at the bottom of the foundation pit is completed, the grouting pump 13 injects the filling slurry 005 into the drain pipe 3 in the reverse direction. The grouting pump 13 is equipped with a precise pressure control and flow regulation system, which can ensure that the filling slurry 005 evenly and stably fills the gaps and holes between the drain pipe 3, the collecting pipe 2, the filter support 1 and the gravel 4, so as to ensure the integrity of the foundation soil 002.

[0034] A method for using a negative pressure dewatering and drainage device at the bottom of a foundation includes the following steps:

[0035] Installation preparation stage:

[0036] According to the actual situation of the foundation 003, plan the excavation positions and quantities of the strip grooves. The collector pipe 2 is buried in the grooves excavated in the foundation soil 002 at the bottom of the foundation 003. Select appropriate specifications of the collector pipe 2, drain pipe 3, filter support 1 and other device components. Place the collector pipe 2 and the filter support 1 in the area with groundwater 001, and place the drain pipe 3 in the area without groundwater 001. Connect the collector pipe 2 and the drain pipe 3 in the same groove, and then backfill and compact the selected gravel 4. Install a pressure sensor 5, a drain pipe valve 6, a valve controller 7, and an air delivery pipe 9 on the drain pipe 3, and then extend and collect each group of drain pipes 3 and connect them to the mixer 10. Connect the air delivery pipe 9 to the air compressor 8. Connect the mixer 10 to components such as the main drain pipe 11 and the main drain pipe valve 12. Ensure that all components are firmly connected and the pipelines are unobstructed.

[0037] Negative pressure dewatering stage:

[0038] Start the air compressor 8 and input high-pressure compressed air 004 into the mixer 10 through the air delivery pipe 9. The mixer 10 generates negative pressure based on the Venturi tube effect, driving multiple drain pipes 3 to perform drainage operations. After the groundwater 001 is filtered by the filter support 1, it enters the collector pipe 2 through the water inlet 2-1, then flows into the drain pipe 3, is sucked into the mixer 10 under negative pressure, and is discharged through the main drain pipe 11 after being mixed with the compressed air 004. During the drainage process, the pressure sensor 5 monitors the pressure changes in the drain pipe 3 in real time. When the groundwater 001 within the influence range of a certain group of collector pipes 2 and drain pipes 3 is drained dry, air will enter the collector pipe 2, causing the negative pressure in the drain pipe 3 to decrease sharply. The pressure sensor 5 transmits the signal to the valve controller 7, and the valve controller 7 immediately closes the drain pipe valve 6 of this group and simultaneously opens the drain pipe valve 6 of the next group to ensure that the drainage work continues without interruption. This cycle continues to continuously dewater the residual groundwater 001 at the bottom of the foundation 003.

[0039] Backwashing and slag removal stage:

[0040] When the drainage flow rate decreases and it is judged that the collector pipe 2 and the drain pipe 3 may be blocked by mud, close the main drain pipe valve 12 and all drain pipe valves 6 to stop the normal drainage operation. Start the air compressor 8 and input compressed air 004 into the mixer 10 through the air delivery pipe 9. Open the drain valves on each group of drain pipes 3 in sequence to input high-pressure compressed air 004 into each group of collector pipes 2 and drain pipes 3 in the reverse direction. The compressed air 004 flows reversely, strongly impacting the mud residues in the collector pipe 2 and the drain pipe 3, blowing them out of the drain pipe 3 and the filter support 1, and then restart the normal drainage operation.

[0041] Grouting and compaction stage:

[0042] After the foundation pit bottom is drained by negative pressure to meet the design requirements, the pressure sensor 5, drain pipe valve 6, valve controller 7, mixer 10, etc. are removed, and only the drain pipe 3 and the collecting pipe 2 are retained. Connect the grouting pump 13 to the drain pipe 3 and debug the grouting pressure and flow parameters. Start the grouting pump 13 and reverse-press the filling slurry 005 into each drain pipe 3 in turn. Under the action of pressure, the filling slurry 005 enters the gaps and holes of the filter support 1 and the gravel 4 along the drain pipe 3. During the grouting process, closely monitor the change of grouting pressure and adjust the grouting parameters in a timely manner to ensure that the filling slurry 005 fully fills each gap. After the filling slurry 005 is completely solidified, the drain pipe 3, the collecting pipe 2, the filter support 1 and the gravel 4 form a tight whole, improving the density and stability of the bottom of the foundation 003 and creating good conditions for the subsequent foundation construction.

[0043] All the electrical components mentioned in this article are electrically connected to the external main controller and the 220V mains power supply. The main controller can be a conventional known device such as a computer for control. In the specific implementation mode of the present disclosure, the detailed description of known functions and known components is omitted. To ensure the compatibility of the equipment, the operation means adopted are consistent with the parameters of market instruments.

[0044] The above describes the present invention and its implementation manners. Such description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar structural manners and embodiments without creative efforts without departing from the spirit of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A negative pressure dewatering and drainage device at the bottom of a foundation, characterized in that: It includes an inverse filter support (1), a collector pipe (2), a drain pipe (3), gravel (4), a pressure sensor (5), a drain pipe valve (6), a valve controller (7), an air compressor (8), an air delivery pipe (9), a mixer (10), a main drain pipe (11), a main drain pipe valve (12), and a grouting pump (13); The collector pipe (2) is buried in a trench excavated inside the foundation soil (002) at the bottom of the foundation (003). The lower part of the collector pipe (2) is provided with a water inlet (2-1). The inverse filter support (1) is arranged below the water inlet (2-1). The gravel (4) is filled in the gaps between the collector pipe (2), the inverse filter support (1), and the trench. One end of the drain pipe (3) located outside the foundation (003) is connected to the collector pipe (2), and the other end of the drain pipe (3) is connected to the mixer (10). A pressure sensor (5) and a drain pipe valve (6) are arranged near the mixer (10) for each group of drain pipes (3). The air compressor (8) is connected to the mixer (10) through the air delivery pipe (9). One end of the mixer (10) is connected to the main drain pipe (11), and the other end is connected to multiple groups of drain pipes (3). A main drain pipe valve (12) is arranged on the main drain pipe (11); The pressure sensor (5) is signal-connected to the valve controller (7). The grouting pump (13) is used to reversely press the filling slurry (005) into the drain pipe (3) after drainage and dewatering.

2. The base bottom negative pressure dewatering and drainage device according to claim 1, characterized in that: The inverse filter support (1) includes a support hoop (1-1), a support outer wall (1-2), a primary inverse filter filler (1-3), a primary inverse filter screen (1-4), a secondary inverse filter filler (1-5), a secondary inverse filter screen (1-6), a tertiary inverse filter screen (1-7), and a water inlet grille (1-8). The support hoop (1-1) surrounds the outside of the collector pipe (2). The support outer wall (1-2) is in a funnel shape and connects the support hoop (1-1) to the water inlet (2-1). The water inlet grille (1-8) is arranged at the bottom of the support outer wall (1-2). The primary inverse filter screen (1-4), the primary inverse filter filler (1-3), the secondary inverse filter screen (1-6), the secondary inverse filter filler (1-5), and the tertiary inverse filter screen (1-7) are sequentially installed inside the support outer wall (1-2).

3. The usage method of a kind of basic bottom negative pressure dewatering and drainage device according to any one of claims 1-2, characterized in that: It includes the following steps: Step 1, Installation preparation stage: Plan the positions and quantities of the trenches, excavate the trenches, place the collector pipe (2), the inverse filter support (1), and the drain pipe (3) and backfill with gravel (4), connect the pipes and connect them to the mixer (10), and install each component to ensure firm connection and unobstructed pipes; Step 2, Negative pressure dewatering stage: Start the air compressor (8) to input high-pressure compressed air (004) into the mixer (10). The mixer (10) generates negative pressure to drive the drain pipe (3) to discharge groundwater (001). The groundwater (001) enters the collecting pipe (2) and the drain pipe (3) after being filtered by the filter support (1), is sucked into the mixer (10), mixed with the compressed air, and then discharged through the main drain pipe (11). The pressure sensor (5) monitors in real time, and the valve controller (7) controls the drain pipe valve (6) according to the pressure change to ensure continuous drainage; When the groundwater (001) within the influence range of a certain group of collecting pipes (2) and drain pipes (3) is drained dry, air will enter the collecting pipe (2), causing the negative pressure in the drain pipe (3) to decrease sharply. The pressure sensor (5) transmits the signal to the valve controller (7), and the valve controller (7) immediately closes the drain pipe valve (6) of this group, and at the same time opens the drain pipe valve (6) of the next group, repeating the above steps to ensure continuous drainage work and continuously drain the residual groundwater (001) at the bottom of the foundation (003); Step 3, Backwashing and slag discharging stage: When it is judged that the collecting pipe (2) and the drain pipe (3) are blocked due to the decrease in the discharge flow of groundwater (001), close the main drain pipe valve (12) and all drain pipe valves (6), start the air compressor (8) to input compressed air (004) into the mixer (10), and sequentially open the drain pipe valve (6) of each group to input high-pressure compressed air (004) in the reverse direction to impact and clean the mud residue in the collecting pipe (2) and the drain pipe (3), and then restart normal drainage; Step 4, Grouting and compaction stage: After the drainage and dewatering meet the design requirements, remove some components, retain the drain pipe (3) and the collecting pipe (2), connect the drain pipe (3) to the grouting pump (13), start the grouting pump (13) to press the filling slurry (005) into the drain pipe (3) in the reverse direction after debugging the parameters, pay attention to the change of the grouting pressure, and adjust the parameters in a timely manner to ensure sufficient filling. Wait for the filling slurry (005) to solidify to improve the compactness and stability of the bottom of the foundation (003).

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