Soft soil foundation consolidation device and method based on vacuum preloading and plunger

Abstract

The invention discloses a soft soil foundation consolidation device and method based on vacuum preloading and plungers, and belongs to the technical field of soft soil foundation treatment. The device comprises a bulk filtering and collecting system, a vacuumizing drainage system and a plunger lifting system. The bulk filtering and collecting system filters soil particles and prevents the soil particles from entering a floral tube to cause loss of foundation soil; the vacuumized drainage system accelerates the accumulation of water in the soft soil foundation into the floral tube; the plunger lifting system quickly empties water stored in the floral tube through lifting of a plunger; through reasonable combination and periodic operation, efficient consolidation of the soft soil foundation can be achieved, the problem that water drainage of the soil body is difficult is solved, and therefore the reinforcement effect of the soil body and the construction engineering quality are improved.

Description

Technical Field

[0001] The invention relates to the technical field of soft soil foundation treatment, and in particular to a soft soil foundation consolidation device and method based on vacuum preloading and a plunger. Background Art

[0002] In the field of civil engineering and foundation treatment, the treatment of soft soil foundation has always been a technical problem. Soft soil usually has the characteristics of high water content, low strength, and easy compression deformation. These characteristics make the soft soil foundation prone to settlement and uneven deformation when bearing building loads, thus affecting the safety and stability of the project. Therefore, improving the consolidation efficiency and reinforcement effect of soft soil foundation is an important measure to ensure the quality and safety of the project.

[0003] Traditional soft soil foundation treatment methods include drainage consolidation method, replacement method, preloading method, etc. (Gong Xiaonan. Foundation treatment technology and development prospects [M]. Beijing: China Architecture & Building Press, 2014.). Among them, vacuum preloading method is a widely used soft soil foundation reinforcement method. By laying a sealing membrane and vacuuming under the membrane, the moisture in the foundation soil is discharged under the action of negative pressure, thereby improving the strength and stability of the foundation (Liu Fang. Discussion on vacuum preloading reinforcement treatment technology for soft soil foundation [J]. Construction Workers, 2024, 45 (12): 4-6.). However, the traditional vacuum preloading method often faces the problem of drainage difficulties in practical applications, especially when the soil permeability is poor, the drainage efficiency is often severely restricted.

[0004] In order to overcome the shortcomings of the traditional vacuum preloading method, researchers are constantly exploring new soft soil foundation reinforcement technologies. In recent years, plunger technology has achieved remarkable results in the field of oil and gas extraction (Yi Min. Application of plunger-type oil and gas mixed transmission device in small block oil fields [J]. Neijiang Science and Technology, 2021, 42(01): 16+96.), and its ability to quickly clear liquid provides a new idea for soft soil foundation treatment. Plunger technology can quickly empty the liquid in the pipeline and improve drainage efficiency through the up and down movement of the plunger. However, how to effectively apply plunger technology to the field of soft soil foundation treatment and combine it with the traditional vacuum preloading method to achieve more efficient and reliable soft soil foundation reinforcement is still a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a soft soil foundation consolidation device and method based on vacuum preloading and plunger, the device comprising a bulk filtration and collection system, a vacuum drainage system and a plunger lifting system, the bulk filtration and collection system is used to filter soft soil particles, the vacuum drainage system accelerates the accumulation of water in the bulk filtration and collection system, and finally the plunger lifting system is used to empty the liquid accumulated in the bulk filtration and collection system; the present invention can achieve efficient consolidation of soft soil foundation and solve the problem of soil drainage difficulties through reasonable combination and periodic operation, thereby improving the soil reinforcement effect and construction project quality.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A soft soil foundation consolidation device based on vacuum preloading and plunger, comprising: a bulk filtering and collecting system, a vacuum drainage system and a plunger lifting system;

[0008] The bulk filtration collection system is used to filter soft soil particles;

[0009] The vacuum drainage system is used to accelerate the accumulation of water in the soft soil foundation 1 into the bulk filtration and collection system;

[0010] The plunger lift system is used to empty the liquid accumulated in the bulk filtration collection system.

[0011] The bulk filtration and collection system comprises: a bulk material pile 2 and a flower tube 3;

[0012] The bulk material pile 2 is erected inside the soft soil foundation 1;

[0013] The flower tube 3 is erected inside the bulk material pile 2 .

[0014] The vacuum drainage system comprises: a sealing membrane 6, an air extraction drainage pipe 11, a drainage valve 12, an air extraction valve 13, a vacuum pump 14 and a water outlet 15;

[0015] The sealing film 6 is laid on the surface of the soft soil foundation 1;

[0016] One end of the vacuum drainage pipe 11 is connected to the upper part of the flower tube 3, and the other end is connected to the vacuum pump 14 and the water outlet 15 through a three-way interface. The front end of the air inlet of the vacuum pump 14 is provided with a vacuum valve 13, and the front end of the water outlet 15 is provided with a drainage valve 12.

[0017] A ground drainage groove 16 is provided at the water outlet 15 .

[0018] The plunger lifting system comprises: a plunger 4, a lifting rod 5 and a motor 10;

[0019] The upper section of the lifting rod 5 is a rack structure meshing with the gear 10 - 1 set at the end of the power output shaft of the motor 10 , and the lower end is fixedly connected to the plunger 4 , which is set inside the flower tube 3 and fits with the side wall of the flower tube 3 .

[0020] The bulk material pile 2 is a sand layer placed in the soft soil foundation 1 and arranged around the flower tube 3.

[0021] The plunger 4 includes a top plate 4-1 and a bottom plate 4-2, a hollow plug body 4-3 is provided between the top plate 4-1 and the bottom plate 4-2, a plurality of through holes 4-4 are provided on the top plate 4-1 and the bottom plate 4-2, a valve disc upper pressure plate 4-5 is provided in the plug body 4-3, the valve disc upper pressure plate 4-5 covers the through holes 4-4 provided on the bottom plate 4-2, and a spring 4-6 is provided between the valve disc upper pressure plate 4-5 and the top plate 4-1.

[0022] The internal cavity of the plug body 4-3 is thin at both ends close to the top plate 4-1 and the bottom plate 4-2, thick in the middle, and has an arc-shaped side.

[0023] The lifting rod 5 passes through the top plate 4-1, the spring 4-6, the valve disc upper pressure plate 4-5 and the center of the bottom plate 4-2 in sequence and is threadedly connected with the bolt 4-7 fixed to the bottom plate 4-2.

[0024] The soft soil foundation consolidation method comprises the following steps:

[0025] Step 1: Install the device and debug it correctly;

[0026] Step 2: Turn on the motor 10 to rotate the gear 10-1 clockwise / counterclockwise, drive the lifting rod 5 to descend through the rack structure, and make the plunger 4 descend to the bottom of the flower tube 3 and then close, and then seal the top of the flower tube 3;

[0027] Step 3: Close the drain valve 12, open the air extraction valve 13, and start the vacuum pump 14;

[0028] Step 4: Continue to measure the vacuum degree below the sealing film 6. When the set value is reached, close the vacuum pump 14 and the air extraction valve 13, and wait for the flower tube 3 to be filled with water. When the water content in the flower tube 3 does not meet the design requirements, repeat steps 3 to 4 until the water content meets the requirements.

[0029] Step 5: Open the drain valve 12, and at the same time open the blockage on the top of the flower tube 3 in step 2, start the motor 10 to make the gear 10-1 rotate in the opposite direction, drive the lifting rod 5 to rise through the rack structure, and use the plunger 4 to rise with the lifting rod 5, thereby driving the water in the flower tube 3 to rise, and flow from the water outlet 15 into the ground drainage groove 16 through the air extraction drainage pipe 11;

[0030] Step 6: Repeat steps 2 to 5, and continue to test the surface settlement and the vacuum degree under the membrane. The acceptance standard is that the measured settlement reaches more than 80% of the calculated settlement value or the measured soil settlement rate is less than or equal to 0.5 mm / d for five consecutive days. Turn off all equipment after reaching the acceptance standard.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. The bulk filtration and collection system of the present invention is provided with bulk material piles 2 and flower pipes 3 in a soft soil foundation 1, thereby avoiding the loss of foundation soil and significantly improving the reinforcement effect of the soil and the quality of the construction project.

[0033] 2. The vacuum drainage system of the present invention is provided with a sealing membrane 6 and a vacuum pump 14 to increase the drainage speed.

[0034] 3. The plunger lifting system of the present invention is provided with a plunger 4, and the effect of rapid night clearing is achieved through the mutual cooperation between the motor 10 and the lifting rod 5, as well as the mutual cooperation between the cavity with a thick middle and thin ends set inside the plunger 4 and the spring 4-6, the pressure plate 4-5 on the valve disc and the through hole 4-4.

[0035] 4. The method and device of the present invention effectively solve the problem of soil drainage difficulties by periodically operating vacuum preloading and plunger drainage. The implementation steps are clear, the operation is simple, and it has wide applicability and practicality.

[0036] In summary, the soft soil foundation consolidation device and method based on vacuum preloading and plunger of the present invention combines the rapid liquid clearing ability of the plunger and the characteristics of rapid drainage by vacuum extraction, which significantly improves the consolidation efficiency and quality of the soft soil foundation 1. The problem of soil drainage difficulties is effectively solved by periodic operation of vacuum preloading and plunger drainage. The filtering and collecting system designed by the present invention avoids the loss of foundation soil and significantly improves the reinforcement effect of the soil and the quality of the construction project. In addition, the method of the present invention has clear implementation steps, is easy to operate, has wide applicability and practicality, and provides an efficient and reliable solution for the field of soft soil foundation treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the overall layout diagram of the soft soil foundation consolidation device of the present invention.

[0038] Figure 2 It is a schematic diagram of the meshing of the gear 10-1 of the present invention and the rack structure of the upper section of the lifting rod.

[0039] Figure 3 It is a schematic diagram of laying the gasket 7 of the present invention.

[0040] Figure 4 It is a schematic diagram of the structure of the plunger 4 of the present invention.

[0041] In the figure, 1 represents soft soil foundation; 2 represents bulk material pile; 3 represents flower pipe; 4 represents plunger; 4-1 represents top plate; 4-2 represents bottom plate; 4-3 represents plug body; 4-4 represents through hole; 4-5 represents disc upper pressure plate; 4-6 represents spring; 4-7 represents bolt; 5 represents lifting rod; 6 represents sealing film; 7 represents gasket; 7-1 represents inner edge of gasket; 7-2 represents outer edge of gasket; 8 represents bracket; 9 represents bracket support; 10 represents motor; 10-1 represents gear; 11 represents vacuum drain pipe; 12 represents drain valve; 13 represents vacuum valve; 14 represents vacuum pump; 15 represents water outlet; 16 represents ground drain trough. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0043] like Figure 1 As shown, a soft soil foundation consolidation device based on vacuum preloading and plunger includes: a bulk filtering and collecting system, a vacuum drainage system and a plunger lifting system;

[0044] The bulk filtration and collection system is used to filter soft soil particles, and includes: bulk material piles 2 and flower tubes 3. The bulk material piles 2 are erected inside the soft soil foundation 1 and surround the flower tubes 3 to filter the soft soil particles in the soft soil foundation 1. The bulk material uses a sand layer; the flower tubes 3 are erected inside the bulk material piles 2.

[0045] The vacuum drainage system is used to accelerate the accumulation of moisture in the soft soil foundation 1 into the bulk filtration and collection system, including: a sealing membrane 6, an air extraction drainage pipe 11, a drainage valve 12, an air extraction valve 13, a vacuum pump 14 and a water outlet 15. The sealing membrane 6 is laid on the surface of the soft soil foundation 1, and protective measures such as geotextile are laid above the sealing membrane 6 to prevent the sealing membrane 6 from being damaged during construction; one end of the air extraction drainage pipe 11 is connected to the upper part of the flower tube 3, and the other end is connected to the vacuum pump 14 and the water outlet 15 respectively through a three-way interface. The front end of the air inlet of the vacuum pump 14 is provided with an air extraction valve 13, the front end of the water outlet 15 is provided with a drainage valve 12, and the water outlet 15 is provided with a ground drainage trough 16. The air extraction drainage pipe 11 has the functions of both extraction and drainage. The conversion of its functions is controlled by the opening and closing of the air extraction valve 13 and the drainage valve 12. The opening and closing of the drainage valve 12 and the air extraction valve 13 can be manually controlled or operated by an intelligent control system.

[0046] The plunger lifting system is used to empty the liquid accumulated in the bulk filtration collection system, such as Figure 1 , including: a plunger 4, a lifting rod 5, a support frame 8, a support platform 9 and a motor 10, see Figure 2The upper section of the lifting rod 5 is a rack structure and penetrates the bracket base 9 and is meshed with the gear 10-1 set at the end of the power output shaft of the motor 10. The lower end is fixedly connected to the plunger 4. The plunger 4 is set inside the flower tube 3 and fits with the side wall of the flower tube 3. The length of the rack structure is determined according to the lifting height of the plunger 4; three support frames 8 are set around the bottom of the bracket base 9, and a gasket 7 is set on the sealing membrane 6 under the support frame 8. The gasket 7 can be set separately at the bottom of each bracket, or it can be connected as a whole to increase the bearing capacity. When it is a whole, the diameter of the inner edge 7-1 of the gasket 7 should be larger than the outer diameter of the flower tube 3 so that the flower tube 3 can pass through the hole. The shape of the outer edge 7-2 of the gasket 7 includes but is not limited to Figure 3 The circular shape shown in the figure should be flexibly set according to the site conditions and the processing material conditions. The motor 10 is fixed to the upper surface of the bracket support 9.

[0047] like Figure 4 As shown, the plunger 4 includes a top plate 4-1 and a bottom plate 4-2, a hollow plug body 4-3 is formed between the top plate 4-1 and the bottom plate 4-2, two through holes 4-4 are formed on the top plate 4-1 and the bottom plate 4-2, a valve disc upper pressure plate 4-5 is provided in the plug body 4-3, the valve disc upper pressure plate 4-5 covers the through hole 4-4 formed on the bottom plate 4-2, a spring 4-6 is provided between the valve disc upper pressure plate 4-5 and the top plate 4-1, and the internal cavity of the plug body 4-3 is close to the top plate 4-1 and The bottom plate 4-2 is thin at both ends, thick in the middle, and has an arc-shaped side surface, so that the lower part of the valve disc upper pressure plate 4-5 is subjected to liquid resistance and pressure from the upper spring 4-6, and then breaks away from the contact with the bottom plate 4-2, so that the through hole 4-4 opened on the top plate 4-1 and the bottom plate 4-2 forms a channel with the internal cavity of the plug body 4-3, and the lifting rod 5 passes through the top plate 4-1, the spring 4-6, the valve disc upper pressure plate 4-5 and the center of the bottom plate 4-2 in turn and is threadedly connected with the bolt 4-7 fixed to the bottom plate 4-2. When the lifting rod 5 drives the plunger 4 to descend, under the action of the air pressure or liquid pressure below, the pressure plate 4-5 on the valve disc is pushed and the spring 4-6 is compressed, and the valve disc moves upward along the lifting rod 5 relative to the internal cavity; in the above process, a channel connecting the upper and lower parts is formed in the internal cavity, so that the gas and liquid below the plunger 4 can flow into the space above the plunger 4 through the connected internal cavity; similarly, when the lifting rod 5 brings the plunger 4 to rise, under the action of the air pressure and liquid pressure above, the pressure plate 4-5 on the valve disc is pushed to stretch the spring 4-6 and move downward. At this time, the pressure plate 4-5 on the valve disc contacts the bottom plate 4-2, so that the internal cavity forms a bowl-like structure closed at the bottom, thereby preventing the liquid and gas above the plunger 4 from flowing downward, and finally achieving the purpose of the liquid and gas above the plunger 4 rising and being discharged.

[0048] The soft soil foundation consolidation method comprises the following steps:

[0049] Step 1: Install the device and debug it correctly;

[0050] Step 2: Turn on the motor 10 to rotate the gear 10-1 clockwise / counterclockwise, and drive the lifting rod 5 to descend through the rack structure, so that the plunger 4 descends to the bottom of the flower tube 3 and then closes, and then the top of the flower tube 3 is blocked. When the plunger 4 descends and returns to its original position, the upper pressure plate 4-5 of the valve disc of the plunger 4 is subjected to the resistance of the air and liquid below the plunger 4 and the action of the upper spring 4-6, so that it cannot contact the plug body 4-3, thereby forming a channel running through the upper and lower parts in the internal cavity of the plug body 4-3;

[0051] Step 3: Close the drain valve 12, open the air extraction valve 13, and start the vacuum pump 14;

[0052] Step 4: Continue to measure the vacuum degree below the sealing film 6. When the set value is reached, close the vacuum pump 14 and the air extraction valve 13, and wait for the flower tube 3 to be filled with water. When the water content in the flower tube 3 does not meet the design requirements, repeat steps 3 to 4 until the water content meets the requirements.

[0053] Step 5: Open the drain valve 12, and at the same time open the blockage on the top of the flower tube 3 in step 2, start the motor 10 to make the gear 10-1 rotate in the opposite direction, drive the lifting rod 5 to rise through the rack structure, and use the plunger 4 to rise with the lifting rod 5, thereby driving the water in the flower tube 3 to rise, and flow from the water outlet 15 into the ground drain groove 16 through the air suction drain pipe 11. When the plunger 4 rises, the upper pressure plate 4-5 of the valve disc of the plunger 4 is subjected to the liquid pressure and spring thrust to cover the through hole 4-4 opened on the bottom plate 4-2, thereby preventing the upper liquid from flowing downward;

[0054] Step 6: Repeat steps 2 to 5, and continue to test the surface settlement and the vacuum degree under the membrane. The acceptance standard is that the measured settlement reaches more than 80% of the calculated settlement value or the measured soil settlement rate is less than or equal to 0.5 mm / d for five consecutive days. Turn off all equipment after reaching the acceptance standard.

[0055] The above is only one of the structures required in the proposed method. The specific number and distribution should be determined according to the size of the site.

Claims

1. A soft soil foundation consolidation device based on vacuum preloading and plunger, characterized in that: include: Bulk filtration collection system, vacuum drainage system and plunger lifting system; The bulk filtration collection system is used to filter soft soil particles; The vacuum drainage system is used to accelerate the accumulation of water in the soft soil foundation (1) into the bulk filtration and collection system; The plunger lift system is used to empty the liquid accumulated in the bulk filtration collection system.

2. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 1, characterized in that: The bulk filtering and collecting system comprises: a bulk material pile (2) and a flower tube (3); The bulk material pile (2) is erected inside the soft soil foundation (1); The flower tube (3) is erected inside the bulk material pile (2).

3. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 2, characterized in that: The vacuum drainage system comprises: a sealing membrane (6), an air extraction drainage pipe (11), a drainage valve (12), an air extraction valve (13), a vacuum pump (14) and a water outlet (15); The sealing film (6) is laid on the surface of the soft soil foundation (1); One end of the air extraction and drainage pipe (11) is connected to the upper part of the flower tube (3), and the other end is connected to the vacuum pump (14) and the water outlet (15) respectively through a three-way interface. The front end of the air inlet of the vacuum pump (14) is provided with an air extraction valve (13), and the front end of the water outlet (15) is provided with a drainage valve (12).

4. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 3, characterized in that: A floor drainage trough (16) is provided at the water outlet (15).

5. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 2, characterized in that: The plunger lifting system comprises: a plunger (4), a lifting rod (5) and a motor (10); The upper section of the lifting rod (5) is a rack structure meshing with a gear (10-1) arranged at the end of the power output shaft of the motor (10), and the lower end is fixedly connected to a plunger (4), which is arranged inside the flower tube (3) and fits against the side wall of the flower tube (3).

6. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 1, characterized in that: The bulk material pile (2) is a sand layer placed in the soft soil foundation (1) and arranged around the flower tube (3).

7. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 5, characterized in that: The plunger (4) comprises a top plate (4-1) and a bottom plate (4-2); a hollow plunger body (4-3) is disposed between the top plate (4-1) and the bottom plate (4-2); a plurality of through holes (4-4) are provided on the top plate (4-1) and the bottom plate (4-2); a valve disc upper pressure plate (4-5) is disposed in the plunger body (4-3); the valve disc upper pressure plate (4-5) covers the through holes (4-4) provided on the bottom plate (4-2); and a spring (4-6) is disposed between the valve disc upper pressure plate (4-5) and the top plate (4-1).

8. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 7, characterized in that: The internal cavity of the plug body (4-3) is thin at both ends close to the top plate (4-1) and the bottom plate (4-2), thick in the middle, and has an arc-shaped side surface.

9. A soft soil foundation consolidation device based on vacuum preloading and plunger according to claim 7, characterized in that: The lifting rod (5) passes through the top plate (4-1), the spring (4-6), the valve disc upper pressure plate (4-5) and the center of the bottom plate (4-2) in sequence and is threadedly connected to the bolt (4-7) fixed to the bottom plate (4-2).

10. A soft soil foundation consolidation method based on the device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Install the device and debug it correctly; Step 2: Turn on the motor (10) to rotate the gear (10-1) clockwise / counterclockwise, drive the lifting rod (5) to descend through the rack structure, and make the plunger (4) descend to the bottom of the flower tube (3) and then close, and then seal the top of the flower tube (3); Step 3: Close the drain valve (12), open the air extraction valve (13), and start the vacuum pump (14); Step 4: Continuously measure the vacuum degree below the sealing film (6). When the set value is reached, close the vacuum pump (14) and the air extraction valve (13), and wait for the flower tube (3) to be filled with water. When the amount of water in the flower tube (3) does not meet the design requirements, repeat steps 3 to 4 until the amount of water meets the requirements. Step 5: Open the drainage valve (12), and at the same time open the blockage on the top of the flower tube (3) in step 2, start the motor (10) to make the gear (10-1) rotate in the opposite direction, drive the lifting rod (5) to rise through the rack structure, use the plunger (4) to rise along with the lifting rod (5), thereby driving the water in the flower tube (3) to rise, and flow into the ground drainage groove (16) from the water outlet (15) through the air extraction drainage pipe (11); Step 6: Repeat steps 2 to 5, and continue to test the surface settlement and the vacuum degree under the membrane. The acceptance standard is that the measured settlement reaches more than 80% of the calculated settlement value or the measured soil settlement rate is less than or equal to 0.5 mm / d for five consecutive days. Turn off all equipment after reaching the acceptance standard.

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