SOFT SOIL FOUNDATION SINGLE-HOLE DEPTH AIR COMPRESSION DRAINAGE DEVICE AND WORKING METHOD THEREOF

Abstract

The present invention discloses a soft soil foundation single-hole depth air compression drainage device and working method thereof, comprising an air compression pipe and a water drainage pipe. A water drainage cavity body and an air diffusion cavity body are buried respectively in a soft soil foundation, and the air diffusion cavity body is located below the water drainage cavity body. Connecting to the air diffusion cavity body, the air compression pipe protrudes out of ground surface along a vertical direction of the soft soil foundation and communicates with an inflation pump; connecting to the water drainage cavity body, one end of the water drainage pipe protrudes to the bottom of the water drainage cavity body, and the other end protrudes out of the ground surface, thus achieving deep drainage and a drainage consolidation time of the deep soft soil foundation is shortened.

Claims

1. A soft soil foundation single-hole depth air compression drainage device, comprising an air compression pipe (1) and a water drainage pipe (2), wherein a water drainage cavity body (3) and an air diffusion cavity body (4) are buried respectively in a soft soil foundation (6); the air diffusion cavity body (4) is located below the water drainage cavity body (3); a connection opening is opened on a top end surface of the air diffusion cavity body (4) and is connected with the air compression pipe (1), and the air compression pipe (1) protrudes out of ground surface along a vertical direction of the soft soil foundation (6) and communicates with an inflation pump (5); a connection opening is opened on a top end surface of the water drainage cavity body (3) and is connected with the water drainage pipe (2), one end of the water drainage pipe (2) protrudes to the bottom of the water drainage cavity body (3), and the other end protrudes out of the ground surface along the vertical direction of the soft soil foundation (6).

2. The soft soil foundation single-hole depth air compression drainage device of claim 1, wherein the air diffusion cavity body (4) comprises a rigid bracket (41) and a geofabric (42); the rigid bracket (41) is a cylindrical body which is externally wrapped with the geofabric (42) and buried along a vertical direction of the soft soil foundation (6).

3. The soft soil foundation single-hole depth air compression drainage device of claim 1, wherein the water drainage cavity body (3) is enclosed by a water-permeable pipe and buried along the vertical direction of the soft soil foundation (6).

4. The soft soil foundation single-hole depth air compression drainage device of claim 1, wherein the air diffusion cavity body (4) has an outer diameter greater than or equal to an outer diameter of the water drainage cavity body (3), and the air diffusion cavity body (4) is located right below the water drainage cavity body (3).

5. The soft soil foundation single-hole depth air compression drainage device of claim 1, wherein the distance between the water drainage cavity body (3) and the ground surface of the soft soil foundation (6) is more than 8 m, and the distance between the air diffusion cavity body (4) and the water drainage cavity body (3) is 5 m to 10 m.

6. A working method using the soft soil foundation single-hole depth air compression drainage device of claim 1, which includes the following steps: step S1, drill a deep hole with a depth of at least 13 m in the soft soil foundation (6), place an air diffusion cavity body (4) with air compression pipe (1) at the bottom of the deep hole; fill the soil into the deep hole until the height of the soil reaches at least 5 m or above, then place the water drainage cavity body (3) with water drainage pipe (2) on the filled soil, and fill the soil into the deep hole again until they are flush with the ground surface of the soft soil foundation (6); step S2, an inflation pump (5) is used to compress air into the air compression pipe (1) such that the air diffusion cavity body (4) forms a high air pressure and maintains the pressure in the air diffusion cavity body (4) greater than a pore water pressure of surrounding soil body and less than a self-weight pressure of the soil body, and the air in the air diffusion cavity body (4) is squeezed and diffused toward surrounding soil bodies to drive groundwater in the soil bodies to flow along a maximum pressure gradient direction; step S3, during an inflation process of the air diffusion cavity body (4), the pressure in the water drainage cavity body (3) rises; when a pressure head in the water drainage cavity body (3) reaches the ground surface, groundwater seeping into the water drainage cavity body (3) flows out of the ground surface through the water drainage pipe (2).

7. A working method using the soft soil foundation single-hole depth air compression drainage device of claim 2, which includes the following steps: step S1, drill a deep hole with a depth of at least 13 m in the soft soil foundation (6), place an air diffusion cavity body (4) with air compression pipe (1) at the bottom of the deep hole; fill the soil into the deep hole until the height of the soil reaches at least 5 m or above, then place the water drainage cavity body (3) with water drainage pipe (2) on the filled soil, and fill the soil into the deep hole again until they are flush with the ground surface of the soft soil foundation (6); step S2, an inflation pump (5) is used to compress air into the air compression pipe (1) such that the air diffusion cavity body (4) forms a high air pressure and maintains the pressure in the air diffusion cavity body (4) greater than a pore water pressure of surrounding soil body and less than a self-weight pressure of the soil body, and the air in the air diffusion cavity body (4) is squeezed and diffused toward surrounding soil bodies to drive groundwater in the soil bodies to flow along a maximum pressure gradient direction; step S3, during an inflation process of the air diffusion cavity body (4), the pressure in the water drainage cavity body (3) rises; when a pressure head in the water drainage cavity body (3) reaches the ground surface, groundwater seeping into the water drainage cavity body (3) flows out of the ground surface through the water drainage pipe (2).

8. A working method using the soft soil foundation single-hole depth air compression drainage device of claim 3, which includes the following steps: step S1, drill a deep hole with a depth of at least 13 m in the soft soil foundation (6), place an air diffusion cavity body (4) with air compression pipe (1) at the bottom of the deep hole; fill the soil into the deep hole until the height of the soil reaches at least 5 m or above, then place the water drainage cavity body (3) with water drainage pipe (2) on the filled soil, and fill the soil into the deep hole again until they are flush with the ground surface of the soft soil foundation (6); step S2, an inflation pump (5) is used to compress air into the air compression pipe (1) such that the air diffusion cavity body (4) forms a high air pressure and maintains the pressure in the air diffusion cavity body (4) greater than a pore water pressure of surrounding soil body and less than a self-weight pressure of the soil body, and the air in the air diffusion cavity body (4) is squeezed and diffused toward surrounding soil bodies to drive groundwater in the soil bodies to flow along a maximum pressure gradient direction; step S3, during an inflation process of the air diffusion cavity body (4), the pressure in the water drainage cavity body (3) rises; when a pressure head in the water drainage cavity body (3) reaches the ground surface, groundwater seeping into the water drainage cavity body (3) flows out of the ground surface through the water drainage pipe (2).

9. A working method using the soft soil foundation single-hole depth air compression drainage device of claim 4, which includes the following steps: step S1, drill a deep hole with a depth of at least 13 m in the soft soil foundation (6), place an air diffusion cavity body (4) with air compression pipe (1) at the bottom of the deep hole; fill the soil into the deep hole until the height of the soil reaches at least 5 m or above, then place the water drainage cavity body (3) with water drainage pipe (2) on the filled soil, and fill the soil into the deep hole again until they are flush with the ground surface of the soft soil foundation (6); step S2, an inflation pump (5) is used to compress air into the air compression pipe (1) such that the air diffusion cavity body (4) forms a high air pressure and maintains the pressure in the air diffusion cavity body (4) greater than a pore water pressure of surrounding soil body and less than a self-weight pressure of the soil body, and the air in the air diffusion cavity body (4) is squeezed and diffused toward surrounding soil bodies to drive groundwater in the soil bodies to flow along a maximum pressure gradient direction; step S3, during an inflation process of the air diffusion cavity body (4), the pressure in the water drainage cavity body (3) rises; when a pressure head in the water drainage cavity body (3) reaches the ground surface, groundwater seeping into the water drainage cavity body (3) flows out of the ground surface through the water drainage pipe (2).

10. A working method using the soft soil foundation single-hole depth air compression drainage device of claim 5, which includes the following steps: step S1, drill a deep hole with a depth of at least 13 m in the soft soil foundation (6), place an air diffusion cavity body (4) with air compression pipe (1) at the bottom of the deep hole; fill the soil into the deep hole until the height of the soil reaches at least 5 m or above, then place the water drainage cavity body (3) with water drainage pipe (2) on the filled soil, and fill the soil into the deep hole again until they are flush with the ground surface of the soft soil foundation (6); step S2, an inflation pump (5) is used to compress air into the air compression pipe (1) such that the air diffusion cavity body (4) forms a high air pressure and maintains the pressure in the air diffusion cavity body (4) greater than a pore water pressure of surrounding soil body and less than a self-weight pressure of the soil body, and the air in the air diffusion cavity body (4) is squeezed and diffused toward surrounding soil bodies to drive groundwater in the soil bodies to flow along a maximum pressure gradient direction; step S3, during an inflation process of the air diffusion cavity body (4), the pressure in the water drainage cavity body (3) rises; when a pressure head in the water drainage cavity body (3) reaches the ground surface, groundwater seeping into the water drainage cavity body (3) flows out of the ground surface through the water drainage pipe (2).

11. The working method using the soft soil foundation single-hole depth air compression drainage device of claim 6, wherein in steps S2 and S3, when the air compression pipe (1) is pressurized, the air diffusion cavity body (4) is in a high pressure state; by using the high pressure condition of the air diffusion cavity body (4), groundwater of its surrounding soil bodies is driven to flow to a neighboring water drainage cavity body (3) having lower pressure and then discharged out of ground surface by the water drainage pipe (2).

12. The working method using the soft soil foundation single-hole depth air compression drainage device of claim 7, wherein in steps S2 and S3, when the air compression pipe (1) is pressurized, the air diffusion cavity body (4) is in a high pressure state; by using the high pressure condition of the air diffusion cavity body (4), groundwater of its surrounding soil bodies is driven to flow to a neighboring water drainage cavity body (3) having lower pressure and then discharged out of ground surface by the water drainage pipe (2).

13. The working method using the soft soil foundation single-hole depth air compression drainage device of claim 8, wherein in steps S2 and S3, when the air compression pipe (1) is pressurized, the air diffusion cavity body (4) is in a high pressure state; by using the high pressure condition of the air diffusion cavity body (4), groundwater of its surrounding soil bodies is driven to flow to a neighboring water drainage cavity body (3) having lower pressure and then discharged out of ground surface by the water drainage pipe (2).

14. The working method using the soft soil foundation single-hole depth air compression drainage device of claim 9, wherein in steps S2 and S3, when the air compression pipe (1) is pressurized, the air diffusion cavity body (4) is in a high pressure state; by using the high pressure condition of the air diffusion cavity body (4), groundwater of its surrounding soil bodies is driven to flow to a neighboring water drainage cavity body (3) having lower pressure and then discharged out of ground surface by the water drainage pipe (2).

15. The working method using the soft soil foundation single-hole depth air compression drainage device of claim 10, wherein in steps S2 and S3, when the air compression pipe (1) is pressurized, the air diffusion cavity body (4) is in a high pressure state; by using the high pressure condition of the air diffusion cavity body (4), groundwater of its surrounding soil bodies is driven to flow to a neighboring water drainage cavity body (3) having lower pressure and then discharged out of ground surface by the water drainage pipe (2).

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0016] FIG. 1 is a structural schematic diagram illustrating a soft soil foundation single-hole depth air compression drainage device according to the present invention.

[0017] FIG. 2 is a structural schematic diagram illustrating an air diffusion cavity body according to the present invention.

[0018] The numerals of the drawings are described below: 1. air compression pipe, 2. water drainage pipe, 3. water drainage cavity body, 4. air diffusion cavity body, 5. inflation pump, 6. soft soil foundation, 41. rigid bracket, 42. geofabric.

DETAILED DESCRIPTIONS OF EMBODIMENTS

[0019] The present invention will be detailed in combination with accompanying drawings. As shown in FIG. 1, the present invention comprises an air compression pipe 1 and a water drainage pipe 2. A water drainage cavity body 3 and an air diffusion cavity body 4 are buried respectively in a soft soil foundation 6. The air diffusion cavity body 4 is located below the water drainage cavity body 3. A connection opening is opened on a top end surface of the air diffusion cavity body 4 and is connected with the air compression pipe 1, and the air compression pipe 1 protrudes out of ground surface along a vertical direction of the soft soil foundation 6 and communicates with an inflation pump 5. A connection opening is opened on a top end surface of the water drainage cavity body 3 and is connected with the water drainage pipe 2, and one end of the water drainage pipe 2 protrudes to the bottom of the water drainage cavity body 3 such that water seeping into the water drainage cavity body 3 from the soil body can be discharged out of the ground surface through the water drainage pipe 2 as possible and meanwhile unnecessary consumption of drainage drive pressure can be avoided. The other end of the water drainage pipe 2 protrudes out of the ground surface along the vertical direction of the soft soil foundation 6. The drainage drive pressure of the water drainage cavity body 3 comes from a seepage pressure conveyed by the air pressure. The vertical direction mentioned above refers to a direction perpendicular to the ground surface, such that the air compression of the air compression pipe 1 to the air diffusion cavity body 4 and the air compression and drainage efficiency of the water drainage cavity body 3 to the water drainage pipe 2 are more efficient. In this case, a path for air compression and water drainage is greatly shortened, helping more to shorten the drainage consolation time of the deep soft soil foundation.

[0020] As shown in FIG. 2, the air diffusion cavity body 4 comprises a rigid bracket 41 and a geofabric 42. The rigid bracket 41 is a cylindrical body which is externally wrapped with the geofabric 42 and buried along a vertical direction of the soft soil foundation 6. The water drainage cavity body 3 is enclosed by a water-permeable pipe and buried along the vertical direction of the soft soil foundation 6. The vertical burying mentioned above means that axes of the two cavities are perpendicular to the ground surface. In this way, the spatial arrangement will be more compact and the drainage efficiency will be higher. At the same time, deep soft soil consolidation treatment can be achieved for a bearing pile on an effective and narrow unit area for the structure.

[0021] The air diffusion cavity body 4 has an outer diameter greater than or equal to an outer diameter of the water drainage cavity body 3. Since the hole drilled is deep enough for a convenient placement of the air diffusion cavity body 4 and the water drainage cavity body 3, and the air diffusion cavity body 4 is located right below the water drainage cavity body 3, that is, the axe of the air diffusion cavity body 4 and the axe of the water drainage cavity body 3 are located on the same straight line, the air pressure of the air diffusion cavity body 4 can be always uniformly surrounded around the water drainage cavity body 3, in this way, the transmission of the air pressure driving seepage pressure is more efficient, which further promotes the underground water in the soil permeate into the water drainage cavity body 3 and meanwhile the drainage efficiency of the water drainage pipe 2 is further improved.

[0022] As a principle, air and liquid always flow along a maximum pressure gradient direction and a pressure gradient is directly proportional to a pressure difference between two points and inversely proportional to a distance of two points. The distance between the water drainage cavity body 3 and the ground surface of the soft soil foundation 6 is more than 8 m, and the distance between the air diffusion cavity body 4 and the water drainage cavity body 3 is 5 m to 10 m. The larger the distance between the air diffusion cavity body 4 and the water drainage cavity body 3 is, the longer the water drainage takes. But, based on actual requirements, if the deep soft soil drainage consolidation is large in depth, it is required to increase the distance between the air diffusion cavity body 4 and the water drainage cavity body 3 while increasing the distance between the water drainage cavity body 3 and the ground surface of the soft soil foundation 6. In this way, the extension of the drainage consolidation time of the deep soft soil can be overcome, and better adapt to deep soft soil consolidation treatment for bearing piles which have different lengths on an effective and narrow unit area of structures.

[0023] A working method using the soft soil foundation single-hole depth air compression drainage device, which includes the following steps.

[0024] Step S1, drill a deep hole with a depth of at least 13 m in the soft soil foundation 6, place an air diffusion cavity body 4 with air compression pipe 1 at the bottom of the deep hole; fill the soil into the deep hole until the height of the soil reaches at least 5 m or above, then place the water drainage cavity body 3 with water drainage pipe 2 on the filled soil, and fill the soil into the deep hole again until they are flush with the ground surface of the soft soil foundation 6. The depth of the deep hole is commonly 15 m, the filled soil body does not need to be compacted, and the water drainage pipe 2 on the water drainage cavity body 3 and the air compression pipe 1 on the air diffusion cavity body 4 are distributed in a staggered mode, so that the water drainage cavity body 3 cannot be interfered when the air compression pipe 1 extends out of the ground surface,

[0025] Step S2, an inflation pump 5 is used to compress air into the air compression pipe 1 such that the air diffusion cavity body 4 forms a high air pressure and maintains the pressure in the air diffusion cavity body 4 greater than a pore water pressure of surrounding soil body and less than a self-weight pressure of the soil body, and the air in the air diffusion cavity body 4 is squeezed and diffused toward surrounding soil bodies to drive groundwater in the soil bodies to flow along a maximum pressure gradient direction.

[0026] Step S3, during an inflation process of the air diffusion cavity body 4, the pressure in the water drainage cavity body 3 rises. When a pressure head in the water drainage cavity body 3 reaches the ground surface, groundwater seeping into the water drainage cavity body 3 flows out of the ground surface through the water drainage pipe 2.

[0027] In steps S2 and S3, when the air compression pipe 1 is pressurized, the air diffusion cavity body 4 is in a high pressure state; by using the high pressure condition of the air diffusion cavity body 4, groundwater of its surrounding soil bodies is driven to flow to a neighboring water drainage cavity body 3 having lower pressure and then discharged out of ground surface by the water drainage pipe 2. The driving pressure of the water drainage cavity body 3 comes from the transmission of the seepage pressure driven by the air pressure in the air diffusion cavity body 4, when the water drainage cavity body 3 and the air diffusion cavity body 4 is relatively close, the driving efficiency of the compressed air in the air diffusion cavity body 4 entering the water drainage cavity body 3 through the soil body is more efficient, the drainage efficiency can be further improved, and the drainage consolidation time of the deep soft soil is shortened.

[0028] The present invention is not limited to the above embodiments, and any changes to its shape or material shall be considered as a variation of the present invention and fall in the scope of protection of the present invention as long as the structural design of the present invention is adopted.