DEVICE FOR SOFT SOIL FOUNDATION TREATMENT BY MEANS OF VACUUM-MEMBRANE-FREE VACUUM PRELOADING AND TREATMENT METHOD

Abstract

The invention relates to a device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading and a treatment method. The device comprises includes several top plates for being laid on the surface of soft soil foundation and several vertical plates for being vertically driven into the soft soil foundation, wherein the vertical plates are driven against the symmetrical side edges of the top plates; the vertical plate has an inner chamber, the top surface of the vertical plate is provided with a vertical plate main-hole in communication with the inner chamber of the vertical plate, both sides of the vertical plate are provided with several vertical plate vacuum mini-holes in communication with the inner chamber of the vertical plate; the vertical plate main-hole is in communication with vacuum equipment. The invention is applicable to applicable to the field of geotechnical engineering techniques.

Claims

1. A device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading, characterized by having a plurality of top plates (1) for being laid on the surface of soft soil foundation and a plurality of vertical plates (2) for being vertically driven into the soft soil foundation; wherein the vertical plates (2) are driven against the symmetrical side edges of the top plates (1); the vertical plate (2) has an inner chamber, the top surface of the vertical plate is provided with a vertical plate main-hole (2-1-1) in communication with the inner chamber of the vertical plate, both sides of the vertical plate (2) are provided with several vertical plate vacuum mini-holes (2-2-1) in communication with the inner chamber of the vertical plate; and the vertical plate main-hole (2-1-1) is in communication with vacuum equipment.

2. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 1, characterized in that, the top plate (1) has an inner chamber, the top surface of the top plate is provided with a top plate main-hole (1-1-1) in communication with the inner chamber of the top plate, the bottom surface of the top plate (1) is provided with several top plate vacuum mini-holes (1-2-1) in communication with the inner chamber of the top plate (1); the top plate main-hole (1-1-1) is in communication with the vacuum equipment or pressurizing device.

3. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 1, characterized in that, the diameter of the vertical plate vacuum mini-holes (2-2-1) is 0.001 to 2 mm; when the diameter of the vertical plate vacuum mini-holes (2-2-1) is greater than 0.01 mm, non-woven filter cloth covering the vertical plate vacuum mini-holes (2-2-1) is adhered externally onto both sides of the vertical plate (2).

4. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 3, characterized in that, on both sides of the vertical plate (2) are side thin-plates (2-2) having a thickness of 5 mm to 10 mm, the periphery of the two side thin-plates (2-2) of the vertical plate is sealed by a vertical plate sealing plate (2-1) and a chamber is formed between the two side thin-plates (2-2); the two side thin-plates (2-2) of the vertical plate (2) are welded and connected by means of several steel strips (5).

5. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 2, characterized in that, the diameter of the top plate vacuum mini-holes (1-2-1) is 0.001 to 2 mm; when the diameter of the top plate vacuum mini-holes (1-2-1) is greater than 0.01 mm, a non-woven filter cloth covering the top plate vacuum mini-holes (1-2-1) is adhered externally on the bottom surface of the top plate (1).

6. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 5, characterized in that, the top and bottom surfaces of the top plate (1) are a top thin-plate (1-1) and a bottom thin-plate (1-2) having a thickness of 10 to 20 mm, the periphery of the top thin-plate (1-1) and the bottom thin-plate (1-2) of the top plate is sealed by a top plate sealing plate (1-3) and a chamber is formed between the top thin-plate (1-1) and the bottom thin-plate (1-2); the top thin-plate (1-1) and the bottom thin-plate (1-2) of the top plate are welded and connected by means of several steel strips (5).

7. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 1, characterized in that, the top plates (1) and the vertical plates (2) are welded and connected by means of steel bars, and the gaps between the top plates (1) and the vertical plates (2) are sealed with a sealing material.

8. The device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 1, characterized in that, the degree of consolidation of the soil between the two vertical plates (2) on both sides of the top plate (1) is calculated as follows:
U.sub.t=1e.sup.t where, U.sub.t is the average degree of consolidation within the depth range of the soft soil foundation treatment; $=\frac{8}{{}^2};.Math.=\frac{{}^2.Math.c_h}{D^2};$ D is the spacing between vertical plates (2); C.sub.h is the horizontal consolidation coefficient of the soft soil foundation.

9. A treatment method of the device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 1, characterized by: laying several said top plates (1) on the surface of soft soil foundation, and leaving a gap with a width adapted to the thickness of the vertical plate between top plates (1); driving the vertical plates (2) against the symmetrical side edges of the top plate (1) vertically into the soft soil foundation to a designed depth; communicating vacuum equipment with the vertical plates (2); turning on the vacuum equipment to perform vacuum preloading treatment of the soft soil foundation.

10. A treatment method of the device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading according to claim 1, characterized by: laying several said top plates (1) on the surface of soft soil foundation, and leaving a gap with a width adapted to the thickness of the vertical plate (2) between top plates (1); driving the vertical plates (2) against the symmetrical side edges of the top plate (1) vertically into the soft soil foundation to a designed depth; connecting and fixing the top plates (1) and the vertical plates (2) by means of steel bars, sealing the gaps between the top plates (1) and the vertical plates (2) with a sealing material; communicating vacuum equipment with the vertical plates (2), communicating pressurizing device with the top plates (1); turning on the vacuum equipment and the pressurizing device to perform vacuum combined pressurization of the soft soil foundation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a schematic structural view of an embodiment.

[0027] FIG. 2 is a top view of the embodiment.

[0028] FIG. 3 is a sectional view of a vertical plate in the embodiment.

[0029] FIG. 4 is a sectional view of a top plate in the embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] As shown in FIG. 1 and FIG. 2, the present embodiment is a device for soft soil foundation treatment by means of vacuum-membrane-free vacuum preloading, having several top plates 1 for being laid on the surface of soft soil foundation and several vertical plates 2 for being vertically driven into the soft soil foundation, wherein the vertical plates 2 are driven against the symmetrical side edges of the top plates 1.

[0031] As shown in FIG. 3, in the present embodiment, on the left and right sides of the vertical plate 2 are side thin-plates 2-2 having a thickness of 5 to 10 mm, and the periphery of the two side thin-plates 2-2 of the vertical plate is sealed by a vertical plate sealing plate 2-1 having a thickness of 10 to 20 mm, thereby forming a chamber between the two side thin-plates 2-2. The two side thin-plates 2-2 are welded and connected by means of several steel strips 5, and the steel strips 5 are arranged in a square grid shape.

[0032] In this example, the two side thin-plates 2-2 of the vertical plate 2 are provided evenly with several vertical plate vacuum mini-holes 2-2-1 communicating the inner chamber of the vertical plate 2 with the outside of the vertical plate 2, and the diameter of the vertical plate vacuum mini-holes 2-2-1 is 0.001 to 2 mm. When the diameter of the vertical plate vacuum mini-holes 2-2-1 is greater than 0.01 mm, non-woven filter cloth covering the vertical plate vacuum mini-holes 2-2-1 is adhered externally to the side thin-plates 2-2. The vertical plate sealing plate 2-1 at the top of the vertical plate 2 is provided with a vertical plate main-hole 2-1-1 in communication with the inner chamber of the vertical plate 2, and the diameter of the vertical plate main-hole 2-1-1 is 20 to 30 mm.

[0033] As shown in FIG. 4, the top surfaces and bottom surfaces of the top plate 1 are a top thin-plate 1-1 and a bottom thin-plate 1-2 having a thickness of 10 to 20 mm, the periphery of the top thin-plate 1-1 and the bottom thin-plate 1-2 of the top plate is sealed by the top plate sealing plate 1-3 having a thickness of 10 to 20 mm, thereby forming a chamber between the top thin-plate 1-1 and the bottom thin-plate 1-2. The top thin-plate 1-1 and the bottom thin-plate 1-2 are welded and connected by means of several steel strips 5, and the steel strips 5 are arranged in a square grid shape.

[0034] The bottom thin-plate 1-2 of the top plate 1 is provided evenly with several top plate vacuum mini-holes 1-2-1 communicating the inner chamber of the top plate 1 with the outside of the top plate 1, and the diameter of the vertical plate vacuum mini-holes 2-2-1 is 0.001 to 2 mm. When the diameter of the vertical plate vacuum mini-holes 2-2-1 is greater than 0.01 mm, non-woven filter cloth covering the vertical plate vacuum mini-holes 2-2-1 is adhered externally to the side thin-plate 2-2. The top thin-plate 1-1 of the top plate 1 is provided with a top plate main-hole 1-1-1 in communication with the inner chamber of the top plate 1, and the diameter of the top plate main plate 1-1-1 is 30 to 50 mm.

[0035] In this embodiment, the vertical plate 2 is in communication with vacuum equipment, and the vacuum equipment includes a vacuum pump 3 and a vacuum tube 4, one end of the vacuum tube 4 being in communication with the vertical plate main-hole 2-1-1, the other end of the vacuum tube 4 being in communication with the vacuum pump 3.

[0036] The vacuum preloading treatment method in the present embodiment is as follows:

[0037] laying several said top plates 1 on the surface of soft soil foundation, and leaving a gap with a width adapted to the thickness of the vertical plate between top plates 1;

[0038] driving the vertical plates 2 against the symmetrical side edges of the top plate 1 vertically into the soft soil foundation to a designed depth;

[0039] communicating vacuum equipment with the vertical plates 2;

[0040] turning on the vacuum equipment to perform vacuum preloading treatment of the soft soil foundation.

[0041] A vacuum pump 3 is turned on to keep the vacuum pressure above 90 kPa, and the settlement of the top plates 1 is measured, the degree of consolidation is estimated according to a standard method or the following formula,

[0042] U.sub.t=1e.sup.t, and the vacuuming is stopped when the degree of consolidation satisfies design requirements.

[0043] Where, U.sub.t is the average degree of consolidation within the depth range of the soft soil foundation treatment;

[00002]$=\frac{8}{{}^2};.Math.=\frac{{}^2.Math.c_h}{D^2};$

D is the spacing between the vertical plates 2; C.sub.h is the horizontal consolidation coefficient of the soft soil foundation.

[0044] When the vacuum combined pressurization treatment is adopted, the top plates 1 and the vertical plates 2 are welded and connected by means of steel bars to ensure that the top plates 1 do not lift when pressurization is performed; the gaps between the top plates 1 and the vertical plates 2 are sealed with a sealing material such as a sealant, to ensue that there is no water and air leakage when pressurization is performed. pressurizing device is in communication with the top plates 1, and the pressurizing device includes a pressure pump 6 and a pressure tube 7, one end of the pressure tube 7 being in communication with the top plate main-hole 1-1-1, the other end of the pressure tube 7 being in communication with the pressure pump 6. In this way, the soft soil foundation can be pressurized, and combined with vacuum, vacuum combined pressurization treatment of the soft soil foundation can be performed.

[0045] The vacuum combined pressurization treatment method of the present embodiment is as follows:

[0046] laying several top plates 1 on the surface of soft soil foundation, and leaving a gap with a width adapted to the thickness of the vertical plate between top plates 1;

[0047] driving the vertical plates 2 against the symmetrical side edges of the top plate 1 vertically into the soft soil foundation to a designed depth;

[0048] connecting and fixing the top plates 1 and the vertical plates 2 by means of steel bars, sealing the gaps between the top plates 1 and the vertical plates 2 with a sealing material;

[0049] communicating vacuum equipment with the vertical plates 2, communicating pressurizing device with the top plates 1;

[0050] turning on the vacuum equipment and the pressurizing device to perform vacuum combined pressurization of the soft soil foundation.