Jetting, expansion and extrusion combined pile, construction method thereof and spiral jetting, expansion and extrusion drilling rig used in method

Abstract

The present invention discloses a jetting, expansion and extrusion combined pile, a construction method thereof and a spiral jetting, expansion and extrusion drilling rig used in the method. A pile of the combined pile comprises a pile body (101), an expanded body (103) and a pile end (106). At least one double-frustum-shaped expanded body (103), which is integrally formed with the pile body (101), is arranged on the pile body (101). The expanded body (103) is located in a vertical soil layer position, which has higher deformation modulus and shear strength, of the pile body (101), and at least two wing plates (102) which are uniformly distributed in the circumference direction and basically perpendicular to the axis of the pile are arranged on the pile body (101). The diameter of the pile above the expanded body (103) is larger than or equal to that of the pile below the expanded body (103). The drilling rig in the present invention comprises an upper section and a lower section, the diameter of the upper section is larger than that of the lower section, and the expanded body can be produced in any required position conveniently. When the expanded body (103) is located at the upper part or in the middle of the combined pile, if the diameter of the pile above the expanded body (103) is larger than that of the pile below the expanded body (103), the consumption of concrete can be greatly reduced.

Claims

1. A jetting, expansion and extrusion combined pile with a high bearing capacity, wherein the pile is composed of a pile body, an expanded body and a pile end, and at least one double-frustum-shaped expanded body, which is integrally formed with the pile body, is arranged on the pile body, wherein the double-frustum-shaped expanded body is a high-pressure jet grouting double-frustum-shaped rigid expanded body externally wrapped with a layer of compacted cement soil and concrete.

2. The jetting, expansion and extrusion combined pile of claim 1, wherein the pile is internally provided with a reinforcement cage.

3. The jetting, expansion and extrusion combined pile of claim 1, wherein the expanded body is located in a vertical bearing layer position, which has higher deformation modulus and shear strength, of the pile body, and at least two wing plates which are uniformly distributed in a circumference direction and perpendicular to the axis of the pile are arranged on the pile body.

4. The jetting, expansion and extrusion combined pile of claim 3, wherein a diameter of the pile above the expanded body is larger than or equal to that of the pile below the expanded body.

5. The jetting, expansion and extrusion combined pile of claim 4, wherein an included angle α between a lower inclined plane of the expanded body and a central axis of the pile is in a range of greater than or equal to 10° and less than or equal to 80°.

6. The jetting, expansion and extrusion combined pile of claim 5, wherein the wing plate has a width of 5-25 cm and a thickness of 2-12 cm.

7. A construction method of the jetting, expansion and extrusion combined pile of claim 1, comprising the following steps: (1) drilling to a designed depth through a drilling rig, and stopping drilling; (2) adjusting a nozzle pressure of a grout injection nozzle on a drill rod to 2-40 MPa, and adjusting the lifting speed of the drill rod to 6-60 cm/min; and while lifting a spiral hollow drill rod, performing rotary jet grouting on cement slurry at the designed depth with the nozzle on the grout injection nozzle, and vibrating a drill rod to fill under pressure a superfluid concrete to manufacture a double-frustum-shaped expanded body to a set elevation, with a height being 0.5-3.0m; and (3) adjusting the lifting speed of the drill rod to 0.5-2m/min, keeping the nozzle pressure to be unchanged, changing from performing rotary jet grouting to performing directional jet grouting on the wing plate of the pile body, and simultaneously filling under pressure the superfluid concrete to a designed elevation, to form a plain concrete pile.

8. The construction method of claim 7, wherein after the plain concrete pile is formed, a reinforcement cage is inserted into the superfluid concrete in a pile hole to a designed depth, to form a reinforced concrete foundation pile.

9. A spiral jetting, expansion and extrusion drilling rig adopted in the construction method of claim 7, comprising a spiral hollow drill rod and a power head, and a high-pressure grout injection pipe is installed from top to bottom at one side of an outer wall or an inner wall of a core tube of the spiral hollow drill rod, wherein the spiral hollow drill rod comprises an upper drill rod and a lower drill rod, wherein the upper drill rod and the lower drill rod are connected together through a flange, the radius of the helical blade of the upper drill rod is larger than the radius of the helical blade of the lower drill rod, the lower end of the high-pressure grout injection pipe is provided with multiple layers of grout injection nozzles, and each layer of grout injection nozzle is located below the outer edge of the helical blade at the bottom of the upper drill rod.

10. The spiral jetting, expansion and extrusion drilling rig of claim 9, wherein the length l.sub.1 of the upper drill rod is larger than 5m, the length l.sub.2 of the lower drill rod is larger than 6m, the diameter d of the upper drill rod is equal to 700 mm to 800 mm, and the diameter d.sub.1 of the lower drill rod is equal to 500 mm to 600 mm, and d is equal to the sum of d.sub.1 and 0.2m.

11. The spiral jetting, expansion and extrusion drilling rig of claim 10, wherein the number of layers of the grout injection nozzles is 2-10.

12. The spiral jetting, expansion and extrusion drilling rig of claim 11, wherein each layer of grout injection nozzle is provided with 1-6 nozzles, and the bearing pressure of each nozzle is 2-40 MPa.

13. The spiral jetting, expansion and extrusion drilling rig of claim 12, wherein the spacing between two adjacent upper and lower grout injection nozzles is 5-30 cm, the horizontal spacing between two adjacent nozzles in each layer of grout injection nozzle is 1-6 cm, and the diameter of the nozzle is 2-10 mm.

14. The spiral jetting, expansion and extrusion drilling rig of claim 13, wherein the number of layers of the grout injection nozzles is 3, each layer of grout injection nozzle is provided with two nozzles, and the diameter of the nozzle is 2 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structural schematic diagram of a spiral jetting, expansion and extrusion drilling rig.

(2) In FIG. 2, (a) is a partial enlarged view of the connecting position of the upper drill rod and the lower drill rod; and (b) is an overhead perspective of the three layers of grout injection nozzles;

(3) in FIG. 3, (a) is a sectional view of the 1-1 section in FIG. 3d, (b) is a sectional view of 2-2 section in FIG. 3d, (c) is the sectional view of 3-3 section in FIG. 3d, and (d) is the structural schematic diagram of the combined pile in which the expanded body is located in the middle of the combined pile and the sectional view of each part;

(4) in FIG. 4, (a) to (d) are schematic diagrams of the construction step of the combined pile in FIG. 3;

(5) in FIG. 5, (a) is the sectional view of 1-1 section in FIG. 5d, (b) is the sectional view of 2-2 section in FIG. 5d, (c) is the sectional view of 3-3 section in FIG. 5d, and (d) is the structural schematic diagram of the combined pile in which the expanded body is located in the middle of the combined pile and the sectional view of each part.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiment 1

(6) In combination with FIG. 1 to FIG. 2, a spiral jetting, expansion and extrusion drilling rig includes a spiral hollow drill rod 1 and a power head 2, and a high-pressure grout injection pipe 5 is installed from top to bottom at one side of an outer wall of a core tube of the spiral hollow drill rod 1, wherein the spiral hollow drill rod 1 includes an upper drill rod 3 and a lower drill rod 4, wherein the upper drill rod 3 and the lower drill rod 4 are connected together through a flange, the radius of the helical blade of the upper drill rod 3 is larger than the radius of the helical blade of the lower drill rod 4, the lower end of the high-pressure grout injection pipe 5 is provided with multiple layers of grout injection nozzles 6, and each layer of grout injection nozzle 6 is located below the outer edge of the helical blade at the bottom of the upper drill rod 3.

(7) The length l.sub.1 of the upper drill rod 3 is 6 m, the length l.sub.2 of the lower drill rod 4 is 8 m, the diameter d of the upper drill rod 3 is equal to 700 mm, and the diameter d.sub.1 of the lower drill rod 4 is equal to 500 mm, and d is equal to the sum of d.sub.1 and 0.2 m.

(8) In other deformation embodiments, according to the actual construction requirements, the upper drill rod 3 only needs to ensure that the length his larger than 5 m, and the lower drill rod 4 only needs to ensure that the length l.sub.2 is larger than 6 m, the diameter of the upper drill rod 3 can be 700 mm to 800 mm, the diameter of the lower drill rod 4 can be 500 mm to 600 mm, and d is equal to the sum of d.sub.1 and 0.2 m.

(9) The number of layers of the grout injection nozzles 6 is 3, and the grout injection nozzles 6 are welded on the last three layers of helical blades at the bottom of the upper drill rod 3. Each layer of grout injection nozzle 6 is provided with two nozzles; the bearing pressure of each nozzle is 2-40 MPa. The spacing between two adjacent upper and lower layers of grout injection nozzles 6 is 20 cm; the horizontal spacing between two adjacent nozzles in each layer of grout injection nozzle 6 is 4 cm, and the diameter of the nozzle is 2 mm.

(10) In other deformation embodiments, according to actual construction requirements, the number of layers of grout injection nozzles 6 is 2-10. Each layer of grout injection nozzle 6 can be provided with 1-6 nozzles; the bearing pressure of each nozzle is 2-40 MPa. The spacing between two adjacent upper and lower layers of grout injection nozzles 6 is 5-30 cm; the horizontal spacing between two adjacent nozzles in each layer of grout injection nozzle 6 is 1-6 cm, and the diameter of the nozzle is 2-10 mm.

Embodiment 2

(11) As shown in FIG. 3, a jetting, expansion and extrusion combined pile with a high bearing capacity is provided, and the pile is composed of a pile body 101, an expanded body 103 and a pile end 106, wherein the pile body 101 is provided with at least one double-frustum-shaped expanded body 103 which is integrally formed with the pile body. The pile body is internally provided with a reinforcement cage. The double-frustum shape is a structure which is big in the middle and gradually smaller in the upper and lower parts.

(12) The expanded body 103 is arranged at the sand layer at which the pile body 101 is located, the pile body 101 is provided with a layer of wing plates 102 which are basically perpendicular to the axis of the pile body, three wing plates 102 are arranged on each layer, and are uniformly distributed in the circumference direction. The wing plate 102 has a width of 5-25 cm and a thickness of 2-12 cm.

(13) The diameter of the pile above the expanded body 103 is larger than that of the pile below the expanded body 103.

(14) The included angle α between the lower inclined plane of the expanded body 103 and the central axis of the pile is in a range of greater than or equal to 10° and less than or equal to 80°.

(15) The expanded body 103 is a high-pressure jet grouting double-frustum-shaped rigid expanded body which is formed when a drill bit vibrates to extrude the superfluid concrete to form a concrete expanded head 105 and which is externally wrapped with a layer of compacted cement soil 104 and concrete.

(16) The specific steps of the construction method are as follows:

(17) (1) drilling through the drilling rig of embodiment 1 and the three-point pile-driver tower, as shown in FIG. 4a, drilling to a designed depth, and stopping rotating the drill rod;

(18) (2) adjusting the nozzle pressure of the grout injection nozzle on the drill rod to 20 MPa, and adjusting the lifting speed of the drill rod to 20 cm/min; while lifting the spiral hollow drill rod, performing rotary jet grouting on the cement slurry at the designed depth with a nozzle on the grout injection nozzle, filling superfluid concrete under pressure by the vibration of the drill rod, to manufacture the double-frustum-shaped expanded body to a designed elevation, with the height being 2.0 m, as shown in FIG. 4b;

(19) (3) adjusting the lifting speed of the drill rod to 1.5 m/min, keeping the nozzle pressure unchanged, changing from performing rotary jet grouting to performing directional jet grouting on the wing plate of the pile body, and simultaneously filling superfluid concrete under pressure to a designed elevation; spraying at three directions when the wing plate of a pile body is subjected to directional jet grouting, as shown in FIG. 4c, to form the plain concrete pile; and

(20) (4) inserting the reinforcement cage into superfluid concrete in a pile hole to a designed depth, to form a reinforced concrete foundation pile, as shown in FIG. 4d.

(21) In other deformation embodiments, according to actual construction requirements, wherein the nozzle pressure of the grout injection nozzle in step (2) can be 2-40 MPa, the lifting speed of the drill rod can be 6-60 cm/min; the height of the double-frustum-shaped expanded body can be 0.5-3.0 m. The lifting speed of the drill rod in step (3) can be 0.5-2 m/min.

Embodiment 3

(22) As shown in FIG. 5, a jetting, expansion and extrusion combined pile with a high bearing capacity is provided. The pile is composed of a pile body 201, an expanded body 203, a pile body 206, the expanded body 208 and a pile end 211, wherein the expanded body 203 and the expanded body 208 are both double-frustum-shaped and are integrally formed with the pile body. The pile is internally provided with a reinforcement cage. The double-frustum shape is a structure which is big in the middle and gradually smaller in the upper and lower parts.

(23) The expanded body 203 and the expanded body 208 are arranged in a vertical bearing layer position, which has higher shear strength, of the pile body. The pile body 201 and the pile body 206 are respectively provided with a layer of wing plates (202, 207) which are basically perpendicular to the axis of the pile body, three wing plates are arranged on each layer, and are uniformly distributed in the circumference direction. The wing plate has a width of 5-25 cm and a thickness of 2-12 cm.

(24) The maximum diameter of the pile above the expanded body 203 is larger than that of the pile below the expanded body 203. The maximum diameter of the pile above the expanded body 208 is equal to that of the pile below the expanded body 208.

(25) The included angle α between the lower inclined plane of the expanded body 203 and the expanded body 208 and the central axis of the pile is in a range of greater than or equal to 10° and less than or equal to 80°.

(26) The expanded body 203 is a high-pressure jet grouting double-frustum-shaped rigid expanded body which is formed when a drill bit vibrates to extrude the superfluid concrete to form a concrete expanded head 205 and which is externally wrapped with a layer of compacted cement soil 204 and concrete.

(27) The expanded body 208 is a high-pressure jet grouting double-frustum-shaped rigid expanded body which is formed when a drill bit vibrates to extrude the superfluid concrete to form a concrete expanded head 210 and which is externally wrapped with a layer of compacted cement soil 209 and concrete.

(28) The above embodiments are merely to describe the preferred embodiments of the present invention, rather than limiting the scope of the present invention. Under the premise of not departing from the designed spirit of the present invention, various transformations and improvements made to the technical solutions of the present invention by those skilled in the art shall all fall within the protection scope determined by the claims of the present invention.

INDUSTRIAL APPLICABILITY

(29) The dedicated drilling rig in the present invention can be used to drill holes and fill concrete under pressure, the multiple layers of nozzles can perform rotary jet grouting on the double-frustum-shaped expanded body, and can also perform directional jet grouting on the wing plate of the pile body, when the drilling rig is used to form a pile, the process is simple, the cost is low, the drilling rig is applicable to multiple geological conditions, and can manufacture special piles of a double-frustum-shaped expanded body at different positions of the pile body; as to the double-frustum-shaped expanded body composed of concrete and cement soil, the diameter of the pile above the expanded body is larger than or equal to that of the pile below the expanded body, the diameter of the pile above the expanded body is sprayed with a wing plate composed of cement soil and concrete, thereby not purely increasing the frictional resistance area, while the cement slurry performing directional jet grouting on the wing plate fills around the whole pile, and plays an effect of post grouting after being extruded by a drill rod; and the dedicated drilling rig has favorable industrial applicability.