Inverted well surface soil treatment method

Abstract

The invention discloses a raise-boring surface soil treatment method which comprises the following steps: calibrating a raise-boring reaming boundary and an outer boundary of a raise-boring machine bearing platform on the ground, sequentially constructing an inner soil protection cast-in-place pile and an outer soil protection cast-in-place pile on the periphery of the raise-boring reaming boundary, and constructing a raise-boring machine bearing cast-in-place pile according to the shape of a raise-boring machine base. And finally, a raise boring machine bearing platform used for supporting the raise boring machine is poured at the designated position. By arranging the inner soil protecting cast-in-place piles and the outer soil protecting cast-in-place piles which form a circle in a surrounding mode, the surface soil layer is supported and strengthened, the raise boring machine is supported, it is guaranteed that a raise reamer bit smoothly expands holes, a large amount of manpower and material resources do not need to be consumed for processing the surface soil layer, and the construction difficulty and the construction cost are reduced; all the cast-in-place piles are drilled into the unweathered rock, pile heads of the cast-in-place piles are fixed by a raise boring machine bearing platform formed by casting, the two ends of the cast-in-place piles are fixed, and the supporting effect on the surface soil layer is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of surface soil treatment in mine well construction, and more specifically to a surface soil treatment method for a well. Background Art

[0002] Reverse well reaming is to use a drilling rig to construct a directional guide hole downward on the ground. After the drill bit is drilled into the underground tunnel, the drill bit is replaced with a large-diameter reverse well reaming drill bit. The drilling rig pulls the reaming drill bit back and reaming the hole from bottom to top. When the drilling rig is working, it will generally encounter a topsoil layer, which is not stable enough. During the directional drilling rig guide hole construction, the gap between the drill rod and the hole wall is small. When the drilling fluid carries the slag back, it is easy to scour the well wall, which may cause the soil and well wall to collapse and make it difficult to drill. During the reverse well drilling rig reaming construction, the drilling rig pulls back and applies pressure, and the roller cutter teeth squeeze and cut the rock, causing the rock and soil between the reaming drill bit and the drilling rig base to bear huge pressure. When expanding to the topsoil layer, the well wall may collapse due to insufficient compressive strength, and even the drilling rig may fall into the well.

[0003] At present, the surface soil treatment method of the reverse drilling process adopts the "soil replacement and pile chiseling method". The specific method is to use an excavator or manual labor to dig holes in the surface soil that needs to be treated, forming a cylindrical space on the surface soil, and then fill the cylindrical space with concrete. After the concrete solidifies, a concrete pile is formed. When the reverse drilling machine expands the hole, the center is hollowed out, and the remaining cylindrical ring serves as the well wall. This method of surface soil treatment in the reverse drilling process is called the soil replacement and pile chiseling method.

[0004] The "replacement of soil and pile drilling method" has the following disadvantages: 1. The cost of pile digging is high. When the pile diameter is greater than 2m and the depth is greater than 5m, the temporary installation cost is high and the construction period is long; 2. Most of the concrete after replacement is broken during hole expansion, resulting in a large amount of waste, and high-strength concrete cannot be used; 3. Poor safety. Manual excavation of the topsoil in the positive well may cause safety problems such as landslides, hole collapse and water gushing, and the depth of manual excavation is strictly limited. Therefore, how to deal with the topsoil layer economically and safely is one of the difficulties in the existing reverse well expansion. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide an economical and safe method for treating the topsoil layer.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for treating topsoil in an inverted well, comprising the following steps:

[0007] Step A: Leveling the site, marking the boundary of the raise hole and the outer boundary of the raise drilling rig cap that matches the shape of the raise drilling rig base on the ground, and the boundary of the raise hole is located within the outer boundary of the raise drilling rig cap;

[0008] Step B: using a directional drill to drill inner circle pile holes on the periphery of the reverse well expansion boundary, constructing inner retaining cast-in-place piles in the inner circle pile holes until a circle of continuous inner retaining cast-in-place piles is formed on the periphery of the reverse well expansion boundary;

[0009] Step C: using a directional drill to drill an outer ring pile hole on the periphery of two adjacent inner retaining cast-in-place piles, constructing outer retaining cast-in-place piles in the outer ring pile hole, until outer retaining cast-in-place piles are arranged on the periphery of any two adjacent inner retaining cast-in-place piles;

[0010] Step D: using a raise boring machine to drill a bearing pile hole on the ground, the bearing pile hole is located in the area between the outer boundary of the raise boring machine cap and the outer circle pile hole, and then constructing the raise boring machine bearing cast-in-place pile in the bearing pile hole;

[0011] Step E: Casting the raise boring machine cap on the ground area between the outer boundary of the raise boring machine cap and the boundary of the raise boring hole, the raise boring machine cap is connected with the pile head of the inner retaining cast-in-place pile, the pile head of the outer retaining cast-in-place pile and the pile head of the raise boring machine bearing cast-in-place pile;

[0012] Step F: When the raise boring rig cap is solidified and cured to reach the specified strength, the raise boring rig is installed on the raise boring rig cap to carry out the raise boring construction.

[0013] In the above-mentioned method for treating topsoil in a reverse well, in step B, the distance A between the axis of the inner retaining cast-in-place pile and the boundary of the reverse well expansion hole is greater than or equal to 30 cm and less than or equal to 50 cm.

[0014] In the above-mentioned method for treating topsoil in a reverse well, in step B, the gap between two adjacent inner retaining cast-in-place piles is 0.

[0015] In the above-mentioned method for treating topsoil in a reverse well, in step C, the outer peripheral surface of each outer retaining cast-in-place pile is arranged to be tangent to the outer peripheral surfaces of two adjacent inner retaining cast-in-place piles.

[0016] In the above-mentioned method for treating topsoil in a raise well, the distance B between the axis of the outer retaining cast-in-place pile and the outer boundary of the raise well drilling rig cap is greater than or equal to 50 cm and less than or equal to 100 cm.

[0017] In the above-mentioned method for treating topsoil in a raise well, the inner soil-retaining cast-in-place piles, the outer soil-retaining cast-in-place piles and the raise well drilling rig-bearing cast-in-place piles penetrate the topsoil layer and drill into the unweathered rock for 3-5 m.

[0018] In the above-mentioned method for treating topsoil in a raise pit, pile heads of the inner soil-retaining cast-in-place piles, the outer soil-retaining cast-in-place piles and the raise pit drilling rig-bearing cast-in-place piles are all implanted with pile head steel bars, and the implantation depth of the pile head steel bars is 1m.

[0019] In the above-mentioned method for processing topsoil in a raise well, in step E, the raise boring machine cap is connected to the pile head of the inner retaining cast-in-place pile, the pile head of the outer retaining cast-in-place pile and the pile head of the raise boring machine bearing cast-in-place pile through a steel mesh, and the distance between the steel mesh and the boundary of the raise well expansion hole is greater than or equal to 0.

[0020] In the above-mentioned method for treating topsoil during a raise boring operation, in step E, at least a portion of the raise boring machine cap is buried in the topsoil layer.

[0021] In the above-mentioned method for treating topsoil in a raise well, raise drilling rig-bearing cast-in-place piles are symmetrically arranged on both sides of the outer circle pile hole, and the edge of the raise drilling rig cap extends to the position of the raise drilling rig-bearing cast-in-place piles and is connected to the pile heads of the raise drilling rig-bearing cast-in-place piles.

[0022] The technical solution of the present invention achieves the following beneficial technical effects:

[0023] 1. By setting up inner and outer retaining cast-in-place piles in a circle, the topsoil layer is supported and strengthened and the raise drilling rig is supported, ensuring the smooth expansion of the raise drilling rig. It does not require a lot of manpower and material resources to deal with the topsoil layer, reducing the construction difficulty and cost. Each cast-in-place pile is drilled into the unweathered rock, and the pile head of the cast-in-place pile is fixed by the cast raise drilling rig cap. Both ends of the cast-in-place pile are fixed, further improving the support effect on the topsoil layer. The pressure of the raise drilling rig's reverse pull acts on each cast-in-place pile and the raise drilling rig cap, so that the raise drilling rig can operate stably and effectively avoid the collapse of the topsoil layer.

[0024] 2. When the well-reaming drill bit passes through the topsoil layer, the pressure exerted by the back-pull of the reaming drill bit acts on the soil between the well-reaming rig and the reaming drill bit. The soil is located within a circle of inner retaining cast-in-place piles. The soil is severely squeezed by the back-pull pressure of the reaming drill bit, while the soil outside the inner retaining cast-in-place piles and the outer retaining cast-in-place piles is basically not squeezed due to the obstruction of the cast-in-place piles. The squeezed soil is strengthened, that is, the soil inside the inner retaining cast-in-place piles is strengthened, which not only plays the effect of supporting the cast-in-place piles, but also can avoid the collapse of the well wall and improve the hole strength after the well-reaming of the topsoil layer. Since the shaft drilling rig is always in a stable state, the overall quality of the well-reaming is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the planar layout structure of the present invention;

[0026] Figure 2 A schematic cross-sectional view of the present invention along the depth direction;

[0027] Figure 3 Schematic diagram of the present invention during reverse well expansion.

[0028] The reference numerals in the figure are as follows: 1-outer boundary of the raise boring rig cap; 2-boundary of the raise boring hole expansion; 3-raise boring rig cap; 4-inner circle pile hole; 5-outer circle pile hole; 6-bearing pile hole; 7-raise boring rig bearing cast-in-place pile; 8-topsoil layer; 9-unweathered rock; 10-inner retaining cast-in-place pile; 11-outer retaining cast-in-place pile. DETAILED DESCRIPTION

[0029] The method for treating the topsoil in the reverse well in this embodiment is suitable for soils with a solidity coefficient greater than or equal to 0.6 [Class II soil and above], such as Figure 1-2 As shown, the following steps are included:

[0030] Step A: Leveling the site, marking the raise hole boundary 2 and the raise drilling rig cap outer boundary 1 matching the shape of the raise drilling rig base on the ground, and the raise hole boundary 2 is located within the raise drilling rig cap outer boundary 1;

[0031] Step B: using a directional drill to drill an inner circle pile hole 4 on the periphery of the reverse well expansion boundary 2, the inner circle pile hole 4 passes through the topsoil layer 8 and is drilled into the unweathered rock 9 by 3-5m, and inner retaining soil cast-in-place piles 10 are constructed in the inner circle pile hole 4, so that the inner retaining soil cast-in-place piles 10 enter the unweathered rock 9 by 3-5m, until a circle of continuous inner retaining soil cast-in-place piles 10 is formed on the periphery of the reverse well expansion boundary 2, the distance A between the axis of the inner retaining soil cast-in-place pile 10 and the reverse well expansion boundary 2 is greater than or equal to 30cm and less than or equal to 50cm, and the gap between two adjacent inner retaining soil cast-in-place piles 10 is 0, that is, the two adjacent piles are tightly fitted;

[0032] Step C: using a directional drill to drill an outer ring pile hole 5 on the periphery of two adjacent inner retaining cast-in-place piles 10, the outer ring pile hole 5 drills through the topsoil layer 8 and drills into the unweathered rock 9 for 3-5m, constructing an outer retaining cast-in-place pile 11 in the outer ring pile hole 5, and the outer retaining cast-in-place pile 11 enters the unweathered rock 9 for 3-5m, until the outer retaining cast-in-place piles 11 are arranged on the periphery of any two adjacent inner retaining cast-in-place piles 10, the outer peripheral surface of each outer retaining cast-in-place pile 11 is tangent to the outer peripheral surfaces of the two adjacent inner retaining cast-in-place piles 10, the distance B between the axis of the outer retaining cast-in-place pile 11 and the outer boundary 1 of the raise boring machine cap is greater than or equal to 50cm and less than or equal to 100cm, and the inner retaining cast-in-place piles 10 and the outer retaining cast-in-place piles 11 cooperate with each other to form a complete, continuous and closed pile group;

[0033] Step D: using a raise boring machine to drill a bearing pile hole 6 on the ground, the bearing pile hole 6 is located in the area between the outer boundary 1 of the raise boring machine cap and the outer circle pile hole 5, and then constructing a raise boring machine bearing cast-in-place pile 7 in the bearing pile hole 6, the bearing pile hole 6 is drilled through the topsoil layer 8 and drilled into the unweathered rock 9 by 3-5m, and the raise boring machine bearing cast-in-place pile 7 enters the unweathered rock 9 by 3-5m;

[0034] Step E: Casting a raise boring machine cap 3 on the ground area between the outer boundary 1 of the raise boring machine cap and the boundary 2 of the raise boring hole, wherein at least a part of the raise boring machine cap 3 is buried in the topsoil layer, and raise boring machine bearing cast-in-place piles 7 are symmetrically arranged on both sides of the outer circle pile hole 5, and the edge of the raise boring machine cap 3 extends to the position of the raise boring machine bearing cast-in-place pile 7 and is connected to the pile head of the raise boring machine bearing cast-in-place pile 7, and the raise boring machine cap 3 is connected to the pile head of the inner retaining cast-in-place pile 10, the pile head of the outer retaining cast-in-place pile 11 and the pile head of the raise boring machine bearing cast-in-place pile 7;

[0035] Step F: After the raise boring machine cap 3 solidifies and is cured to reach a specified strength, a raise boring machine is installed on the raise boring machine cap 3 to carry out raise boring construction.

[0036] In step E, pile heads of the inner retaining cast-in-place piles 10, the outer retaining cast-in-place piles 11 and the raise boring machine bearing cast-in-place piles 7 are all implanted with pile head steel bars, and the depth of the pile head steel bars implantation is 1m; the raise boring machine cap 3 is connected to the pile heads of the inner retaining cast-in-place piles 10, the outer retaining cast-in-place piles 11 and the raise boring machine bearing cast-in-place piles 7 through steel mesh, and the distance between the steel mesh and the raise boring machine expansion hole boundary 2 is greater than or equal to 0. By arranging the pile head steel bars and the steel mesh, the strength of the raise boring machine cap 3 itself and the connection strength with the pile heads can be improved.

[0037] The method for treating topsoil in the reverse well in this embodiment was tested in the construction of a second-phase ventilation shaft of a certain project, with a depth of 320m, a hole expansion diameter of 4.0m, a hole expansion angle of 90 degrees [vertical well], and a topsoil layer depth of 15.2m; and in the third-phase mixed well construction test, with a depth of 436m, a hole expansion diameter of 2.5m, a hole expansion angle of 90 degrees [vertical well], and a topsoil layer depth of 16m. The actual tests were very successful. During the reverse well expansion process, the reverse well drilling rig was in a stable state, the topsoil layer did not collapse, the well wall of the topsoil expansion section was smooth and complete, and the overall reverse well expansion quality was high.

[0038] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A method for treating topsoil in an inverted well, characterized in that: The following steps are involved: Step A: Leveling the site, marking the boundary of the raise hole (2) and the outer boundary of the raise drilling rig cap (1) matching the shape of the raise drilling rig base on the ground, and the boundary of the raise hole (2) is located within the outer boundary of the raise drilling rig cap (1); Step B: using a directional drill to drill inner circle pile holes (4) on the periphery of the reverse well expansion boundary (2), constructing inner soil protection cast-in-place piles (10) in the inner circle pile holes (4), until a circle of continuous inner soil protection cast-in-place piles (10) is formed on the periphery of the reverse well expansion boundary (2); Step C: using a directional drill to drill an outer ring pile hole (5) on the periphery of two adjacent inner retaining cast-in-place piles (10), and constructing an outer retaining cast-in-place pile (11) in the outer ring pile hole (5), until the outer retaining cast-in-place piles (11) are arranged on the periphery of any two adjacent inner retaining cast-in-place piles (10); Step D: using a raise boring machine to drill a bearing pile hole (6) on the ground, the bearing pile hole (6) is located in the area between the outer boundary (1) of the raise boring machine cap and the outer circle pile hole (5), and then constructing a raise boring machine bearing cast-in-place pile (7) in the bearing pile hole (6); Step E: Casting a raise boring machine cap (3) on the ground area between the outer boundary (1) of the raise boring machine cap and the boundary (2) of the raise boring machine expansion hole, wherein the raise boring machine cap (3) is connected to the pile head of the inner retaining cast-in-place pile (10), the pile head of the outer retaining cast-in-place pile (11) and the pile head of the raise boring machine bearing cast-in-place pile (7); Step F: After the raise boring machine cap (3) solidifies and is cured to reach a specified strength, a raise boring machine is installed on the raise boring machine cap (3) to carry out raise boring construction.

2. A method for treating topsoil in an inverted well according to claim 1, characterized in that: In step B, the distance A between the axis of the inner retaining cast-in-place pile (10) and the boundary of the reverse well expansion hole (2) is greater than or equal to 30 cm and less than or equal to 50 cm.

3. A method for treating topsoil in an inverted well according to claim 1, characterized in that: In step B, the gap between two adjacent inner soil-retaining cast-in-place piles (10) is 0.

4. A method for treating topsoil in an inverted well according to claim 1, characterized in that: In step C, the outer circumference of each outer soil-retaining cast-in-place pile (11) is arranged to be tangent to the outer circumferences of two adjacent inner soil-retaining cast-in-place piles (10).

5. The method for treating topsoil in an inverted well according to claim 1, characterized in that: The distance B between the axis of the outer retaining cast-in-place pile (11) and the outer boundary (1) of the raise boring machine cap is greater than or equal to 50 cm and less than or equal to 100 cm.

6. A method for treating topsoil in an inverted well according to claim 1, characterized in that: The inner soil-retaining cast-in-place piles (10), the outer soil-retaining cast-in-place piles (11) and the raise boring machine-bearing cast-in-place piles (7) penetrate the topsoil layer (8) and drill into the unweathered rock (9) for 3-5 m.

7. The method for treating topsoil in an inverted well according to claim 1, characterized in that: Pile head steel bars are implanted in the pile heads of the inner soil-retaining cast-in-place piles (10), the pile heads of the outer soil-retaining cast-in-place piles (11) and the pile heads of the raise boring machine bearing cast-in-place piles (7), and the implantation depth of the pile head steel bars is 1 m.

8. The method for treating topsoil in an inverted well according to claim 1, characterized in that: In step E, the raise boring machine cap (3) is connected to the pile head of the inner retaining cast-in-place pile (10), the pile head of the outer retaining cast-in-place pile (11) and the pile head of the raise boring machine bearing cast-in-place pile (7) through a steel mesh, and the distance between the steel mesh and the raise boring hole boundary (2) is greater than or equal to 0.

9. The method for treating topsoil in an inverted well according to claim 1, characterized in that: In step E, at least a portion of the raise boring machine cap (3) is buried in the topsoil layer.

10. The method for treating topsoil in an inverted well according to claim 1, characterized in that: Raise boring machine bearing cast-in-place piles (7) are symmetrically arranged on both sides of the outer ring pile hole (5), and the edge of the raise boring machine cap (3) extends to the position of the raise boring machine bearing cast-in-place piles (7) and is connected to the pile heads of the raise boring machine bearing cast-in-place piles (7).

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