Structure and Method for Solving the Collapse of Large-Diameter Mechanical Rotary Piles in Filling Areas Using Ton Bags

Abstract

This invention discloses a structure and method for solving the problem of borehole collapse in large-diameter mechanical rotary drilling piles in fill areas using ton bags. The method is characterized by: filling the pile hole with ton bags filled with soil; backfilling with low-grade (C20) plain concrete around the pile hole to form a cement-soil retaining wall; and using a concrete guide pipe extending beyond the upper section of the pile hole as a protective section. Borehole collapse is a common problem in large-diameter mechanical rotary drilling piles in fill areas. The purpose of this invention is to propose a method using ton bags to effectively reduce the construction cost of large-diameter mechanical rotary drilling pile boreholes while ensuring the quality of the borehole formation.

Description

Technical Field

[0001] This invention relates to the field of mechanical rotary drilling pile construction methods, specifically to a structure and method for solving the problem of large-diameter mechanical rotary drilling pile hole collapse in a backfill area using ton bags. Background Technology

[0002] my country has a vast territory with diverse soil types. The southwest region, in particular, features karst landforms, with common surface features such as stone teeth, stone forests, and solution grooves. Due to the inherent uncertainty in engineering site selection, construction sites in the southwest region are frequently created through land reclamation.

[0003] Common foundation types for buildings include isolated foundations, raft foundations, pile foundations, and pile-raft foundations. Isolated foundations and raft foundations are used only when the soil is of good quality, with minimal uneven deformation and bearing capacity that meets design requirements. Pile foundations and pile-raft foundations are not limited by the project site and are typically used in areas with poor soil quality and deep bearing layers. Pile foundations are used when groundwater is abundant or when a structural slab is required.

[0004] The engineering site formed by the dumping has a relatively deep rock stratum, and the engineering design will use large-diameter piles with a diameter of 1.5m or more. In the dumping area, there is a serious problem of hole collapse when mechanically excavating engineering piles with a diameter of 1.5m or more. The current technical measures to deal with the hole collapse of mechanical rotary drilling piles are mainly to backfill with low-grade concrete and re-drill the hole.

[0005] The gaps between the boulders in the filling site are large, and a large amount of low-grade concrete is needed for backfilling, which increases the construction cost of mechanical drilling. Since the degree of collapse of the hole at each pile location is not predictable, the cost is uncontrollable.

[0006] Regarding the technical measures for re-grouting and re-drilling low-grade concrete, a technical method is proposed that can save costs, improve construction technology, and keep costs under control. Summary of the Invention

[0007] Therefore, to address the aforementioned shortcomings, this invention provides a structure and method for resolving borehole collapse in large-diameter mechanical rotary drilling piles in fill areas using ton bags. Borehole collapse is a common problem in large-diameter mechanical rotary drilling piles in fill areas. The purpose of this invention is to propose a method using ton bags to effectively reduce the construction cost of drilling large-diameter mechanical rotary drilling piles while ensuring borehole quality.

[0008] The present invention is implemented as follows: a structure is constructed to solve the problem of large-diameter mechanical rotary pile hole collapse in the filling area using ton bags; characterized in that: ton bags filled with soil are filled into the pile hole; low grade (C20) plain concrete is backfilled along the perimeter of the pile hole to form a cement-soil protective wall; the upper section of the pile hole is a protective section for the upper section of the pile hole, and a concrete guide pipe extends out of the protective section for the upper section of the pile hole.

[0009] The present invention relates to a structure for solving the collapse of large-diameter mechanical rotary drilling pile holes in a filling area using ton bags; characterized in that: the distance between the ton bag and the edge of the collapsed hole area is approximately 300mm, the top elevation of the ton bag is slightly higher than the collapsed hole surface; and the ton bag has ton bag lifting lugs.

[0010] The present invention relates to a structure for solving the collapse of large-diameter mechanical rotary drilling piles in fill areas using ton bags; characterized in that the ton bags are commonly available woven bags, and the volume of a single ton bag is controlled to be 0.7m³. 3 (If the volume of the ton bag is too large, the gap between the ton bags will be larger, increasing the amount of concrete used); the concrete slump is controlled at about 200mm, so that the concrete uses the fluidity generated by its own weight to fill the gap between the collapsed hole edge and the ton bag, so as to ensure the formation of cement-soil retaining wall in the second drilling; the main mechanism is: before the hole is formed, although the backfill soil has large gaps, the force transmission path between soil blocks is still basically effective, so the soil is still in a state of equilibrium. However, after drilling, the soil in a limited range around the hole loses support, and then the hole wall undergoes severe loosening deformation until the hole collapses. After the hole collapses, this part of the soil is in a new state of equilibrium, but the pile hole has not been formed and drilling needs to continue. To ensure that the continued drilling can form a normal hole, it is necessary to inhibit or prevent the soil around the pile hole from collapsing further; this invention uses an inexpensive cement-soil mixture to form a highly viscous cement-soil retaining wall around the pile hole by rotating the rotary drilling bit. The horizontal thrust generated by the cement-soil retaining wall forms a mechanical balance mechanism with the limited earth pressure generated by the collapse of the pile hole.

[0011] A method for solving the problem of large-diameter mechanical rotary drilling pile collapse in a filling area using ton bags, characterized in that;

[0012] The method is performed in the following steps:

[0013] A. On-site positioning and layout shall be carried out according to the construction drawings to ensure that the pile locations are within the allowable range of the specifications;

[0014] B. The rotary drilling rig is positioned and drills a hole at the pile location;

[0015] C. Do not deal with hole collapse during the initial hole formation process until the rotary drilling rig drill rod can no longer continue drilling, then remove the rotary drilling rig drill rod;

[0016] D. The prepared volume is approximately 0.7m³. 3 A ton bag filled with soil is placed into the pile hole using a crane. The distance between the ton bag and the edge of the collapsed area is about 300mm, and the top of the ton bag is slightly higher than the collapsed surface.

[0017] E. Use low-grade (C20) plain concrete to backfill around the pile hole, and control the slump of the low-grade plain concrete to within 200mm.

[0018] F. Place ton bags according to the backfilling situation of low-grade plain concrete and the diameter of the pile collapse area to reduce the amount of low-grade plain concrete backfilling.

[0019] G. After the concrete has initially set and reached a certain strength (let it stand for 12 hours), the rotary drilling rig will drill the hole for the second time.

[0020] H. Continue drilling until the rotary drilling rig can no longer drill a hole, then remove the rotary drilling rig.

[0021] I. Repeat steps D to H above (after the low-grade concrete hardens, a cement-soil retaining wall is formed around the pile hole) until the design and geological survey requirements are met.

[0022] J. Treat the same collapsed pile holes using the method described above.

[0023] This invention has the following advantages: It provides a structure and method for solving the problem of borehole collapse in large-diameter mechanical rotary drilling piles in fill areas using ton bags. Borehole collapse is a common problem in large-diameter mechanical rotary drilling piles in fill areas. The purpose of this invention is to propose a method using ton bags to effectively reduce the construction cost of borehole formation for large-diameter mechanical rotary drilling piles, while ensuring the quality of the formed holes.

[0024] In this invention: the ton bags are commonly available woven bags, and the volume of a single ton bag is controlled to be 0.7m³. 3 (The volume of the ton bags is too large, which will increase the gaps between the ton bags and increase the amount of concrete used.) The concrete slump is controlled at around 200mm. This allows the concrete to fill the gaps between the collapsed hole and the ton bags using its own weight and fluidity, ensuring the formation of a cement-soil retaining wall during the second drilling. The main mechanism is as follows: Before drilling, although the backfill soil has large gaps, the force transmission path between soil blocks is still basically effective, so the soil is still in a state of equilibrium. However, after drilling, the soil in a limited area around the hole loses support, and then the hole wall undergoes severe loosening and deformation until the hole collapses. After the hole collapses, this part of the soil is in a new state of equilibrium, but the pile hole has not been formed and drilling needs to continue. To ensure that the continued drilling can form a normal hole, it is necessary to inhibit or prevent the soil around the pile hole from collapsing further. This invention uses an inexpensive cement-soil mixture to form a highly viscous cement-soil retaining wall around the pile hole through the rotation of the rotary drilling rig. The horizontal thrust generated by the cement-soil retaining wall forms a mechanical balance mechanism with the limited earth pressure generated by the collapse of the pile hole.

[0025] The present invention also has the following advantages:

[0026] (1) Using ton bags to solve the problem of large-diameter mechanical rotary drilling pile collapse in the dumping area can effectively reduce the amount of concrete soil used compared with the traditional low-grade plain concrete backfilling method.

[0027] (2) This invention provides a solution for dealing with the collapse of large-diameter mechanical rotary drilling piles in the filling area, and has been verified through actual projects. Compared with traditional low-grade plain concrete backfilling, it can effectively reduce construction costs and significantly improve the secondary drilling speed, which can effectively shorten the hole formation time. Attached Figure Description

[0028] Figure 1 This is the mechanical positioning diagram in this invention;

[0029] Figure 2 This is a diagram showing the relationship between the ton bag and the collapsed hole in this invention;

[0030] Figure 3 This is a diagram of the ton bag in this invention;

[0031] Figure 4 This describes the finished product effect in this invention.

[0032] In the diagram: 1-Rotary drilling rig, 2-Rotary drilling rig drill rod, 3-Pile location, 4-Pile hole, 5-Upper section protection of pile hole, 6-Collapsed area, 7-Ton bag, 8-Concrete guide pipe, 9-Low-grade plain concrete, 10-Ton bag lifting lug, 11-Soil inside ton bag, 12-Cement-soil retaining wall. Detailed Implementation

[0033] The following will be combined with the appendix Figures 1-4 This invention will be described in detail, and the technical solutions in the embodiments of this invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] This invention provides an improved structure and method for solving the problem of borehole collapse in large-diameter mechanical rotary drilling piles in landfill areas. Borehole collapse is a common problem in large-diameter mechanical rotary drilling piles in landfill areas. The purpose of this invention is to propose a method using ton bags to effectively reduce the construction cost of drilling large-diameter mechanical rotary drilling piles while ensuring the quality of the borehole formation. To achieve the above objective, the invention is implemented through the following technical solution: using ton bags to solve the problem of borehole collapse in large-diameter mechanical rotary drilling piles in landfill areas, characterized by the following steps:

[0035] like Figure 2 As shown; a ton bag 7 filled with soil 11 is filled into the pile hole 4; low grade (C20) plain concrete 9 is backfilled around the pile hole 4 to form a cement-soil retaining wall 12; the upper section of the pile hole 4 is the upper section protection section 5, and the concrete guide pipe 8 extends out of the upper section protection section 5.

[0036] During implementation, the distance between the ton bag 7 and the side of the collapsed hole area 6 is about 300mm, and the top elevation of the ton bag 7 is slightly higher than the collapsed hole surface; the ton bag 7 has ton bag lifting lugs 10.

[0037] The ton bags used are common woven bags available on the market, with a single ton bag volume controlled at 0.7m³. 3 (If the volume of the ton bag is too large, the gap between the ton bags will be larger, increasing the amount of concrete used); the concrete slump is controlled at about 200mm, so that the concrete uses the fluidity generated by its own weight to fill the gap between the collapsed hole edge and the ton bag, so as to ensure the formation of cement-soil retaining wall in the second drilling; the main mechanism is: before the hole is formed, although the backfill soil has large gaps, the force transmission path between soil blocks is still basically effective, so the soil is still in a state of equilibrium. However, after drilling, the soil in a limited range around the hole loses support, and then the hole wall undergoes severe loosening deformation until the hole collapses. After the hole collapses, this part of the soil is in a new state of equilibrium, but the pile hole has not been formed and drilling needs to continue. To ensure that the continued drilling can form a normal hole, it is necessary to inhibit or prevent the soil around the pile hole from collapsing further; this invention uses an inexpensive cement-soil mixture to form a highly viscous cement-soil retaining wall around the pile hole by rotating the rotary drilling bit. The horizontal thrust generated by the cement-soil retaining wall forms a mechanical balance mechanism with the limited earth pressure generated by the collapse of the pile hole.

[0038] like Figures 1 to 4 A method for solving the problem of large-diameter mechanical rotary pile collapse in a filling area using ton bags, the method is carried out in the following steps:

[0039] A. The construction site shall be positioned and laid out according to the construction drawings to ensure that pile point 3 is within the allowable range of the specifications;

[0040] B. Rotary drilling rig 1 is in place and drills a hole at pile point 3;

[0041] C. Do not deal with hole collapse during the initial hole formation process until the rotary drilling rig drill rod 2 can no longer continue drilling, then remove the rotary drilling rig drill rod 2;

[0042] D. The prepared volume is approximately 0.7m³. 3 A ton bag 7 is filled with soil 11. A crane is used to place the ton bag 7 filled with soil 11 into the pile hole 4. The distance between the ton bag 7 and the side of the collapsed hole area 6 is about 300mm. The top elevation of the ton bag 7 is slightly higher than the collapsed hole surface.

[0043] E. Use low-grade (C20) plain concrete 9 to backfill around the pile hole 4, and control the slump of the low-grade plain concrete 9 to within 200mm.

[0044] F. Based on the backfilling situation of low-grade plain concrete 9 and the diameter of the pile collapse zone 6, place ton bags to reduce the amount of low-grade plain concrete 9 backfilled.

[0045] G. After the concrete has initially set and reached a certain strength (let it stand for 12 hours), rotary drilling rig 1 will drill the hole for the second time.

[0046] H. Until the rotary drilling rig drill rod 2 can no longer drill, remove the rotary drilling rig drill rod 2;

[0047] I. Repeat steps D to H above (after the low-grade concrete hardens, a cement-soil retaining wall is formed around the pile hole 12) until the design and geological survey requirements are met.

[0048] J. Treat the same collapsed pile hole 4 using the method described above.

[0049] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A structure for solving the problem of large-diameter mechanical rotary pile hole collapse in a filling area using ton bags; characterized in that... ； A ton bag (7) filled with soil (11) is placed in the pile hole (4); low-grade plain concrete (9) is backfilled around the pile hole (4) to form a cement-soil retaining wall (12); the upper section of the pile hole (4) is the upper section protection section (5), and the concrete guide pipe (8) extends out of the upper section protection section (5); the ton bag (7) has ton bag lifting lugs (10). The structure is constructed sequentially according to the following steps: A. The construction site shall be positioned and laid out according to the construction drawings to ensure that the pile point (3) is within the allowable range of the specifications; B. The rotary drilling rig (1) is in place and drills a hole at the pile point (3); C. Do not deal with the hole collapse during the first hole formation process until the rotary drilling rig drill rod (2) can no longer form a hole, then remove the rotary drilling rig drill rod (2). D. The prepared volume is approximately 0.7m³. 3 A ton bag (7) is filled with soil (11). A crane is used to place the ton bag (7) filled with soil (11) into the pile hole (4). The distance between the ton bag (7) and the side of the collapsed hole area (6) is about 300mm. The top elevation of the ton bag (7) is slightly higher than the collapsed hole surface. E. Use low-grade plain concrete (9) to backfill around the pile hole (4), and control the slump of the low-grade plain concrete (9) to within 200mm; F. Place ton bags according to the backfilling situation of low-grade plain concrete (9) and the diameter of the pile collapse zone (6) to reduce the amount of low-grade plain concrete (9) backfilling; G. Let stand for 12 hours until the concrete has initially set and reached a certain strength, then use the rotary drilling rig (1) to form a second hole. H. Until the rotary drilling rig drill rod (2) can no longer form a hole, remove the rotary drilling rig drill rod (2). I. Repeat steps D to H above until the design and geological survey requirements are met; J. Treat the same collapsed pile holes as described above (4).

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