A device for preventing hole collapse of a cast-in-place pile suitable for a karst rock stratum

Abstract

The utility model relates to borehole construction equipment technical field discloses a kind of borehole cast-in-place pile hole collapse prevention devices suitable for karst cave rock stratum, including the sleeve assembly for directly supporting outer hole wall, the outer wall of sleeve assembly is provided with the fixed component for the sleeve assembly connection fixation, sleeve assembly lower end is equipped with the cutting component for cutting rock stratum, by the radial locking force of bolt one and screw rod one, to connect the steel casing outer tube and steel casing inner tube closely, prevent double-layer casing from producing relative displacement due to vibration or stress in construction, lower end node plate one and node plate two are fastened by bolt two and screw rod two, sleeve in double-layer casing outer wall, further enhance the overall connection strength of outer tube and inner tube, form multi-point, multidirectional fixed system, ensure when borehole in karst cave rock stratum, double-layer casing structure is stable, resist hole wall pressure and construction disturbance.

Description

Technical Field

[0001] This utility model relates to the field of drilling construction equipment technology, specifically to a device for preventing collapse of drilled piles in karst rock formations. Background Technology

[0002] The rock strata of the karst cave are mainly composed of soluble rocks such as limestone and dolomite. Through long-term erosion and dissolution by water, they have formed complex geological features such as solution channels, solution troughs, caves, and tectonic zones. Their geological conditions are unstable, with pores and fissures, and the mechanical properties of the rocks vary greatly. Some areas may contain loose filling materials, and groundwater activity is frequent. Chinese patent CN220978058U discloses a device for preventing collapse of bored piles in complex geological conditions. The device includes an outer support pile with an internal support mechanism that enhances the support effect on the inner wall of the borehole. The support mechanism includes a reinforcing seat fixedly installed on the inner circumferential wall of the outer support pile, and a connecting plate welded between four adjacent reinforcing seats. An inner support pile is fixedly installed on the side of the reinforcing seat away from the outer support pile. This device, through the action of the reinforcing seat, connecting plate, inner support pile, reinforcing frame, and slider, improves the supporting force of the inner circumferential wall of the outer support pile, preventing long-term pressure deformation. The positioning rod engages a cover plate on the top of the outer support pile to prevent rainwater from entering the pile and to prevent pressure differences between the top and bottom of the outer support pile from affecting its support effect. However, the following shortcomings still exist: When using existing devices, the inner and outer sleeves of the protective cylinder often become loose or even disconnected due to insufficient connection strength or uneven force during lowering, making it difficult to maintain tightness. At the same time, due to improper length adjustment, the drill bit cannot adapt to the undulations of the karst rock strata, resulting in the inability to be lowered to the designed depth. Therefore, those skilled in the art provide a borehole anti-collapse device for bored piles suitable for karst rock strata to solve the problems mentioned in the background art. Utility Model Content

[0003] The purpose of this utility model is to provide a borehole anti-collapse device for bored piles in karst rock formations, and to solve the problems mentioned in the background art above.

[0004] This utility model provides the following technical solution: a borehole anti-collapse device for bored piles suitable for karst rock formations, including a sleeve assembly for directly supporting the outer hole wall, the outer wall of the sleeve assembly is provided with a fixing component for connecting and fixing the sleeve assembly, and the lower end of the sleeve assembly is equipped with a cutting component for cutting the rock formation.

[0005] As a preferred embodiment of the above technical solution, the sleeve assembly includes a steel outer tube, and a steel inner tube is fixedly installed on the inner wall of the steel outer tube.

[0006] As a preferred embodiment of the above technical solution, a slurry discharge pipe is fixedly connected to one side of the connection between the outer steel casing and the inner steel casing, and a water injection pipe is fixedly connected to the other side of the connection between the outer steel casing and the inner steel casing. A mudguard is fixedly installed at the lower end of the inner steel casing.

[0007] As a preferred embodiment of the above technical solution, the fixing component includes a bolt, which is bolted to the outer wall of the outer tube of the steel casing. The inner wall of the bolt is threaded with a screw, which extends through the outer tube of the steel casing to the inner wall of the inner tube of the steel casing. Several bolts and screws are provided.

[0008] As a preferred embodiment of the above technical solution, a node plate 1 is fixedly connected to the lower end of the bolt, and a node plate 2 is fixedly connected to the lower end of the node plate 1. Both the node plate 1 and the node plate 2 are sleeved on the outer wall of the outer tube and the inner tube of the steel casing. Several bolts 2 are threadedly connected inside the node plate 1 and the node plate 2, and screw rods 2 are threadedly connected inside the several bolts 2.

[0009] As a preferred embodiment of the above technical solution, the cutting assembly includes a support plate, which is fixedly installed at the lower end of the mudguard. Jacks are provided at the four corners of the support plate, and fixed plates are fixedly installed at the lower ends of the four jacks. A drill rod is rotatably connected to the lower end of the fixed plate, and a drill bit is rotatably connected to the lower end of the drill rod.

[0010] Compared with the prior art, the beneficial effects of this utility model are: This utility model uses the radial locking force of bolt one and screw one to tightly connect the outer and inner pipes of the steel casing, preventing relative displacement of the double-layer casing due to vibration or stress during construction. The lower end node plate one and node plate two are axially fastened by bolt two and screw two, and are sleeved on the outer wall of the double-layer casing, further enhancing the overall connection strength between the outer and inner pipes, forming a multi-point, multi-directional fixing system. This ensures the stability of the double-layer casing structure when drilling in karst formations, resisting borehole pressure and construction disturbances. The support plate is fixed to the lower end of the mudguard plate to provide support. The four corner jacks adjust the height and level of the fixing plate to ensure balanced force on the drill bit. The drill rod is driven, causing the drill bit to rotate at high speed, which, together with the pressure of the jacks, cuts and breaks the rock. The jacks can also buffer impact vibration, protect the equipment, and improve efficiency. Attached Figure Description

[0011] Figure 1 This is a right-side three-dimensional structural diagram of a borehole anti-collapse device for cast-in-place piles suitable for karst rock formations. Figure 2This is a left-side three-dimensional structural diagram of a borehole anti-collapse device for cast-in-place piles suitable for karst rock formations. Figure 3 This is a schematic diagram of the cross-sectional structure of the connection between the outer tube and the inner tube of the steel casing. Figure 4 This is a schematic diagram of the cutting assembly.

[0012] 1. Sleeve assembly; 101. Outer steel casing tube; 102. Inner steel casing tube; 103. Slurry discharge pipe; 104. Water injection pipe; 105. Mudguard; 2. Fixing assembly; 201. Bolt 1; 202. Screw 1; 203. Node plate 1; 204. Node plate 2; 205. Bolt 2; 206. Screw 2; 3. Cutting assembly; 301. Support plate; 302. Jack; 303. Fixing plate; 304. Drill rod; 305. Drill bit. Detailed Implementation

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0014] Please see Figures 1-4 As shown, this utility model provides a technical solution: a borehole anti-collapse device for bored piles suitable for karst rock formations, including a sleeve assembly 1 for directly supporting the outer hole wall, a fixing assembly 2 for connecting and fixing the sleeve assembly 1 on the outer wall, and a cutting assembly 3 for cutting the rock formation at the lower end of the sleeve assembly 1.

[0015] As one implementation method in this embodiment, please refer to Figures 3-4 As shown, the sleeve assembly 1 includes a steel outer tube 101, a steel inner tube 102 fixedly installed on the inner wall of the steel outer tube 101, a slurry discharge pipe 103 fixedly connected to one side of the connection between the steel outer tube 101 and the steel inner tube 102, a water injection pipe 104 fixedly connected to the other side of the connection between the steel outer tube 101 and the steel inner tube 102, and a mudguard 105 fixedly installed at the lower end of the steel inner tube 102; Furthermore, the outer steel casing 101 and the inner steel casing 102 form a double-layer protective structure, which enhances the stability of the borehole wall through rigid support and resists the collapse pressure of the karst strata. The slurry discharge pipe 103 and the water injection pipe 104 connected on both sides form a circulation system. The water injection pipe 104 injects mud or clean water, which reinforces the borehole wall through mud protection on the one hand, and assists the drill bit 305 in breaking rocks on the other hand. The slurry discharge pipe 103 promptly discharges the rock debris and waste slurry generated during drilling to avoid accumulation and affect construction. The mud baffle 105 at the lower end of the inner casing can prevent the loose rock and soil or karst filling material from rising from the bottom, further ensuring the cleanliness and stability of the borehole and providing a safe working environment for the drill bit 305 to drill efficiently in complex karst strata.

[0016] As one implementation method in this embodiment, please refer to Figure 2 As shown, the fixing component 2 includes bolt 201, which is bolted to the outer wall of the outer tube 101 of the steel casing. Bolt 201 is threaded to the inner wall of bolt 201 and screw 202 extends through the outer tube 101 to the inner wall of the inner tube 102 of the steel casing. There are several bolts 201 and screw 202. The lower end of bolt 201 is fixedly connected to node plate 203. The lower end of node plate 203 is fixedly connected to node plate 204. Node plate 203 and node plate 204 are both sleeved on the outer walls of the outer tube 101 and the inner tube 102 of the steel casing. There are several bolts 205 threaded inside node plate 203 and node plate 204. Screw 206 is threaded inside the several bolts 205. Furthermore, through the cooperation of bolt 201 and screw 202, the outer tube 101 of the steel casing is penetrated through the outer wall to the inner wall of the inner tube 102 of the steel casing. The radial locking force of multiple sets of bolts and screws tightly connects the outer tube 101 and the inner tube 102 of the steel casing, preventing relative displacement of the double casing due to vibration or stress during construction. The lower node plate 203 and node plate 204 are fitted on the outer wall of the double casing and axially fastened by several bolts 205 and screws 206, further enhancing the overall connection strength between the outer and inner tubes. This forms a multi-point, multi-directional fixing system, ensuring the stability of the double casing structure during drilling in karst formations and resisting borehole pressure and construction disturbances.

[0017] As one implementation method in this embodiment, please refer to Figures 2-4 As shown, the cutting assembly 3 includes a support plate 301, which is fixedly installed on the lower end of the mudguard 105. Jacks 302 are provided at the four corners of the support plate 301. Fixing plates 303 are fixedly installed at the lower ends of the four jacks 302. Drill rods 304 are rotatably connected to the lower end of the fixing plates 303. Drill bits 305 are rotatably connected to the lower end of the drill rods 304. Furthermore, the support plate 301 is fixed to the lower end of the mudguard 105 as a load-bearing foundation, providing stable support for the entire component. The jacks 302 at the four corners can adjust the height and level of the fixed plate 303 through telescopic adjustment to adapt to the undulations of the karst rock strata and ensure that the drill bit 305 is subjected to balanced force. The drill rod 304 at the lower end of the fixed plate 303 is driven by external equipment, which drives the drill bit 305 to rotate at high speed. Under the pressure of the jacks 302, the rock below is precisely cut and broken. At the same time, with the buffering effect of the jacks 302, the impact vibration of the drill bit 305 when it encounters hard rock strata is reduced, protecting the equipment and improving drilling efficiency.

[0018] Working principle: The outer steel casing 101 and the inner steel casing 102 form a double-layer rigid protection, which enhances the stability of the borehole wall to resist the pressure of the cave collapse. The slurry discharge pipes 103 and the water injection pipes 104 on both sides form a circulation system. The water injection pipes 104 inject mud or clean water, which not only strengthens the borehole wall through mud protection, but also assists the drill bit 305 in breaking rocks. The slurry discharge pipes 103 promptly discharge rock debris and waste slurry to avoid accumulation and affect construction. The mud baffle 105 at the lower end of the inner casing prevents loose rock and soil or cave filling material from rising from the bottom, ensuring the cleanliness and stability of the borehole and providing a safe environment for the drill bit 305 to drill efficiently in complex cave formations. Bolt 201 and screw 202 are radially locked to connect the outer tube 101 and the inner tube 102 of the steel casing into one unit, preventing vibration or displacement under force. The lower end node plate 203 and node plate 204 are axially fastened to screw 206 by bolt 205, and are fitted on the outside of the double-layer casing to enhance the integrity and form multi-point and multi-directional fixation to ensure the stability of the casing when drilling in karst caves and resist the pressure of the borehole wall and construction disturbance. The support plate 301 is supported on the lower end of the mudguard plate 105. The four corner jacks 302 adjust the fixing plate 303 to ensure that the drill bit 305 is subjected to balanced force. The drill rod 304 drives the drill bit 305 to rotate, and the pressure of the jacks 302 breaks the rock. The jacks 302 also buffer the equipment and improve efficiency.

[0019] The above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit it.

Claims

1. A device for preventing collapse of bored piles in karst rock formations, comprising a sleeve assembly (1) for directly supporting the outer borehole wall, characterized in that: The outer wall of the sleeve assembly (1) is provided with a fixing component (2) for connecting and fixing the sleeve assembly (1), and the lower end of the sleeve assembly (1) is equipped with a cutting component (3) for cutting rock formations.

2. The anti-collapse device for bored piles suitable for karst rock formations according to claim 1, characterized in that: The sleeve assembly (1) includes a steel outer tube (101), and a steel inner tube (102) is fixedly installed on the inner wall of the steel outer tube (101).

3. The anti-collapse device for bored piles suitable for karst rock formations according to claim 2, characterized in that: A slurry discharge pipe (103) is fixedly connected to one side of the connection between the outer pipe (101) and the inner pipe (102) of the steel casing, and a water injection pipe (104) is fixedly connected to the other side of the connection between the outer pipe (101) and the inner pipe (102) of the steel casing. A mudguard (105) is fixedly installed at the lower end of the inner pipe (102) of the steel casing.

4. The anti-collapse device for bored piles suitable for karst rock formations according to claim 2, characterized in that: The fixing component (2) includes a bolt (201), which is bolted to the outer wall of the outer tube (101) of the steel casing. The inner wall of the bolt (201) is threaded with a screw (202), which extends through the outer tube (101) of the steel casing to the inner wall of the inner tube (102) of the steel casing. Several bolts (201) and screws (202) are provided.

5. The anti-collapse device for bored piles suitable for karst rock formations according to claim 4, characterized in that: The lower end of the bolt one (201) is fixedly connected to the node plate one (203), and the lower end of the node plate one (203) is fixedly connected to the node plate two (204). The node plate one (203) and the node plate two (204) are both sleeved on the outer wall of the outer tube (101) and the inner tube (102) of the steel casing. The node plate one (203) and the node plate two (204) are both threaded with a number of bolts two (205), and the bolts two (205) are all threaded with screws two (206).

6. The anti-collapse device for bored piles suitable for karst rock formations according to claim 3, characterized in that: The cutting assembly (3) includes a support plate (301), which is fixedly installed at the lower end of the mudguard (105). Jacks (302) are provided at the four corners of the support plate (301). Fixing plates (303) are fixedly installed at the lower ends of the four jacks (302). Drill rods (304) are rotatably connected to the lower end of the fixing plates (303). Drill bits (305) are rotatably connected to the lower end of the drill rods (304).

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