Construction equipment and construction method for pouring concrete into a karst cave

Abstract

The present invention belongs to the field of foundation and basic engineering technology, specifically a construction equipment for pouring concrete into a karst cave and a construction method thereof, the construction equipment includes a drilling rig, a hollow spiral drill rod, a drill rod with a casing, a drill rod guide device, a concrete pumping vehicle, and a rubber hose, and concrete is poured into the karst cave through a pipeline in the power head of the drilling rig, a hollow spiral drill rod, a hollow pipeline of the drill rod with a casing, and a reaming drill bit with a slurry outlet. The present invention is provided with a drill rod with a casing at the bottom of the hollow spiral drill rod, and a movable casing is provided on the drill rod with the casing. When concrete is injected into the karst cave, the outer cylinder of the movable casing moves downward under the action of gravity, and the concrete solidifies rapidly in the outer cylinder, thereby reducing the disadvantage of concrete spreading outward in the traditional construction method, further reducing the loss of materials, and greatly improving the bearing capacity of the upper foundation of the karst cave.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation and basic engineering, and specifically relates to construction equipment and a construction method for pouring concrete into a karst cave. Background Art

[0002] Caves are underground spaces formed within soluble rocks by karst action. They form as a result of long-term groundwater dissolution in limestone regions. China is a country rich in caves, and its karst area accounts for approximately one-quarter of the world's total subtropical karst area.

[0003] Construction on karst (soil) caves often requires necessary preparation to ensure sufficient bearing capacity for the building foundation. Currently, the main method is to drill and then fill the cave to reduce the risk of structural instability and collapse, but this often results in significant material waste. Furthermore, current construction methods require repeated hammering after filling, which complicates the equipment and takes a long time. Summary of the Invention

[0004] In order to solve the problems in the above-mentioned background technology, the present invention provides a construction equipment and a construction method for pouring concrete into a cave, which can solve the technical problems of large consumption of cave treatment materials, complex construction, long construction period, etc., and further improve the bearing capacity of the treated foundation.

[0005] The first object of the present invention is to provide a construction equipment for pouring concrete into a karst cave, comprising a drilling rig, a hollow auger rod, a concrete pumping truck and a connecting pipe, wherein the drilling rig is provided with a power head, one end of the hollow auger rod and one end of the connecting pipe are respectively connected to the power head, the other end of the connecting pipe is connected to the concrete pumping truck, and the interiors of the concrete pumping truck, the connecting pipe, the power head and the hollow auger rod are sequentially connected, and the equipment also comprises a drill rod with a casing, which is fixed vertically downward at the other end of the hollow auger rod.

[0006] Furthermore, the drill rod with casing includes a hollow steel pipe, spiral blades, a movable casing and a drill bit. The hollow steel pipe is fixedly connected to the hollow spiral drill rod, the spiral blades are arranged at the upper part of the hollow steel pipe, the movable casing is arranged at the lower part of the hollow steel pipe, the drill bit is arranged at the bottom end of the hollow steel pipe, and a concrete pouring outlet is provided on the drill bit.

[0007] Furthermore, the movable casing includes an inner tube, an outer tube, a connecting piece and a limiting mechanism. The inner tube is connected to the lower part of the hollow steel pipe through a bearing. The outer surface of the inner tube is evenly provided with grooves that pass through the upper and lower parts along the circumference. A slider is provided in the groove. The slider is connected to the outer tube through a connecting piece. The groove is also provided with a limiting mechanism for limiting the sliding of the slider along the groove.

[0008] Furthermore, the drill bit is provided with hole-expanding wings, which are symmetrically arranged on the outer surface of the drill bit.

[0009] Furthermore, the upper edge of the expansion wing is arc-shaped.

[0010] Furthermore, a sealing cover is provided on the outside of the concrete pouring outlet, and a spring member is provided between the inner side of the sealing cover and the inner side of the concrete pouring outlet. In the initial state, the spring member is in a stretched state.

[0011] Furthermore, the limiting mechanism is connected to the spring member, and when the sealing cover is forced to open, the spring member triggers the limiting mechanism to release the slider.

[0012] Furthermore, it also includes a drill rod guide device, which is connected to the drilling rig, and the drill rod with casing and the hollow spiral drill rod vertically downward pass through the drill rod guide device.

[0013] Furthermore, the drill rod guide device includes a base, a guide steel cylinder arranged on the base, a rubber sleeve arranged on the inner side of the guide steel cylinder, reinforcing ribs located at the connection between the base and the guide steel cylinder, and leveling cylinders evenly distributed along the circumference at the lower end of the base.

[0014] Furthermore, the construction equipment is also provided with an automatic drill rod correction device, including a column arranged on the drilling rig, a pressure sensor arranged between the rubber sleeve and the guide steel cylinder, and a leveling terminal connected to the pressure sensor.

[0015] The construction equipment for pouring concrete into a karst cave of the present invention has the following beneficial effects:

[0016] (1) The present invention provides a drill rod with a casing at one end of the hollow spiral drill rod close to the cave, and a movable casing is provided on the drill rod with the casing. When concrete is injected into the cave, the outer tube of the movable casing moves downward under the action of gravity, and the concrete falls into the outer tube and solidifies quickly, thereby reducing the disadvantage of the concrete spreading outward in the traditional construction method and effectively reducing the loss of materials.

[0017] (2) The present invention provides a drill rod guide device on the drilling rig, which can be adjusted to a horizontal position by a leveling cylinder at the lower end of the base. If the drill rod is tilted, an extrusion force will be generated between the drill rod and the rubber sleeve. The pressure sensor measures the distribution of the extrusion force and transmits it to the leveling terminal, so that the direction of the column can be adjusted in a targeted manner, thereby correcting the deviation of the hollow spiral drill rod.

[0018] (3) The present invention provides reaming wings on the drill bit, and the upper outer edge of the reaming wings is arc-shaped. When drilling downward, the reaming wings open outward under the action of cutting force to assist in reaming. The diameter of the reamed hole is larger than the diameter of the outer tube of the movable casing, so that the movable casing and the hollow spiral drill rod are lowered at the same time; when pouring concrete, under the action of confining pressure, the reaming wings shrink inward into the outer tube, so that the outer tube can slide downward under the action of gravity, so that the concrete filled in the cave is completely confined in the outer tube, forming a concrete column with a fixed shape.

[0019] (4) The present invention provides a limiting mechanism in the groove. When the spring member is in the initial state and the sealing cover is closed, the limiting mechanism prevents the slider from sliding in the groove. The outer tube and the inner tube are at the same height. In this way, the movable casing does not interfere with the drilling process when drilling. When the spring member is subjected to force to open the sealing cover (i.e., when pouring concrete), the limiting effect of the limiting mechanism on the slider disappears. The slider and the outer tube connected to it slide downward along the groove under the action of gravity. The outer tube stops descending after descending to the bottom of the cave. The shape of the concrete column is limited by the shape of the outer tube. On the one hand, the bearing capacity of the treated foundation is better improved, and on the other hand, concrete materials are saved.

[0020] A second object of the present invention is to use any of the above-mentioned karst cave pouring concrete construction equipment to carry out karst cave pouring concrete construction, comprising the following steps:

[0021] S1: Install and move the drilling rig to the designed location for pouring concrete;

[0022] S2: Install the drill rod guide device and start the leveling cylinder to level the drill rod guide device;

[0023] S3: Connect the first section of hollow auger drill rod and the casing drill rod with a pin, connect the top end of the first section of hollow auger drill rod to the power head, and pass the bottom end of the casing drill rod through the drill rod guide device;

[0024] S4: The test drilling power head corrects the deviation of the hollow spiral drill pipe and the drill pipe with casing;

[0025] S5: Drill with the power head in forward direction and clean the debris at the hole mouth;

[0026] S6: When the hollow auger rod above the ground is 1.0m-2.0m higher than the ground, hoist the next section of the hollow auger rod. Connect the top of the newly hoisted hollow auger rod to the power head through a latch, and connect the bottom to the previous section of the hollow auger rod whose top is above the ground through a latch;

[0027] S7: After the drill bit reaches the designed depth at the bottom of the cave, clean water is first injected into the cave through the channel connected by the power head, the hollow auger drill rod, and the drill rod with casing to clean the borehole; then concrete is pumped into the cave while the hollow auger drill rod is slowly lifted to form a concrete column.

[0028] S8: When the drill bit is raised to the designed elevation above the cave, stop pumping concrete.

[0029] S9: Lift all hollow spiral drill rods and drill rods with casing to the ground and rinse them with clean water.

[0030] S10: Insert a steel cage or steel pipe into the concrete to enhance the bearing capacity of the concrete column.

[0031] S11: In the same cave area, steps S1-S10 can be repeated to arrange several concrete columns according to the plane projection area to meet the requirements of foundation bearing capacity.

[0032] Furthermore, the concrete is low-slump plain concrete mixed with an accelerating setting agent.

[0033] The construction method of pouring concrete into a cave of the present invention uses a concrete pedestal formed by the special equipment provided by the present invention, which can stabilize the rock layer at the bottom of the cave, greatly improve the bearing capacity of the upper foundation, and the construction equipment has a high degree of mechanization. Compared with traditional cave treatment methods, the construction period is greatly shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 It is a structural schematic diagram of the construction equipment for pouring concrete into a karst cave according to the present invention;

[0036] Figure 2 This is a structural schematic diagram of a drill rod guide device in the construction equipment for pouring concrete into a karst cave according to the present invention;

[0037] Figure 3 This is a schematic diagram of the drill rod structure with casing in the construction equipment for pouring concrete into a karst cave according to the present invention;

[0038] Figure 4 This is a cross-sectional view of the drill bit structure in the construction equipment for pouring concrete into a karst cave according to the present invention;

[0039] Figure 5This is a schematic diagram of the connection between the sealing cover and the spring in the construction equipment for pouring concrete into a karst cave according to the present invention;

[0040] Figure 6 This is a cross-sectional view of a drill rod structure with casing in the construction equipment for pouring concrete into a karst cave according to the present invention;

[0041] Figure 7 A schematic diagram of a concrete platform column formed by the construction method of pouring concrete into a karst cave according to the present invention;

[0042] Among them: 1-drilling rig, 11-power head, 12-column, 2-hollow spiral drill rod, 3-drill rod with casing, 31-hollow steel pipe, 32-spiral blade, 33-removable casing, 331-inner cylinder, 332-outer cylinder, 333-connecting piece, 334-bearing, 335-groove, 336-slider, 34-drill bit, 341-reaming wing, 342-concrete pouring outlet, 343-sealing steel sheet, 344-spring, 4-drill rod guide device, 41-base, 42-guide steel cylinder, 43-reinforcement rib, 44-leveling cylinder, 45-rubber sleeve, 5-concrete pumping truck, 6-rubber hose, 7-ball joint, 8-covering soil, 9-concrete column, 10-cavity. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0044] like Figure 1-6 As shown, the present invention provides a construction device for pouring concrete into a karst cave, comprising a drilling rig 1, a hollow auger rod 2, a drill rod with a casing 3, a drill rod guide 4, a concrete pumping truck 5, and a connecting pipe, preferably a rubber hose 6. It should be noted that the present invention includes at least one hollow auger rod 2, and multiple hollow auger rods 2 can be connected in sequence to accommodate karst caves of different depths.

[0045] Specifically, the drill rod with casing 3 is arranged at the bottom of a plurality of hollow spiral drill rods 2 connected in a plug-in manner, and the top of the plurality of hollow spiral drill rods 2 connected in a plug-in manner is fixedly connected to the power head 11 of the drilling rig 1. It can be known that the power head 11 of this embodiment can directly provide drilling torque to the hollow spiral drill rod 2; the drill rod with casing 3 and the plurality of hollow spiral drill rods 2 connected in a plug-in manner pass through the drill rod guide device 4 to vertically excavate downward to form a borehole; the drill rod guide device 4 is connected to the drilling rig 1 through a ball joint 7, and the drill rod guide device 4 includes a base 41, a guide steel cylinder 42, a reinforcing rib 43, a plurality of leveling cylinders 44 and a rubber sleeve 45 evenly distributed along the circumference, wherein the hollow spiral drill rod 2 and the drill rod with casing 3 are connected to the hollow spiral drill rod 2 in a plug-in manner. The casing drill rod 3 passes through the guide steel cylinder 42 and drills a hole vertically downward. The reinforcing rib 43 is arranged at the connection between the base 41 and the guide steel cylinder 42 to further improve the strength of the drill rod guide device 4. The rubber sleeve 45 is arranged on the inner side of the guide steel cylinder 42 to avoid the extrusion force between the hollow spiral drill rod 2 and the guide steel cylinder 42 that causes irreversible deformation of the components due to the deflection of the hollow spiral drill rod 2. The leveling cylinder 44 is arranged at the bottom of the base 41 to level the drill rod guide device 4. In this embodiment, the number of leveling cylinders 44 is 3. Of course, those skilled in the art can increase the number of leveling cylinders according to actual working conditions. As long as the leveling effect can be achieved, it falls within the scope of protection of the present invention.

[0046] Specifically, the hollow auger rod 2 is provided with an auger rod channel for concrete or water to pass through; the power head 11 is provided with a pipe for concrete or water to pass through, one end of the pipe is connected to the top of the auger rod channel, and the other end is provided with a protruding opening. The two ends of the rubber hose 6 are respectively connected to the protruding opening and the slurry outlet of the concrete pumping truck 5 through connecting joints. Among them, the function of the rubber hose 6 is to connect the power head 11 and the concrete pumping truck 5, so those skilled in the art can choose any connecting pipe with a connecting function to achieve the purpose of the present invention.

[0047] Specifically, the casing drill rod 3 includes a hollow steel pipe 31, a spiral blade 32, a movable casing 33 and a drill bit 34; the hollow steel pipe 31 is correspondingly connected to the bottom of the hollow spiral drill rod channel; the spiral blade 32 is arranged at the upper part of the hollow steel pipe 31; the movable casing 33 is arranged at the lower part of the hollow steel pipe 31, and the drill bit 34 is fixedly arranged at the bottom end of the hollow steel pipe 31. The drill bit 34 is provided with several concrete pouring outlets 342 connected to the hollow steel pipe 31 of the casing drill rod 3, so that concrete or water enters the cave 10 in sequence through the rubber hose 6, the power head 11 and the hollow spiral drill rod 2, the hollow steel pipe 31 and the concrete pouring outlets 342.

[0048] Specifically, the movable casing 33 includes an inner tube 331, an outer tube 332, a connector 333, and a limiting mechanism (not shown). The inner tube 331 is connected to the lower portion of the hollow steel tube 31 via a bearing 334, allowing the inner tube 331 to freely rotate around the hollow steel tube 31. The inner tube 331 has a plurality of grooves 335 evenly distributed along its circumference. Sliders 336 that can slide along the grooves 335 are arranged in the grooves 335. The limiting mechanism is disposed in the grooves 335 to limit the sliding of the slides 336 along the grooves 335. This embodiment does not specifically limit the length of the movable casing 33, and those skilled in the art can design it according to actual working conditions. It can be understood that the present invention preferably selects a movable casing 33 with a length greater than the depth of the cave, which can better limit the shape of the concrete pillar 9.

[0049] Specifically, one end of the reaming wings 341 of the drill bit 34 is connected to the main body of the drill bit 34 via a pin hinge (i.e., the reaming wings 341 are disposed on the outer surface of the drill bit 34). Under the action of cutting force, the reaming wings 341 expand outward to assist in reaming. The diameter of the reamed hole is larger than the diameter of the outer tube of the movable casing, allowing the movable casing 33 and the hollow auger rod 2 to descend simultaneously. During concrete pouring, under the action of confining pressure, the reaming wings 341 retract inward into the outer tube 332. The outer tube 332 can slide downward under the gravity of the concrete in the hollow steel tube 31, thereby completely confining the concrete filling the cave 10 within the outer tube 332, forming a fixed concrete column 9. The upper edge of the reaming wings 341 of this embodiment is curved, which can reduce the contact pressure generated when the outer tube 332 descends, making it easier for the reaming wings 341 to retract into the outer tube 332.

[0050] Specifically, such as Figure 5 As shown, a sealing cover is provided on the exterior of the concrete pouring outlet 342. In this embodiment, the sealing cover is a sealing steel sheet 343. A spring member 344 is provided between the inner side of the sealing steel sheet 343 and a fixed point inside the concrete pouring outlet 342. The spring member can be a tension spring or a spring sheet. The spring member 344 is initially in a stretched state. When no concrete is poured, the concrete pouring outlet 342 is tightly sealed by the sealing steel sheet 343 under the tension of the spring member 344. Under a certain concrete pressure, the concrete can break through the sealing steel sheet 343. In this embodiment, the sealing steel sheet 343 is selected as the sealing cover, which provides a certain degree of rigidity and good pressure-bearing capacity. When drilling downward, the sealing steel sheet 343 is not easily deformed or opened.

[0051] Specifically, the spring member 344 is connected to the limiting mechanism. When the spring member 344 is in the initial position and the sealing steel sheet 343 is closed, the limiting mechanism prevents the slider 336 from sliding in the groove 335. The outer cylinder 332 and the inner cylinder 331 are at the same height. During drilling, the outer cylinder 332 and the hollow steel pipe 31 are fixed relative to each other, and the outer cylinder 332 does not interfere with the drilling process. When the spring member 344 is subjected to force to open the sealing steel sheet 343 (i.e., when pouring concrete), the limiting effect of the limiting mechanism on the slider 336 disappears. The slider 336 and the outer cylinder 332 connected to it slide downward along the groove 335 under the action of gravity. The outer cylinder 332 descends to the bottom of the cave 10, restricting the shape of the concrete column 9. On the one hand, it better improves the bearing capacity of the treated foundation, and on the other hand, it saves concrete material. It is understood that the present invention does not limit the specific structure of the limiting mechanism. Those skilled in the art can select any limiting mechanism in the prior art to achieve the limiting effect on the slider 336 of the present invention, which falls within the scope of protection of the present invention.

[0052] Specifically, the construction equipment is also equipped with an automatic drill rod deviation correction device, which includes a column 12 mounted on the drilling rig 1, a thin film pressure sensor disposed between the rubber sleeve 45 and the guide steel cylinder 42, and a leveling terminal (not shown) connected to the thin film pressure sensor. It should be noted that the column 12 mounted on the drilling rig 1 is rotatable. The leveling terminal of this embodiment is similar to a processing terminal. The leveling terminal can interpret the data from the pressure sensor as the rotation of the column 12, thereby maintaining the hollow auger drill rod 2 in a vertical position.

[0053] Specifically, the drill rod guide device 4 of this embodiment can be adjusted to a horizontal position by the leveling cylinder 44 at the lower end of the base. If the direction of the hollow spiral drill rod 2 is tilted, an extrusion force will be generated between it and the rubber sleeve 45. The thin film pressure sensor measures the distribution of the extrusion force and transmits it to the leveling terminal, so that the direction of the column 12 can be adjusted in a targeted manner, thereby correcting the deviation of the hollow spiral drill rod 2.

[0054] The present invention provides a drill rod 3 with a casing at the end of the hollow spiral drill rod 2 close to the cave, and a movable casing 33 is provided on the drill rod 3 with the casing. When concrete is injected into the cave, the outer tube 332 of the movable casing 33 moves downward under the action of gravity, and the concrete falls into the outer tube 332 and solidifies quickly, thereby reducing the disadvantage of the concrete spreading outward in the traditional construction method and effectively reducing the loss of material.

[0055] The present invention also provides a construction method for pouring concrete into a karst cave, such as Figure 7 As shown, the following steps are included:

[0056] S1: Install and move the drilling rig 1 to the vicinity of the designed position for pouring concrete;

[0057] S2: Install the drill rod guide device 4 and start the leveling cylinder 44 to level the drill rod guide device 4;

[0058] S3: Connect the first section of hollow auger drill rod 2 and the casing drill rod 3 through a pin, connect the top end of the first section of hollow auger drill rod 2 to the power head 11, and pass the bottom end of the casing drill rod 3 through the drill rod guide device 4 into the position where the hole needs to be drilled;

[0059] S4: The test drilling power head 11 corrects the deviation of the hollow spiral drill rod 2 and the drill rod with casing 3;

[0060] S5: The power head 11 rotates forward to drill, and the debris is brought out of the hole through the spiral blades on the casing drill rod 3 and the hollow spiral drill rod 2. At the same time, the debris at the hole is continuously cleaned until the drill bit drills into the designed position of the bottom surface of the cave 10.

[0061] S6: When the hollow auger rod 2 above the ground is 1.0m-2.0m higher than the ground, the next section of the hollow auger rod 2 is hoisted, the top of the newly hoisted hollow auger rod 2 is connected to the power head 11 by a pin, and the bottom is connected to the previous section of the hollow auger rod whose top is higher than the ground by a pin, and drilling continues. The present invention can realize the construction of caves 10 of different depths through several plug-in hollow auger rods 2, thereby achieving the purpose of simplifying the construction process and shortening the construction period.

[0062] S7: After the drill bit 34 passes through the covering soil 8 and reaches the designed position of the bottom surface of the karst cave 10, clean water is first injected into the concrete pumping truck 5. Under the action of water pressure, the concrete pumping truck 5 injects clean water into the karst cave 10 through the connecting structure of the pipeline in the power head 11, the hollow spiral drill rod 2, the hollow steel pipe 31 with the casing drill rod 3, and the concrete pouring outlet 342 of the drill bit 34 to flush and clean the filling in the karst cave 10. By flushing the karst cave 10, the filling such as garbage in the karst cave 10 can be flushed out of the drill hole, further improving the quality of concrete molding; then the concrete pumping truck 5 is turned on. The slurry outlet of vehicle 5 pumps low-slump plain concrete mixed with an accelerator into the cave 10 while slowly lifting the hollow auger rod 2. Under the action of the concrete's gravity, the sealing steel sheet 343 opens, and the spring member 344 triggers the limiting mechanism to cancel the limiting effect on the slider 336. The slider 336 and the outer cylinder 332 connected to it slide downward along the groove until the outer cylinder 332 descends to the bottom of the cave 10. At this time, the concrete enters the space enclosed by the outer cylinder 332 through the concrete pouring outlet 342, restricting the shape of the concrete column and ultimately forming a concrete column 9 with a certain shape. It should be noted that the low-slump plain concrete used in this embodiment has good vibration resistance. After the fresh concrete is strongly vibrated, it is not prone to bleeding, stratification, or laitance. It can well maintain the uniformity of the concrete and has good wrapping and workability. In addition, due to the low slump, the water consumption of the concrete is reduced, the strength guarantee rate is higher, the concrete shrinks less during drying, and the crack resistance is enhanced.

[0063] S8: When the drill bit 34 is lifted to the designed elevation above the cave 10, the concrete pumping is stopped.

[0064] S9: Lift the hollow spiral drill rod 2 and the drill rod with casing 3 to the ground and rinse them with clean water.

[0065] S10: Inserting a steel cage or steel pipe into the concrete to enhance the bearing capacity of the concrete column.

[0066] S11: In the same cave 10 area, several concrete columns can be arranged by repeating S1-S10 according to the plane projection area to meet the needs of foundation bearing capacity.

[0067] The construction method of pouring concrete into a cave of the present invention adopts the concrete platform 9 formed by the special equipment provided by the present invention, which can stabilize the rock layer at the bottom of the cave, greatly improve the bearing capacity of the upper foundation, and the construction equipment has a high degree of mechanization. Compared with the traditional cave treatment method, the construction period is greatly shortened.

[0068] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in this field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A construction equipment for pouring concrete into a karst cave, comprising a drilling rig, a hollow auger rod, a concrete pumping vehicle and a connecting pipe, wherein the drilling rig is provided with a power head, one end of the hollow auger rod and one end of the connecting pipe are respectively connected to the power head, the other end of the connecting pipe is connected to the concrete pumping vehicle, the interiors of the concrete pumping vehicle, the connecting pipe, the power head and the hollow auger rod are sequentially connected, and the invention is characterized in that: It also includes a drill rod with a casing, which is fixed vertically downwardly on the other end of the hollow spiral drill rod; The casing drill rod comprises a hollow steel pipe, a spiral blade, a movable casing and a drill bit, the hollow steel pipe is fixedly connected to the hollow spiral drill rod, the spiral blade is arranged at the upper part of the hollow steel pipe, the movable casing is arranged at the lower part of the hollow steel pipe, the drill bit is arranged at the bottom end of the hollow steel pipe, and a concrete pouring outlet is arranged on the drill bit; The movable casing includes an inner cylinder, an outer cylinder, a connecting piece and a limiting mechanism. The inner cylinder is connected to the lower part of the hollow steel pipe through a bearing. The outer surface of the inner cylinder is evenly provided with grooves that penetrate up and down along the circumference. A slider is provided in the groove. The slider is connected to the outer cylinder through the connecting piece. A limiting mechanism for limiting the sliding of the slider along the groove is also provided in the groove.

2. The construction equipment for pouring concrete into a karst cave according to claim 1, characterized in that: The drill bit is provided with hole-expanding wings, which are symmetrically arranged on the outer surface of the drill bit, and the upper edges of the hole-expanding wings are arc-shaped.

3. The construction equipment for pouring concrete into a karst cave according to claim 1, characterized in that: A sealing cover is arranged outside the concrete pouring outlet, and a spring member is arranged between the inner side of the sealing cover and the inner side of the concrete pouring outlet. In an initial state, the spring member is in a stretched state.

4. The construction equipment for pouring concrete into a karst cave according to claim 3, characterized in that: The limiting mechanism is connected to the spring component, and when the sealing cover is opened by force, the spring component triggers the limiting mechanism to release the sliding block.

5. The construction equipment for pouring concrete into a karst cave according to claim 1, characterized in that: It also includes a drill rod guiding device, which is connected to the drilling rig, and the drill rod with casing and the hollow spiral drill rod vertically and downwardly penetrate the drill rod guiding device.

6. The construction equipment for pouring concrete into a karst cave according to claim 5, characterized in that: The drill rod guide device includes a base, a guide steel cylinder arranged on the base, a rubber sleeve arranged in the guide steel cylinder, a reinforcing rib located at the connection between the base and the guide steel cylinder, and a leveling cylinder evenly distributed along the circumference at the lower end of the base.

7. The construction equipment for pouring concrete into a karst cave according to claim 6, characterized in that: The construction equipment is also provided with an automatic drill rod deviation correction device, which includes a column arranged on the drilling rig, a pressure sensor arranged between the rubber sleeve and the guide steel cylinder, and a leveling terminal connected to the pressure sensor.

8. A construction method for the construction equipment for pouring concrete into a karst cave based on any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Install and move the drilling rig to the vicinity of the designed location for pouring concrete; S2: Install the drill rod guide device and start the leveling cylinder to level the drill rod guide device; S3: Connect the first section of the hollow spiral drill rod and the drill rod with casing through a pin, connect the top end of the first section of the hollow spiral drill rod to the power head, and pass the bottom end of the drill rod with casing through the drill rod guide device; S4: The test drilling power head corrects the hollow spiral drill rod and the drill rod with casing; S5: Drill with the power head in the forward direction and clean the debris at the hole; S6: When the hollow auger rod above the ground is 1.0m-2.0m higher than the ground, hoist the next section of the hollow auger rod, connect the top of the newly hoisted hollow auger rod to the power head through a latch, and connect the bottom to the previous section of the hollow auger rod whose top is higher than the ground through a latch; S7: After the drill bit reaches the designed depth at the bottom of the cave, clean water is first injected into the cave through the channel connected by the power head, the hollow auger rod, and the casing drill rod to clean the borehole; then concrete is pumped into the cave while the hollow auger rod is slowly lifted to form a concrete column; S8: When the drill bit is lifted to the designed elevation above the cave, the concrete pumping is stopped; S9: Lift all hollow auger drill rods and casing drill rods to the ground and rinse with clean water; S10: Insert steel cages or steel pipes into the concrete to enhance the bearing capacity of the concrete columns; S11: In the same cave area, several concrete columns can be arranged by repeating S1-S10 according to the plane projection area to meet the needs of foundation bearing capacity.

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