Construction method of water stopping curtain based on weathered rock stratum

Abstract

The application discloses a water-stopping curtain construction method based on medium weathered rock stratum, which comprises the following steps: trench construction, performing water-stopping curtain trench excavation operation at a specified position; drilling construction above the rock stratum, performing drilling operation by using drilling operation equipment until the medium weathered rock stratum surface; rock stratum drilling construction, lifting a spiral drilling device, then starting a high-pressure jet grouting drilling device and a high-pressure cement pump to make cement slurry enter a jet grouting drill rod through a high-pressure spray pipe, and then the cement slurry is sprayed out of the opening to form a water jet, and the water jet cuts the surrounding medium weathered rock stratum; secondary drilling construction, lifting the spiral drilling device upward, taking out the jet grouting drill rod, then lowering the spiral drilling device, and performing grouting operation by using the high-pressure spray pipe. The method is constructed by using the two modes of rotary drilling and high-pressure jet grouting drilling, can be suitable for the geology with medium weathered rock stratum, has high construction efficiency, good drilling forming effect, reduces the use amount of operation equipment, and saves construction cost.

Description

Technical Field

[0001] This invention relates to the field of water-stop curtain construction technology, specifically to a water-stop curtain construction method based on moderately weathered rock strata. Background Technology

[0002] With the continuous development and utilization of underground space, civil engineering projects are expanding into deeper areas, resulting in a large number of deep foundation pit projects. Deep foundation pits are highly susceptible to groundwater during excavation. Excessive groundwater inflow can render the foundation pit unusable and may even lead to safety accidents. Therefore, dewatering measures are extremely important in deep foundation pit projects. Water-stop curtains are an important structure for water-stopping in existing deep foundation pits. Currently, triaxial water-stop curtain drilling rigs are commonly used for drilling operations. However, in construction of moderately to strongly weathered rock strata, conventional methods result in slow drilling speeds, low hole formation efficiency, and damage to the borehole walls due to the long drilling time. Furthermore, the varying degrees of weathering in the rock strata can easily cause borehole deviation, leading to poor construction quality, slow progress, and increased construction costs. Summary of the Invention

[0003] The purpose of this invention is to provide a method for constructing a water-stop curtain based on moderately weathered rock strata. This method utilizes a combination of rotary drilling and high-pressure jet grouting, which can be adapted to geological conditions with moderately weathered rock strata. It has high construction efficiency, good drilling results, reduces the amount of equipment used, and saves construction costs.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for constructing a water-stop curtain based on moderately weathered rock strata, the method comprising the following steps:

[0006] Step 1: Guide channel construction. According to the design and construction drawings, the guide channel for the water-stop curtain is excavated at the designated location, and the inner wall of the guide channel for the water-stop curtain is cleaned.

[0007] Step two involves drilling above the rock strata. Drilling equipment is used to drill down to the surface of the moderately weathered rock strata. This equipment includes a support base, a guide support device mounted on the support base, a spiral drilling device mounted on the guide support device, and a high-pressure jet grouting drilling device. The guide support device includes a guide rail hinged to the support base at one end, a main drive motor mounted on the support base, a drum powered by the main drive motor, a steel wire rope wound on the drum, and a pulley mounted at the other end of the guide rail. The other end of the steel wire rope is connected to the spiral drilling device via the pulley. The spiral drilling device includes a first mounting bracket slidably mounted on the guide rail, a first dual-output reducer mounted on the first mounting bracket, a first drive motor fixedly mounted at the input end of the first dual-output reducer, and a first output reducer fixedly mounted on the first output reducer. The output end has two spiral drill rods and a drill bit installed at the bottom of the spiral drill rods. When the first drive motor is energized and rotates, it drives the two spiral drill rods to rotate through the first dual-output reducer to perform drilling operations. The high-pressure jet grouting drilling device includes a second mounting bracket slidably mounted on a guide rail, a second reducer fixedly mounted on the second mounting bracket, a second drive motor mounted on the input end of the second reducer, a drive rod mounted on the output end of the second reducer, a jet grouting drill rod detachably mounted on one end of the drive rod, a high-pressure nozzle mounted on the second mounting bracket, and a vertical drive assembly mounted on the second mounting bracket. The vertical drive assembly drives the second mounting bracket to slide back and forth linearly on the guide rail. One end of the high-pressure nozzle is connected to the drive rod, and the other end of the high-pressure nozzle is connected to a high-pressure cement pump. Openings are provided on both sides of the bottom of the jet grouting drill rod.

[0008] Step 3: Drilling of the rock strata. After the drilling of the soil layer above the rock strata is completed, the operation of the auger drilling device is stopped, and the auger drilling device is lifted using the main drive motor. Then, the high-pressure jet grouting drilling device is started, and the drive rod and jet grouting drill rod are rotated by the second drive motor. The jet grouting drill rod is inserted downward in conjunction with the vertical drive component. At the same time, the high-pressure cement pump is started so that the cement slurry enters the jet grouting drill rod through the high-pressure nozzle and is then sprayed out from the opening to form a water jet. The water jet cuts the surrounding moderately weathered rock strata.

[0009] Step four, secondary drilling construction: When the high-pressure jet grouting drilling device reaches the bottom elevation, the device is lifted upwards using the vertical drive assembly to remove the jet grouting drill rod located in the moderately weathered rock layer; then, the main drive motor lowers the auger drilling device to continue drilling downwards to the bottom elevation; after construction is completed, the auger drilling device is lifted out, and grouting is performed on the completed hole using a high-pressure nozzle; the construction is repeated until the water-stop curtain construction is completed.

[0010] Preferably, the support base includes a chassis bracket, a main support leg installed at the bottom of the chassis bracket, and multiple adjustable support legs installed at the bottom of the chassis bracket.

[0011] Preferably, the adjustable support leg includes a fixed mounting component, an adjusting screw, and a support plate. One end of the adjusting screw is adjustablely connected to the fixed mounting component via a thread, and the support plate is fixedly mounted on the other end of the adjusting screw. The fixed mounting component is detachably mounted on the chassis bracket.

[0012] Preferably, in step three, the high-pressure cement pump provides a pressure of 30 MPa.

[0013] Preferably, the vertical drive assembly includes a rack fixedly mounted on one side of the guide rail, a third drive motor fixedly mounted on the second mounting bracket, and a gear mounted on the output shaft of the third drive motor, wherein the gear meshes with the rack.

[0014] Preferably, the jet grouting drill rod is located between the two auger drill rods.

[0015] Preferably, the bottom of the jet jet drill rod is provided with an inverted conical drill hole, and helical teeth are fixedly provided on the inverted conical drill hole along its conical surface.

[0016] This invention employs a drilling method that involves first spiral drilling, then high-pressure jet grouting, and finally spiral drilling again. This method solves the problems of poor quality and low efficiency associated with traditional triaxial water-stop curtain drilling rigs in drilling operations on moderately weathered rock strata. The drilling equipment can perform both spiral drilling and high-pressure jet grouting, and can be operated sequentially as much as possible, resulting in good borehole surface quality. This equipment is adaptable to various soil types, including soft soil and moderately weathered rock strata. The ability to perform two drilling methods in one device reduces the amount of equipment needed and saves on construction costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a partial structural diagram of the present invention;

[0019] Figure 3 This is a partial structural diagram of the jet grouting drill rod of the present invention;

[0020] In the diagram: 1. Support base; 2. Guide support device; 3. Spiral drilling device; 4. High-pressure jet grouting drilling device; 5. Support rod; 10. Chassis bracket; 11. Main support leg; 12. Adjustable support leg; 20. Guide rail; 21. Main drive motor; 22. Drum; 23. Wire rope; 24. Pulley; 30. First mounting bracket; 31. First dual-output reducer; 32. First drive motor; 33. Spiral drill rod; 34. Drill bit; 40. Second mounting bracket; 41. Second reducer; 42. Second drive motor; 43. Drive rod; 44. Jet grouting drill rod; 45. High-pressure nozzle; 46. Vertical drive assembly; 47. High-pressure cement pump; 48. Conical drilling section; 49. Spiral gear; 120. Fixed mounting component; 121. Adjusting screw; 122. Support plate; 460. Rack; 461. Third drive motor; 462. Gear. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] like Figure 1 , Figure 2 and Figure 3 The method shown is a construction method for a water-stop curtain based on moderately weathered rock strata. The construction method includes the following steps:

[0023] Step 1: Guide channel construction. According to the design and construction drawings, the guide channel for the water-stop curtain is excavated at the designated location. In this embodiment, the cross-section of the guide channel for the water-stop curtain is rectangular, and the width of the guide channel for the water-stop curtain is greater than the diameter of the borehole to be constructed. After the construction of the guide channel for the water-stop curtain is completed, the inner wall of the guide channel for the water-stop curtain is cleaned to make its inner wall smooth.

[0024] Step two involves drilling above the rock strata using drilling equipment to reach the surface of the moderately weathered rock layer. This drilling equipment includes a support base 1, a guide support device 2 mounted on the support base 1, a spiral drilling device 3 mounted on the guide support device 2, and a high-pressure jet grouting drilling device 4. Specifically, the support base 1 includes a chassis bracket 10, a main support leg 11 fixedly mounted to the bottom of the chassis bracket 10 with fasteners, and multiple adjustable support legs 12 fixedly mounted to the bottom of the chassis bracket 10. The chassis bracket 10 is specifically a rectangular frame structure welded from structural steel, with the main support leg 11 positioned at the center of the bottom of the chassis bracket 10. In one embodiment, the adjustable support leg 12 includes a fixed mounting component 120, an adjusting screw 121, and a support plate 122. One end of the adjusting screw 121 is threadedly adjustable to the bottom of the fixed mounting component 120, and the support plate 122 is welded to the other end of the adjusting screw 121. The fixed mounting component 120 is detachably mounted to the chassis bracket 10 with bolts. Specifically, four or six adjustable outriggers 12 are installed on the chassis support 10.

[0025] The guide support device 2 includes a guide rail 20 hinged to a support base 1 at one end via a pin, a main drive motor 21 fixedly mounted on the support base 1, a drum 22 poweredly connected to the main drive motor 21, a steel wire rope 23 wound on the drum 22, and a pulley 24 rotatably mounted at the other end of the guide rail 20. The other end of the steel wire rope 23 is connected to the spiral drilling device 3 via the pulley 24. A support rod 5 is also mounted on the support base 1. The support rod 5 is used to control the angle of the guide rail 20. In the non-working state, the guide rail 20 is horizontally set on the support base 1. In the working state, the support rod 5 is connected to the guide rail 20, so that the guide rail 20 is in a vertical state. Specifically, the guide rail 20 is made of I-beams.

[0026] The spiral drilling device 3 includes a first mounting bracket 30 slidably mounted on a guide rail 20, a first dual-output reducer 31 fixedly mounted on the first mounting bracket 30 by fasteners, a first drive motor 32 fixedly mounted on the input end of the first dual-output reducer 31, two spiral drill rods 33 fixedly mounted on the output end of the first output reducer 31, and a drill bit 34 mounted on the bottom of the spiral drill rods 33. During operation, the first drive motor 32 is energized and rotates, driving the two spiral drill rods 33 and the drill bit 34 to rotate for drilling. One end of a wire rope 23 is connected to the first mounting bracket 30. During drilling, the wire rope 23 is in an anti-loosening state, and the spiral drilling device 3 uses its own gravity to drill downwards. The spiral blades on the spiral drill rods 33 expel the soil generated during drilling.

[0027] The high-pressure jet grouting drilling device 4 includes a second mounting bracket 40 slidably mounted on a guide rail 20, a second reducer 41 fixedly mounted on the second mounting bracket 40 by fasteners, a second drive motor 42 mounted on the input end of the second reducer 41, a drive rod 43 mounted on the output end of the second reducer 41, a jet grouting drill rod 44 detachably mounted on one end of the drive rod 43 by fasteners, a high-pressure nozzle 45 mounted on the second mounting bracket 40, and a vertical drive assembly 46 mounted on the second mounting bracket 40. The vertical drive assembly 46 can drive the second mounting bracket 40 to reciprocate linearly on the guide rail 20. One end of the high-pressure nozzle 45 is connected to the top of the drive rod 43, and the other end of the high-pressure nozzle 45 is connected to a high-pressure cement pump 47. Openings are provided on both sides of the bottom of the jet grouting drill rod 44. In one embodiment, the jet grouting drill rod 44 is located in the middle between two spiral drill rods 33. The bottom of the jet grouting drill rod 44 is provided with an inverted conical drill hole 48. Spiral teeth 49 are fixedly provided on the inverted conical drill hole 48 along its conical surface. The spiral teeth 49 can facilitate the jet grouting drill rod 44 to drill into the interior of the moderately weathered rock layer.

[0028] The vertical drive assembly 46 includes a rack 460 fixedly mounted on one side of the guide rail 20, a third drive motor 461 fixedly mounted on the second mounting bracket 40, and a gear 462 mounted on the output shaft of the third drive motor 461. The gear 462 meshes with the rack 460. When the third drive motor 461 is energized and rotates forward or in reverse, the second mounting bracket 40 is vertically reciprocated linearly along the guide rail 20 by meshing with the rack 460.

[0029] Step 3: Drilling in the rock strata. After drilling in the soil layer above the rock strata is completed, the operation of the auger drilling device 3 is stopped, the main drive motor 21 is powered on, and the auger drilling device 3 is lifted by the wire rope 23. Then, the high-pressure jet grouting drilling device 4 is started. Different lengths of jet grouting drill rods 44 are selected according to the depth to be drilled and installed on the drive rod 43. Then, the second drive motor 42 drives the drive rod 43 and the jet grouting drill rods 44 to rotate. In conjunction with the vertical drive assembly 46, the jet grouting drill rods 44 are inserted downwards. Simultaneously, the high-pressure cement pump 47 is started, allowing cement slurry to enter the jet grouting drill rods 44 through the high-pressure nozzle 45 and then be sprayed out from the opening on the jet grouting drill rods 44 to form a water jet. This water jet cuts the surrounding moderately weathered rock strata, accelerating the drilling speed. In this embodiment, the high-pressure cement pump 47 provides a pressure of 30 MPa, which can be adjusted according to the degree of weathering of the rock strata to ensure construction efficiency.

[0030] Step four involves secondary drilling. Once the high-pressure jet grouting drilling device 4 reaches the bottom elevation, it is lifted upwards using the vertical drive assembly 46. The jet grouting drill rod 44, located in the moderately weathered rock layer, is then removed and cleaned. Next, the main drive motor 21 loosens the wire rope 23, lowering the auger drilling device 3 so that the two auger drill rods 33 re-enter the hole drilled in step two. The auger drilling device 3 continues drilling downwards to the bottom elevation. At this point, the moderately weathered rock layer has been broken up by the high-pressure jet grouting drilling device 4, resulting in high construction efficiency and good consistency between the two drilling operations. After completion, the auger drilling device 3 is lifted out. Simultaneously, grouting is performed on the completed hole using the high-pressure nozzle 45. The grouting pressure of the high-pressure nozzle 45 is adjusted according to the construction situation. The above steps are repeated until the entire waterstop curtain construction is completed.

[0031] The above embodiments are merely illustrative of the concept and implementation of the present invention and are not intended to limit it. Under the concept of the present invention, technical solutions without substantial changes are still within the scope of protection.

Claims

1. A method for constructing a water-stop curtain based on moderately weathered rock strata, characterized in that: The construction method includes the following steps: Step 1: Guide channel construction. According to the design and construction drawings, the guide channel for the water-stop curtain is excavated at the designated location, and the inner wall of the guide channel for the water-stop curtain is cleaned. Step two involves drilling above the rock strata. Drilling equipment is used to drill down to the surface of the moderately weathered rock strata. This equipment includes a support base, a guide support device mounted on the support base, a spiral drilling device mounted on the guide support device, and a high-pressure jet grouting drilling device. The guide support device includes a guide rail hinged to the support base at one end, a main drive motor mounted on the support base, a drum powered by the main drive motor, a steel wire rope wound on the drum, and a pulley mounted at the other end of the guide rail. The other end of the steel wire rope is connected to the spiral drilling device via the pulley. The spiral drilling device includes a first mounting bracket slidably mounted on the guide rail, a first dual-output reducer mounted on the first mounting bracket, a first drive motor fixedly mounted at the input end of the first dual-output reducer, and a first output reducer fixedly mounted on the first output reducer. The output end has two spiral drill rods and a drill bit installed at the bottom of the spiral drill rods. When the first drive motor is energized and rotates, it drives the two spiral drill rods to rotate through the first dual-output reducer to perform drilling operations. The high-pressure jet grouting drilling device includes a second mounting bracket slidably mounted on a guide rail, a second reducer fixedly mounted on the second mounting bracket, a second drive motor mounted on the input end of the second reducer, a drive rod mounted on the output end of the second reducer, a jet grouting drill rod detachably mounted on one end of the drive rod, a high-pressure nozzle mounted on the second mounting bracket, and a vertical drive assembly mounted on the second mounting bracket. The vertical drive assembly drives the second mounting bracket to slide back and forth linearly on the guide rail. One end of the high-pressure nozzle is connected to the drive rod, and the other end of the high-pressure nozzle is connected to a high-pressure cement pump. Openings are provided on both sides of the bottom of the jet grouting drill rod. Step 3: Drilling of the rock strata. After the drilling of the soil layer above the rock strata is completed, the operation of the auger drilling device is stopped, and the auger drilling device is lifted using the main drive motor. Then, the high-pressure jet grouting drilling device is started, and the drive rod and jet grouting drill rod are rotated by the second drive motor. The jet grouting drill rod is inserted downward in conjunction with the vertical drive component. At the same time, the high-pressure cement pump is started so that the cement slurry enters the jet grouting drill rod through the high-pressure nozzle and is then sprayed out from the opening to form a water jet. The water jet cuts the surrounding moderately weathered rock strata. Step four, secondary drilling construction: When the high-pressure jet grouting drilling device reaches the bottom elevation, the device is lifted upwards using the vertical drive assembly to remove the jet grouting drill rod located in the moderately weathered rock layer; then, the main drive motor lowers the auger drilling device to continue drilling downwards to the bottom elevation; after construction is completed, the auger drilling device is lifted out, and grouting is performed on the completed hole using a high-pressure nozzle; the construction is repeated until the water-stop curtain construction is completed.

2. The construction method of a water-stop curtain based on moderately weathered rock strata according to claim 1, characterized in that: The support base includes a chassis bracket, a main support leg installed at the bottom of the chassis bracket, and multiple adjustable support legs installed at the bottom of the chassis bracket.

3. The method for constructing a water-stop curtain based on moderately weathered rock strata according to claim 2, characterized in that: The adjustable support leg includes a fixed mounting component, an adjusting screw, and a support plate. One end of the adjusting screw is adjustablely connected to the fixed mounting component via a thread, and the support plate is fixedly mounted on the other end of the adjusting screw. The fixed mounting component is detachably mounted on the chassis bracket.

4. A method for constructing a water-stop curtain based on moderately weathered rock strata according to claim 1 or 3, characterized in that: In step three, the high-pressure cement pump provides a pressure of 30 MPa.

5. The method for constructing a water-stop curtain based on moderately weathered rock strata according to claim 1, characterized in that: The vertical drive assembly includes a rack fixedly mounted on one side of the guide rail, a third drive motor fixedly mounted on the second mounting bracket, and a gear mounted on the output shaft of the third drive motor, wherein the gear meshes with the rack.

6. The method for constructing a water-stop curtain based on moderately weathered rock strata according to claim 4, characterized in that: The jet grouting drill rod is located between the two auger drill rods.

7. A method for constructing a water-stop curtain based on moderately weathered rock strata according to claim 1 or 6, characterized in that: The bottom of the jet jet drill rod is provided with an inverted conical drill hole, and helical teeth are fixedly provided on the inverted conical drill hole along its conical surface.

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