Large-diameter long pile micro-disturbance construction method under super-thick hard rock condition in ecological sensitive area

Abstract

The invention discloses a large-diameter long pile micro-disturbance construction method under the condition of super-thick hard rock in an ecological sensitive area, and relates to the field of large-diameter long pile construction. According to the method, the multiple sections of steel casings are lowered to the designed elevation through a lifting appliance, perpendicularity and plane position measurement is conducted multiple times in the lowering process of the steel casings, the perpendicularity of the steel casings is guaranteed, perpendicularity deviation is prevented, and after the steel casings are lowered in place, a vibratory hammer is adopted for vibration, and the perpendicularity of the steel casings is measured. The vibration frequency and amplitude of the vibratory hammer need to be adjusted according to geological conditions and the size of the steel casing, adverse effects of excessive vibration on the surrounding environment are prevented, the perpendicularity of formed holes needs to be repeatedly checked, the quality of the formed holes is ensured, and the pile holes are prevented from being seriously inclined and deviated when the drilling machine drills the formed holes, and the construction efficiency is greatly improved through micro-disturbance construction operation. The disturbance in the engineering construction process is controlled to the minimum degree while the engineering quality is guaranteed, and the influence on the surrounding environment is reduced as much as possible.

Description

Technical Field

[0001] The invention relates to the technical field of large-diameter long pile construction, and in particular to a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in ecologically sensitive areas. Background Art

[0002] Ecologically sensitive areas refer to those areas that are of great significance to the stability of the ecosystem, biodiversity protection, etc. The construction of bridges under ultra-thick hard rock strips in ecologically sensitive areas requires large-diameter long pile construction.

[0003] In the existing technology, since large-diameter long piles are located in deep-water bare rock areas without covering layers, the sinking, rock embedding and anchoring of steel casings are difficult. Since the pile body is long, vertical deviation and other problems are prone to occur. Under ultra-thick hard rock conditions, it is even more difficult to ensure the verticality of the pile body, because the unevenness of the hard rock may cause uneven force on the drilling equipment, which in turn causes deviation and affects the stability of the surrounding rocks. In addition, the drilling process will affect the environment around the ecologically sensitive area. Summary of the invention

[0004] The purpose of the present invention is to provide a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in ecologically sensitive areas, so as to solve the problems raised in the above-mentioned background technology that the pile body is long and prone to vertical deviation, and the drilling process will affect the surrounding environment of the ecologically sensitive area.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for micro-disturbance construction of large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas, comprising the following steps:

[0006] S1. Steel casing docking and lowering: set up a drilling platform, install a guide device on the drilling platform, lift and lower the steel casing to the designed elevation, and pour underwater anchoring concrete;

[0007] S2. Drilling: After the drilling rig is in place, the pile center is released through the control points on the platform and the total station. The center position of the drilling rig is adjusted according to the deviation results obtained by measurement, and the drill bucket is placed on the ground to perform drilling operations;

[0008] S3. Hole quality inspection: After the hole is drilled, the hole is cleaned up and then inspected to see if the hole quality is up to standard. If it is up to standard, the drilling rig is moved.

[0009] S4. Lowering the steel cage: Make the steel cage according to the size requirements, transport the steel cage to the site, and lower the steel cage using a hoist;

[0010] S5. Lowering the conduit: Check whether the conduit is clean and unobstructed, and the integrity of the "O" type sealing ring. Use a truck crane as a lifting device to hoist and lengthen the conduit section by section, and lower it vertically until the bottom of the conduit is 30-40cm away from the bottom of the hole.

[0011] S6. Sediment detection: After the guide tube is installed in place, the sediment thickness is detected by using a measuring rope and a depth hammer. The sediment thickness at the bottom of the hole is calculated based on the final hole depth to determine whether secondary hole cleaning is required.

[0012] S7, concrete pouring: pour the concrete continuously to the bottom of the hole to complete the first sealing, and then pour the pile foundation concrete. After the top surface elevation of the concrete is in place, stop pouring and remove the guide tube;

[0013] S8. Pile foundation testing: Use ultrasonic transmission method to perform non-destructive testing on pile foundation.

[0014] Preferably, in step S1, lowering the steel casing comprises the following steps:

[0015] S11. Set up a drilling platform, use a rotary drill to drill a hole at the pile position, the hole diameter is 2.5m, the hole depth is 3.5m, and the lower frame of the guide device is installed on the top of the drilling platform;

[0016] S12. Use a flatbed truck to move the steel casing to the platform, and use the main and auxiliary hooks of a 50t truck crane to lift and flip the steel casing, and flip the pipe section to a vertical state;

[0017] S13. Use a 50t truck crane to lower the steel casing segment, control the bottom opening to be 1m above the drilling platform, then remove the inner support of the bottom opening and the connection between the auxiliary hook and the segment, move the segment to the pile position, align the bottom opening with the guide device, and then lower it;

[0018] S14. When the pipe segment is lowered to a distance of 1m between the top and the upper layer of the guide device, stop lowering, symmetrically weld four steel brackets on the outer wall of the pipe segment, temporarily place the steel brackets on the upper layer guide frame, remove the internal support of the top, measure and adjust the plane position and verticality of the steel casing pipe segment;

[0019] S15. The crawler crane hoists the next steel casing pipe segment, removes the bottom inner support, and lengthens the pipe segment. After the upper and lower pipe segments are butt-jointed, the verticality of the pipe segment is measured and verified. After the requirements are met, the butt joint annular seam is welded. After the pipe segments are butt-jointed, the casing is lowered until it is extended to the designed length.

[0020] S16. Lift the entire steel casing with a crawler crane, adjust the center position of the steel casing, and continue to lower the steel casing until the bottom is located at the bottom of the guide hole, completing the lowering and positioning of the steel casing. After the steel casing is lowered into place, use a vibrating hammer to vibrate for 3 minutes to make the bottom of the steel casing pass through the sediment at the bottom of the hole to ensure that the bottom of the steel casing is dense.

[0021] Preferably, in step S3, the hole quality inspection includes the inspection of pile position, hole depth, hole diameter, borehole inclination and sedimentation thickness. The pile position is inspected by a total station, the hole depth is inspected by a measuring rope, the hole diameter and borehole inclination are inspected by an ultrasonic hole detector, and the sedimentation thickness is inspected by a sedimentation box and a slag meter.

[0022] Preferably, in step S5, the catheter needs to be subjected to a watertight pressure test before being lowered to detect the airtightness of the catheter.

[0023] Preferably, in step S6, the secondary hole cleaning includes the following steps: using a concrete casting conduit with an elbow on the upper part, connecting a seamless steel pipe in the elbow conduit as an inner air duct, and introducing high-pressure air into the air duct. After the high-pressure air enters the water surface in the conduit, under the action of the water pressure, the high-pressure air will turn to flow out from the elbow. When the high-pressure air flows out, it brings out a large amount of water vapor, driving the sediment at the bottom of the hole to be discharged from the elbow conduit. After cleaning the hole, measure the hole depth with a measuring rope and compare it with the hole depth at the end of the hole. If the sediment thickness is greater than the set value, the above steps are repeated until the requirements are met.

[0024] Preferably, in step S8, the pile foundation detection includes the following steps:

[0025] S81. Prepare concrete strength test pieces and measure the hole diameter, hole shape and inclination using an ultrasonic wall measuring instrument;

[0026] S82. Each pile is subjected to ultrasonic non-destructive testing to check the integrity of the pile;

[0027] S83. After the pile foundation inspection is completed, the acoustic detection pipe and the core drilling hole shall be promptly grout-sealed.

[0028] Preferably, the guide device includes a supporting mechanism, a first guide mechanism and a second guide mechanism, the first guide mechanism and the second guide mechanism have the same structure, the first guide mechanism includes a mounting frame, one end of the mounting frame is fixedly connected to a jack, one end of the jack is fixedly connected to a moving frame, a fixing bolt is installed on one side of the moving frame, one end of the fixing bolt passes through the moving frame and is installed with a positioning nut, a connecting shaft is installed on the outside of the fixing bolt, the outside of the connecting shaft is rotatably connected to a guide wheel, and the outside of the guide wheel is sleeved with a rubber ring.

[0029] Preferably, sliding blocks are fixedly connected to both sides of the movable frame, a guide rail is slidably connected inside the sliding block, and one side of the guide rail is fixedly connected to one side of the installation frame.

[0030] Preferably, the supporting mechanism includes a first fixed frame and a second fixed frame, one side of the first fixed frame is installed between the first guide mechanism, one side of the second fixed frame is installed between the second guide mechanism, a vertical supporting frame is fixedly connected between the first fixed frame and the second fixed frame, a third fixed frame is fixedly connected to the outside of the vertical supporting frame, and a second supporting diagonal rod is fixedly connected between the first fixed frame and the third fixed frame and between the second fixed frame and the third fixed frame.

[0031] Preferably, both sides of the second fixed frame are fixedly connected with reinforcement frames, one side of the reinforcement frame is fixedly connected with a first supporting diagonal rod, one end of the first supporting diagonal rod is fixedly connected to the outer side of the vertical supporting frame, the bottom sides of the second fixed frame and the reinforcement frame are fixedly connected with feet, one end of the reinforcement frame is fixedly connected with a fixing block, and a positioning nail is installed in the middle of the fixing block.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention installs a guide device on the drilling platform, uses a hanger to lower multiple sections of steel casing to the designed elevation, and measures the verticality and plane position of the steel casing for multiple times during the lowering process to ensure the verticality of the steel casing and prevent verticality deviation, pour underwater anchoring concrete, and after the steel casing is lowered into place, use a vibrating hammer to vibrate for 3 minutes to ensure that the bottom of the steel casing is dense. The vibration frequency and amplitude of the vibrating hammer should be adjusted according to the geological conditions and the size of the steel casing to prevent excessive vibration from causing adverse effects on the surrounding environment. When the drilling rig drills a hole, it is necessary to repeatedly check the verticality of the hole to ensure the quality of the hole. When it is found that the drill rod is shaking or difficult to drill, it is necessary to immediately lift the drill for inspection to prevent the pile hole from being seriously tilted or offset. Through the implementation of micro-disturbance construction operations, while ensuring the quality of the project, the disturbance in the construction process is controlled to a minimum, and the impact on the surrounding environment is minimized, thereby realizing the combined drilling of ultra-thick hard rock large-diameter long piles in the ecological reservoir area.

[0034] 2. In the present invention, the jack works to push the moving frame to move, so that the guide wheel and the rubber ring move to contact the outer surface of the steel casing. The setting of the rubber ring can reduce the wear on the surface of the steel casing. At the same time, the guide wheel provides the guiding strength of the steel casing. When the rubber ring is worn, the connecting shaft and the guide wheel can be removed from the moving frame by rotating the fixing bolts, and the rubber ring can be replaced. The first guide mechanism and the second guide mechanism are staggered, which can perform multi-point limit guiding on the outer side of the steel casing, thereby improving the guiding effect on the steel casing.

[0035] 3. In the present invention, the guide device can be fixed on the drilling platform by cooperating with the positioning nails and the fixing blocks, and the pads can be fitted on the drilling platform to reduce the sliding between the guide device and the drilling platform, while reducing the vibration transmission. The overall strength of the support mechanism can be enhanced by setting the first supporting diagonal rod, the vertical supporting frame, the second supporting diagonal rod and the third fixing frame. The arrangement of the diagonal braces can form a stable triangular structure, which can effectively resist the horizontal force and overturning moment generated by the steel casing during the installation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A pile foundation construction flow chart of a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in an ecologically sensitive area according to the present invention;

[0037] Figure 2 A flow chart of the steel casing lowering construction of a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in an ecologically sensitive area according to the present invention;

[0038] Figure 3 It is a three-dimensional structural schematic diagram of a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in an ecologically sensitive area according to the present invention;

[0039] Figure 4 A schematic diagram of the first guide mechanism connection structure of a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in an ecologically sensitive area according to the present invention;

[0040] Figure 5 A schematic diagram of the installation frame connection structure of a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in an ecologically sensitive area according to the present invention;

[0041] Figure 6 It is a schematic diagram of the disassembled structure of the installation frame of a micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to the present invention;

[0042] Figure 7 The present invention is a schematic diagram of the support mechanism connection structure of a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in an ecologically sensitive area.

[0043] In the figure: 1. supporting mechanism; 11. first fixed frame; 12. second fixed frame; 13. foot; 14. reinforcing frame; 15. positioning nail; 16. fixing block; 17. first supporting diagonal rod; 18. vertical supporting frame; 19. second supporting diagonal rod; 110. third fixed frame; 2. first guiding mechanism; 3. second guiding mechanism; 21. mounting frame; 22. guide wheel; 23. rubber ring; 24. guide rail; 25. jack; 26. fixing bolt; 27. sliding block; 28. positioning nut; 29. ​​connecting shaft; 210. moving frame. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described 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 creative work are within the scope of protection of the present invention.

[0045] Example 1: Reference Figure 1 - Figure 2 As shown: A micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas, comprising the following steps:

[0046] Step 1: Lower the steel casing: Set up a drilling platform, install a guide device on the drilling platform, lift and lower the steel casing to the designed elevation, and pour underwater anchoring concrete;

[0047] The lowering of the steel casing includes the following steps:

[0048] 11. Set up a drilling platform and use a rotary drill to drill a hole at the pile position with a diameter of 2.5m and a depth of 3.5m. Install the lower frame of the guide device on the top of the drilling platform;

[0049] 12. Use a flatbed truck to move the steel casing to the platform, and use the main and auxiliary hooks of a 50t truck crane to lift and flip the steel casing, and flip the pipe section to a vertical state;

[0050] 13. Use a 50t truck crane to lower the steel casing pipe section, control the bottom opening to be 1m above the drilling platform, then remove the inner support of the bottom opening and the connection between the auxiliary hook and the pipe section, move the pipe section to the pile position, and lower it after aligning the bottom opening with the guide device;

[0051] 14. When the pipe segment is lowered to a distance of 1m between the top and the upper layer of the guide device, stop lowering, symmetrically weld 4 steel brackets on the outer wall of the pipe segment, temporarily place the steel brackets on the upper guide frame, remove the internal support of the top, measure and adjust the plane position and verticality of the steel casing pipe segment;

[0052] 15. The crawler crane hoists the next steel casing pipe segment, removes the bottom inner support, and lengthens the pipe segment. After the upper and lower pipe segments are butt-jointed, the verticality of the pipe segment is measured and verified. After the requirements are met, the butt joint annular seam is welded. After the pipe segment is butt-jointed, it is lowered continuously until the steel casing is extended to the designed length.

[0053] 16. Lift the entire steel casing with a crawler crane, adjust the center position of the steel casing, and continue to lower the steel casing until the bottom is located at the bottom of the pilot hole to complete the lowering and positioning of the steel casing. After the steel casing is lowered into place, vibrate it with a vibrating hammer for 3 minutes to make the bottom of the steel casing pass through the sediment at the bottom of the hole to ensure that the bottom of the steel casing is dense;

[0054] Before the rotary drill starts working, various parameters including drilling speed and torque must be adjusted. During the drilling process, pay close attention to the verticality of the borehole and monitor it in real time through the verticality monitor on the drill pipe. Once the deviation is found, adjust it in time. After the hole is completed, the hole wall must be cleaned to prevent hole wall collapse and debris residue. When using a vibratory hammer to vibrate the steel casing, the vibration frequency and amplitude of the vibratory hammer must be adjusted according to the geological conditions and the size of the steel casing to prevent excessive vibration from causing adverse effects on the surrounding environment.

[0055] Step 2: Drilling: After the drilling rig is in place, the pile center is released through the control points on the platform and the total station. The center position of the drilling rig is adjusted according to the deviation results obtained by measurement, and the drill bucket is placed on the ground to perform drilling operations;

[0056] When starting the drilling operation, you should first apply gentle pressure and drill slowly, gradually increase the drilling pressure and speed, and continuously inject mud into the hole to facilitate wall protection, slag removal and cooling of the drill bit. Regularly check the depth, verticality and aperture of the borehole. Use a measuring rope to check the depth, a verticality tester to check the verticality, and a boremeter to check the aperture, and make adjustments in a timely manner;

[0057] Step 3: Hole quality inspection: After the hole is drilled, the mud and sediment in the hole are cleaned up to ensure that the performance index of the mud meets the requirements of pouring concrete. Then the hole quality inspection is carried out to check whether the hole quality is qualified. When the hole quality inspection is qualified, the drilling rig is moved to the next pile position for construction;

[0058] The hole quality inspection includes the inspection of pile position, hole depth, hole diameter, borehole inclination and sedimentation thickness. The pile position is inspected by a total station, the hole depth is inspected by a measuring rope, the hole diameter and borehole inclination are inspected by an ultrasonic hole detector, and the sedimentation thickness is inspected by a sedimentation box and a slag meter.

[0059] Step 4: Lowering the steel cage: Make the steel cage according to the size requirements, transport the steel cage to the site, and use the sling to lower the steel cage;

[0060] During transportation, the steel cage should be prevented from deformation. A special transport vehicle should be used to place the steel cage flat on the vehicle and secure it. When lowering the steel cage, it should be kept vertical and slowly placed into the hole to avoid collision with the hole wall.

[0061] Step 5: Lower the conduit: Check whether the conduit is clean and unobstructed, and the integrity of the "O" type sealing ring. Use a truck crane as a lifting device to hoist and lengthen the conduit section by section, and lower it vertically. Lower the conduit until the bottom of the conduit is 35cm from the bottom of the hole to ensure that the bottom can be sealed smoothly when the first batch of concrete is poured, and at the same time, the conduit will not be inserted into the sediment at the bottom of the hole;

[0062] Before lowering the catheter, it needs to be subjected to a watertight pressure test to check the airtightness of the catheter.

[0063] Step 6: Sediment detection: After the guide tube is installed in place, use a measuring rope and a depth hammer to detect the sediment thickness. According to the final hole depth, calculate the sediment thickness at the bottom of the hole to determine whether secondary hole cleaning is required.

[0064] The secondary hole cleaning includes the following steps: using a concrete casting conduit with an elbow on the upper part, connecting a seamless steel pipe in the elbow conduit as an inner air duct, and introducing high-pressure air into the air duct. After the high-pressure air enters the water surface in the conduit, under the action of water pressure, the high-pressure air will turn to flow out from the elbow. When the high-pressure air flows out, it brings out a large amount of water vapor, driving the sediment at the bottom of the hole to be discharged from the elbow conduit. The wind pressure of the air duct is set to 0.6MPa. Excessive air pressure may damage the hole wall and cause the hole to collapse. If the air pressure is too low, the sediment cannot roll over, affecting the hole cleaning effect. After cleaning the hole, use a measuring rope to measure the hole depth and compare it with the hole depth at the end of the hole. If the sediment thickness is greater than the set value, the above steps are repeated until it meets the requirements.

[0065] Step 7: Concrete pouring: pour the concrete continuously to the bottom of the hole to complete the first seal, and then pour the pile foundation concrete. After the top surface elevation of the concrete is in place, stop pouring and remove the guide tube;

[0066] Step 8. Pile foundation testing: Use ultrasonic transmission method to perform non-destructive testing on the pile foundation.

[0067] Pile foundation testing includes the following steps:

[0068] 81. Prepare concrete strength test pieces and use ultrasonic wall measuring instrument to measure the hole diameter, hole shape and inclination;

[0069] 82. Each pile is subjected to ultrasonic non-destructive testing to check the integrity of the pile;

[0070] 83. After the pile foundation inspection is completed, the sonic detection tube and the core drill hole should be promptly sealed by grouting. When grouting, the grouting tube should be inserted into the bottom of the sonic detection tube or the core drill hole, and cement slurry should be slowly injected until the cement slurry overflows from the hole mouth. After grouting, the hole mouth should be sealed to prevent debris from entering.

[0071] Embodiment 2: Figure 3 - Figure 7As shown, the guide device includes a support mechanism 1, a first guide mechanism 2 and a second guide mechanism 3. The first guide mechanism 2 has the same structure as the second guide mechanism 3. The first guide mechanism 2 includes a mounting frame 21. One end of the mounting frame 21 is fixedly connected to a jack 25. One end of the jack 25 is fixedly connected to a moving frame 210. A fixing bolt 26 is installed on one side of the moving frame 210. One end of the fixing bolt 26 passes through the moving frame 210 and is installed with a positioning nut 28. A connecting shaft 29 is installed on the outside of the fixing bolt 26. The outside of the connecting shaft 29 is rotatably connected to a guide wheel 22. A rubber ring 23 is sleeved on the outside of the guide wheel 22. Sliding blocks 27 are fixedly connected to both sides of the moving frame 210. The inside of the sliding block 27 is slidably connected to a guide rail 24. One side of the guide rail 24 is fixedly connected to one side of the mounting frame 21. The support mechanism 1 includes a first fixed frame 11 and a second fixed frame 1 2, one side of the first fixed frame 11 is installed between the first guide mechanism 2, one side of the second fixed frame 12 is installed between the second guide mechanism 3, a vertical support frame 18 is fixedly connected between the first fixed frame 11 and the second fixed frame 12, a third fixed frame 110 is fixedly connected to the outside of the vertical support frame 18, and a second supporting diagonal rod 19 is fixedly connected between the first fixed frame 11 and the third fixed frame 110, and between the second fixed frame 12 and the third fixed frame 110; both sides of the second fixed frame 12 are fixedly connected with a reinforcement frame 14, one side of the reinforcement frame 14 is fixedly connected with a first supporting diagonal rod 17, one end of the first supporting diagonal rod 17 is fixedly connected to the outside of the vertical support frame 18, the bottom sides of the second fixed frame 12 and the reinforcement frame 14 are fixedly connected with a foot 13, one end of the reinforcement frame 14 is fixedly connected with a fixed block 16, and a positioning nail 15 is installed in the middle of the fixed block 16.

[0072] In this embodiment, by arranging reinforcement frames 14 on both sides of the second fixed frame 12, the positioning nails 15 on the outside of the two reinforcement frames 14 cooperate with the fixing blocks 16, so that the guide device can be fixed on the drilling platform, and one side of the second fixed frame 12 and the reinforcement frame 14 are fixed with pads 13, which are used to fit on the drilling platform to reduce the sliding between the guide device and the drilling platform, and at the same time reduce the vibration transmission, the first fixed frame 11 and the second fixed frame 12 are connected by a vertical support frame 18, and a third fixed frame 110 is installed on the outside of the vertical support frame 18, the first fixed frame 11 and the third fixed frame 110, the second fixed frame 12 and the third fixed frame 110 are connected by an inclined second support diagonal rod 19, and the vertical support frame 18 and the reinforcement frame 14 are connected by an inclined first support diagonal rod 17, which can enhance the overall strength of the support mechanism 1, and the arrangement of the diagonal braces can form a stable triangular structure, which can effectively resist the steel casing. The horizontal force and overturning moment generated during the installation process, when guiding the steel casing, by setting the first guide mechanism 2 and the second guide mechanism 3, the first guide mechanism 2 and the second guide mechanism 3 have the same structure, the jack 25 works to push the moving frame 210 to move, the sliding block 27 slides on the outside of the guide rail 24, and the fixed moving frame 210 moves linearly, so that the guide wheel 22 and the rubber ring 23 move to contact the outer surface of the steel casing. The setting of the rubber ring 23 can reduce the wear on the surface of the steel casing. At the same time, the guide wheel 22 provides the guiding strength of the steel casing. When the rubber ring 23 is worn, the connecting shaft 29 and the guide wheel 22 can be removed from the moving frame 210 by rotating the fixing bolt 26, and the rubber ring 23 sleeved in the guide wheel 22 is taken out for replacement, and the first guide mechanism 2 and the second guide mechanism 3 are staggered at 45 degrees, which can perform multi-point limit guiding on the outer side of the steel casing, thereby improving the guiding effect of the steel casing.

[0073] The usage and working principle of this device: First, build a drilling platform at the construction site, install a guide device on the drilling platform, transport the disassembled and processed steel casing to the construction site, use a hoist to lift and lower the first section of the steel casing, temporarily fix and weld the steel casing, and lower the steel casing to the designed elevation. During the lowering process of the steel casing, perform verticality and plane position measurements multiple times to ensure the verticality of the steel casing and prevent verticality deviation. Pour underwater anchoring concrete. After the steel casing is lowered into place, use a vibrating hammer to vibrate for 3 minutes to ensure that the bottom of the steel casing is dense. The vibration frequency and amplitude of the vibrating hammer should be adjusted according to the geological conditions and the size of the steel casing to prevent excessive vibration from causing adverse effects on the surrounding environment. Put the drilling rig in place and drill holes. The holes need to be checked repeatedly during the drilling process. The verticality of the hole is ensured to ensure the quality of the hole. When the drill rod is found to be shaking or difficult to drill, the drill needs to be lifted and checked immediately to prevent the pile hole from being seriously tilted or offset. After the hole is cleaned, the hole quality is tested, the prepared steel cage is transported to the construction site, and the steel cage is lowered by a hoist. Then the qualified conduit is lowered to 35cm from the bottom of the hole and stopped to ensure that the bottom can be sealed smoothly when the first batch of concrete is poured, and at the same time, the conduit will not be inserted into the sediment at the bottom of the hole. After the conduit is installed in place, the sediment thickness is tested and the hole is cleaned for the second time to ensure that the sediment thickness meets the operation requirements. After the pile foundation concrete is poured, the conduit is removed and the pile foundation quality is tested. Through the implementation of micro-disturbance construction operations, while ensuring the quality of the project, the disturbance during the construction process is controlled to a minimum to minimize the impact on the surrounding environment.

[0074] After the guide device is transported to the drilling platform, the guide device can be fixed on the drilling platform by cooperating with the positioning nail 15 and the fixing block 16. A foot 13 is fixed on one side of the second fixing frame 12 and the reinforcement frame 14, which is used to fit on the drilling platform to reduce the sliding between the guide device and the drilling platform and reduce the vibration transmission. The overall strength of the support mechanism 1 can be enhanced by the arrangement of the first support diagonal rod 17, the vertical support frame 18, the second support diagonal rod 19 and the third fixed frame 110. The arrangement of the diagonal braces can form a stable triangular structure. It can effectively resist the horizontal force and overturning moment generated by the steel casing during the installation process. When guiding the steel casing, the jack 25 works to push the moving frame 210 to move, so that the guide wheel 22 and the rubber ring 23 move to contact the outer surface of the steel casing. The setting of the rubber ring 23 can reduce the wear on the surface of the steel casing. At the same time, the guide wheel 22 provides the guiding strength of the steel casing. When the rubber ring 23 is worn, the connecting shaft 29 and the guide wheel 22 can be removed from the moving frame 210 by rotating the fixing bolt 26, and the rubber ring 23 sleeved in the guide wheel 22 can be taken out for replacement.

[0075] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas, characterized in that: The following steps are involved: S1. Steel casing docking and lowering: set up a drilling platform, install a guide device on the drilling platform, lift and lower the steel casing to the designed elevation, and pour underwater anchoring concrete; S2. Drilling: After the drilling rig is in place, the pile center is released through the control points on the platform and the total station. The center position of the drilling rig is adjusted according to the deviation results obtained by measurement, and the drill bucket is placed on the ground to perform drilling operations; S3. Hole quality inspection: After the hole is drilled, the hole is cleaned up and then inspected to see if the hole quality is up to standard. If it is up to standard, the drilling rig is moved. S4. Lowering the steel cage: Make the steel cage according to the size requirements, transport the steel cage to the site, and lower the steel cage using a hoist; S5. Lowering the conduit: Check whether the conduit is clean and unobstructed, and the integrity of the "O"-ring. Use a truck crane as a lifting device to hoist and lengthen the conduit section by section, and lower it vertically until the bottom of the conduit is 30-40cm away from the bottom of the hole. S6. Sediment detection: After the guide tube is installed in place, the sediment thickness is detected by using a measuring rope and a depth hammer. The sediment thickness at the bottom of the hole is calculated based on the final hole depth to determine whether secondary hole cleaning is required. S7, concrete pouring: pour the concrete continuously to the bottom of the hole to complete the first sealing, and then pour the pile foundation concrete. After the top surface elevation of the concrete is in place, stop pouring and remove the guide tube; S8. Pile foundation testing: Use ultrasonic transmission method to perform non-destructive testing on pile foundation.

2. According to claim 1, a large-diameter long pile micro-disturbance construction method under ultra-thick hard rock conditions in ecologically sensitive areas is characterized by: In step S1, the lowering of the steel casing includes the following steps: S11. Set up a drilling platform, use a rotary drill to drill a hole at the pile position, the hole diameter is 2.5m, the hole depth is 3.5m, and the lower frame of the guide device is installed on the top of the drilling platform; S12. Use a flatbed truck to move the steel casing to the platform, and use the main and auxiliary hooks of a 50t truck crane to lift and flip the steel casing, and flip the pipe section to a vertical state; S13. Use a 50t truck crane to lower the steel casing segment, control the bottom opening to be 1m above the drilling platform, then remove the inner support of the bottom opening and the connection between the auxiliary hook and the segment, move the segment to the pile position, align the bottom opening with the guide device, and then lower it; S14. When the pipe segment is lowered to a distance of 1m between the top and the upper layer of the guide device, stop lowering, symmetrically weld four steel brackets on the outer wall of the pipe segment, temporarily place the steel brackets on the upper layer guide frame, remove the internal support of the top, measure and adjust the plane position and verticality of the steel casing pipe segment; S15. The crawler crane hoists the next steel casing pipe segment, removes the bottom inner support, and lengthens the pipe segment. After the upper and lower pipe segments are butt-jointed, the verticality of the pipe segment is measured and verified. After the requirements are met, the butt joint annular seam is welded. After the pipe segments are butt-jointed, the casing is lowered until it is extended to the designed length. S16. Lift the entire steel casing with a crawler crane, adjust the center position of the steel casing, and continue to lower the steel casing until the bottom is located at the bottom of the guide hole, completing the lowering and positioning of the steel casing. After the steel casing is lowered into place, use a vibrating hammer to vibrate for 3 minutes to make the bottom of the steel casing pass through the sediment at the bottom of the hole to ensure that the bottom of the steel casing is dense.

3. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 1 is characterized by: In step S3, the hole quality inspection includes the inspection of pile position, hole depth, hole diameter, borehole inclination and sedimentation thickness. The pile position is inspected by a total station, the hole depth is inspected by a measuring rope, the hole diameter and borehole inclination are inspected by an ultrasonic hole detector, and the sedimentation thickness is inspected by a sedimentation box and a slag meter.

4. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 2 is characterized by: In step S5, the conduit needs to be subjected to a watertight pressure test before being lowered to detect the tightness of the conduit.

5. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 4 is characterized by: In step S6, the secondary hole cleaning includes the following steps: using a concrete casting conduit with an elbow on the upper part, connecting a seamless steel pipe in the elbow conduit as an inner air duct, and introducing high-pressure air into the air duct. After the high-pressure air enters the water surface in the conduit, under the action of the water pressure, the high-pressure air will turn to flow out from the elbow. When the high-pressure air flows out, it brings out a large amount of water vapor, driving the sediment at the bottom of the hole to be discharged from the elbow conduit. After cleaning the hole, measure the hole depth with a measuring rope and compare it with the hole depth at the end of the hole. If the sediment thickness is greater than the set value, the above steps are repeated until it meets the requirements.

6. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 1 is characterized by: In step S8, the pile foundation detection includes the following steps: S81. Prepare concrete strength test pieces and measure the hole diameter, hole shape and inclination using an ultrasonic wall measuring instrument; S82. Each pile is subjected to ultrasonic non-destructive testing to check the integrity of the pile; S83. After the pile foundation inspection is completed, the acoustic detection pipe and the core drilling hole shall be promptly grout-sealed.

7. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 1 is characterized by: The guide device comprises a support mechanism (1), a first guide mechanism (2) and a second guide mechanism (3); the first guide mechanism (2) and the second guide mechanism (3) have the same structure; the first guide mechanism (2) comprises a mounting frame (21); one end of the mounting frame (21) is fixedly connected to a jack (25); one end of the jack (25) is fixedly connected to a moving frame (210); a fixing bolt (26) is installed on one side of the moving frame (210); one end of the fixing bolt (26) passes through the moving frame (210) and is installed with a positioning nut (28); a connecting shaft (29) is installed on the outside of the fixing bolt (26); the outside of the connecting shaft (29) is rotatably connected to a guide wheel (22); and a rubber ring (23) is sleeved on the outside of the guide wheel (22).

8. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 7 is characterized by: Sliding blocks (27) are fixedly connected to both sides of the moving frame (210), the interior of the sliding block (27) is slidably connected to a guide rail (24), and one side of the guide rail (24) is fixedly connected to one side of the installation frame (21).

9. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 7 is characterized by: The support mechanism (1) comprises a first fixed frame (11) and a second fixed frame (12); one side of the first fixed frame (11) is installed between the first guide mechanism (2), and one side of the second fixed frame (12) is installed between the second guide mechanism (3); a vertical support frame (18) is fixedly connected between the first fixed frame (11) and the second fixed frame (12); a third fixed frame (110) is fixedly connected to the outside of the vertical support frame (18); and a second supporting diagonal rod (19) is fixedly connected between the first fixed frame (11) and the third fixed frame (110), and between the second fixed frame (12) and the third fixed frame (110).

10. The micro-disturbance construction method for large-diameter long piles under ultra-thick hard rock conditions in ecologically sensitive areas according to claim 9, characterized in that: Both sides of the second fixed frame (12) are fixedly connected to a reinforcement frame (14), one side of the reinforcement frame (14) is fixedly connected to a first support diagonal rod (17), one end of the first support diagonal rod (17) is fixedly connected to the outer side of the vertical support frame (18), the bottom sides of the second fixed frame (12) and the reinforcement frame (14) are fixedly connected to a pad (13), one end of the reinforcement frame (14) is fixedly connected to a fixing block (16), and a positioning nail (15) is installed in the middle of the fixing block (16).

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