Broaching anchor cable construction structure and method for coastal high-permeability stratum

Abstract

The invention relates to the technical field of anchor cable construction in foundation support, in particular to a coastal high-permeable stratum chambering anchor cable construction structure and method. The anchor cable construction structure comprises a hole forming assembly, a non-return assembly and a leaking stoppage assembly. The hole forming assembly comprises an outer sleeve, an inner drill rod, a drilling bit and a rotary spraying bit, the outer sleeve is connected to the outer side of the inner drill rod in a sleeving mode, and the drilling bit and the rotary spraying bit are installed at the inner end of the inner drill rod; the non-return assembly is installed on the inner drill rod, one end of the non-return assembly is provided with a non-return plate, and the outer edge of the non-return plate abuts against the inner wall of the outer sleeve; the leaking stoppage assembly comprises a middle air bag connected to the anchor cable in a sleeving mode, and the space between the middle air bag and the anchor cable is filled with leaking stoppage materials. The problems that in the prior art, hole collapse is prone to occurring, high-pressure rotary jet grouting is not full, and secondary water leakage occurs after the anchor cable is tensioned are solved.

Description

Technical Field

[0001] The invention relates to the technical field of anchor cable construction in foundation support, and in particular to a hole-enlarging anchor cable construction structure and method for a high-permeability stratum near the sea. Background Art

[0002] Anchor cable is a tension member anchored in the soil deep in the foundation. Its working principle is to use the anchoring force to connect the structure to the foundation, thereby improving the stability of the structure. When performing anchor cable support, the anchor cable passes through the waist beam and the water-stop curtain in sequence. The inner end of the anchor cable is anchored in the soil to form an anchor section, and the outer end of the anchor cable is exposed outside the waist beam to form a connecting section. The connecting section is connected to an anchor head, which is used to lock the anchor cable. A pad is provided between the anchor head and the waist beam.

[0003] In soft formations, the method of expanding the anchor diameter can effectively alleviate the defects of mud flow and insufficient anchor holding force during the artificial hole forming process of conventional tension-type anchor cables. In formations with high groundwater levels and strong permeability, the existing hole-enlarging anchor cable technology often has problems such as insufficient grouting pressure, slurry easily gushing out of the anchor hole, water leakage inside the anchor hole, and cement slurry gushing out of the anchor hole. After the anchor cable is tensioned and locked, water leakage to varying degrees may occur at the anchor head position. Long-term anchor cable leakage will cause the settlement of surrounding pipelines and buildings (structures) to increase or exceed the standard. In order to eliminate the safety hazards caused by anchor cable leakage to the foundation pit, it is usually adopted to drill several grouting holes on the pad of the anchor head, and use a high-pressure grouting machine to inject grouting liquid for plugging, such as the invention patent "foundation pit support anchor cable leakage double liquid closed grouting plugging construction structure" (publication number CN113529702A). However, in the process of drilling and grouting holes, it may be difficult to accurately locate the grouting holes at the leakage site due to construction deviations, and a large amount of labor is involved. Moreover, only grouting can be used to plug leakage problems that occur during the tensioning process, and groundwater leakage problems cannot be solved in a timely manner during the anchor cable construction process. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the embodiments of the present invention is to provide a hole expansion anchor cable construction structure and method for high-permeability formations near the sea, so as to solve the problems existing in the prior art such as easy hole collapse, incomplete high-pressure rotary jet grouting, and secondary water leakage after anchor cable tensioning.

[0005] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A hole expansion anchor cable construction structure for high-permeability formations near the sea, comprising: a hole-forming component, a non-return component and a leak-proof component; the hole-forming component comprises an outer casing, an inner drill rod, a drilling drill bit and a rotary jet drill bit, the outer casing is sleeved on the outside of the inner drill rod, and the drilling drill bit and the rotary jet drill bit are installed on the inner end of the inner drill rod; the non-return component is installed on the inner drill rod, one end of the non-return component is provided with a non-return plate, the outer edge of the non-return plate abuts against the inner wall of the outer casing; the leak-proof component comprises an intermediate air bag sleeved on the anchor cable, and the space between the intermediate air bag and the anchor cable is filled with leak-proof material.

[0007] The embodiment of the present invention also provides a construction method for the above-mentioned coastal high-permeability stratum hole expansion anchor cable construction structure, including: anchor hole forming construction: installing a drilling bit on the head of the inner drill rod, the inner drill rod first rotates to drill into the soil, and then drills into the outer casing to the designed depth; rotary jet hole expansion section construction: removing the drilling bit, fixing the grouting check assembly on the inner drill rod, replacing the rotary jet drill bit, putting the inner drill rod into the outer casing and sending it to the bottom of the hole, connecting a grouting pump to the tail of the inner drill rod, first lifting the outer casing section by section and then lifting the inner drill rod, and performing high-pressure rotary jet grouting; ordinary anchor section construction: adjusting the grouting pressure after the rotary jet hole expansion section construction is completed, lifting the rotary jet drill bit and the outer casing, and completing the grouting construction of the ordinary anchor section; installing the leak plugging assembly: inserting all the air bags into the anchor cable from the end of the anchor cable, pre-inflating the air bags on both sides, sending the anchor cable to the intersection of the anchor hole and the water-stop curtain, inflating the air bags to the rated working pressure, and then performing grouting to fill the anchor hole wall; waist beam construction.

[0008] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0009] The anchor hole forming structure that uses an inner drill rod and an outer casing can effectively solve the groundwater leakage problem and ensure the quality of the hole when constructing anchor holes in strata with high groundwater levels. The grouting check assembly can ensure the grouting pressure during the rotary jet hole expansion construction process, reduce the outflow of slurry, and improve the construction efficiency. In addition, the grouting check assembly can fix the working position of the inner drill rod so that it is located in the center of the borehole, further ensuring the quality of the hole expansion construction. The airbag plugging assembly can seal the anchor hole in a short time, effectively reducing the outflow of slurry in the anchor hole to the outside of the hole caused by groundwater leakage, and solve the problem of secondary water leakage after the anchor cable is tensioned.

[0010] Advantages of additional aspects of the present invention will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In addition, the spacing or size between each other is exaggerated to show the position of each part, and the schematic diagram is only used for illustration.

[0012] Figure 1 is a schematic diagram of a hole-forming assembly provided by an embodiment of the present invention with a drilling bit installed;

[0013] Figure 2 is a schematic diagram of a hole-forming assembly provided by an embodiment of the present invention with a jet-jet drill bit installed;

[0014] Figure 3 is a schematic diagram of a non-return assembly provided by an embodiment of the present invention;

[0015] Figure 4 is a schematic diagram of a leak plugging assembly provided by an embodiment of the present invention;

[0016] Figure 5 It is a schematic diagram of the plugging material, anchor cable and intermediate air bag provided in an embodiment of the present invention;

[0017] Figure 6 is a schematic cross-sectional view of an intermediate airbag provided by an embodiment of the present invention;

[0018] Figure 7 is a schematic diagram of a three-way pipeline provided by an embodiment of the present invention;

[0019] Figure 8 It is a schematic diagram of the rotary jet hole expansion construction provided by an embodiment of the present invention;

[0020] Fig. 9 is a schematic diagram of the final state provided by an embodiment of the present invention;

[0021] In the figure: 1. hole-forming assembly; 11. drilling bit; 12. outer casing; 13. inner drill rod; 14. rotary jet drill bit; 15. slurry outlet hole; 2. check assembly; 21. pressure rod; 22. support rod; 23. fastening ring; 24. pipe body; 25. fixing hole; 26. check plate; 3. plugging assembly; 31. expansion ring; 32. plugging material; 33. inflation check valve; 34. grouting port; 35. grouting pipeline; 36. inflation pipeline; 37. outer air bag; 38. middle air bag; 39. inner air bag; 4. anchor cable; 5. three-way pipeline. DETAILED DESCRIPTION

[0022] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] Example 1

[0024] In order to solve the problems of hole collapse and incomplete grouting during the anchor hole drilling process in highly permeable strata such as those near the sea and lakes, this embodiment proposes a rotary jet hole expansion anchor cable construction structure suitable for high water level and highly permeable strata conditions, which improves the quality of anchor cable construction, reduces construction costs, improves construction efficiency, and reduces the impact on the surrounding environment.

[0025] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the anchor cable construction structure includes a hole-forming component 1, a non-return component 2 and a leak-proof component 3; the hole-forming component 1 includes an outer sleeve 12, an inner drill rod 13, a drilling bit 11 and a rotary jet drill bit 14, the outer sleeve 12 is sleeved on the outside of the inner drill rod 13, the drilling bit 11 and the rotary jet drill bit 14 are installed on the inner end of the inner drill rod 13 (along the axial direction of the anchor cable 4, the inward end) at different construction stages; the non-return component 2 is installed on the inner drill rod 13, and one end of the non-return component 2 is provided with a non-return plate 26, and the outer edge of the non-return plate 26 abuts against the inner wall of the outer sleeve 12; the leak-proof component 3 includes an intermediate air bag 38 sleeved on the anchor cable 4, and the space between the intermediate air bag 38 and the anchor cable 4 is filled with leak-proof material 32.

[0026] The outer sleeve 12 is a hollow tubular structure, which serves to provide guidance and protection for the inner drill rod 13 during the drilling process, and can also form a protective wall after the hole is formed to prevent the hole wall from collapsing and groundwater leakage. The drilling drill bit 11 is used for initial drilling of the soil, and the rotary jet drill bit 14 is used for subsequent high-pressure rotary jet hole expansion operations. The non-return assembly 2 is installed on the inner drill rod 13, and the outer edge surface of the non-return plate 26 abuts against the inner wall of the outer sleeve 12 to ensure that the cement slurry will not flow back during the high-pressure rotary jet grouting process, ensure the grouting quality, prevent the loss of slurry, and improve the construction efficiency. The plugging assembly 3 includes an intermediate air bag 38 and a plugging material 32 filled between the intermediate air bag 38 and the anchor cable 4. The intermediate air bag 38 is made of wear-resistant rubber material, which can form a closed space in the anchor hole after inflation to prevent groundwater from leaking out of the anchor hole. The plugging material 32 can dissolve the outer shell under the action of water and release the internal hydrogel plugging material to fill the gap between the anchor cable 4 and the middle air bag 38, further enhancing the anti-seepage effect.

[0027] The inner drill rod 13 is a hollow tube, and the end of the drilling bit 11 has a drill blade, and there is a gap between the drill blades and connected to the inner drill rod 13. Normal pressure cement slurry is injected from the inner drill rod 13, so that the cement slurry overflows from the hole mouth, which can not only take out the sand and soil debris in the casing in the hole, but also squeeze out the accumulated water in the hole. At the same time, the lubrication effect of the cement slurry can be used to facilitate the removal of the wall casing. The jet grouting drill bit 14 is a tubular structure, and the tube wall is provided with slurry outlet holes 15. These slurry outlet holes 15 spray high-pressure cement slurry during the jet grouting operation, which is used to cut the soil and form an enlarged head, thereby achieving the purpose of expanding the hole.

[0028] The outer casing 12 is connected by threads. The number of pipe sections is selected according to the designed depth of the borehole. The length of each pipe section is 4m. The inner drill rod 13 is connected by threads in the same way as the outer casing 12. The diameter is smaller than the inner diameter of the outer casing 12. It is formed by a single drill rod with a length of 3m connected by threads. The drilling bit 11 is made of cemented carbide material and is connected to the inner drill rod 13 by threads. The jet drilling bit 14 is also connected to the inner drill rod 13 by threads.

[0029] The end of the anti-return assembly 2 away from the anti-return plate 26 is a tube body 24, and the outer wall of the tube body 24 is tapered. This tapered design facilitates the installation and fixation of the anti-return assembly 2 on the inner drill rod 13. A slit is provided on the tube wall, and a fastening ring 23 is sleeved on the outer wall of the tube body 24. The fastening ring 23 can move along the axial direction of the tube body 24. By cooperating with the slit, the anti-return assembly 2 can be firmly installed on the inner drill rod 13, and can adapt to inner drill rods 13 of different diameters, thereby improving the firmness and applicability of the anti-return assembly 2.

[0030] like Figure 3 As shown, the anti-return assembly 2 further includes a pressure rod 21 and a support rod 22, one end of the pressure rod 21 is hinged to the anti-return assembly 2 body, the other end of the pressure rod 21 is provided with a fixing hole 25, one end of the support rod 22 is hinged to the fastening ring 23, and the other end of the support rod 22 is hinged to the middle of the pressure rod 21. Through the coordinated use of the pressure rod 21 and the support rod 22, the fixing and release of the anti-return assembly 2 can be effectively controlled, which is convenient for construction personnel to operate.

[0031] The anti-return plate 26 is funnel-shaped, and the tail tube body 24 is a petal-shaped hard rubber structure with gaps, and is partially thickened near the tail. The fastening ring 23, the pressure rod 21, the support rod 22 (a pair of identical pressure rods 21 and support rods 22 are provided above and below), and the body of the tube 24 are all hinged. In addition, a circle of rubber sealing strips can be set on the outside of the bottom of the grouting anti-return assembly 2 to make the grouting anti-return assembly 2 in close contact with the outer sleeve 12.

[0032] Installation method of the anti-return assembly 2: After removing the drilling bit 11, rotate the pressure rod 21 and the support rod 22 synchronously toward the right head, so that the fastening ring 23 moves to the right, and the left tail opens at this time. Insert the anti-return assembly 2 from the head end of the inner drill rod 13 into the inner drill rod 13, and move it to a position about 2m away from the end of the inner drill rod 13. Rotate the upper and lower pressure rods 21 in the direction indicated by the arrow in the figure at the same time, drive the support rod 22 to move along the tube body 24 toward the tail, thereby squeezing the tail rubber structure, so that the device is fixed on the inner drill rod 13. Finally, the directions of the upper and lower pressure rods 21 are almost horizontal, which does not affect the placement of the inner drill rod 13 into the outer sleeve 12. After fixing, use cable ties to pass through the fixing holes 25 on the upper and lower pressure rods 21 in turn, and tighten the cable ties to prevent the vibration of the rotary jet drill bit 14 during operation from loosening the grouting anti-return assembly 2.

[0033] During the anchor hole drilling construction process, the drilling bit 11 is first installed at the end of the inner drill rod 13, and the drilling bit 11 and the inner drill rod 13 are connected by threads. The inner drill rod 13 is first drilled, and the drilling bit 11 enters the soil body about 0.5m, and then the outer sleeve 12 is drilled. Thereafter, the outer sleeve 12 and the inner drill rod 13 are drilled together, and the front end of the drilling bit 11 and the front end of the outer sleeve 12 are about 0.5m apart along the axis (the drilling bit 11 is in front and the outer sleeve 12 is in the back), leaving enough working space for the drill bit. The outer sleeve 12 can provide timely support for the soil body around the hole, and can also effectively block the seepage path in the anchor hole in time. After reaching the designed hole depth, the inner drill rod 13 and the outer sleeve 12 stop drilling, and the outer sleeve 12 is left in the hole to form a protective wall to prevent the hole from collapsing and groundwater leakage. The inner drill rod 13 is slowly pulled out from the outer casing 12 section by section, the drilling bit 11 at the end is rotated and removed, the grouting check assembly 2 is installed about 2m away from the front end of the inner drill rod 13, and then the jet drill bit 14 is installed. The inner drill rod 13 is lowered to the bottom of the anchor hole again, and while the inner drill rod 13 and the outer casing 12 are slowly lifted up, the jet drill bit 14 is used to rotate and spray cement slurry to perform high-pressure jetting hole expansion. The high-pressure jetted cement slurry in the jet drill bit 14 cuts the soil around the anchor hole and mixes with the cement slurry, thereby forming an enlarged head at the end of the anchor hole, such as Figure 8 shown.

[0034] Since the water-stop curtain needs to be penetrated during the construction of the anchor hole, causing the groundwater behind the support pile to penetrate into the surface layer, the focus will be on the intersection of the anchor hole and the water-stop curtain to carry out water blocking and anti-leakage measures. The leak-blocking component 3 also includes an inner airbag 39 and an outer airbag 37. Along the axial direction of the anchor cable 4, the inner airbag 39 and the outer airbag 37 are respectively located on both sides of the middle airbag 38. There is a partition between the three airbags, and the composition material of the partition is the same as the airbag material. The design of the inner airbag 39 and the outer airbag 37 helps to form a seal at both ends of the middle airbag 38, and cooperates with the middle airbag 38 to strengthen the sealing of the main leakage area.

[0035] like Figure 5 As shown, the plugging material 32 includes a shell and a hydrogel material, wherein the shell is coated on the outside of the hydrogel material, and the shell is a water-soluble material. The capsule plugging material 32 and the reserved steel strand hole wall of the intermediate air bag 38 are integrated, the shell is a water-soluble material, and the internal hydrogel plugging material 32 has good fluidity and solidifies in a short time after contacting with air, thereby timely cutting off the groundwater leakage channel and achieving the purpose of rapid plugging.

[0036] like Figure 4 , Figure 6 As shown, the leak-proof component 3 also includes a grouting pipe 35 and an inflation pipe 36. The grouting pipe 35 passes through the outer airbag 37. The grouting port 34 of the grouting pipe 35 is located between the outer wall of the outer airbag 37 and the anchor hole, so that the grouting material can be directly injected into the gap between the airbag and the hole wall, ensuring that the grouting material can be fully filled and form an effective seal.

[0037] The inflation pipe 36 leads to an opening in each airbag, and a gas check valve is provided at the opening to prevent the gas in the airbag from flowing back. When the airbag is inflated by the air pump, the gas check valve opens toward the inside of the airbag. After the inflation is completed, due to the pressure difference between the inside and outside of the airbag, the inflation check valve 33 is closed to ensure the air pressure in the airbag.

[0038] The segmented airbag anchor hole plugging component 3 is put on the anchor cable 4 in advance according to the distance between the foundation pit surface and the water-stop curtain before anchoring. After the grouting is completed, the airbag is inflated with high pressure to fill the entire anchor hole to form a closed space, which can effectively prevent the problem of slurry outflow in the anchor hole caused by groundwater leakage after grouting.

[0039] The airbag is made of a wear-resistant rubber composite material. After being inflated, it can be in close contact with the steel strand, cutting off the leakage channel of groundwater along the anchor cable 4, thereby achieving the effect of sealing the anchor hole and preventing the slurry from gushing out of the hole. A number of holes are reserved in the middle of the airbag for inserting the steel strand and the inflation pipe 36.

[0040] The application of segmented capsule-encapsulated water-soluble plugging material 32 effectively alleviates the groundwater leakage problem. The cracks generated during the tensioning of the anchor cable 4 can be sealed in a timely manner, and a portion of the capsule-type plugging material 32 is reserved as a guarantee, which effectively avoids the construction of grouting again.

[0041] The tail of the inner airbag 39 and the contact part with the steel strand are filled with a water-expanding ring 31, which can expand after contact with water and then come into close contact with the steel strand, preventing water in the hole from seeping into the gap between the middle airbag 38 and the steel strand when the anchor cable 4 is lowered, causing the capsule-type plugging material 32 to take effect prematurely.

[0042] A three-way pipe 5 (such as Figure 7 As shown), the inflation pipe 36 and the grouting pipe 35 are led to the outside of the waist beam along the anchor cable 4 through the tee, which is convenient for later inflation and grouting after installation. The arrangement of the tee pipe 5 is as shown Fig. 9 The three-way pipe 5 reserved in the waist beam can not only solve the placement problem of the inflation pipe 36 and the grouting pipe 35, but also exist as a grouting plugging channel, which simplifies the construction steps of drilling holes in the surface layer and then grouting in the conventional anchor cable 4 plugging measures, improves the construction efficiency, reduces the input of labor and machinery, and further ensures the construction safety.

[0043] Example 2

[0044] This embodiment proposes a construction method for the anchor cable construction structure in Embodiment 1:

[0045] Anchor hole construction: First, measurement and positioning are carried out. After the drilling rig is in place, the drilling bit 11 is installed at the head of the inner drill rod 13. The inner drill rod 13 is first rotated to drill into the soil. After the drilling bit 11 enters the soil for about 0.5m, it drills into the outer casing 12. After that, the outer casing 12 and the inner drill rod 13 are drilled at the same time. The inner drill rod 13 is formed by a single drill rod with a length of 4m and connected by threads, and the outer casing 12 is formed by a single casing with a length of 3m and connected by threads. During the drilling process, the inner drill rod 13 is first connected in sections and then connected to the outer casing 12, and the drilling is carried out to the designed depth. During the drilling construction, the distance between the drilling bit 11 and the outer casing 12 is about 0.5m, leaving enough working space for the drilling bit 11. The outer casing 12 forms a wall protection effect on the anchor hole during the drilling process. During the drilling process of the drill rod, P.O42.5 ordinary silicate cement slurry should be used for circulating wall protection throughout the process, and the water-cement ratio is about 1.0. After the drilling bit 11 reaches the designed depth, the outer casing 12 also stops drilling. Normal pressure cement slurry is injected from the inner drill rod 13, and the grouting pressure is not less than 0.5MPa, so that the cement slurry overflows from the hole mouth, which can not only take out the sand and soil debris in the casing in the hole, but also squeeze out the accumulated water in the hole. At the same time, the lubrication effect of the cement slurry can be used to facilitate the extraction of the wall casing.

[0046] Construction of the rotary jet hole expansion section: the inner drill rod 13 is pulled out section by section from the outer casing 12, and the drilling bit 11 at the end of the inner drill rod 13 is removed. The grouting check assembly 2 is fixed at a position about two meters away from the drilling bit 11 on the inner drill rod 13, the rotary jet drill bit 14 is replaced and tightened, and a trial jet test is carried out on the drill rod to check whether the rotary jet drill bit 14 is in good condition.

[0047] The inner drill rod 13 is connected section by section and put into the outer casing 12 and slowly sent to the bottom of the hole. Then, a high-pressure grouting pump is connected to the tail of the inner drill rod 13 (the end left outside the hole) for high-pressure rotary jet grouting. The grouting pressure is not less than 25Mpa. During the rotary jetting process, the rotary jet drill bit 14 is lifted at a speed of 20-25cm / min, and the length of the high-pressure pipe connecting the high-pressure grouting pump and the drilling rig for conveying high-pressure radioactive liquid should not be greater than 50m. The rotary jet drill bit 14 should rotate at a uniform speed and be lifted or lowered uniformly. During the hole expansion construction process, the outer casing 12 and the rotary jet drill bit 14 are kept at a distance of 0.5m (the outer casing 12 is at the back and the rotary jet drill bit 14 is at the front). The outer casing 12 is first lifted section by section and then the inner drill rod 13 is lifted.

[0048] The grouting check assembly 2 can reduce the loss of slurry during the jet grouting process, ensure the pressure during jet grouting, and fully mix the soil and slurry. It can also assist in fixing the position of the jet grouting drill bit 14 so that it operates at the center of the anchor hole, further ensuring the grouting effect.

[0049] Construction of ordinary anchoring section: after the construction of the rotary jet hole expansion section is completed, adjust the grouting pressure, adjust the grouting pressure of the rotary jet drill bit 14 to 2.5MPa, and continue to slowly lift the rotary jet drill bit 14 and the outer casing 12 at a speed of 20 to 25cm / min to complete the grouting construction of the ordinary anchoring section.

[0050] Install the segmented airbag plugging component 3: During the construction of the rotary jet hole expansion, the anchor cable 4 is cut and made, and the plugging component 3 is installed and positioned. The airbag is inserted into the anchor cable 4 (steel strand) from the end of the anchor cable 4, and each steel strand passes through the reserved hole of the airbag. The airbag is ensured to be smooth during the placement process. After the positioning is completed, the outer airbag 37 is pre-inflated to 1 / 3 of the working volume, and then the position of the outer airbag 37 is fixed with a nylon tie, and the airbag inflation pipe 36 and the grouting pipe 35 are tied to the steel strand for preliminary fixation, and then led to the outside of the anchor hole, and protective measures are taken. The anchor cable 4 is slowly sent to the anchor hole, and it is important to avoid the airbag from hitting the anchor hole wall and causing the hole wall to collapse. The segmented airbag plugging component 3 is placed at the intersection of the anchor cable 4 and the water-stop curtain, and then the inflation pipe 36 is used to inflate the airbag to the rated working pressure, and then the grouting pipe 35 in the airbag is grouted to fill the anchor hole wall to achieve plugging at the anchor hole.

[0051] Waist beam construction: During the construction of the waist beam tying the steel cage, a three-way pipe 5 with an inner diameter of 75 mm and an anti-bonding pipe (used to prevent bonding) are placed close to the anchor hole, and the three-way pipe 5 is arranged vertically upward.

[0052] During the placement of the three-way pipe 5, the inflation pipe 36 and the grouting pipe 35 in the airbag are passed through the vertical pipe of the three-way pipe 5 and are well protected.

[0053] The three-way pipe 5 can also be used as a channel for the anchor cable 4 to be grouted again for plugging. The plugging material can be injected into the vertical pipe again to consolidate the plugging effect, avoiding the construction step of manual drilling again in the conventional plugging operation. During the pouring and curing of the waist beam, attention should be paid to the protection of the three-way pipe 5 and the inflation pipe to prevent the pipe from being blocked by materials such as concrete and affecting the later process.

[0054] Before tensioning, the entire airbag plugging assembly 3 is re-aired to prevent a large amount of water seepage during the tensioning process. When the waist beam is tensioned, the steel strand will be stretched outward, which will cause displacement between the anchor body and the steel strand, the steel strand and the airbag, and the airbag and the hole wall, which is easy to generate new seepage channels. At this stage, when the groundwater contacts the capsule plugging material 32, the shell of the capsule begins to dissolve, and the hydrogel plugging material 32 inside is exposed. Under the squeezing action of the inner airbag 39, the micro cracks between the steel strand and the airbag are quickly filled and solidified, and the groundwater leakage channel is cut off in time to achieve the plugging effect of the anchor hole. At the same time, the quick-setting slurry is injected into the outside of the airbag through the grouting pipe 35 inside the airbag. The quick-setting slurry flows in the gap between the airbag and the hole wall, which can achieve the plugging of the gap between the airbag and the hole wall, and then the water seepage channel in the water-stop curtain generated by the drilling of the anchor cable 4 is completely blocked.

[0055] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A hole expansion anchor cable construction structure for high permeability formation near the sea, characterized in that: include: Hole forming components, non-return components and leak plugging components; The hole forming assembly comprises an outer sleeve, an inner drill rod, a drilling drill bit and a rotary jet drill bit, wherein the outer sleeve is sleeved on the outer side of the inner drill rod, and the drilling drill bit and the rotary jet drill bit are installed on the inner end of the inner drill rod; The anti-return assembly is installed on the inner drill rod, and one end of the anti-return assembly is provided with an anti-return plate, and the outer edge of the anti-return plate abuts against the inner wall of the outer casing; The plugging component comprises a middle air bag sleeved on the anchor cable, and the space between the middle air bag and the anchor cable is filled with plugging material.

2. The seaside high permeability stratum hole expansion anchor cable construction structure as claimed in claim 1, characterized in that: The inner drill rod is a hollow tube, the end of the drilling drill bit is provided with drill blades, gaps are provided between the drill blades and the drill blades are connected with the inner drill rod, and the jet jet drill bit is a tubular structure with slurry outlet holes arranged on the tube wall.

3. The seaside high permeability stratum hole expansion anchor cable construction structure as claimed in claim 1, characterized in that: The end of the non-return assembly away from the non-return plate is a tube body, the outer wall of the tube body is conical, a slit is opened on the tube wall, a fastening ring is sleeved on the outer wall of the tube body, and the fastening ring can move along the axial direction of the tube body.

4. The seaside high permeability stratum hole expansion anchor cable construction structure as claimed in claim 3, characterized in that: The anti-return assembly also includes a pressure rod and a support rod, one end of the pressure rod is hinged to the anti-return assembly body, the other end of the pressure rod is provided with a fixing hole, one end of the support rod is hinged to the fastening ring, and the other end of the support rod is hinged to the middle part of the pressure rod.

5. The seaside high permeability stratum hole expansion anchor cable construction structure as claimed in claim 1, characterized in that: The leak-proof component further comprises an inner airbag and an outer airbag, and along the axial direction of the anchor cable, the inner airbag and the outer airbag are respectively located on both sides of the middle airbag.

6. The hole-enlarging anchor cable construction structure for high-permeability seabed strata as claimed in claim 5, characterized in that: The plugging material comprises an outer shell and a hydrogel material. The outer shell is coated on the outside of the hydrogel material and is a water-soluble material.

7. The hole-enlarging anchor cable construction structure for high-permeability seawater strata according to claim 5, characterized in that: The leak plugging assembly also includes a grouting pipe and an inflation pipe. The grouting pipe passes through the outer airbag. The grouting port of the grouting pipe is located between the outer wall of the outer airbag and the anchor hole. The inflation pipe is connected to the three airbags respectively, and an inflation check valve is provided on the inflation pipe.

8. The seaside high permeability stratum hole expansion anchor cable construction structure as claimed in claim 5, characterized in that: The leak-proof component also includes an expansion ring, which is arranged at the front end of the inner airbag.

9. A construction method for a seaside high permeability stratum hole enlargement anchor cable construction structure as claimed in any one of claims 1 to 8, characterized in that: include: Anchor hole construction: install the drilling bit on the head of the inner drill rod, and the inner drill rod is rotated to drill into the soil, and then drilled into the outer casing to the designed depth; Construction of rotary jet hole expansion section: remove the drilling bit, fix the grouting check assembly on the inner drill rod, replace the rotary jet drill bit, put the inner drill rod into the outer casing and send it to the bottom of the hole, connect the grouting pump to the tail of the inner drill rod, first lift the outer casing section by section and then lift the inner drill rod, and carry out high-pressure rotary jet grouting; Construction of common anchoring section: after the construction of jet grouting hole expansion section is completed, adjust the grouting pressure, lift the jet grouting drill bit and outer casing, and complete the grouting construction of common anchoring section; Install the plugging assembly: insert all the air bags into the anchor cable from the end of the anchor cable, pre-inflate the air bags on both sides, send the anchor cable to the intersection of the anchor hole and the water-stop curtain, inflate the air bags to the rated working pressure, and then perform grouting to fill the anchor hole wall; Waist beam construction.

10. The construction method according to claim 9, characterized in that: include: During the anchor hole drilling construction phase, normal pressure cement slurry is injected from the inner drill rod to make the cement slurry overflow from the hole mouth.

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