Bottom sealing and grouting method for anchor rod, anchor cable and casing pipe below shoe sleeve type underground water level line

Abstract

The invention relates to a bottom sealing grouting method for an anchor rod, an anchor cable and a sleeve under a shoe sleeve type underground water level line, which comprises the following steps: preparing bentonite slurry, cement slurry and water glass, and preparing a shoe sleeve; an outer sleeve and an inner drill rod are used for drilling at the hole position to form an anchor hole, and a grouting machine injects bentonite slurry into the outer sleeve through the inner drill rod; after the outer sleeve is filled with the bentonite slurry, one end of a pressure maintaining grouting device is connected with the outer sleeve, one end of an inner drill rod is connected with a power head of a drilling machine, and the other end of the inner drill rod penetrates through the pressure maintaining grouting device and extends into the anchor hole; grouting is conducted on the bottom area, located in the anchor hole, of the outer sleeve through the inner drill rod, so that a grouting consolidation body is formed at the bottom of the outer sleeve; and after the grout is solidified, the pressure maintaining grouting device and the inner drill rod are dismantled, and the shoe sleeve is jacked into the grouting solidification body.

Description

Technical Field

[0001] The invention relates to the field of engineering below the groundwater level, in particular to an anchor rod and anchor cable construction method in engineering below the groundwater level, and more specifically to a boot-type anchor rod and anchor cable casing bottom sealing grouting method below the groundwater level. Background Art

[0002] With economic development and the expansion of urban construction, high-rise buildings, large buildings and various underground facilities are increasing, and the scale of foundation pits and other underground projects is also getting larger and larger. In the construction process of underground projects, the support form of "enclosing structure + anchor rods (anchor cables)" is often used.

[0003] In the past, the support work required for underground facilities was relatively shallow, only about 10 meters, while the groundwater level was about 30 meters. Therefore, the support effect could be easily achieved by using the traditional enclosure structure combined with the support form of anchor rods or anchor cables. However, as people's environmental awareness increases, the protection measures for groundwater are becoming more mature, and the height of the groundwater level is also rising year by year.

[0004] However, with the rise of the groundwater level, the depth of underground construction is required to be deeper and deeper, sometimes even reaching a depth of 20 to 30 meters underground, which intersects with the groundwater level. At this time, when the traditional "enclosure structure + anchor rod (anchor cable)" support form is adopted, if the groundwater level is high during the construction of anchor rods or anchor cables, a large amount of groundwater will gush out during the drilling process, accompanied by a large amount of medium loss in the stratum, causing the enclosure structure to settle and deform significantly, thereby affecting the safety of surrounding structures and posing serious safety hazards.

[0005] In addition, during the construction process of water-rich sand layers, when drilling is carried out using casing follow-up construction, due to the poor cohesion of the sand layer, under the action of water pressure, after drilling to the designed depth, water and sand will gush out from the end of the casing, causing the casing to be blocked by sand and the anchor rods or cables to be unable to be installed smoothly.

[0006] Therefore, it is an urgent problem to be solved in the industry to provide a boot-type anchor cable casing bottom grouting method below the groundwater level that is suitable for below the groundwater level and can successfully complete the installation of anchor cables. Summary of the invention

[0007] In view of the above problems, one of the objects of the present invention is to provide a boot-type bottom grouting method for anchor rod and cable casing below the groundwater level line, which realizes the smooth construction of anchor rods and cables below the groundwater level line by controlling the sand gushing from the hole mouth, reinforcing the stratum by grouting at the bottom of the hole and installing the boot, thus providing a new choice for the construction of anchor rods and cables below the water level line in the industry.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] The present invention provides a boot-type anchor bolt and anchor cable casing bottom sealing grouting method below the groundwater level line, which comprises the following steps:

[0010] (1) Prepare bentonite slurry, cement slurry and water glass, and prepare boot covers;

[0011] (2) Setting a hole position on the enclosure structure, and installing a hole opening anti-burst device at the hole opening of the hole position;

[0012] (3) drilling an anchor hole at the hole position using an outer casing and an inner drill rod, and injecting bentonite slurry into the outer casing through the inner drill rod using a grouting machine;

[0013] (4) After the outer casing is filled with the bentonite slurry, one end of the pressure-maintaining grouting device is connected to the outer casing, one end of the inner drill rod is connected to the power head of the drilling rig, and the other end of the inner drill rod is passed through the pressure-maintaining grouting device and extended into the anchor hole;

[0014] (5) grouting the bottom area of ​​the outer casing located in the anchor hole through the inner drill rod, so that a grouting consolidation body is formed at the bottom of the outer casing; and

[0015] (6) After the slurry solidifies, the pressure-maintaining grouting device and the inner drill rod are removed, and the boot sleeve is pushed into the grouting consolidation body.

[0016] In some embodiments, in step (2), the enclosure structure is a ground-connected wall or other structure.

[0017] In some embodiments, in step (2), before installing the orifice anti-bumping device, the periphery of the orifice of the hole is roughened and leveled.

[0018] In some embodiments, in step (3), the drilling method is air drilling, water drilling or mud wall drilling, and the outer casing follows the process.

[0019] In some embodiments, in step (3), the outer diameter of the outer casing is set to 60 mm to 200 mm, and the outer diameter of the inner drill rod is set to 50 mm to 114 mm.

[0020] Among them, in step (3), the bentonite slurry is injected to replace the mud and sand in the outer casing. Since the bentonite slurry has a certain viscosity and specific gravity, it can wrap the mud and sand in the middle outer casing and bring it out of the hole. Then, the pressure-maintaining grouting device is installed to make most of the interior of the outer casing filled with bentonite slurry, preventing the slurry from entering during subsequent grouting and preventing the slurry from solidifying, so as to facilitate the removal of the inner drill rod.

[0021] In some embodiments, in step (3), the bentonite slurry is injected at normal pressure, and the bentonite slurry includes the following components in parts by weight: 100 parts of water and 50 parts of bentonite.

[0022] In some embodiments, in step (5), the inner drill rod is used to deepen the borehole by 1 to 5 meters before grouting.

[0023] In some embodiments, in step (5), the grouting pipe is connected to the power head of the drilling rig to perform drill rod retreat staged grouting.

[0024] In some embodiments, in step (5), the bottom reinforcement zone is set to a stratum 1 to 5 meters away from the bottom of the outer casing.

[0025] In some embodiments, the grouting slurry used in step (5) has the characteristics of anti-dispersion, fast setting, and high permeability.

[0026] In some embodiments, in step (5), the grouting pressure is set to 0.1 to 1.5 MPa, the grouting slurry includes: cement slurry and water glass slurry in a volume ratio of 1:1 to 1:0.2, and the setting time of the grouting slurry is set to 3 to 10 minutes.

[0027] In some embodiments, in step (5), the cement slurry includes the following components in parts by weight: 100 parts of water and 100 parts of cement, wherein the cement is ordinary Portland cement, and its model can be, for example, 42.5 Portland cement, 42.5R Portland cement, 52.5 Portland cement, 52.5R Portland cement, 62.5 Portland cement or 62.5R Portland cement.

[0028] In some embodiments, in step (6), after the slurry solidifies, wait for 30 to 120 minutes before removing the pressure-maintaining grouting device and the inner drill rod, and then push the boot into the grouting consolidation body through the inner drill rod.

[0029] In some embodiments, in step (6), the boot cover includes the boot cover columnar body and a cone connected to the bottom of the columnar body, and the outer diameter of the boot cover is set to 60 mm to 200 mm, and the length is set to 50 cm to 200 cm.

[0030] In some embodiments, in step (6), the boot is made of a steel tube that is 5 to 10 mm smaller than the inner diameter of the outer sleeve.

[0031] In some embodiments, a barbed steel bar or steel pipe with a length of 50 to 100 cm is provided at the bottom of the cone of the boot cover, the diameter of the steel bar is set to 18 to 25 mm, and the diameter of the steel pipe is set to 20 to 50 mm.

[0032] In some embodiments, in step (2), the orifice anti-bumping device includes: a fixing plate group, a sealing plate and a positioning plate group, wherein the fixing plate group includes a first end plate fixed to the enclosure structure, a first connecting plate connected to the top end of the first end plate and extending outward, a second connecting plate connected to the bottom end of the first end plate and extending outward, and a second end plate connected between the first connecting plate and the second connecting plate, the length of the first connecting plate is less than the length of the second connecting plate, the sealing plate is arranged on the outer surface of the second end plate, the positioning plate group is pressed at the outer edge of the sealing plate and fixed to the second end plate, a first through hole is opened in the center of the first end plate, a second through hole is opened in the center of the second end plate, and a central through hole is opened in the center of the sealing plate, so that the outer casing passes through the central through hole, the second through hole and the first through hole in sequence to enter the underground, and the angle between the first end plate and the second end plate is set to 15 to 25 degrees.

[0033] In some embodiments, a sealing gasket is sandwiched between the first end plate of the orifice anti-bumping device and the enclosure structure.

[0034] In some embodiments, the positioning plate group of the orifice anti-bumping device includes a plurality of pressure plate sheets, each of which is arranged around the outer edge of the sealing plate.

[0035] In some embodiments, the first end plate of the orifice burst prevention device is connected to the enclosure structure by expansion bolts.

[0036] In some embodiments, the diameter of the central through hole of the orifice anti-bumping device is smaller than the diameter of the outer sleeve, and the diameters of the first through hole and the second through hole are larger than the diameter of the outer sleeve.

[0037] In some embodiments, the first end plate and the second end plate of the orifice burst prevention device are both steel plates.

[0038] In some embodiments, the first end plate and the second end plate of the orifice anti-bumping device are provided with bolt holes.

[0039] In some embodiments, the sealing plate of the orifice anti-burst device is a rubber plate.

[0040] In some embodiments, the sealing gasket plate of the orifice anti-bumping device is a rubber plate or a polyurethane plate.

[0041] In some embodiments, in step (4), the pressure-maintaining grouting device includes: a hollow cavity, a casing port provided at one end of the hollow cavity, a first grouting end plate provided at the other end of the hollow cavity, a second grouting end plate bolted to the first grouting end plate, and a sealing chamber body clamped between the first grouting end plate and the second grouting end plate, wherein the inner wall of the casing port is provided with an internal thread for threaded connection with the outer casing, the first grouting end plate, the second grouting end plate and the sealing chamber body are provided with coaxial through holes, a sealing member is provided in the sealing chamber body, and the inner diameter of the sealing member matches the outer diameter of the inner drill rod.

[0042] In some embodiments, the outer diameter of the inner drill rod is 1 to 2 cm smaller than the diameter of the through hole of the sealed chamber.

[0043] In some embodiments, the diameter of the through hole of the first grouting end plate is 1 to 2 cm larger than the outer diameter of the inner drill rod.

[0044] In some embodiments, the seal is a V-type composite seal.

[0045] In some embodiments, the hollow cavity is integrally connected to the first end plate.

[0046] By adopting the above technical scheme, the present invention has at least achieved the following technical effects: (1) It is suitable for the bottom grouting construction of anchor rods and anchor cables in the strata prone to sudden surge below the groundwater level. When drilling, the hole mouth anti-surge device is used to limit the water and sand gushing out of the casing; (2) Grouting is carried out by a pressure-maintaining grouting device to prevent the slurry from returning to the hole mouth, thereby ensuring the grouting effect; (3) After the grouting is used to reinforce the stratum in the bottom area of ​​the hole, the boot sleeve is used to limit the sand gushing, thereby enhancing the grouting effect, thereby preventing the situation where the anchor rods and anchor cables are not installed properly, and providing conditions for the smooth installation of the subsequent anchor rods and anchor cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A flowchart showing the steps of the boot-type anchor bolt and cable casing bottom sealing grouting method below the groundwater level line of the present invention is shown;

[0048] Figure 2 A schematic diagram showing the state of step S2 of the boot-type anchor bolt and cable casing bottom sealing grouting method below the groundwater level line of the present invention;

[0049] Figure 3 A schematic diagram showing the state of step S3 of the boot-type anchor bolt and cable casing bottom sealing grouting method below the groundwater level line of the present invention;

[0050] Figure 4A schematic diagram showing the state of step S4 of the boot-type anchor bolt and cable casing bottom sealing grouting method below the groundwater level line of the present invention;

[0051] Figure 5 A schematic diagram showing the state of step S5 of the boot-type anchor bolt and cable casing bottom sealing grouting method below the groundwater level line of the present invention;

[0052] Fig. 6A and Figure 6B A schematic diagram showing the state of step S6 of the boot-type anchor bolt and cable casing bottom sealing grouting method below the groundwater level line of the present invention;

[0053] Figure 7 A schematic diagram of the structure of the boot cover of the present invention is shown;

[0054] Figure 8 A side cross-sectional view of the orifice anti-burst device of the present invention is shown;

[0055] Fig. 9 A front view of the orifice anti-burst device of the present invention is shown;

[0056] Fig.10 The schematic structural diagram of the pressure-maintaining grouting device of the present invention is shown;

[0057] Fig.11 A schematic diagram showing the use state of the pressure-maintaining grouting device of the present invention is shown;

[0058] Description of reference numerals:

[0059] 0-embedded hole, 1-enclosure structure, 2-drilling rig, 3-power head, 4-outer casing, 5-inner drill rod, 6-grouting consolidation body, 7-mixing barrel, 8-grouting machine, 9-grouting pipe, 10-shoe sleeve, 101-shoe sleeve columnar body, 102-cone, 103-rebar, 12-high-speed pulping machine, K-hole mouth anti-burst device, K1-fixed plate group, K2-sealing plate, K3-positioning plate group, K1-fixed plate group, K11-first end plate, K110-first through hole , K12-second end plate, K120-second through hole, KL1-first connecting plate, KL2-second connecting plate, K2-sealing plate, K20-center through hole, K3-positioning plate group, K30-pressure plate, K4-sealing pad, J-pressure maintaining grouting device, J1-hollow cavity, J2-casing port, J21-internal thread, J3-first end plate, J4-second end plate, J5-sealing chamber, J6-seal, Q-bolt, P-expansion bolt, S-underground. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0061] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc., are used to define components, only for the convenience of distinguishing the above components, and unless otherwise stated, the above terms have no special meanings and cannot be understood as indicating or implying relative importance.

[0062] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] Next, the boot-type anchor rod and anchor cable casing bottom sealing grouting method below the groundwater level line of the present invention will be described in detail with reference to the accompanying drawings.

[0064] like Figure 1As shown, as a non-limiting embodiment, the present invention provides a boot-type anchor bolt anchor cable casing bottom grouting method below the groundwater level line. First, in step S1, bentonite slurry, cement slurry and water glass are first configured, and a boot is prepared. Then, in step S2, a hole position is set on the enclosure structure, and a hole mouth anti-burst device is installed at the hole mouth of the hole position. Then, in step S3, an outer sleeve and an inner drill rod are used to drill holes at the hole position to form an anchor hole, and a grouting machine injects bentonite slurry into the outer sleeve through the inner drill rod. In step S4, after the outer sleeve is filled with bentonite slurry, one end of the pressure-maintaining grouting device is connected to the outer sleeve, one end of the inner drill rod is connected to the power head of the drilling rig, and the other end of the inner drill rod is passed through the pressure-maintaining grouting device and extended into the anchor hole. Then, in step S5, the bottom area of ​​the outer sleeve located in the anchor hole is grouted through the inner drill rod, so that a grouting consolidation body is formed at the bottom of the outer sleeve. Finally, in step S6, after the slurry solidifies, the pressure-maintaining grouting device and the inner drill rod are removed, and the boot sleeve is pushed into the grouting consolidation body.

[0065] Specifically, first, in step S1, cement slurry is stirred in the mixing barrel 7, and water glass is prepared in advance, wherein the cement slurry is composed of the following raw materials in parts by weight: 100 parts of water and 100 parts of cement; the Baume degree of the water glass is set to 35.

[0066] Then, in step S2, as Figure 2 As shown, the periphery of the embedded hole 0 of the anchor rod body or anchor cable body on the surface of the enclosure structure 1 is first roughened, and then the hole mouth anti-burst device K is installed, wherein the hole mouth anti-burst device K is firmly connected to the enclosure structure 1 using expansion bolts P.

[0067] Then, in step S3, Figure 3 As shown, the drilling rig 2 uses an outer casing 4 and an inner drill rod 5 to simultaneously drill a hole to a designed depth to form an anchor hole, connects a grouting machine 8 and a drilling rig power head 3 via a grouting pipe 9, and then uses the grouting machine 8 to inject the bentonite slurry stirred in a high-speed pulping machine 12 into the outer casing 4.

[0068] Next, in step S4, Figure 4 As shown, when the outer casing 4 is filled with bentonite slurry, the power head 3 of the drilling rig 2 is separated from the outer casing 4 and the inner drill rod 5, and then the pressure-maintaining grouting device J is installed at the tail end of the outer casing 4, the inner drill rod 5 is inserted into the pressure-maintaining grouting device J, and connected to the power head 3.

[0069] Then, in step S5, Figure 5 As shown, the inner drill rod 5 is drilled deeper by 1 to 5 meters using a drilling rig 2, and then cement slurry is stirred in a mixing barrel 7. Then, the cement slurry and water glass are injected into the formation through the power head 3 and the inner drill rod 5 connected by the grouting pipe 9 by a grouting machine 8 to form a grouting consolidation body 6.

[0070] Finally, in step S6, Fig. 6A and 6B As shown, the pressure-maintaining grouting device J and the inner drill rod 5 are removed by the drilling rig 2, the power head 3 of the drilling rig 2 is connected to the inner drill rod 5, and the pre-made boot sleeve 10 is pushed into the outer sleeve 4 until the conical part of the boot sleeve 10 is inserted into the grouting consolidation body 6.

[0071] like Figure 7 As shown, the boot cover 10 of the present invention comprises a boot cover columnar body 101 and a cone 102 connected to the bottom of the columnar body 101 , and a barbed steel bar 103 with a length of 80 cm is provided at the bottom of the cone 102 .

[0072] As another non-limiting embodiment, Figure 8 As shown, the hole mouth anti-burst device K in step S2 includes: a fixing plate group K1, a sealing plate K2 and a positioning plate group K3.

[0073] Specifically, the fixing plate group K1 includes: a first end plate K11, a second end plate K12, a first connecting plate KL1 and a second connecting plate KL2. The first end plate K11 is firmly connected to the enclosure structure 1 through expansion bolts P, the first connecting plate KL1 is welded to the top end of the first end plate K11 and extends outward, the second connecting plate KL2 is welded to the bottom end of the first end plate K11 and extends outward, and the second end plate K12 is welded between the first connecting plate KL1 and the second connecting plate KL2. Fig.11 As shown, the length of the first connecting plate KL1 is less than the length of the second connecting plate KL2, so that a certain angle is formed between the first end plate K11 and the second end plate K12, thereby achieving the effect of oblique insertion of the outer sleeve and oblique stretching of the anchor rod and anchor cable. In this non-limiting embodiment, the first connecting plate KL1 and the second connecting plate KL2 can be steel pipes or steel plates.

[0074] like Figure 8 and Fig. 9 As shown, a sealing plate K2 made of a rubber plate is arranged on the outer surface of the second end plate K12, a positioning plate group K3 is pressed on the outer edge of the sealing plate K2, and is fixed to the second end plate K12 by bolts Q, a first through hole K110 is opened at the center of the first end plate K11, a second through hole K120 is opened at the center of the second end plate K12, and a central through hole K20 is opened at the center of the sealing plate K2, so that the outer sleeve 4 can pass through the central through hole K20, the second through hole 110 and the first through hole 120 in sequence to enter the underground S.

[0075] In this non-limiting embodiment, in order to prevent water and sand from gushing between the first end plate K11 and the enclosure structure 1 , a sealing pad K4 made of a rubber plate or a polyurethane plate is sandwiched between the first end plate K11 and the enclosure structure 1 .

[0076] In order to prevent underground mud and sand from gushing out from the outer wall of the outer casing, the diameter of the central through hole K20 of the present invention is smaller than the diameter of the outer casing 4, thereby utilizing the elasticity of the sealing plate itself so that the central through hole K20 can tightly clamp the outer wall of the outer casing 4.

[0077] As another non-limiting embodiment, Fig. 9 The positioning plate group K3 includes a plurality of pressure plate pieces K30, each of which is arranged around the outer edge of the sealing plate K3 and then fixed to the second end plate K12 by bolts, thereby achieving a fixing effect of the sealing plate K3.

[0078] Therefore, when using the hole mouth anti-bumping device K, firstly, the first end plate K11 is firmly connected to the enclosure structure 1 by the expansion bolts P, and the first end plate K11 and the enclosure structure 1 are sealed by a sealing pad K4 made of a rubber plate or a polyurethane plate, and the second end plate K12 is inclined at an angle of 20 degrees to the first end plate through the first connecting plate KL1 and the second connecting plate KL2, and the central through hole K20 of the sealing plate K2 is aligned with the second through hole K120 of the second end plate K12, and then the outer sleeve 4 is successively passed through the central through hole K20, the second through hole K120 and the first through hole K110 to the underground S, and then each pressure plate K30 is pressed on the sealing plate K2 and fixed to the second end plate K12 by bolts Q, thereby completing the entire installation process.

[0079] In this non-limiting embodiment, the pressure-maintaining grouting device J used in step S4 is as follows: Fig.10 As shown, it includes: a hollow cavity J1, a first end plate J3, a second end plate J4 and a sealing chamber J5. Specifically, one end of the hollow cavity J1 is provided with a casing port J2, and the other end of the hollow cavity J1 is provided with an integrally connected first end plate J3, the second end plate J4 is connected to the first end plate J3 by a bolt Q, and the sealing chamber J5 is sandwiched between the first end plate J3 and the second end plate J4, wherein the first end plate J3, the second end plate J4 and the sealing chamber J5 are provided with coaxial through holes, and a sealing member J6 is provided in the sealing chamber J5. The aperture of the casing port J2 matches the aperture of the outer sleeve 4, the inner wall of the casing port J2 is provided with an internal thread J21, so that it can be threadedly connected with the outer sleeve 4, and the inner diameter of the sealing member J6 matches the outer diameter of the inner drill rod 5, thereby, the inner drill rod 5 can achieve a sealing effect by using the sealing member J6.

[0080] During use, before grouting the bottom, if Fig.11As shown, the pressure-maintaining grouting device J is connected to the outer casing 4 through the casing port J2. Since the interior of the pressure-maintaining grouting device J is a hollow structure, the inner drill rod 5 passes through the second end plate J4, the sealing chamber J5, and the first end plate J3 in sequence, and passes through the interior of the hollow cavity J1. A V-shaped combined seal J6 is installed in the sealing chamber J5. The tightness of the V-shaped combined seal J6 is controlled by the bolts Q on the second end plate J4 and the first end plate J3 to seal the inner drill rod 5 tightly, and then grouting is performed to achieve the effect of maintaining pressure in the outer casing and preventing the slurry from flowing back into the outer casing.

[0081] In the underwater anchor construction in Yujingwan Community, Tongzhou District, Beijing, the boot-type anchor cable casing bottom grouting method provided by the present invention below the groundwater level was used for experimental construction. After the bottom grouting was completed, sand gushing no longer occurred, and the anchor cable could be smoothly installed after the boot was installed, achieving good economic and social benefits.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A boot-type anchor bolt and cable casing bottom grouting method below the groundwater level, characterized in that: The steps include: (1) Prepare bentonite slurry, cement slurry and water glass, and prepare boot covers; (2) Setting a hole position on the enclosure structure, and installing a hole opening anti-burst device at the hole opening of the hole position; (3) drilling an anchor hole at the hole position using an outer casing and an inner drill rod, and injecting bentonite slurry into the outer casing through the inner drill rod using a grouting machine; (4) After the outer casing is filled with the bentonite slurry, one end of the pressure-maintaining grouting device is connected to the outer casing, one end of the inner drill rod is connected to the power head of the drilling rig, and the other end of the inner drill rod is passed through the pressure-maintaining grouting device and extended into the anchor hole; (5) Grouting the bottom area of ​​the outer casing located in the anchor hole through the inner drill rod, so that a grouting consolidation body is formed at the bottom of the outer casing; as well as (6) After the slurry solidifies, the pressure-maintaining grouting device and the inner drill rod are removed, and the boot sleeve is pushed into the grouting consolidation body.

2. The method for sealing and grouting the bottom of the anchor rod and cable casing below the groundwater level according to claim 1 is characterized in that: In step (2), before installing the hole mouth anti-burst device, the periphery of the hole mouth of the hole position is roughened and leveled.

3. The method for sealing and grouting the bottom of the anchor rod and anchor cable casing below the groundwater level according to claim 1 is characterized in that: In step (3), the outer diameter of the outer casing is set to 60 mm to 200 mm, and the outer diameter of the inner drill rod is set to 50 mm to 114 mm.

4. The method for sealing and grouting the bottom of the anchor rod and cable casing below the groundwater level according to claim 1 is characterized in that: In step (3), the bentonite slurry is injected at normal pressure, wherein the bentonite slurry comprises the following components in parts by weight: 100 parts of water and 50 parts of bentonite.

5. The method for sealing and grouting the bottom of the anchor rod and anchor cable casing below the groundwater level according to claim 1 is characterized in that: In step (5), a drilling rig is used to deepen the inner drill rod hole by 1 to 5 meters before grouting. The grouting pipe is connected to the power head of the drilling rig to perform drill rod backward segmented grouting.

6. The method for sealing and grouting the bottom of the anchor rod and anchor cable casing below the groundwater level according to claim 5 is characterized in that: In step (5), the grouting pressure is set to 0.1-1.5 MPa, and the grouting slurry includes: cement slurry and water glass slurry in a volume ratio of 1:1-1:0.2, and the setting time of the grouting slurry is set to 3-10 minutes.

7. The method for sealing and grouting the bottom of the anchor rod and cable casing below the groundwater level according to claim 6 is characterized in that: In step (5), the cement slurry comprises water and cement in a weight ratio of 1:

1.

8. The method for sealing and grouting the bottom of anchor rod and cable casing below the groundwater level according to claim 1 is characterized in that: In step (6), after the slurry solidifies, wait for 30 to 120 minutes before removing the pressure-maintaining grouting device and the inner drill rod, and then push the boot sleeve into the grouting consolidation body through the inner drill rod.

9. The method for sealing and grouting the bottom of anchor rod and anchor cable casing below the groundwater level according to claim 1, characterized in that: In step (6), the boot cover includes a boot cover columnar body and a cone connected to the bottom of the columnar body. The outer diameter of the boot cover is set to 60 mm to 200 mm, and the length is set to 50 cm to 200 cm.

10. The method for sealing and grouting the bottom of the anchor rod and cable casing below the groundwater level according to claim 9, characterized in that: A barbed steel bar or steel pipe with a length of 50 to 100 cm is provided at the bottom of the cone of the boot cover. The diameter of the steel bar is set to 18 to 25 mm, and the diameter of the steel pipe is set to 20 to 50 mm.

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