Anti-floating anchor rod and construction technology of high-pressure jet grouting rear anti-floating anchor rod

Abstract

The anti-floating anchor rod comprises a rod body, a base plate and an anchorage device, the base plate and the anchorage device are arranged at the top of the rod body and matched with the rod body, and the anti-floating anchor rod further comprises a raft plate layer; the cable-stayed reinforcing steel bars are bidirectionally arranged and connected with the raft plate surface of the raft plate layer, and the cable-stayed reinforcing steel bars are arranged between the rod body and the base plate; the rod body is sleeved with the water stop ring, and the water stop ring is embedded in the bottom of the raft plate layer; the waterproof layer is arranged at the bottom of the raft plate layer. Compared with traditional independent foundation treatment or anti-floating design, under the conditions of high underground water level, poor geological conditions, limited site and budget limit, the construction technology is very beneficial to anchor rod construction of the gravelly clayed soil foundation, the hole collapse problem in the anchor rod construction process can be effectively solved, and the foundation bearing capacity is improved; and the cost can be effectively controlled, and better economic benefits can be created.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, in particular to an anti-floating anchor rod and a construction process of a high-pressure rotary grouting post-placed anti-floating anchor rod. Background Art

[0002] As an anti-floating measure, anti-floating anchor rods have strong anti-floating ability, flexible arrangement, easy construction, and are conducive to uniform stress on the bottom plate. At the same time, they have good stratum adaptability. They are often used in anti-floating design to resist the buoyancy of groundwater on buildings. Existing anti-floating anchor rods are inconvenient for anchor rod construction on gravel and clay foundations when the groundwater level is high, the geological conditions are poor, the site is limited, and the budget limit is limited. There are problems of hole collapse during the construction process, the bearing capacity of the foundation is poor, and the cost is increased. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the embodiment of the present invention provides a construction process of an anti-floating anchor rod and a high-pressure rotary grouting post-placed anti-floating anchor rod, which can effectively solve the hole collapse problem during the anchor rod construction process, improve the bearing capacity of the foundation, and effectively control the cost.

[0004] On the one hand, an embodiment of the present invention provides an anti-floating anchor rod, comprising a rod body and a pad and an anchor arranged on the top of the rod body and matched therewith, and further comprising: Raft layer; The inclined steel bars are bidirectionally arranged and connected to the raft surface of the raft layer, and the inclined steel bars are arranged between the rod body and the pad; A water stop ring, which is sleeved on the rod body and embedded in the bottom of the raft layer; A waterproof layer, arranged at the bottom of the raft layer; The cushion layer is arranged at the bottom of the waterproof layer; the structural design of the anti-floating anchor rod is concise and clear, the functions of each component are clear, and it is easy to install and debug during the construction process, which can improve the construction efficiency and reduce the construction cost.

[0005] According to some embodiments of the present invention, the waterproof layer includes, from bottom to top, a first waterproof coating, a second waterproof coating, a first waterproof roll, the second waterproof roll and a sealing layer in sequence; the diameters of the first waterproof coating, the second waterproof coating and the first waterproof roll are the same; the second waterproof roll includes a right-side second waterproof roll and a left-side second waterproof roll; the right-side second waterproof roll covers the upper surface of the first waterproof roll and extends to the right; the left-side second waterproof roll covers the upper surface of the first waterproof roll and extends to the right; the sealing layer covers the upper surfaces of the right-side second waterproof roll and the left-side second waterproof roll and fills the gap between the left and right second waterproof rolls; the sealing layer cooperates with the first waterproof coating, the second waterproof coating and the first waterproof roll to form a continuous and tight waterproof system; the waterproof materials at various levels from bottom to top work synergistically to significantly improve the sealing of the entire waterproof layer, which can better resist the penetration of moisture.

[0006] According to some embodiments of the present invention, the first waterproof coating comprises a cement-based penetrating crystalline waterproof coating; The second waterproof coating comprises a non-curing rubber asphalt waterproof coating; The first waterproof membrane comprises a self-adhesive polymer modified asphalt waterproof membrane; The second waterproofing coiled material comprises a reverse-adhesive polymer self-adhesive film waterproofing coiled material; The sealing layer includes asphalt waterproof paste, which can penetrate into the interior of the concrete, react chemically with the components in the concrete, generate water-insoluble crystals, block the capillary pores inside the concrete, and achieve deep waterproofing from the inside out.

[0007] According to some embodiments of the present invention, the rod body adopts prestressed threaded steel bars with strength ≥ SPB1080 grade. For high-strength steel bar materials, its strength exceeds SPB1080 grade steel bars and can provide greater tensile strength.

[0008] According to some embodiments of the present invention, the surface of the rod body is coated with an epoxy coating, and the thickness of the epoxy coating is ≥240 μm. The epoxy coating can effectively block groundwater, chemicals in the soil and other corrosive media from direct contact with the rod body, thereby preventing the rod body from rusting.

[0009] On the other hand, an embodiment of the present invention provides a construction process for high-pressure rotary grouting and post-installed anti-floating anchor rods, and the construction process steps include: S1. Equipment preparation: put the drilling rig in place, center it and stabilize it, make the vertical axis vertical, the vertical deviation is less than 1%, the hole position deviation is ±50mm, put the drill hole into the steel sleeve on the bottom plate, and start the drilling rig and high-pressure grouting pump; S2, rotary jet drilling: adjust the distance between the drilling rig injection hole and the high-pressure grouting pump to no more than 50m, control the grouting pressure, the rotary jetting footage speed is less than 200mm / min, the rotation rate is 15r / min~20r / min, the grouting pressure is reduced to 10MPa within 1m below the bottom plate, and spray once. After drilling each section of drill rod, reverse the drilling rig, disconnect the drill rod from the drilling rig, connect the long drill rod and continue drilling to a depth greater than 200mm~300mm. After the hole reaches the designed depth, drill steadily for 1min~2min; For S3 anchor installation, match the rod joint with the in-situ jet grouting drill joint, then rotate it into the hole. Stagger the rod straight thread sleeve and the rod joint. The total amount of rod joints allowed in the same connection section is less than 50%. When the top of each section of the rod is placed in the hole and there is still 100mm~200mm away from the raft surface, fix the rod, rotate the jet grouting drill in the opposite direction, disengage the rotator from the rod, extend the rod, and continue to rotate it into the hole.

[0010] According to some embodiments of the present invention, the specific steps of stabilizing the drilling rig after centering it and verticalizing the vertical axis with a vertical deviation of less than 1% include: Move the drilling rig to the intended location on the construction site; Precise alignment using spirit levels and measuring tools; After the alignment is completed, stabilize the drilling rig and use ground anchors and support equipment to firmly fix the drilling rig on the ground; Use a theodolite and plumb line to check the verticality of the vertical axis of the drilling rig, and make fine adjustments to keep the vertical axis in a vertical state. During the adjustment process, continuous measurements are taken to ensure that the vertical deviation is less than 1%.

[0011] According to some embodiments of the present invention, controlling the shotcrete pressure in step S2 specifically includes: Before controlling the shotcrete pressure, check whether the pressure gauge and valve components are normal; Be familiar with the geological conditions of the construction site and set the shotcrete pressure according to the geological conditions and design requirements; During the drilling process, the drilling depth is monitored in real time; When the borehole reaches 1m below the bottom plate, adjust the pressure output of the high-pressure grouting pump, and gradually reduce the shotcrete pressure from the normal pressure value to 10MPa. After the pressure is adjusted to 10MPa, immediately re-spray once, start the grouting pump, and spray the slurry into the soil around the borehole again at a pressure of 10MPa. When the borehole reaches 1m below the bottom plate, adjust the shotcrete pressure to 10MPa and re-spray. This can make the slurry be more fully sprayed in a specific area, thereby enhancing the reinforcement effect of the soil in that area. This helps to improve the stability of the entire anti-floating structure, reduce possible problems in the later stage, and reduce maintenance costs.

[0012] According to some embodiments of the present invention, the grouting material of the high-pressure grouting pump is cement mortar, which includes cement, sand, lime and water, wherein the water-cement ratio is 0.85:1~1:1. Within this water-cement ratio range, the cement can be fully hydrated to form sufficient cementitious material, so that the cement mortar has a higher strength, which is crucial for strengthening the soil, improving the bearing capacity of anti-floating anchors and ensuring the stability of the waterproof layer.

[0013] According to an embodiment of the present invention, the rod body diameter is 650mm, and the rod body joint is a 600mmx600mmx600mm concrete anchor head.

[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: The anti-floating anchor rod proposed in the present invention is used to treat clay foundation and increase the bearing capacity of the foundation; the high-pressure rotary grouting process is combined with the anti-floating anchor rod, and compared with the traditional independent foundation treatment or anti-floating design, it is very beneficial for the anchor rod construction of gravel clay foundation under the conditions of high groundwater level, poor geological conditions, limited site and budget limit. It can not only effectively solve the hole collapse problem in the anchor rod construction process and improve the bearing capacity of the foundation; it can also effectively control costs and create better economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the anti-floating anchor structure of the present invention; Figure 2 It is a schematic diagram of the waterproof layer structure of the present invention; Figure 3 The present invention is a construction process flow chart of the high-pressure rotary grouting post-mounted anti-floating anchor rod.

[0016] In the figure: 1. anchor; 2. water stop ring; 3. raft layer; 4. waterproof layer; 11. rod body; 6. pad; 7. inclined steel bar; 5. pad; 41. first waterproof coating; 42. second waterproof coating; 43. first waterproof membrane; 44. second waterproof membrane; 441. second waterproof membrane on the right; 442. second waterproof membrane on the left; 45. sealing layer. DETAILED DESCRIPTION

[0017] 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 described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1 and Figure 3 The embodiment of the present invention provides an anti-floating anchor rod, comprising a rod body 11 and a pad 6 and an anchor 1 arranged on the top of the rod body 11 and matched therewith, and also comprising: a raft layer 3, a diagonal steel bar 7, a water stop ring 2, and a cushion layer 5, wherein the diagonal steel bar is bidirectionally arranged and connected to the raft surface of the raft layer 3, and the diagonal steel bar is arranged between the rod body 11 and the pad 6; the water stop ring 2 is sleeved on the rod body 11 and embedded in the bottom of the raft layer 3; the waterproof layer 4 is arranged at the bottom of the raft layer 3; the cushion layer 5 is arranged at the bottom of the waterproof layer 4; the bidirectionally arranged diagonal steel bars connect the raft layer The raft surface, located between the rod body and the pad, can effectively disperse the uplift force borne by the anti-floating anchor to a larger area, which can reduce the local stress concentration of the rod body and prevent the rod body from being damaged due to excessive force, thereby enhancing the stability of the entire anti-floating structure. As a part of the foundation structure, the raft layer has a large area and rigidity. It can evenly transfer the force of the anti-floating anchor to the foundation and reduce the risk of uneven settlement. At the same time, the raft layer can also provide a stable connection point for the inclined steel bars, further enhancing the integrity of the structure.

[0019] Specifically, the waterproof layer is located at the bottom of the raft layer, which can effectively prevent groundwater from penetrating upwards and protect the raft layer and the interior of the building from water damage. Different types of waterproof layer materials can be selected according to specific engineering requirements to ensure the best waterproof effect. The water stop ring is arranged on the rod body and embedded in the bottom of the raft layer, which can effectively prevent groundwater from penetrating through the junction of the rod body and the raft layer. The sealing of the water stop ring can prevent the invasion of moisture, thereby improving the waterproof performance of the entire anti-floating structure. The cushion layer is arranged at the bottom of the waterproof layer. On the one hand, it can provide a flat base layer for the waterproof layer to ensure the laying quality of the waterproof layer; on the other hand, the cushion layer can also play a buffering role, reduce the pressure of the superstructure on the waterproof layer, and protect the waterproof layer from damage. The structural design of this anti-floating anchor can provide all-round protection for the foundation structure, from preventing damage by upward pull-out force to waterproofing and moisture-proofing, and then to protecting the foundation structure from external damage. The various components work together to ensure the safety and stability of the building. The structural design of this anti-floating anchor rod is simple and clear, and the functions of each component are clear. During the construction process, it is easy to install and debug, which can improve construction efficiency and reduce construction costs. If problems arise during the use of the building, this structure is also easy to maintain and repair. If the waterproof layer is damaged, it can be repaired or replaced more conveniently without causing too much impact on the entire anti-floating structure.

[0020] In some embodiments, the waterproof layer includes, from bottom to top, a first waterproof coating 41, a second waterproof coating 42, a first waterproof roll 43, a second waterproof roll 44 and a sealing layer 45. The diameters of the first waterproof coating 41, the second waterproof coating 42 and the first waterproof roll 43 are the same. The second waterproof roll 44 includes a right-side second waterproof roll 441 and a left-side second waterproof roll 442. The right-side second waterproof roll 441 covers the upper surface of the first waterproof roll 43 and extends to the right side. The left-side second waterproof roll 441 covers the upper surface of the first waterproof roll 43 and extends to the right side. The sealing layer 45 covers the upper surfaces of the right-side second waterproof roll 441 and the left-side second waterproof roll 442 and fills the gap between the left and right second waterproof rolls 441 and 442.

[0021] In some embodiments, the first waterproof coating 41 includes a cement-based permeable crystalline waterproof coating, and the diameter of the coverage surface is 900 mm; the second waterproof coating 42 includes a non-curing rubber asphalt waterproof coating, which covers the upper surface of the first waterproof coating 41; the first waterproof roll 43 includes a self-adhesive polymer modified asphalt waterproof roll, which covers the upper surface of the second waterproof coating 42; the second waterproof roll 44 includes a reverse-adhesive polymer self-adhesive film waterproof roll, and its thickness is 1.5 mm; the sealing layer 45 includes asphalt waterproof paste, and its coverage surface diameter is 600 mm. The use of the above-mentioned layers of materials for the waterproof layer and the planning of the coverage surface can ensure the adhesion and stability of the waterproof layer, and further improve the waterproof performance and stability of the anchor rod.

[0022] In some embodiments, the rod body 11 is made of prestressed threaded steel bars with a strength ≥ SPB1080, the material of the anti-floating anchor rod is high-strength steel bar material, and the material of the anti-floating anchor rod also includes 42CrMo4 steel.

[0023] With regard to the high-strength steel bar material in this application, its strength exceeds that of SPB1080 grade steel bars, and it can provide greater tensile strength, effectively resisting the upward pull of the building caused by the buoyancy of groundwater, and ensuring the stability and safety of the building under complex geological conditions and high water level environments.

[0024] In order to improve the anti-oxidation ability of the rod body 11 , in some embodiments, the surface of the rod body 11 is coated with an epoxy coating, and the thickness of the epoxy coating is ≥240 μm.

[0025] A construction process of a high-pressure rotary grouting post-mounted anti-floating anchor, the construction process steps comprising: S1. Equipment preparation: put the drilling rig in place, center it and stabilize it, make the vertical axis vertical, the vertical deviation is less than 1%, the hole position deviation is ±50mm, put the drill hole into the steel sleeve on the bottom plate, and start the drilling rig and high-pressure grouting pump; S2, rotary jet drilling: adjust the distance between the drilling rig injection hole and the high-pressure grouting pump to no more than 50m, control the grouting pressure, the rotary jetting footage speed is less than 200mm / min, the rotation rate is 15r / min~20r / min, the grouting pressure is reduced to 10MPa within 1m below the bottom plate, and spray once. After drilling each section of drill rod, reverse the drilling rig, disconnect the drill rod from the drilling rig, connect the long drill rod and continue drilling to a depth greater than 200mm~300mm. After the hole reaches the designed depth, drill steadily for 1min~2min; S3 anchor installation, after the rod body joint is matched with the in-situ jet grouting drill joint, rotate it into the hole, stagger the rod body straight thread sleeve and the rod body joint, the total amount of rod body joints allowed in the same connection section is less than 50%, when the top of each section of the rod body is placed in the hole and there is 100mm~200mm left from the raft surface, fix the rod body 11, rotate the jet grouting drill in the opposite direction, disengage the rotator from the rod body 11, extend the rod body 11 and continue to rotate it into the hole.

[0026] In step S1 of the present application, the drilling rig is positioned, centered and stabilized to ensure that the vertical axis is vertical and the deviation is less than 1%, and the hole position deviation is controlled within ±50mm, which can ensure the accuracy of the drilling, make the subsequent anchor installation more accurate, and improve the stability of the entire anti-floating anchor system. Strictly controlling the rotary jetting footage speed and rotation rate is helpful to form a uniform and regular borehole, providing a good installation environment for the anchor. Accurate control of the shotcrete pressure, especially adjusting the pressure and re-spraying within 1m below the bottom plate, can ensure the reinforcement effect of the key area. Steady drilling for 1-2 minutes can make the bottom of the borehole more stable, avoid collapse problems, and improve the quality of the borehole. In step S3, the straight thread sleeve connection of the anchor steel bar requires that the joints are staggered and the total amount of steel bar joints in the same connection section is less than 50%, which can effectively disperse the stress and improve the overall strength and reliability of the anchor. The precise installation method and the meticulous treatment of the anchor extension ensure the continuity and integrity of the anchor and enhance the anchoring performance of the anti-floating anchor.

[0027] Furthermore, the drilling rig is positioned and centered, and then stabilized, and the vertical axis is vertical, and the specific steps of vertical deviation is less than 1% include: Move the drilling rig to the intended location on the construction site; Precise alignment using spirit levels and measuring tools; After the alignment is completed, stabilize the drilling rig and use ground anchors and support equipment to firmly fix the drilling rig on the ground; Use a theodolite and plumb line to check the verticality of the vertical axis of the drilling rig, and make fine adjustments to keep the vertical axis in a vertical state. During the adjustment process, continuous measurements are taken to ensure that the vertical deviation is less than 1%.

[0028] The down-the-hole drill rig of the present application has a powerful drilling capability and can quickly perform drilling operations in the soil. Compared with other types of drilling rigs, the down-the-hole drill rig can complete the drilling task in a shorter time, greatly improving the construction efficiency. The high-pressure rotary jet technology can quickly inject cement mortar into the soil to form a concrete wall. This construction method can be carried out continuously, reducing pauses and waiting time during construction, and further speeding up the progress of the project.

[0029] Furthermore, in step 2, the grouting process of the jet-jet drilling hole adopts single-weight tube grouting, and the slurry pressure is 20MPa-45MPa.

[0030] Further, controlling the shotcrete pressure in step S2 specifically includes: Before controlling the shotcrete pressure, check whether the pressure gauge and valve components are normal; Be familiar with the geological conditions of the construction site and set the shotcrete pressure according to the geological conditions and design requirements; During the drilling process, the drilling depth is monitored in real time; When the borehole reaches 1m below the bottom plate, adjust the pressure output of the high-pressure grouting pump, and gradually reduce the shotcrete pressure from the normal pressure value to 10MPa. After the pressure is adjusted to 10MPa, immediately carry out a re-spraying, start the grouting pump, and spray the slurry into the soil around the borehole again at a pressure of 10MPa.

[0031] After the first grouting of this application, there may be some tiny gaps in the soil that have not been completely filled with slurry. During the re-spraying, under a pressure of 10MPa, the slurry can be forcefully squeezed into these gaps again, further improving the density of the slurry in the soil. The dense slurry filling can reduce the porosity in the soil, enhance the integrity and bearing capacity of the soil, and effectively resist the uplift effect of the buoyancy of groundwater on the building. Higher density can also reduce the permeability of the soil, prevent groundwater from flowing in the soil and weaken the anchoring effect of the anti-floating anchor, which is crucial for buildings that are in an environment with high groundwater levels for a long time, and can extend the service life of the anti-floating anchor system.

[0032] The grouting material of the high-pressure grouting pump is cement mortar, which includes cement, sand, lime and water, wherein the water-cement ratio is 0.85:1~1:1.

[0033] The rod body 11 has a diameter of 650 mm, and the rod body joint adopts a 600 mm x 600 mm x 600 mm concrete anchor head.

[0034] The grouting material of the present application is cement mortar, which can be tightly combined with the surrounding soil after grouting to form a strong anchoring force. This anchoring force can effectively resist the buoyancy of groundwater and ensure the stability of the building. The rotary spraying anchor consolidator is used for consolidation treatment, and its strength is greater than that of 43 grade ordinary Portland cement, which further enhances the bonding strength between the anchor and the soil and improves the anchoring effect. The rotary spraying process can make the consolidating agent evenly distributed around the anchor, fill the soil gaps, increase the contact area between the anchor and the soil, and thus improve the anchoring force.

[0035] The embodiments of the present invention have been subjected to feasibility design research and experimental testing according to the following specific scenarios: Specific scenarios ① The construction area of ​​the project site is extremely limited, and it is located in a densely populated office and study area in the city center, so it is necessary to avoid the nuisance caused by construction; ② The cost of traditional cast-in-place piles is far beyond the estimated cost; ③ The gravel viscous layer collapses when exposed to water, which has an adverse effect on the bearing capacity of the foundation; Based on the above restrictions, through multi-scheme design research and experimental testing, the details are shown in Table 1 below: Table 1 The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. An anti-floating anchor rod, comprising a rod body (11) and a pad (6) and an anchor (1) arranged on the top of the rod body (11) and matched therewith, characterized in that: Also includes: Raft layer (3); Diagonal steel bars (7), the diagonal steel bars are bidirectionally arranged and connected to the raft surface of the raft layer (3), and the diagonal steel bars are provided between the rod body (11) and the pad (6); A water stop ring (2), the water stop ring (2) being sleeved on the rod body (11) and embedded in the bottom of the raft layer (3); A waterproof layer (4) is arranged at the bottom of the raft layer (3); A cushion layer (5) is arranged at the bottom of the waterproof layer (4).

2. The anti-floating anchor rod according to claim 1, characterized in that: The waterproof layer comprises, from bottom to top, a first waterproof coating (41), a second waterproof coating (42), a first waterproof roll (43), the second waterproof roll (44) and a sealing layer (45); the first waterproof coating (41), the second waterproof coating (42) and the first waterproof roll (43) have the same diameter; the second waterproof roll (44) comprises a right second waterproof roll (441) and a left second waterproof roll (442); the right second waterproof roll (441) covers the upper surface of the first waterproof roll (43) and extends to the right; the left second waterproof roll (441) covers the upper surface of the first waterproof roll (43) and extends to the right; the sealing layer (45) covers the upper surfaces of the right second waterproof roll (441) and the left second waterproof roll (442) and fills the gap between the left and right second waterproof rolls (441, 442).

3. The anti-floating anchor rod according to claim 2, characterized in that: The first waterproof coating (41) comprises a cement-based permeable crystalline waterproof coating; The second waterproof coating (42) comprises a non-curing rubber asphalt waterproof coating; The first waterproofing membrane (43) comprises a self-adhesive polymer modified asphalt waterproofing membrane; The second waterproofing coiled material (44) comprises a reverse-adhesive polymer self-adhesive film waterproofing coiled material; The sealing layer (45) comprises asphalt waterproofing paste.

4. The anti-floating anchor rod according to claim 1, characterized in that: The rod body (11) is made of prestressed threaded steel bars with a strength ≥ SPB1080.

5. The anti-floating anchor rod according to claim 1, characterized in that: The surface of the rod body (11) is coated with an epoxy coating, and the thickness of the epoxy coating is ≥240 μm.

6. A construction process for high-pressure rotary grouting and post-installed anti-floating anchor rods, characterized in that: The construction process steps include: S1. Equipment preparation: put the drilling rig in place, center it and stabilize it, make the vertical axis vertical, the vertical deviation is less than 1%, the hole position deviation is ±50mm, put the drill hole into the steel sleeve on the bottom plate, and start the drilling rig and high-pressure grouting pump; S2, rotary jet drilling: adjust the distance between the drilling rig injection hole and the high-pressure grouting pump to no more than 50m, control the grouting pressure, the rotary jetting footage speed is less than 200mm / min, the rotation rate is 15r / min~20r / min, the grouting pressure is reduced to 10MPa within 1m below the bottom plate, and spray once. After drilling each section of drill rod, reverse the drilling rig, disconnect the drill rod from the drilling rig, connect the long drill rod and continue drilling to a depth greater than 200mm~300mm. After the hole reaches the designed depth, drill steadily for 1min~2min; The S3 anchor rod is installed by matching the rod body joint with the in-situ jet grouting drill joint and rotating it into the hole. The rod body straight thread sleeve and the rod body joint are staggered. The total amount of rod body joints in the same connection section is allowed to be less than 50%. When the top of each section of the rod body is placed in the hole and there is 100 mm to 200 mm left from the raft surface, the rod body (11) is fixed, the jet grouting drill rotates in the reverse direction, the rotator is separated from the rod body (11), and the rod body (11) is extended and then rotated and placed into the hole.

7. The construction process of a high-pressure rotary grouting post-mounted anti-floating anchor according to claim 6 is characterized in that: The specific steps of stabilizing the drilling rig after centering it and verticalizing the vertical axis with a vertical deviation of less than 1% include: Move the drilling rig to the intended location on the construction site; Precise alignment using spirit levels and measuring tools; After the alignment is completed, stabilize the drilling rig and use ground anchors and support equipment to firmly fix the drilling rig on the ground; Use a theodolite and plumb line to check the verticality of the vertical axis of the drilling rig, and make fine adjustments to keep the vertical axis in a vertical state. During the adjustment process, continuous measurements are taken to ensure that the vertical deviation is less than 1%.

8. The construction process of a high-pressure rotary grouting post-mounted anti-floating anchor according to claim 7 is characterized in that: Controlling the shotcrete pressure in step S2 specifically includes: Before controlling the shotcrete pressure, check whether the pressure gauge and valve components are normal; Be familiar with the geological conditions of the construction site and set the shotcrete pressure according to the geological conditions and design requirements; During the drilling process, the drilling depth is monitored in real time; When the borehole reaches 1m below the bottom plate, adjust the pressure output of the high-pressure grouting pump, and gradually reduce the shotcrete pressure from the normal pressure value to 10MPa. After the pressure is adjusted to 10MPa, immediately re-spray once, start the grouting pump, and spray the slurry into the soil around the borehole again at a pressure of 10MPa.

9. The construction process of a high-pressure rotary grouting post-mounted anti-floating anchor according to claim 6 is characterized by: The grouting material of the high-pressure grouting pump is cement mortar, which includes cement, sand, lime and water, wherein the water-cement ratio is 0.85:1~1:

1.

10. The construction process of a high-pressure rotary grouting post-mounted anti-floating anchor according to claim 6, characterized in that: The rod body (11) has a diameter of 650 mm, and the rod body joint adopts a 600 mm x 600 mm x 600 mm concrete anchor head.

Images