High-pressure jet grouting pile construction process and tunnel engineering structure

Abstract

The invention discloses a high-pressure jet grouting pile construction process and a tunnel engineering structure, and the high-pressure jet grouting pile construction process comprises the following steps: S1, measuring and positioning: obtaining a jet grouting pile hole position according to a control pile and a design drawing; s2, drilling holes; s3, pipe insertion and trial spraying are carried out, and construction technical parameters and grouting materials are determined; s4, high-pressure rotary jet grouting is conducted, and pipe descending, grout jetting, rotary swing lifting and waste grout treatment are included; s5, grouting is completed, and a machine tool is cleaned; and S6, transferring to a next hole site, and repeating the steps S1 to S5. According to the construction technology, multiple construction steps are arranged, so that high-pressure jet grouting pile construction is more normalized and standardized, the comprehensiveness and completeness of high-pressure jet grouting pile construction are effectively guaranteed, and the high-pressure jet grouting pile construction efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel shield construction, in particular to a high-pressure rotary jet grouting pile construction process. In addition, the present invention also relates to a tunnel engineering structure including the high-pressure rotary jet grouting pile construction process. Background Art

[0002] In the prior art, subway construction in various places adopts shield construction on a large scale. The shield starts from the working shaft and enters the tunnel stratum or is pushed out from the end of the tunnel to enter the working shaft. When the stratum around the shield working shaft is loose sand or saturated water-containing clay with poor self-stabilization ability and strong permeability, if it is not reinforced, a large amount of soil and groundwater will inevitably collapse into the working shaft behind the working shaft enclosure structure, causing a large area of ​​surface subsidence around the tunnel, endangering underground pipelines and nearby buildings. Therefore, before the shield machine enters and exits the tunnel, the stratum at the tunnel entrance must be reinforced, that is, the end reinforcement. End reinforcement is an important part of the shield starting and arrival technology. The success or failure of end reinforcement directly affects whether the shield can start and arrive safely. The start and arrival of the shield are the most prone to accidents, and the failure of end reinforcement is the main reason for the frequent accidents.

[0003] As the mileage of shield tunnels continues to increase, cases of failure of shield engineering end reinforcement occur from time to time. Therefore, strengthening the control of end reinforcement construction is an important link to ensure the smooth construction of shield. The existing relatively mature construction technology for shield departure and arrival mainly uses cement reinforcement in the form of a combination of three-axis mixing piles and high-pressure rotary jet piles. However, the existing high-pressure rotary jet pile construction is relatively simple, and the construction process of high-pressure rotary jet piles lacks comprehensive and complete construction steps, which affects the construction efficiency of high-pressure rotary jet piles. Summary of the invention

[0004] The invention provides a high-pressure rotary jet grouting pile construction process and a tunnel engineering structure to solve the technical problem that the existing high-pressure rotary jet grouting pile construction process is imperfect and affects the construction efficiency.

[0005] According to one aspect of the present invention, a high-pressure jet grouting pile construction process is provided, which is applied to tunnel shield construction, comprising:

[0006] S1. Measure and locate, and obtain the location of the jet grouting pile according to the control pile and design drawing;

[0007] S2. Drilling;

[0008] S3. Insert pipes and test spray to determine construction technical parameters and grouting materials;

[0009] S4. High-pressure rotary grouting, including pipe lowering, slurry injection, rotary swing lifting and waste slurry treatment;

[0010] S5. Complete grouting and clean the equipment;

[0011] S6. Move to the next hole and repeat steps S1 to S5.

[0012] As a further improvement of the above technical solution, step S1 includes:

[0013] S11. Measure and lay out the construction axis according to the designed construction drawings and coordinate points;

[0014] S12. Determine the hole position. Determine the hole position on the construction axis, assign the pile number, hole number and serial number, and measure the ground elevation of each hole opening based on the reference point.

[0015] As a further improvement of the above technical solution, step S2 includes:

[0016] S21. Check the straightening and deviation correction. Use a plumb bob to check from two vertical directions. If deviation is found, add an adjustment block under the machine base for adjustment.

[0017] S22. Drill holes according to the determined pile positions, control the plane position deviation, and use original soil slurry to protect the wall;

[0018] S23. Measure the hole depth and the length of the drill pipe and drilling tools when the hole is completed.

[0019] As a further improvement of the above technical solution, step S22 includes: aligning the main drill rod of the drilling rig with the hole position, measuring the horizontality of the machine body and the verticality of the vertical axis with a spirit level, and ensuring that the drilling rig pad is stable and firm; the borehole diameter should be 20 to 50 mm larger than the outer diameter of the injection pipe, and slurry should not be emitted; measuring the horizontality of the machine body and the verticality of the vertical axis with a spirit level once every 5 m of drilling; paying attention to stratum changes during drilling, and making detailed records of hole depth, hole collapse, and slurry leakage; when the construction site survey data is unknown, arranging a pilot hole every 20 m to check the stratum changes at the final hole; the final hole depth of the drilling should be 0.5 to 1.0 m greater than the injection depth; when the hole depth is less than 30 m, the hole slope is not greater than 1%.

[0020] As a further improvement of the above technical solution, step S3 includes: measuring the length of the injection pipe, measuring whether the center line of the nozzle is consistent with the direction arrow of the injection pipe, adjusting the test spray to the designed injection pressure, conducting ground water, air, and slurry test sprays, and the designed injection pressure + pipeline pressure is the standard injection pressure for construction; if the nozzle is replaced, re-debugging is performed.

[0021] As a further improvement of the above technical solution, step S4 also includes: during the rotary jetting process, slurry is sprayed first and then rotated and lifted; during the grouting process, if the slurry supply or gas supply is stopped, the nozzle is sunk to a preset height below the stop point, and then lifted after the supply is resumed; it is lifted to a preset depth position below the designed pile top at a first preset speed, and lifted to the designed elevation at a second preset speed; after the spraying operation is completed, the slurry that emerges is re-injected into the hole until it stops sinking.

[0022] As a further improvement of the above technical solution, before step S4, the high-pressure jet grouting pile construction process includes: setting up slurry drainage ditches and mud pools; checking high-pressure equipment and pipeline systems; recording hole positions, hole depths, underground obstacles corresponding to the hole positions, and grouting volumes.

[0023] As a further improvement of the above technical solution, step S4 also includes: when the spraying pipe is disassembled during the spraying process, it should be dropped and overlapped for re-spraying, and the overlap length should be not less than 0.2m; when the spraying process is interrupted and the spraying is resumed, re-spraying is carried out, and the overlap length is not less than 0.5m; when the spraying is interrupted for more than the initial setting time of the slurry, the hole is swept, and when the spraying is resumed, the overlap length of the re-spraying is not less than 1m.

[0024] As a further improvement of the above technical solution, step S4 also includes: filling and re-injection. After the high-pressure jet grouting of each hole is completed, grout is filled into the hole until it is full and the grout surface at the hole mouth no longer sinks.

[0025] According to another aspect of the present invention, there is also provided a tunnel engineering structure, which includes the above-mentioned high-pressure jet grouting pile construction process.

[0026] The present invention has the following beneficial effects:

[0027] After the drilling position is determined according to the control pile and the design drawing, the drilling rig is put in place and calibrated to ensure the verticality of the drill rod axis and the center of the hole. The final hole inspection is carried out to ensure the quality of the drilling. A trial spraying is carried out before the high-pressure jet trolley rotary spraying operation to debug and determine the construction technical parameters. The high-pressure rotary spray grouting can be carried out according to the construction parameters determined by the debugging. The rotary spray grouting is carried out from bottom to top, and the waste slurry is processed. After the grouting is completed, the machinery is cleaned to prevent clogging by the solidified slurry and affect the subsequent construction. Through the setting of multiple construction steps of this process, the construction of high-pressure rotary spray piles is more standardized and standardized, which effectively ensures the comprehensiveness and perfection of the construction of high-pressure rotary spray piles and effectively improves the construction efficiency of high-pressure rotary spray piles.

[0028] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 It is a process flow chart of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0032] Figure 1 It is a process flow chart of a preferred embodiment of the present invention.

[0033] like Figure 1 As shown, the high-pressure jet grouting pile construction process of this embodiment is applied to tunnel shield construction, including:

[0034] S1. Measure and locate, and accurately place the jet grouting pile holes according to the control piles and design drawings;

[0035] S2. Drilling: The drilling rig is in place and moved according to the on-site layout to align the drill rod head with the center of the hole. To ensure that the drilling rig reaches the verticality required by the design, the drilling rig must be horizontally corrected after it is in place to align the axis of the drill rod vertically with the center of the hole to ensure that the verticality of the hole does not exceed 1%;

[0036] S3. Insert pipes and test spray to determine construction technical parameters and grouting materials; grouting materials are mainly cement and water, and a small amount of admixtures are added when necessary; the type and grade of cement used for high-pressure jet grouting should be determined according to the environment and project needs. Under normal circumstances, ordinary Portland cement should be used, and its strength grade should not be lower than 42.5. When using other cement for grouting, design permission should be obtained; the cement used for grouting should comply with the provisions of "Portland Cement, Ordinary Portland Cement" GB 175-2007. The cement used for high-pressure jet grouting must meet the quality standards, should be strictly moisture-proof and have a shorter storage time. Sampling inspections should be carried out during construction, and expired and damp and agglomerated cement should not be used. High-pressure jet grouting generally uses pure cement slurry. According to needs and design requirements, admixtures such as fine sand, fly ash, early strength agent, accelerator, water glass, etc. can be added to the cement slurry.

[0037] S4. High-pressure rotary grouting, including pipe lowering, slurry injection, rotary swing lifting and waste slurry treatment;

[0038] S5. Complete grouting and clean the equipment;

[0039] S6. Move to the next hole and repeat steps S1 to S5.

[0040] It can be understood that after this construction process determines the drilling position based on the control piles and design drawings, the drilling rig is in place and calibrated to ensure the verticality of the drill rod axis and the center of the hole, the final hole inspection is carried out to ensure the quality of the drilling, and a trial spraying is carried out before the high-pressure jet trolley rotary spraying operation to debug and determine the construction technical parameters. The high-pressure rotary spray grouting can be carried out according to the construction parameters determined by the debugging. The rotary spray grouting is carried out from bottom to top, and the waste slurry is processed. After the grouting is completed, the machinery is cleaned to prevent clogging by the solidified slurry and affect the subsequent construction. Through the setting of multiple construction steps of this process, the comprehensiveness and perfection of the high-pressure rotary spray pile construction are effectively guaranteed, and the construction efficiency of the high-pressure rotary spray pile is effectively improved.

[0041] Specifically, step S1 includes:

[0042] S11. Measure and lay out the construction axis according to the designed construction drawings and coordinate points;

[0043] S12. Determine the hole position. Determine the hole position on the construction axis, assign the pile number, hole number and serial number, and measure the ground elevation of each hole opening based on the reference point.

[0044] Specifically, step S2 includes:

[0045] S21. Check the straightening and deviation correction. Use a plumb bob to check from two vertical directions (at a height of not less than 2 meters) to ensure that the verticality does not exceed 1%. If deflection is found, add adjustment blocks under the machine base for adjustment. Thin wooden blocks can be used for adjustment.

[0046] S22. Drill holes according to the determined pile positions, control the plane position deviation, and use original soil slurry to protect the wall; for example, if the hole diameter is φ125mm, drill holes strictly according to the determined pile positions, and the plane position deviation shall not exceed 50mm;

[0047] S23. Measure the hole depth and the length of the drill pipe and drill tools when the hole is completed. Measure the length of the drill pipe and drill tools when the hole is completed.

[0048] Specifically, step S22 includes: aligning the main drill rod of the drilling rig with the hole position, measuring the horizontality of the machine body and the verticality of the vertical axis with a spirit level, and ensuring that the drilling rig pad is stable and firm; the borehole diameter should be 20-50mm larger than the outer diameter of the injection pipe, and slurry should not be emitted; measuring the horizontality of the machine body and the verticality of the vertical axis with a spirit level once every 5m of drilling; paying attention to stratum changes during the drilling process, and making detailed records of hole depth, hole collapse, and slurry leakage; when the construction site survey data is unclear, arrange a pilot hole every 20m to check the stratum changes at the final hole; the final hole depth of the drilling should be 0.5-1.0m greater than the injection depth; when the hole depth is less than 30m, the hole slope is not greater than 1%; the drilling record should be filled out clearly and neatly, and handed over to the technical team on the same day after being signed by the supervisor, quality inspector, and construction worker. High-pressure jet grouting can only be carried out after the drilling is accepted.

[0049] Preferably, step S3 includes: measuring the length of the injection pipe, measuring whether the center line of the nozzle is consistent with the direction arrow of the injection pipe, marking the scale on the injection pipe, placing the nozzle near the high-pressure water pump, the pressure test pipeline should be less than 20m, the test spray is adjusted to the design injection pressure, and the ground water, air, and slurry test spray is carried out. The design injection pressure + pipeline pressure is the standard injection pressure for construction; it should be noted that if the nozzle is replaced during construction, it should be re-debugged.

[0050] In this embodiment, before step S4, the high-pressure jet grouting pile construction process includes:

[0051] Set up drainage trenches and mud pools; specifically, during the construction process, the waste slurry will be introduced or discharged into the mud pool, and after sedimentation and condensation, it will be transported to the outside for storage or disposal; during the jet grouting construction, a lot of waste slurry will be generated. In order to ensure the cleanliness of the site and smooth construction, a mud pool is planned to be set up on the site before construction. The mud will be pumped into the mud pool during construction and transported out for treatment after the mud solidifies;

[0052] Check the high-pressure equipment and piping system; Specifically, check the high-pressure equipment and piping system before jet grouting. The pressure and flow rate must meet the design requirements. There must be no debris in the grouting pipe and nozzle, and the sealing ring of the grouting pipe joint must be in good condition.

[0053] Record the hole location, hole depth, underground obstacles corresponding to the hole location, and grouting volume;

[0054] When preparing cement slurry, the water-cement ratio must comply with the design requirements and must not be changed at will. During the spraying process, the cement slurry should be prevented from settling to reduce the concentration. The mixing time after each feeding must not be less than 3 minutes. Before grouting, pour the slurry into the collection hopper. The cement slurry should be used as soon as it is mixed.

[0055] In this embodiment, step S4 also includes: when the grouting pipe penetrates the soil and the nozzle reaches the design elevation, the grouting can be sprayed according to the determined construction parameters; when spraying, the predetermined spraying pressure should be reached first, and then the grouting pipe should be gradually lifted after the volume is normal, and the grouting should be rotary sprayed from bottom to top; during the rotary spraying process, the grouting is first sprayed and then rotated and lifted to prevent the slurry pipe from twisting off; when abnormal conditions such as sudden drop, rise or large amount of slurry appear during the high-pressure jet grouting process, the cause should be found out and timely measures should be taken; during the grouting process, if the slurry supply or gas supply is stopped, the nozzle will be sunk to a preset height below the stop point (preferably 0.3m), and then lifted after resupply; it will be lifted to a preset depth position (for example 1m) below the designed pile top at a first preset speed, and lifted to the designed elevation at a second preset speed, wherein the first preset speed is greater than the second preset speed, that is, the lifting speed is slowed down when lifting to the end; after the spraying operation is completed, the slurry that has emerged is re-injected into the hole until it stops sinking.

[0056] In this embodiment, the construction process also includes: the rotation speed and mixing capacity of the mixer should be adapted to the type of slurry being mixed and the discharge volume of the grouting pump, respectively, and should be able to ensure uniform and continuous mixing of the slurry, ensure continuous supply of slurry for high-pressure jet grouting, mix cement slurry according to the designed water-cement ratio, and the mixing time of the cement slurry should be no less than 60 seconds when using a high-speed mixer; and no less than 180 seconds when using an ordinary mixer; the mixing and storage time of pure cement slurry should be less than 2.5 hours from preparation to use; the slurry should be used after screening, and its density should be tested regularly; the slurry material can be weighed by mass or volume measurement, and the error should not be greater than 5%; heat protection measures should be taken during construction, and the slurry temperature should be maintained at 5-40°C.

[0057] In this embodiment, in step S4, when jet grouting is performed, the operation is continuous from bottom to top, and the nozzle is a double nozzle. When the grouting pipe is lowered to the designed depth and the nozzle reaches the designed elevation, the grouting can be jetted; the gas and slurry that meet the design requirements are fed into the spraying, and after the slurry returns to the orifice normally, the swing lifting is started; if a sudden drop or surge in pressure occurs during the high-pressure jet grouting process, the cause must be found out and handled in time; when the jet pipe is disassembled during the spraying process, it should be dropped, overlapped and sprayed again, and the overlap length should be not less than 0.2m; the injection process is interrupted and the injection is stopped. When resuming spraying, re-spraying shall be carried out with an overlap length of not less than 0.5m; if the spraying interruption exceeds the initial setting time of the slurry, the hole shall be swept, and when resuming spraying, the overlap length of the re-spraying shall be not less than 1m; if there is slurry leakage in the hole during the spraying process, stop lifting until there is no leakage, and then continue lifting; if there is serious slurry leakage in the hole during the spraying process, stop spraying, remove the spraying pipe, and take plugging measures; for grouting holes with special requirements, re-spraying can be used to increase the spraying length and intensity. During the spraying process, record the entire construction time of each high-pressure jet grouting hole;

[0058] It should be noted that the amount of grouting from the orifice of high-pressure jet grouting can reflect the grouting effect of the jet-cut stratum; whether the grouting from the orifice can be recycled depends on the engineering design and the quality of the grouting. The return grout should be used as much as possible in the construction project.

[0059] It is understandable that the solidified body can be formed into the shape required by the design by high-pressure jet grouting, such as a cylindrical shape by rotary grouting;

[0060] In this embodiment, step S4 also includes: filling and recharging. After the high-pressure jet grouting of each hole is completed, the cement slurry in the hole will soon produce water precipitation, and the hole is filled with grout in time until it is full and the slurry surface at the hole mouth no longer sinks. It should be understood that after the final spraying, filling and grouting is a very important process. The quality of recharging will directly affect the quality of the project, and it is necessary to focus on completing the filling and recharging work. Specifically, during filling and recharging, the grouting pipe is inserted 2m below the slurry surface in the hole, and the slurry used for grouting is input for filling and grouting; filling and grouting need to be repeated many times, and the full hole mouth and the slurry surface at the hole mouth no longer sinking are used as the recharging standard; in addition, when there are high strength requirements for the high-pressure jet grouting solid, it is strictly forbidden to use slurry and recharging for filling and recharging. When there are only anti-seepage requirements for the high-pressure jet grouting solid, slurry and recharging can be used for filling and recharging; record the recharging time, number of times, grouting amount, cement dosage and recharging quality.

[0061] In step S5, after the high-pressure jet grouting is completed, the grouting pipe should be quickly pulled out to thoroughly clean the slurry pipe and grouting pump, and the equipment should be flushed to prevent clogging by solidified slurry. After the high-pressure jet grouting of each hole is completed, the grouting pump and slurry pipeline should be cleaned in time to prevent the slurry from settling and agglomerating in the slurry pipeline due to untimely and incomplete cleaning, thereby blocking the slurry pipeline and nozzle and affecting the construction of the next hole.

[0062] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0063] 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.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-pressure jet grouting pile construction process, applied to tunnel shield construction, characterized in that: include: S1. Measure and locate, and obtain the location of the jet grouting pile according to the control pile and design drawing; S2. Drilling; S3. Insert pipes and test spray to determine construction technical parameters and grouting materials; S4. High-pressure rotary grouting, including pipe lowering, slurry injection, rotary swing lifting and waste slurry treatment; S5. Complete grouting and clean the equipment; S6. Move to the next hole and repeat steps S1 to S5.

2. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Step S1 includes: S11. Measure and lay out the construction axis according to the designed construction drawings and coordinate points; S12. Determine the hole position. Determine the hole position on the construction axis, assign the pile number, hole number and serial number, and measure the ground elevation of each hole opening based on the reference point.

3. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Step S2 includes: S21. Check the straightening and deviation correction. Use a plumb bob to check from two vertical directions. If deviation is found, add an adjustment block under the machine base for adjustment. S22. Drill holes according to the determined pile positions, control the plane position deviation, and use original soil slurry to protect the wall; S23. Measure the hole depth and the length of the drill pipe and drilling tools when the hole is completed.

4. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Step S22 includes: aligning the main drill rod of the drilling rig with the hole position, measuring the horizontality of the drilling rig and the verticality of the vertical axis with a spirit level, and ensuring that the drilling rig pad is stable and firm; the diameter of the drill hole should be 20-50mm larger than the outer diameter of the injection pipe, and slurry should not be emitted; measuring the horizontality of the drilling rig and the verticality of the vertical axis with a spirit level once every 5m of drilling; paying attention to stratum changes during drilling, and making detailed records of hole depth, hole collapse, and slurry leakage; when the construction site survey data is unknown, arranging a pilot hole every 20m to check the stratum changes at the final hole; the final hole depth of the drilling should be 0.5-1.0m greater than the injection depth; when the hole depth is less than 30m, the hole slope is not greater than 1%.

5. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Step S3 includes: measuring the length of the injection pipe, measuring whether the center line of the nozzle is consistent with the direction arrow of the injection pipe, adjusting the test spray to the designed injection pressure, conducting ground water, air and slurry test sprays, and the designed injection pressure + pipeline pressure is the standard injection pressure for construction; if the nozzle is replaced, re-debugging is performed.

6. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Step S4 also includes: during the rotary jetting process, grouting is first performed followed by rotation and lifting; during the grouting process, if the slurry supply or gas supply is stopped, the nozzle is sunk to a preset height below the stop point, and then lifted after the supply is resumed; it is lifted to a preset depth position below the designed pile top at a first preset speed, and is lifted to the designed elevation at a second preset speed; after the spraying operation is completed, the surging slurry is re-injected into the hole until it stops sinking.

7. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Before step S4, the high-pressure jet grouting pile construction process includes: setting up slurry drainage ditches and slurry pools; checking high-pressure equipment and pipeline systems; and recording hole positions, hole depths, underground obstacles corresponding to the hole positions, and grouting volumes.

8. The high-pressure jet grouting pile construction process according to claim 1 is characterized in that: Step S4 also includes: when the spraying pipe is disassembled during the spraying process, it should be dropped and overlapped for re-spraying, and the overlap length should be not less than 0.2m; when the spraying process is interrupted and the spraying is resumed, re-spraying is carried out, and the overlap length is not less than 0.5m; when the spraying is interrupted for more than the initial setting time of the slurry, the hole is swept, and when the spraying is resumed, the overlap length of the re-spraying is not less than 1m.

9. The high-pressure jet grouting pile construction process according to claim 1, characterized in that: Step S4 also includes: filling and re-injection. After the high-pressure jet grouting of each hole is completed, the hole is filled with grout until it is full and the grout surface at the hole mouth no longer sinks.

10. A tunnel engineering structure, characterized in that: The high-pressure jet grouting pile construction process according to any one of claims 1 to 9 is applied.

Images